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,, Influence of Land Management on Wildlife Historical attitudes toward the land and its products were discussed in Chapter 1. Over the past century, the elaboration of land-use concepts and the development of policy guidelines have accompanied the inten- sification of management. The growing expectation that every area can yield more products and services through applied technology than through single-purpose exploitation has raised issues with which land managers were not earlier concerned. It became evident that benefits of several kinds might be obtained through a recognition of the diverse values that any particular land type might provide for various segments of the population. That the general public has an interest and a respon- sibility in effecting and perpetuating sound management policies for all natural resources has been inherent in the conservation idea from its beginning. MULTIPLE USE A significant and commonly accepted policy relating to land husbandry is that of "multiple use." Logically it developed first as a guide to oper- ations on certain public properties, especially the national forests, although its applicability to other types and ownerships is becoming progressively evident. Since -wildlife is a public resource, commonly of secondary value in land-use economics, its status and utilization as a land and water product generally depend on effective multiple-use policies. How such policies vary and how they are implemented in dif 92
Influence of Land Management on Wildlife 93 ferent economic situations must be understood in determining relative investments for, and expected returns from, the wildlife resource. Policies on Public Lands In 1960, after many years of multiple-purpose operations by the U.S. Forest Service, Congress authorized and directed the Secretary of Agri- culture to develop and administer the renewable surface resources of the national forests for multiple use and sustained yield (PL86-5 17; 16 USCA 528-53 1; 74 Stat 2153. In this act a definition was included: "Multiple use" means: The management of all the various renewable surface re- sources of the national forests so that they are utilized in the combination that will best meet the needs of the American people; making the most judicious use of the land for some or all of those resources or related services over areas large enough to provide sufficient latitude for periodic adjustments in use to conform to changing needs and conditions; that some land will be used for less than all of the resources; and harmonious and coordinated management of the various re- sources, each with the other, without impairment of the productivity of the land, with consideration being given to the relative values of the various resources, and not necessarily the combination of uses that will give the greatest dollar return or the greatest unit output. This definition is remarkably similar to the 1905 directive of the Secretary of Agriculture to the Forester concerning the national forests-" . . . when conflicting interests must be reconciled the ques- tion will always be decided from the standpoint of the greatest good of the greatest number in the long run."* Both imply the satisfaction of minority interests as well as those of a simple majority. In 1964, the Congress instructed the Secretary of the Interior to develop and administer for multiple use and sustained yield those pub- lic lands under the administration of the Bureau of Land Management consistent with and supplemental to the Taylor Grazing Act (48 Stat 1269; 43USC 3151. The definition of multiple use in this act (PL 88- 607; 43USCA 141: (b); 78 Stat 987) is nearly identical with that apply ing to national forests except that the 1964 act includes also nonrenew- able and subsurface resources. Wildlife and outdoor recreation are recognized resources under both acts. Thus the Congress has established a national policy of multiple use, *In a letter of February 1, 1905, from James Wilson, Secretary of Agriculture, to Gifford Pinchot, Forester, upon transfer of the Forest Reserves (now national forests) to the Depart- ment of Agriculture.
94 Land Use and Wildlife Resources including wildlife resources, in the administration of national forests (186 million acres), and on lands temporarily under the administration of the Bureau of Land Management (459 million acres) pending their classification for retention in federal ownership or disposal to private ownership. * The administrator of federal lands is subject to competitive demands from different segments of the public, not all of whom are likely to be fully satisfied. Pressures also arise from specialized staff personnel within the agency, and the desire of each of several specialists to pro- duce the maximum output from "his" resource. Under multiple-purpose management, a given use seldom can attain its maximum production; rather, the objective is optimum benefits from all or several uses in combination. Ridd (1965) stated: Multiple use management of the land may be accomplished by any one of the fol- lowing three options, or by combination of the three: (1) concurrent and con- tinuous use of the several resources obtainable on a given land unit; (2) alternating or rotational use of the various resources or resource combinations on the unit, so that multiple use is achieved on a time basis; or (3) geographical separation of uses or use combinations so that multiple use is accomplished across a mosaic of units. All of these are legitimate multiple use practices and should be applied in the most suitable combination on lands under public administration. It is here that a form of zoning is essential-zoning, not for a single use, but in terms of a dominant value. For specific areas within a large planning unit, one use may be given precedence, with others permitted to the extent that they do not materially conflict with it. Many federal lands other than the national forests and lands admin- istered by the Bureau of Land Management are managed for several uses. Military lands, for example, are being developed for wildlife habitat, hunting, and fishing, when compatible with military objectives. On some wildlife refuges, timber operations, hay cutting, or livestock grazing are beneficial habitat improvement practices. Many state-owned areas are managed similarly. On certain public lands little, if any, management is directed toward marketable products. Thus a primary motive in establishing national parks and wilderness areas has been to reserve some lands from such disturbance factors as mining, cultivation, livestock grazing, forest cutting, and hunting; here the premium is on natural conditions. The Wilderness Act, as passed, did not conform fully to this objective. *The Bureau of Land Management mulEple-use authonzabon expired June 30, 1970
Influence of Land Management on Wildlife Under congressional definitions of multiple use, hunting, fishing, and wildlife habitat development are not required in all places and at all times on the national forests and public domain lands. However, these are acceptable practices on most public lands, and the wildlife resource has generally benefited from them. Appl ications on Private Lands 95 The American Society of Range Management (Hues, 1964) defines mul- tiple use as: Harmonious use of range for more than one of the following purposes: Grazing of livestock, wildlife production, recreation, watershed, and timber production. Not necessarily the combination of uses that will yield the highest economic return or greatest unit output. be: The Society of American Foresters (1964) considers multiple use to The practice of forestry which combines two or more objectives, such as produc- tion of wood or wood-derivative products, forage and browse for domestic live- stock, proper environmental conditions for wildlife, landscape effects, protection against floods and erosion, recreation, production and protection of water sup- plies, and national defense. Orell (1964) describes multiple use from the standpoint of the tim- ber industry as: . . . the accommodation of a maximum of other compatible uses with the highest single use of the land. On private commercial forest land the highest primary use is the production of successive timber crops. The maximum use of every forest land acre is the objective of every forester. Still another description of multiple use is that of American Forest Products Industries (Sayers, 19661. Continuous growing and harvesting of crops of trees is the primary objective of Tree Farm management. Other multiple-use benefits, including the protection of watersheds, maintenance of desirable wildlife populations, and recreational oppor- tunities are the natural results of well managed forest lands. Multiple use is en- couraged on Tree Farms consistent with the primary objectives of the owners. It is evident that the intensive management of one resource often is not good management for another. The growing of fully stocked pure stands of conifers over extensive areas may preclude game production;
96 Land Use and Wildlife Resources it might well comply with the primary timber objective of the land- owner but would fail in maintaining wildlife populations satisfactory to the hunter. In the coordinated management of timber arid wildlife a moderate reduction of timber yield may permit a more than moderate increase in wildlife production. Yet the incidental improvement of wildlife habitat, or even just the granting of permission to hunt, con- forms with most definitions of multiple use. Hence there is need to analyze the objectives, procedures, and actual results on any unit of land to ascertain the prevailing direction and extent of the application of multiple-use concepts. The fact that multiple use is a desirable policy in the management of most public lands does not mean that it is applicable in equal degree to private lands. Motivations in public land management derive from legis- lation (including appropriations) as a response to public demands; on private lands the motivation is primarily in terms of dollar returns. Subject to ecological limitations, certain governmental controls, and occasional zoning restrictions, the landowner will determine the uses to which his land will be devoted. Wildlife production and utilization may or may not be a management objective, and it is commonly true that the landowner has little economic incentive to develop wildlife habitat or to encourage its utilization. Multiple use can mean different things to different people. Under various definitions and practices the wildlife resource may be benefited greatly or not at all, according to the nature of land and water, the economics of competitive land and water uses, and the mores of various social groups. FO R EST AN D WOO D LAN D MANAG EM E NT Within the 50 states, 759 million acres support forests and woodlands.* Two thirds (509 million acres) of this area is classified as commercial forest land, suitable for growing continuous crops of sawlogs or other industrial timber products. One third (250 million acres) is classified as noncommercial either because of low productivity for timber growing (234 million acres), or because of legal reservation ( 16 million acres) for parks, wilderness, or other nontimber uses (U.S. Forest Service, 1 9651. *Woodland includes both small forested areas, such as farm woodlots, and larger areas of mainly noncommercial species. Many acres classed as forest and woodland are grazed by domestic livestock; hence there is an overlap of areas (244 million acres) in forests and wood- lands and range and pasture.
I Influence of Land Management on Wildlife 97 Of the commercial forest land, 142 million acres are in public owner- ship, of which four fifths is federally owned; 67 million acres are owned by forest industries; 151 million acres are in farms; and 149 million acres are under miscellaneous private ownership. Of the noncommercial (low productivity) forest land, over three fourths is federally owned and situated largely in Alaska and other western states. Covering one-third of the land area of the United States, forest land supports a wide variety of wildlife. Much of the big game, many upland small game species, and some waterfowl are hunted in the forest environ- ment, and nongame species are numerous. Many fishing waters are in, or have their sources in, forested areas. Significantly, from the stand- point of the management of wildlife for public recreation, nearly half of the forested area of the country is under public ownership. Wildlife Habitat Objectives From latitudes 20°N in Hawaii to 60°N in Alaska, at elevations from sea level to 12,000 feet, and showing many different successional stages within the several life zones, forest lands of the United States vary greatly in the composition of their plant and animal communities. For the contiguous 48 states, Kuchler (1964) recognizes 69 potential na- tural types of forest and grassland-forest combinations. The Society of American Foresters recognizes 156 timber types that vary widely with respect to age, species composition, soils, and other conditions. Within this broad spectrum of environmental conditions lie forest-wildlife management opportunities for directing management toward compat- ible objectives. It is here that wildlife managers seek to identify and lessen the adverse effects of such limiting factors as food, cover, water, or space and to attain a range of habitat types favorable to the species of wildlife concerned. Interspersion of Types Aside from seasonal migrations, the ranges of individual animals of dif- ferent species may vary from a few acres or less (cottontail rabbits) to a square mile (deer) to 36 square miles or more (wide-ranging carni- vores). Each individual needs ready access to habitat that meets all of its requirements, and the more home ranges there are in a forest hold- ing the larger the wildlife population is likely to be. Many species of wildlife-deer, rabbits, turkeys, grouse-are "edge" creatures, requiring variety in their ranges. They make extensive use of openings and early forest successions and are benefited by an intimate mixture of vegetative, topographic, and moisture conditions. The need
98 Land Use and Wildlife Resources for "interspersion" in the habitat is an accepted principle among wild- life managers, and to meet this need is a basic objective in developing productive environments in forested areas. Thus extensive stands of a single tree species do not support high populations of wildlife; small farm woodlots, closely associated with croplands and pastures, are more productive. On extensive forest areas the manager frequently has a clearly defined wildlife habitat objective, in terms of variety and edge, that he can approximate in harmony with timber management priorities. Water Conditions Runoff waters from forested watersheds provide the basic resource for a fishery, and for some mammals and birds as well. The physical, chemi- cal, and biological factors that constitute fish habitat are affected by the forest and the activities therein. The temperature of streams and degree of siltation relate to condition of the watershed. The stability of streambanks and the presence or absence of bank cover and shade greatly affect the fishes and their food supplies. Aquatic fish-food organisms depend closely, in species and abundance, on the type of stream bottom; particularly in mountain trout streams, fish food pro- duction in clean rubble stream bottoms exceeds that in silted stream- beds (Chapman, 19629. To an appreciable extent, the amount of runoff and the time and degree of peak flows are influenced by the species of trees and their distribution (Hoover, 19621. To some degree, nearly all actions (or their absence) on the forest watershed affect the suitability of the aquatic habitat for wildlife. Thus the decisions of the forester can result in habitat improvement or deterioriation, depending upon the objectives of management and the ways in which objectives are fulfilled. Through well-coordinated management for timber and wildlife, habitat conditions can be fostered; without coordination they may be damaged. Public clamor for fish hatcheries has often obscured the fact that effective fishery manage- ment starts with land management on the watershed. Timber Management Practices A virgin forest seldom supports an abundance of wildlife-either in number of animals or number of species. Increases in game animals often followed early exploitation of our forests. Today the saw and axe, controlled fire, and chemicals can be employed to improve wild- life habitat without destructive effects. Forest management provides many opportunities for improving wildlife habitat.
Influence of Land Management on Wildlife 99 Incidental wildlife benefits are likely to accompany most modern types of timber harvest and thinning operations. Greater and more predictable benefits result where forest managers plan their operations to favor wildlife habitat as one of the multiple uses of the forest. On the managed national and state forests, and on managed private lands where there is an incentive to do so, wildlife biologists working with timber managers can develop plans that will increase the more useful species of both animals and trees. On unmanaged "preserves" such as the New York State Forest Preserve and some national and state parks, the opportunities are limited or lacking. In recent decades there has appeared to be some division of public opinion relative to forestry; in particular, growing numbers of people generally have opposed harvesting timber crops. Presumably this atti- tude goes considerably beyond the acknowledged need for setting aside certain areas as undisturbed wilderness. It has earned for such individ- uals the somewhat anomalous designation of "preservationist," as op- posed to the "conservationist," who believes in preservation plus use. Perhaps the opposition to harvesting timber crops is a reaction to the early history of "cut-out and get-out" logging in this country and to appreciable areas of recent clear-cutting of large blocks.* It may be fostered also by instances of erosion, scenic defacement, and slash burning-not all condoned by either lay conservationists or professional foresters (Twiss, 19691. Although some logging operations do not pro- vide adequately for watershed protection and esthetics, many do; tim- ber industries in general are recognizing the public's interest in forests. Perhaps the distinction between conservationists and preservationists relates to varying degrees of tolerance of such things as the disturbance of natural conditions by logging-some of which may be unavoidable if forest managment is to be practiced at all. With respect to wildlife, the distinction becomes real to the extent that the saw and axe are tools without which habitat management would be extremely limited. Few question the need for both commodity production areas and natural areas; the difficult questions concern where and how much land shall be devoted to each, and to what extent both needs can be met through multiple use. On federal lands designated for multiple-use management the success of administrators in satisfying diverse interests may determine the duration of delegated authority, which the Con- gress can retract at any time. *Clear-cutUng of blocks of moderate size is an accepted silvicultural practice in several forest types. The distinction between large and small blocks will necessarily vary, and size is un- likely to be determined solely with consideration for wildlife; but, in a multiple-use forest, it need not be a matter of logging economics alone.
100 Land Use and Wildlife Resources Rotations and Cutting Cycles With the decrease of virgin timber stands-in the 1 960's less than 8 per- cent of commercial forests-and the increase of managed forests, the problems and opportunities of wildlife managers are changing. In many cases the old-growth trees are replaced naturally or artificially by spe- cies of lower successional stages, and wildlife communities change. Wildlife management objectives and techniques must be modified to fit the managed forests and, in turn, may influence timber management practices. The development of markets for small trees and more effi- cient equipment for logging and road-building have shortened both the time required to produce merchantable timber (the rotation) and the frequency of practical cuttings (the cutting cycles). To meet anticipated sawtimber demands, more frequent and more extensive cultural cuttings can be expected. Substantial acreages, espe- cially in the Rocky Mountains, support far too many trees per acre for acceptable timber growth. In western Washington and Oregon, for ex- ample, 5 million acres are supporting young stands in which commercial thinning would increase the log harvest. In the South, extensive stand improvement on at least 150 million acres would be needed to reduce the excessive stocking of culls and undesirable trees. Without thinnings, stand densities in many northern forests are expected to increase to the extent of serious overstocking (U.S. Forest Service, 19651. Whether timber cultural operations are favorable or unfavorable to wildlife de- pends upon the objectives of forest management and the degree of coordination between foresters and wildlife managers. Each cutting provides opportunities for wildlife habitat manipulation. For example, on the Allegheny National Forest in Pennsylvania, coordination between timber management and wildlife management is a part of the multiple-use program. Here, in a predominantly northern hardwood forest, black cherry is the favored timber crop; game species include deer, bear, squirrel, snowshoe hare, cottontail rabbit, ruffed grouse, turkey, and woodcock. Both stumpage values and recreational demands are high. Jordan (J. S. Jordan, U S. Forest Service, unpub- lished data) described the program: Under unit area management, the Forest is divided into approximately 1200 com- partments, each averaging about 350 acres in size. Timber management objectives, as they concern wildlife, are: (1 ) to produce high quality hardwoods consisting of 50 percent black cherry, 40 percent in a variety of other commercial hardwoods, 10 percent in coniferous species; (2) maintain 5 percent of the area in coniferous types; (3) make 3,000 acres of regeneration clearcuttings annually in areas 2 to 20 acres in size.
I nf luence of Land Management on W ildl if e 101 Several habitat objectives for the forest have been established: (1) brush stage- about 5 percent of the total area in units of 3 to 5 acres spaced 30 to 40 chains apart; (2) open herbaceous areas-2 to 3 percent in units not less than 0.2 acre in size; (3) coniferous cover-about 8 percent of the area in units i/2 to 2 acres, spaced about 10 chains apart (can be overstory or understory); (4) water sources spaced not less than 40 chains apart. Clearcutting for regeneration will generally be made in mature and over mature stands; but where brush stage is needed to satisfy habitat needs, regeneration cut- tings will also be made in immature stands. This will aid in achieving a better balance in age classes, now skewed strongly to poletimber stands-a common wildlife problem in northeastern forests. In addition to the rotation age of 100 years, 10 years is allowed in the forest regulation period to obtain natural regenera- tion. This time is provided for wildlife utilization following clearcutting. Pre-commercial thinnings in immature stands will be light to moderate release. Where required to meet wildlife needs, heavy release will be made in 1 O-acre blocks spaced about 30 chains apart; all stems except the future crop trees are winter- felled to provide browse for deer in the tops and later from the stumps, and to create much-needed cover for small game. Studies have shown that this practice yields a tenfold increase in browse production in the first year. Wherever possible, cutting blocks are located in relation to other habitat com- ponents to obtain optimum use of the browse and cover created. Under unit area management, each compartment should eventually contain a balance of 10-year age classes, each averaging 35 acres in size and suitability distrib- uted for habitat needs. There is sufficient similarity between compartment size- or multiples of it-and game species home range so that timber management opera- tions will approximately satisfy general habitat needs. Supplementary practices to satisfy other habitat needs are incorporated in the planning. Each compartment is examined at least every 10 years and treatments are pre- scribed which include minimum habitat requirements according to prescribed ob- jectives. A continuous inventory of all vegetation is maintained by sampling 10 percent of the compartments annually. Condition and trend in understory vegeta- tion of the Forest is determined from permanent transects measured at 5-year intervals. Reforestation and Afforestation The popular idea that for every tree cut another should be planted overlooks the fact that in many situations forests are regenerated both naturally and through planned silvicultural operations. Also overlooked is the fact that if planting is necessary, the number of trees planted should exceed the number cut-the excess providing for mortality and to insure quality in the ultimate crop trees. If only one tree were planted to replace a tree cut, there would be less concern by wildlife managers. The U.S. Forest Service (1965) reports that nationally in recent years
102 Land Use and Wildlife Resources tree planting has covered about 1.3 million acres annually, but more than 100 million acres of commercial forest land is either nonstocked (36 million acres) or poorly stocked (76 million acres) with trees of acceptable quality or species. While forest plantings on many sites are not inimical to wildlife (and sometimes are beneficial), extensive solid plantations of a single tree species, especially conifers, leave little favorable habitat. Conifers create cover but soon reduce or eliminate shrubs that yield browse and fruit and herbaceous plants that supply food, ground nesting sites, and a source of insects for young birds (Bailey and Alexander, 19601. Since most hardwood forest types are more productive of wildlife than are the conifers, conversions from the former to the latter gener- ally result in lower wildlife populations. The unfavorable effects can be offset, as in pine plantations on scrub oak sites in Florida, where, on the Apalachicola National Forest, planting is done in strips, with alter- nate strips left for browse and herbage. Within the brush strips domi- nant oaks are released from competition to increase mast production. Large areas of cutover pine lands in the North have been invaded by such pioneer associations as the aspen-birch. These early successional stages are favored habitat for grouse. Because they are potentially pro- ductive pine sites, plantings have been fairly extensive and there has been a loss of grouse habitat. To maintain the multiple uses by provid- ing an interspersion of pine and open land, some large blocks of public lands have been left unplanted and others have been only partly planted. In the iVest, deep snow at high elevations forces deer and elk to winter ranges in the foothills. Early logging and fires changed many of the lower south-facing slopes from timber stands to the brush types that are essential for browse forage. Conversion of these critical winter ranges to tree cover by planting conifers would in time practically eliminate the game. Planting north slopes, where snow accumulates, may be desirable in places where escape cover is needed. Where wildlife habitat is one of the recognized uses, coordination between timber and wildlife managers is essential, both for enhancing wild animal values and for protecting forest regeneration from exces- sive animal damage. An example of afforestation (the establishment of a forest on an area not previously forested) is the Nebraska National Forest in the sandhills of that state. Since 1903, 30,000 acres of natural grasslands have been planted with primarily coniferous trees. Deer were indige- nous, but increased greatly in the plantation areas, to the extent that hunting was permitted in 1945-the first legal hunting of deer in that
I nfluence of Land Management on Wildlife 103 state since 1907 (Mohler et al., 195 11. Favorable habitat in plantations was orate of several factors to which deer responded. Records of orni- thologists show marked increases in the number of bird species (prin- cipally nongame) as the planted areas expanded. Wildlife habitat development was not the reason for afforestation, but it was an inci- dental benefit for some species. Prescribed Burning ~ recent decades great progress has been made in controlling wildfire in forests. From a total of 17.6 million acres burned in 1950 (2 percent of the total forest area), losses were progressively reduced to 4.1 mil- lion acres (about 0.5 percent of the total forest area) in 1962. The average area burned from 1962 through 1967 was 4.5 million acres, or 0.4 percent of the total forest area.* Concurrently, much has been learned about the planned use of fire-prescribed burning-as a tool of forest management to reduce wildfire hazard, control disease, and pre- pare sites for regeneration. Under some conditions, controlled burning can be used beneficially without the catastrophic results of wildfire. Wildlife has benefited incidentally from many of the burns prescribed for timber management, but little has been done experimentally toward burning for wildlife habitat improvement itself (Komarek, 19661. Stoddard ( 193 1 ) pioneered in the controlled burning of southern pine lands for quail habitat; Biswell et al. (1952) and Biswell (1959, 1961) have improved brush range for deer in California; and Lay (1956, 1957) improved forage quality by burning pine land in Texas. Following are brief excerpts from Komarek's ( 1966) paper: In general, the basic condition of the wildlife landscape is variety: forest, brush, grass, weeds, lakes, ponds, creeks. Abundant historical records indicate that during primitive times, it was largely a fire landscape. It depended upon this agent as a source of disturbance to rejuvenate the quality and the distribution of its vegeta- tive composition to which wildlife increase responded, sometimes spectacularly.... How to produce the favorable wildlife response so frequently produced by wild- fire, without the associated destruction of scenic and forest values should be a major concern of wildlife management.... While the techniques developed by forestry and range management may well be useful in the management of the wildlife landscape, the needs of wildlife differ *Figures are from U.S. Forest Service, Fire Statistics, and are compiled in relation to 1,172 million acres needing protection-an area about 50 percent greater than the 759 million acres shown on page 96 as the total area of forest and woodland in the United States; hence some of the acreage burned was probably brush and grassland intermingled with, or managed in con- junction with, forest or woodland.
104 Land Use and Wildlife Resources and experimentation in developing other techniques can be visualized. The forester seeks clean burns and complete coverage; wildlife burning may be less intensive with incomplete coverage to provide sufficient cover until new growth appears. Season of burning, frequency of burning, purpose and size of burn for wildlife purposes do not necessarily coincide with needs of other land uses and, accordingly, will vary with species, habitat and region. Much of the controlled burning for wild- life may well follow more closely the practice of the south Florida cattleman than that of the forester. The cattleman was concerned with providing new growth of grass over longer periods and accordingly his burning was staggered to "stretch out" winter grazing. Protection and distribution of cover, development and main- tenance of scenic vistas, the production of berries, mast, seeds and other food plants are not the primary concern of the forester or range manager but are of essential importance to the wildlife manager. Restricted use of controlled burning, such as the "spot" burning of Stoddard, which is entirely different from the spot burning of the forester, may have special application. and the exerc.i~e of in(s~n,~it should produce new techniques.... -err ~Am V1 1115~11~1~ . . . The forest has been promoted so long with wildlife as an associate and the past history of forest destruction has been repeated so many times that forest preservation has automatically meant wildlife preservation. To preserve forest was to preserve wildlife. But in most cases the reverse has been true. Browse has grown out of reach of big game animals and herbaceous plants have been smothered out by competing vegetation. Trees have marched into the open areas upon which wildlife in reasonable abundance once depended and many wildlife landscapes have become solid, sometimes monotonous, forest landscapes. One example of prescribed burning involves the habitat of a rare bird, the Kirtland's warbler, which has an estimated total population of less than 1,000; it winters in the Bahamas and has been found nesting in only 12 counties in Michigan. It nests on the ground under relatively open stands of jack pine in the 8- to 20-year age classes. To perpetuate the exacting stand requirements of this rare bird, the Audubon Society, the Michigan Conservation Department, and the U.S. Forest Service, with cooperation of the timber industry, have set up management areas in three state forests and the Huron National Forest. Prescribed burn- ing is a major tool; approximately square-mile blocks of mature timber are to be burned on a 5-year cycle to provide a perpetual supply of young jack pines. Selective planting will be used where natural regenera- tion fails (Line, 19641. There are other examples of the use of fire in forest-wildlife habitat management, but the opportunities probably are far greater than have been explored. However, with growing public concern over air pollu- tion, studies of the effects of prescribed burning should not be over- looked.
I nfluence of Land Management on Wildlife Logging 105 Harvesting timber is an essential periodic operation on commercial forest lands. Unavoidably, it disturbs the environment to a degree rang- ing from moderate to profound. Similarly, the effects may be of short or long duration. In contrast with early logging by man and animal power, modern equipment has brought about great changes, some creating more disturbance, some less. Much of the opposition to com- mercial timber operations is motivated by esthetics-a situation deserv- ing industry consideration. From the standpoint of wildlife manage- ment logging may be favorable or unfavorable. Moderate disturbance of the forest floor, along with opening of the forest canopy, may promote herbaceous and shrubby vegetation where little or none was present. Where seeding is practiced to stabilize ex- posed soils, natural plant succession may be artificially improved upon and recovery hastened. Where slopes are steep or soils unstable, fishery values may be severely damaged. In clear-cutting operations, large blocks are less favorable to wildlife than small clearings that provide better interspersion of habitat types. Logging slash in small amounts may furnish desirable cover for small game, but extensive areas of nearly impenetrable accumulations are a detriment. Logging road systems, if properly planned, can provide access for wildlife harvest and management operations. On the other hand, im- properly located, constructed, and maintained roads may bring about nearly irreparable damage to streams and render them useless for recrea- tional purposes. Choking of stream channels with slash and debris, invasion of streambeds by roads or road fills, channel changes, sedi- ment from poor road drainage, and culverts that impede spawning runs are particularly harmful. Studies in the northern Rocky Mountains have indicated that roads were the source of the greatest logging damage to trout streams (Chapman, 19621. Efficient road-building equipment cuts road costs; improved markets encourage shorter cutting cycles; intensive forest management calls for intermediate cuttings; economics dictates fast movement of logs from woods to mill; woods crews live in town rather than in the woods- all these point to the need for better and more permanent road systems. RANG E AN D PASTU R E LAN DS Approximately 1 billion acres, or over 40 percent of the land area of the 50 states, are grazed by domestic livestock. This acreage includes
106 Land Use and Wildlife Resources 645 million acres of pasture and range land,* 244 million acres of forest and woodlands, and 66 million acres of cropland used for pasture only. It excludes an undetermined acreage of hay and cropland pastured after crop removal (U.S. Department of Agriculture, 19629. Of the federal lands grazed (243 million acres), nearly three fourths are administered by the Bureau of Land Management and most of the rest by the Forest Senice. The nonfederal grazed lands are largely in private ownership but include some state and other government areas. Livestock includes primarily cattle, sheep, horses, and goats, totalling approximately 200 million animals. Grazing may be seasonal or year- long and usually continues year after year. Nearly a third of our total area of forest and woodland is so used. Big game animals forage exten- sively on many types of grazed lands. Country-wide, and even locally, native range sites vary greatly in forage productivity. Grazing capacity, in terms of animal-unit-month,: may vary from half an acre on wet meadows in good condition to 30 or more on semi-arid or depleted ranges. The capacity of some grazed lands may be sufficient only to keep the animals alive during a part of the year. A relatively small proportion of the lands grazed by livestock is highly productive range, whereas forage production on extensive areas is low. Forage production on native ranges may vary greatly from year to year-by as much as 300 percent for perennial forage and 1,000 percent for annual vegetation (Stoddart and Smith, 1 9551. Differences largely result from varying precipitation. However, stocking rates tend to re- ma~n relatively stable except during periods of extended drought." *Range is defined by the American Society of Range Management (Hues, 1964) as "all land producing native forage for [wild or domestic] animal consumption, . . ." The acreages shown as grazed by domestic livestock exclude those grazed by game alone. Ranges are further described as suitable and unsuitable, the former being "range which is accessible to livestock or game which can be grazed on a sustained yield basis without damage to other resources." Because of evident damage in some places to forest, wildlife, and watershed values, the acreage shown as grazed by livestock is known to include some lands unsuitable for grazing. While no accurate figures are available for croplands grazed after harvest, such usage is impor- tant as it may reduce wildlife cover in fields or eliminate travel lanes by which wildlife seeks safe passage from one part of its habitat to another, as along fencerows and irrigation ditches. Cone animal-unit-month (AUM) is the amount of feed or forage equivalent to that required by a mature cow with calf for 1 month. Use of AUM as a factor for converting range carrying capacity for one animal species to another is scientifically untenable because it is well estate fished that each animal species has its own food preferences, and that between animals the plant species grazed may overlap much, riffle, or not at all. |:Skeete (1966), answering the question of whether ranchers can adjust to fluctuating forage production, described a ranch operation on the Edwards Plateau of west Texas. The Midyear average annual rainfall was 19.5 inches, with 15 years of less than 13.5 inches. In 3 consecu
Influence of Land Management on Wildlife 107 Reasons include the desire for stability of livestock operations and, perhaps optimistically, the "calculated risk" that permitted use has been set sufficiently low to allow for variations in forage production without permanent damage to the range. Optimism in this respect could relate to the present low production of many ranges compared to their potential, and the need for correction of overgrazing on so much range and pasture land. Atkins (1956), stockman and past president of the American Society of Range Management, said: ". . . overgrazing of ranges has been the besetting sin of stockmen since Biblical times.... A study by the U.S. Department of Agriculture (1965) showed that pasture and range lands are producing forage at no more than half their potential. For the past half century or more, continued overuse has seriously depleted forage resources. Brush, weeds, and other unwanted vegetation have encroached upon millions of acres that once were good grazing land; tons of topsoil are being eroded from them to pollute streams, fill reservoirs, and damage domestic, agricultural, and industrial water supplies. Concerning overgrazing on nonfederal lands, the inventory report shows: Overgrazing is the most widespread hazard to established pastures and ranges. Of the nearly 185 million acres needing only protection of plant cover, 163.2 million acres or 88 percent needs protection from overgrazing. In addition, the 72 million acres needing establishment of new cover and the 107 million acres needing im- provement of existing cover will require protection from overgrazing to make these treatments successful. Altogether, then, about 343 million acres or 68 per- cent of non-federal pasture and range needs additional protection from over- grazing. Much of the federal range needs similar treatment and protection (Clawson et al., 1960~. The Bureau of Land Management (U.S. De- partment of the Intenor, 1960), optimistically in the light of trends on other lands,* set a range management objective to increase forage five years forage production was 1,361, 980, and 371 pounds per acre. Carrying capacity of the range had declined from 125 animal units per section in 1900 to 100 in 1916, and 32 in 1948. Through moderate stocking and a rotation-deferred system, the capacity was raised to 35~0 animal units per section. Stocking was adjusted as necessary through sale of stock from the base herds of cattle and sheep according to spring precipitation. *Permitted livestock use of the national forests rose from 1.0 million cattle and 5.7 million sheep in 1906 to a World War I peak in 1918 of 2.2 million cattle and 8.5 million sheep, and has since declined to 1.4 million cattle and 2.1 million sheep in 1965 (U.S. Bureau of the Census, 1960 and 1965). Livestock AUM's were reduced about 60 percent from 1918 to 1965. Big game AUM's have increased substantially.
108 Land Use and Wildlife Resources production on the public lands from 17 million AUM's in 1959 to 46 million AUM's by the year 2012 - "an increase in livestock and big game of approximately 300 percent." If this nation should need greater livestock production, with the alternatives of grazing more land or improving production from lands now being grazed, the latter appears to offer substantial possibilities. Effects of Livestock on Wildlife Habitat Because of wide variations in range types, species of livestock and wild animals, grazing seasons and management practices, and other factors, it is not possible to generalize concerning livestock-wildlife relationships. Some effects of grazing are direct and obvious; others are indirect and inconspicuous. However, with more than 40 percent of our land grazed by livestock, and many waters affected by sources on range lands, graz- ing probably is the greatest single year-after-year agricultural influence on wildlife. Vegetation Changes Progressive alteration of the composition, stocking, and vigor of the range plant community results from continued livestock use. Taylor and Buechner (1943) described for the Edwards Plateau of Texas six recognizable stages between the climax and bare ground, and indicated the suitability of each stage for game and the suggested livestock man- agement practices. The stages are: climax, perennial tall grass, perennial short grass, weed grass range, unpalatable weed stage, and bare ground. Similar descriptions have been made for other range types. The authors note that perennial grass, and not the climax, may be the most produc- tive stage for livestock. Lower stages usually are undesirable in terms of both grazing and soil stability. Soil Conservation Service methods for determining range sites and conditions are widely used on private lands (Renner and Allred, 19629. Range condition and trend standards have been developed for many range types by federal and state agencies. Parker (1954) lists the more reliable criteria for classifying the condition of vegetation as ( 1 ) density index of plant or forage cover, (2) composition of vegetation as to species, grouped in accordance with their reaction to grazing use, and (3) vigor of the desirable forage species. He lists the more important soil condition factors as (1) amount of litter coverage, (2) current ero- sion, and (3) stability as indicated by amount of living and dead (plant) cover. These are ecological factors with which the wildlife manager is equally concerned.
Influence of Land Management on Wildlife 109 With respect to game animals, seldom will the livestock and wildlife objectives differ as to soil stability standards. In rating vegetation, how- ever, interests may diverge. A given stage in plant succession can seldom provide maximum per-acre production for each of two species of live- stock, or for two or more species of game. However, with coordinated planning, a single successional stage may provide optimum production for one species of livestock together with one or more species of game. The ecological approach to livestock range management does not imply that climax conditions are the ultimate objective, for climax types often are low in livestock and game production. Some wildlife managers have missed opportunities by not working more closely with range managers in developing livestock range condi- tion ratings. While many range managers are aware of the winter range requirements of deer and elk, they may not fully appreciate the rela- tionship between vegetation bordering streams and the fish life in them; the effects of grazing intensity on the success of duck, grouse, or quail nesting; or the dependence of beavers on sustained growths of willow and aspen. Some have considered all herbage as forage, with insufficient regard for vigor of range plants, wildlife cover, or the maintenance of soil conditions. Costello (1956) is an exception; he points out that Any system of judging range, which does not include consideration of all products of the land, is incomplete. We must include measurement or evaluation of factors which affect stream flow, siltation, water yield, wildlife production, and recreation values. Modification of the Fauna The effects of livestock grazing on wildlife may be competitive, benefi- cial, or neutral, depending upon many variables. Such factors as vegeta- tion types, kinds and combinations of livestock, topography, soils, and availability of water are involved. Competition between livestock and game may be direct where both feed on much the same forage species, as do sheep and deer. Where grass seeds are important (as for wild turkeys), grazing may reduce or eliminate that source of food; hogs in hardwood forests may be simi- larly competitive for mast. In many cases, however, big game and live- stock in moderate numbers do not graze the same areas or the same species. Through intensive studies such as those of Julander and Julander etal. ( 1950, 1951, 1955, 1958, 1961, 1962, 1964), also Robinette et al. (1952), and Smith and Julander (1953) in the inter- mountain region, the degree of conflict can be measured; generalities are of little help in solving problems in specific areas. At the risk of oversimplification, the extent of direct competition
110 Land Use and Wildlife Resources ~ ~ ~ ~ ~ Hi 'me I ~ ( w~ ~ ~ ~ A B C D FIGURE 1 for forage between cattle and deer at moderate stocking can be illus- trated diagrammatically (Figure 1), where on a given range area, A-D is the total range of forage species. If cattle eat only species A-C, and deer eat only species B-D, the competition is limited to species B-C. Obviously, where stocking rates are more than moderate or forage plant composition is dissimilar, or where different species of livestock or wildlife are involved, the degree of competition would likely change materially. Again somewhat oversimplified, Figure 2 diagrammatically illustrates a topographic profile of a range terrain. With moderate stocking, cattle may use only slope A-C, and deer only B-D, and the area of competi- tion would be limited to Bee. In this instance, or others, A could rep- resent proximity to livestock water, and D proximity to deer cover, with somewhat similar expectancy of area competition. Indirect effects are numerous although often not clearly evident. Grazing has affected duck nesting favorably in some places and un- favorably in others, depending to a large extent upon degrees of stock- ing and range conditions. Prairie grouse have been affected by habitat changes caused by livestock grazing. The development of a livestock industry on brown bear range on Kodiak Island in Alaska has resulted, as might have been anticipated, in bear damage to livestock, and the current solution is control of the native animal (Erickson, 1 9651. The longer term effects of grazing in changing plant successional stages may be unappreciated until extreme conditions are evident. The - - - ~1 D FIGURE 2
I Influence of Land Management on Wildlife increase of cheat grass, a short-lived introduced annual, on many western ranges has resulted in rapidly spreading range fires that have killed browse plants on deer wintering ranges. 111 Many publications on the interrelationships of livestock grazing and wildlife omit information needed by rangeland managers if uses are to be better coordinated. Often lands are described merely as grazed (or overgrazed) and ungraded; stocking rate, system of grazing, and range condition classification frequently are not given; few relate quantita- tively the response of wildlife to conditions under study. The need is great for research that will determine for each range type the degree and method of grazing that may be beneficial, or least harmful, for the habitat of each desirable wildlife species. Soil and Water Changes Livestock grazing tends to compact soils, with resulting increase in soil density, reduction in pore space, reduction in water infiltration capac- ity, and slowed water movement through the soil; surface runoff may occur more frequently, increase in volume, and result in erosion (Lull, 19591. Infiltration rates decline with lowered range conditions (Leithead, 1950) and heavier rates of stocking (Rhoades et al., 19641. Concerning the effect of grazing farm woodland on watershed values in the south- ern Appalachian Mountains, Johnson (1952) observed that Measurements made over the 9 years of observation show that accumulative effects of browsing and trampling are beginning to influence the quantity, timing, and quality of water that comes off the drainage area in storm periods.... During storms the stream comes up faster and reaches higher flood peaks. These factors, as they may affect streams and lakes, undoubtedly in- fluence the quality of fish habitat. Research directly relating livestock grazing and range conditions to fish production is lacking. Read (1957) reported that according to a survey made in 1954 by the Rocky Mountain Forest and Range Experiment Station, 30 percent of the shelterbelts planted in the Great Plains region between 1935 and 1942 have been seriously damaged by their use as 'stomp and shade lots' for livestock. He reported soil conditions for heavily used and protected shelterbelts, respectively-bulk density, 1.22 and 1.01 grams/cc, total pore space 51.7 and 57.3 percent, and large pore space 7.6 and 14.1 percent. Describing the causes of million-dollar-damage mud-rock floods of 1923 and 1930 in the Farmington-Centerville area of Utah, Bailey et al. (1947) said:
112 Land Use and Wildlife Resources . . . The great bulk of the flood waters originated on areas near the mountain top where the plant and litter cover had been destroyed or reduced and the soil eroded and compacted . . . depleted and eroded barren areas covered less than 10 percent of the total area of the several catchment basins.... The inadequate capacity of the flood-source areas to restrain runoff was unnatural. It was due to a change in the character of the soil. This was brought about by long-continued overgrazing by domestic livestock, and unwise burning. The grazing of livestock along streambanks frequently results in loss of rip arian vegetation such as willow, alder, and birch that serves to protect streambanks, shade the streams, and develop overhanging banks where fish may hide. Boussu's ( 1954) study of the ecological effects of presence and absence of streambank cover on a Montana trout stream, while only simulating commonly observed range and pasture conditions, measured such effects on trout populations. With the re- moval of natural willow cover overhanging 13 percent of the surface area of the stream, the total fish population was reduced 41 percent by weight, and the 7-inch and larger fish were reduced 58 percent. With the application of comparable brush cover on 5~/2 percent of the area of the stream totally lacking cover, the fish population increased 258 percent, and the larger fish 533 percent. With the removal of na- tural overhanging (undercut) banks from less than 2 percent of the stream surface, the total fish population decreased 33 percent, and the number of larger fish 64 percent. Streambanks within cattle ranges are particularly subject to damage because of the preference of cows for the more level lands near water and the greater production there of succulent vegetation.* In some places stream bottoms have been fenced out, and the cost may be justified where necessary to protect fishing values. Muddying of waters by wading livestock and increased water temperatures resulting from destruction of shading vegetation also are common adverse situations on ranges and pastures. Management of Livestock G razing Grazing practices vary widely-for example, from daily barn-to-pasture for dairy cattle to year-long grazing on some ranges; and from single species of livestock to two or more concurrently (termed "common used. Different practices may affect wildlife in different ways and degrees; general and unqualified statements as to the effects of livestock grazing on wildlife mean little. *Such key areas for fish habitat are often treated by range managers as " 'sacrifice areas' . . . intentionally overgrazed to obtain efficient overall use of the management area" (Hues, 1964).
Influence of Land Management on Wildlife 113 The basic grazing management systems recognized by the American Society of Range Management (Hues, 1964) and further described by Driscoll (1967) are: continuous, rotation (or alternate), deferred, deferred-rotation, and rest-rotation. With respect to wildlife food and cover, each of these systems and modifications within them can be expected to result in variations in wildlife habitat conditions. Much of the reported wildlife research refers only to lands as grazed or ungraded. Until researchers recognize the various systems of management being practiced, and the standards for range condition classes, sound bases for grazing and wildlife coordination are lacking; merely comparing "grazed" and "ungraded" is not enough. Fencing is a major tool of range and pasture management, and often a benefit to wildlife habitat if range condition improves as a result; it can also protect key areas for wildlife. Some types of fencing create wildlife problems. One critical problem in the West is the fencing of ranges used by both antelope and domestic sheep, which may prevent the antelope from reaching water or sheltered areas in times of stress. The scarcity of capable sheep herders and other economic factors have resulted in a substantial increase in sheep range fencing, but a fence that will hold sheep and pass antelope has not yet been developed. Similar problems may occur where fences are so high as to be difficult for deer, elk, and moose to jump; many deer hang up on top wires, and elk and moose occasionally tear the fences down. Satisfactory wire- spacing standards have been developed to alleviate such problems but they are not always followed. The tendency of cattle, in particular, to graze waterside areas as long as food is available usually results in loss of key wildlife habitat. To alleviate the problem, the fencing of springs, streams, and portions of stockponds is often recommended and sometimes practiced. Stock water developments, if properly planned and constructed, can provide good wildlife habitat. Day (1966) described how waters of the Crescent Lake and Valentine National Wildlife Refuges in northern Nebraska were originally fenced against grazing. Shoreline vegetation became so lush and dense that use by breeding waterfowl was impaired, predators were favored, and fire hazards were created. Restoration of controlled grazing brought about more favorable conditions and an increased production of ducks. Bue and his associates (1964), discussing stock- ponds in North Dakota, noted that Shallow, completely protected shorelines grow up to tall emergent: plants, such as cattail and bulrush, and are not suitable for dabbling ducks, although occasionally diving ducks use this emergent vegetation. The greatest use is had when the range
114 Land Use and Wildlife Resources is grazed within its carrying capacity. Good range management is also good water- fowl management. This is an example of how light to moderate grazing pressure serves to thin out a vegetation type that is too dense for optimum wildlife pro- duction. Trucking livestock (particularly sheep) to mountain ranges can some- times be practical to avoid damage from the use year after year of established driveways. Related to this, and sometimes a problem in the mountains, is the erosion caused by stockmen, hunters, and fishermen driving motorized vehicles on steep slopes, unstable soils, or boggy areas. Prescribed burning for range improvement is used, particularly in the South. As discussed in the section on forest and woodland, there is need for experimentation in the use of controlled fire for wildlife habitat improvement. Referring to a test showing significant weight gains on cattle on burned range, Komarek (1966) concludes, "It is reasonable to assume that a similar favorable response might be obtained on con- trol burned range occupied by native wild ungulates." Damage to range and livestock by wild animals is discussed in Chap- ter 6. The interrelationship of predator and prey, the methods of animal-damage control and their direct and indirect effects on other wild animals, and the determination of cause and effect of range con- dition are complicated and require specific study. In summary, the attitudes of rangeland owners toward wildlife, rec- reation seekers, and particularly toward sportsmen who seek areas to hunt and fish; the economic and social balance between wildlife bene- fits and costs; the owners' knowledge of causes and effects and their discernment of the difference between the two are all matters that directly or indirectly affect wildlife management on private range and pasture lands. How, where, when, and if wildlife fits into the multiple use of their lands is primarily their own decision. We may conclude that overgrazing by livestock is generally detri- mental to nearly all species of wildlife using or influenced by grazed lands. Moderate grazing has been reported as beneficial, neutral, or harmful, depending upon species and other variables. From evidence that much of the domestic livestock range and pasture is overgrazed and yielding considerably less than its potential, one may infer that better livestock management would frequently result in better wildlife habitat The potential for benefits to both land uses appears to be great. Although the history of the grazing industry is not conducive to optimism, recent progress has been encouraging.
Influence of Land Management on Wildlife Brush Country Problems 115 The West has more than 250 million acres of brushland, most of it used jointly by livestock and wildlife. The brushlands may be either mix- tures of several woody species or relatively pure stands. Some of the major types include mesquite and shinnery oak ranges in the Southwest, pinyonjuniper and scrub oak in the southern Rockies, sagebrush in the intermountain region, and chemise ranges in California. The mixed shrub types of California and the Southwest are often called chaparral, while mixed brushlands of the Rockies are often just called mountain shrub types. In the early 1950's there were many "brush eradication" programs. However, it soon became apparent that a more appropriate term for these efforts would be "brush control." Further consideration of the ecological factors involved, including wildlife, prompted a shift of em- phasis toward the concept of "brushland management." The following discussion deals with brushlands as related to wildlife in the context of brushland management. Mesquite There are an estimated 55 million acres of mesquite in Texas and Okla- homa, 9 million acres in southern Arizona, and 6 million acres in southern New Mexico (Alfred, 1949; Parker and Martin, 19521. Rec- ords of early travelers across Texas indicate that the mesquite and prairie grasses on uplands formed a savanna. However, settlement of the Southwest, with control of fires and introduction of livestock, brought increased densities of the trees and a spread into adjoining grasslands. Livestock operators have been faced with loss of forage and problems of handling animals in the dense thickets. The effect of in- creased density of mesquite may be partial reduction of the understory grasses as noted in a Texas study (Workman et al., 1965), or almost complete reduction of understory grasses as found in southern Arizona (Parker and Martin, 19521. Foliage of the mature mesquite tree fur- nishes little forage to livestock or game, although the beans are taken by livestock and deer. Box and Powell (1965J found that the utiliza- tion of regrowth following mowing was 60 times greater than for the mature foliage, by both deer and cattle. Management of mesquite ranges has emphasized reducing the tree stand to favor understory herbage. Widespread acreages were sprayed with herbicides or otherwise treated during the 50's and 60's in Texas. Herbicide treatments have resulted in only temporary control but pro- vided economical increases in range forage (Workman et al., 1965~.
116 Land Use and Wildlife Resources Joint evaluations by state and federal agencies in Texas determined that planned brush control benefited deer. Planning provided for leav- ing brush on rough areas, along watercourses, and on ridge tops. In studies of mixed brush (which included mesquite) in south Texas, Box and Powell (1965) recommended: If a rancher chose to raise wildlife as well as livestock, he could treat approximately one-fourth of his land each year by mowing or roller chopping. By arranging his treated areas in long strips throughout the ranch, he could be assured of adequate cover for his wildlife, an increase in edge effect, and adequate forage for his animals. Box and Powell's recommendations are based upon the strong sprout- ing characteristics of the brush species. Only 60 percent control of the brush was achieved, and this was short-lived, but retreatment of the brush provided a management system favoring both deer and livestock. The economics of mowing or roller chopping was not determined. These techniques may not be applicable generally throughout the mesquite areas of the Southwest, but the management system suggested appears to have merit where deer or other wildlife species need consideration. Juniper Juniper is often mixed with pinyon, and, either alone or mixed, it occupies about 75 million acres in the Southwest. Two thirds of the juniper acreage is on federal lands. Under long-continued heavy graz- ing, juniper stands have thickened and spread, with resulting decreases in forage, increased erosion, and added difficulty in handling livestock. To reverse this trend, more than 1.2 million acres have been treated in Arizona alone (10 percent of the juniper acreage in the state) at a cost of about S4 million. Cotner (1963) indicated that the acreage treated annually is decreasing because the remaining lands have less potential for improvement. Juniper woodlands may be important winter ranges for deer and, in some localities, for elk. They also provide habitat for wild turkeys, rabbits, and doves. Juniper has been removed by cabling, chaining, burning, or bull- dozing, and grasses have often been seeded immediately thereafter. Results have been variable: in many cases the increases in grazing capac- ity have been economically significant; in others the gain in grasses and shrubs has been insignificant. Unfortunately, the extensive action pro- gram in juniper control was preceded by a minimum of research, and adequate information for successful control and range improvement is still lacking. Predictions on costs, however, are available (Cotner, 19631.
Influence of Land Management on Wildlife 117 There is a similar dearth of facts about the effect of juniper control on game populations. Tentative guidelines have been adopted by the U.S. Forest Service to protect wildlife resources in pinyonjuniper areas where control is planned. These guidelines include: ~ 1 ~ retention of dead woody plant material over at least 15 percent of the area; (2) restriction of treatment areas to less than 120-acre blocks; and (3) preservation of 10- to 15-acre patches of live juniper trees, these patches comprising at least 5 percent of the total area. In Nevada, Utah, and Colorado, pinyonjuniper stands are being im- proved specifically for the benefit of wildlife. The trees are removed by mechanical means and the areas then seeded to a mixture of grasses, fortes, and browse. The objective is to convert closed stands of trees to grass-forte-browse vegetation for use by deer in late winter and spring and by cattle in the spring. Additional benefits are noted for other big game animals, upland game birds, and songbirds, and for erosion con- trol. In the conversions, pinyonjuniper stands are left for cover in areas normally favored by deer for shelter. Sagebrush Sagebrush ranges occupy some 95 million acres in the intermountain region of the West. Much of this range had become depleted prior to World War II, with "closed communities" of sagebrush that contained but little understory of desirable grasses and fortes. Several methods of sagebrush removal became available after the war, and by the late 1950's large acreages were being treated on both federal and private lands. Many studies reported increases of 200 to 300 percent or more in grazing capacity through mechanical or chemical control of sage- brush, or by burning (Pechanec et al., 1 944, 1 954; Ryder and Sneva, 1958; Hervey, 1961; Hyatt, 19661. The immense success of improving sagebrush ranges for livestock and the resulting expansion of control programs aroused the concern of hunters and game managers. As well as constituting a conspicuous feature of the environment of several game species and, presumably, supplying some of their cover needs, big sagebrush and other species of Artemisia contribute signifi- cantly throughout the West to the diets of antelope (Einarsen, 1948; Ferreland Leach, 1950;Cole, 1957;Hooveretal., 1959),sagegrouse (Patterson, 1952; Leach and lIensley, 1954; Rogers, 1964), and mule deer (Dixon, 1 934; Longhurst et al., 1952; Hill, 1 956; Morris and Schwartz, 19571. Elk seem to have little direct dependence on sage- brush, but they use the range type extensively in winter and, in their competition with livestock for forage, are of more direct economic
118 Land Use and Wildlife Resources concern to ranchers (Pickford and Reid, 1943; Murie, 1951; Smith, 1961; Stevens, 1 9661. The concern of individuals, conservation groups, and land manage- ment agencies for resources other than livestock forage has engendered a mounting controversy over sagebrush control. Carson (1962) called it to general public attention in her best-selling book, Silent Spring. It was publicized nationally in a news release of the National Wildlife Federation (Johns, 19651. The Western Association of State Game and Fish Commissioners, meeting in Anchorage in July, 1965, passed a resolution urging federal agencies responsible for public land manage- ment and for technical and financial assistance on private lands to give adequate consideration to wildlife habitat requirements in planning and executing sagebrush control projects. Other authors ascribe to sagebrush control possible improvements in game habitat. Alley (1965) refers to a decrease in sage grouse numbers in Wyoming during years when sagebrush density was increasing and an increase after sagebrush control programs were under way. Wilbert (1963) found that elk, in spring after the snow had left, made more use of two 25-acre sprayed areas than they did of adjacent unsprayed areas. It must be concluded, however, that the influences of sagebrush control on wildlife habitat are still largely speculative. Since sage grouse occur primarily in sage, with occasional seasonal use of adjacent vegetation types, there is little question that the con- tinued existence of these birds depends upon the persistence of sage- brush in proper amounts and patterns. The dependence on sagebrush itself is less critical for deer and elk; they exist equally well on shrub ranges lacking it. Smith (1950) considered sagebrush to be the most important winter deer forage in much of the West, but he learned (1959) in pen feeding that among several browse species fed singly it was taken in the least amounts. Yet, while Utah juniper, Gambel oak, bitterbrush, curlleaf and birchleaf mahogany, chokecherry, and cliff- rose were obviously more palatable, sagebrush was consistently taken when offered in combination with these feeds. Despite the apparent conflict of interest in sagebrush control, little research has been done under field conditions to resolve the problem. However, the grazing habits of livestock and game animals are suffi- ciently well known to suggest certain systems of management of sage- brush ranges to allow improvement for both livestock and big game animals. These systems require an ecological approach to control pro- grams rather than the massive area approach. For example, ridges re- quired for deer winter range should be left in sagebrush, and adjoining swales that may be covered with snow in the winter can be converted
Influence of Land Management on Wildlife 119 to grass for increased use by deer in the spring and by livestock in the summer. Information available on the movement and grazing habits of live- stock and wildlife is being used by federal agencies in planning sage- brush management. State game managers are consulted, and if areas of deer winter range are involved, plans may be adjusted to leave these areas in sagebrush. Likewise, where sage grouse habitat is desired, strips id or i/: mile wide are left adjacent to meadows, booming grounds, and brood sites. On other areas, alternate strips of sagebrush 100 feet or more wide are left. The foregoing methods of management apply to federal lands, but private landowners are not under similar constraints. Thus there is no assurance under present policies that wildlife habitat needs will be con- sidered in sagebrush control on privately owned lands. There is need for more research on the effect of sagebrush control on wildlife, and for incentives to encourage private landowners to utilize practices known to benefit wildlife. California Chaparral "Chaparral" denotes any dense thicket of stiff or thorny shrubs or dwarf trees. In California there are two major types-"true" chaparral and timber chaparral. True chaparral occupies about 11 million acres on dry slopes at elevations between 1,000 and 4,000 feet west of the Sierra Nevada summit and the Mojave Desert. Chamise (Adenostoma fasciculatum) ist the most characteristic and widely distributed species of this type. Sampson and Jesperson (1963) report that foothill chapar- ral occurs in two characteristic situations-as pioneer plants in habitats where the soil mantle is in early stages of development, and in secon- dary successions on disturbed areas. The timber-chaparral community covers extensive areas above the upper limits of the foothill chaparral. It is found on soils too shallow for timber growth and as a stage of secondary succession on disturbed timber areas. Shrub species include manzanita and ceanothus. Dense chaparral stands impede animal movements and many of the mature plants are low in nutritional value. The aim of the wildlife manager is to break up areas of mature brush and provide open stands of young plants. Land management efforts to accomplish the objectives fall into three major classes: 1. Complete conversion of chaparral to grass: A typical treatment of this sort consists of burning the brush (often preceded by crushing), seeding to grass, and following up with spray treatments to kill brush
120 Land Use and Wildlife Resources seedlings or sprouts that become established after the seeding. The opening up of dense chaparral and establishment of grass benefits deer, quail, and doves (Biswell e t al., 1 9 5 2 J. Nearly all brush-to-grass coversions are multipurpose projects aimed at improving range and watershed conditions and reducing fire hazards. Value to game depends upon the size of the converted unit, large areas being generally less valuable to game than small. Where acreages are large, some brush is left standing to provide cover and browse between the areas of grass. Brushpiles are sometimes left in a converted area to provide cover for quail and songbirds. The U.S. Forest Service and the Bureau of Land Management consult with the California Department of Fish and Game during the planning stage prior to field operations. The greatest effort in California in converting brushlands to grass has been by private landowners. From 1956 to 1965 over a million acres were burned under permits issued by the California Division of For- estry for private lands-740,000 acres in 1965 alone. Approximately 28.5 percent of the total acreage was seeded following burning. Fed- eral agencies also play an important role. The Forest Service changed 37,371 acres of chaparral to grass from 1956 to 1965-about 10,000 acres in 1965. The Bureau of Land Management treated 66,000 acres of chaparral from 1956 to 1965. The "fuel-break" program is a specialized form of brushland man- agement. In most brush areas of California the fire hazard is high. Fire fighters find it difficult and sometimes impossible to control fires that rage through extensive stands. The establishment of grass strips along ridge tops breaks up large brushy areas into controllable units. These strips-known as fuel-breaks-permit more rapid movement of fire fighters and equipment and an opportunity to backfire. Fuel-breaks also create excellent interspersion for wildlife. From 1956 to 1965, 13,800 acres of fuel-breaks were constructed. The acreage figures are somewhat misleading in terms of game benefits. Through the creation of desirable edge and forage interspersion, one acre of fuel-break im- proves habitat for many surrounding acres. 2. Encouragement of chaparral sprout growth through cutting, crush- ing, and burning, or burning alone: This treatment differs from conver- sion to grass in that it is aimed specifically at improving browse for deer and cattle. The Forest Service, in most cases cooperatively with the California Department of Fish and Game, burned more than 17,000 acres from 1956 to 1965 in an effort to provide palatable and nutri- tious feed. Included in this total acreage are many miles of "browse- ways." Browseways are narrow strips constructed through dense stands of chaparral that have the specific objective of benefiting large and
Influence of Land Management on Wildlife 121 small game. The strips not only provide much more edge and intersper- sion than do large block treatments, but also improve access for hunters. 3. Conversion of chaparral growing on forest soils back to trees: A common method of replacing chaparral with trees is to bulldoze off the brush in strips and then to plant tree seedlings. This practice im- proves habitat for both game and nongame wildlife species, although in many areas there is depredation of planted trees by deer. From 1956 to 1965, the Forest Service alone undertook to replace brush with trees on 45,000 acres in California. Other Brushlands Chaparral of northern Arizona, shrub mixtures of the Rocky Moun- tains, shinnery oak of Oklahoma and Texas, sand sagebrush of the southern Great Plains, and mixed brush of south Texas are also being managed for re-establishment of a better grass-to-browse ratio to favor livestock or wildlife, or both. Control methods are not so well devel- oped for the Arizona chaparral, Gambel oak, or mixed brush of south Texas as for big sagebrush. However, herbicidal treatments have been developed for sand sagebrush and shinnery oak. On most of these brush- lands there has been little research on the effects of management on wildlife. The emphasis has been to determine the value of control for livestock enterprises. In the Southeast, brush control is practiced on the palmetto of Florida and scrub oak in the South Carolina and Georgia sandhills. There are over 9 million acres of palmetto in central and south Florida. Control methods employing roller choppers or herbicides reduce the palmetto and permit natural increase of native grasses and broadleafed herbs. Biologists often recommend leaving palmetto around sloughs and sand ponds, along drainage ways, and around hammocks to provide cover and feed for deer, turkey, quail, doves, songbirds, and raccoons. Control of scrub oak in the Southeast favors production of wildlife, as indicated by the great increase in doves in cleared areas where poke- berry has replaced the oak. Likewise, deer and bobwhite populations have increased where scrub oak has been cleared and pine planted. Research is needed to fully evaluate techniques for brush control in both the palmetto and scrub oak areas to provide optimum benefits for wildlife and livestock or forestry. Range Seeding Range seeding was stimulated by improved technology and various agricultural support programs after World War II. The major objective
122 Land Use and Wildlife Resources was production of livestock forage on previously cropped land or de- pleted ranges. Consequently, most workers evaluated seeding results in terms of benefits to livestock and did not measure the effects upon wildlife. However, useful observations have been made, such as those by Griffith (1962) in discussing antelope management: . . . antelope have shown response when old cultivated hayfields, and abandoned fields are a part of their present habitat. They have shown intensified use of areas where dominant sagebrush and rabbitbrush have been eradicated and reseeding done of grasses and legumes. Yoakam ( 1962) made similar observations: Here appears our first clue on what and how to increase antelope numbers-we gained knowledge that changing an acre from a predominant sagebrush type to a vegetative cover containing a good mixture of grass, fortes, and low-growing browse species can increase population numbers. Other work indicates that deer favor such introduced species as crested wheatgrass and intermediate wheatgrass early in the spring when new growth starts, which is from 2 to 4 weeks earlier than many of the native grasses. In fact, ranchers are commonly concerned about the protection of newly seeded stands from excessive use by deer. They are also concerned about early spring usage by deer of established grasses intended for later feed for livestock. Preponderant evidence shows that range seedings have benefited both wildlife and livestock, provided that sufficient shrub-forage is available to carry browse-dependent animals through critical winter periods. However, since seedings for livestock often involve only grasses, interest has developed among those concerned with wildlife habitat in the inclusion of browse and legumes in seed mixtures. Hubbard (1962) reviewed the progress in browse-seeding research, and concluded that successful bitterbrush seeding was possible, and that under proper conditions it should provide forage for 0.8 to 2.4 deer- months per acre in California. Seeding is an integral part of type conversions. For example, most of the 20,000 acres of juniper-pinyon so treated in Utah and Nevada in 1965 included a mixture of grasses, fortes, and browse. Several million acres of the juniper-pinyon type in the intermountain region have a potential for similar improvement through tree removal and seeding. One area in Utah so treated increased deer use twentyfold (Plummer et al., 19651. These areas are managed primarily for deer use in winter and early spring, with some cattle use in the late fall and spring. Dual use by cattle and deer appears to help maintain a desirable ratio of
Influence of Land Management on Wildlife browse and herbaceous plants. Other big game animals, upland game birds, and songbirds appear to benefit from the conversion of dense stands of juniper-pinyon to grass-forte-browse mixtures. A few studies have been made of the effects upon wildlife of grass 123 seedings on land placed in the "conservation reserve" under terms of the Soil Bank Act. However, in view of the fact that over 18.5 million acres were converted to grass cover under the conservation reserve pro- gram, there should be much more research on wildlife relationships. Wl LD Ll FE ON CROPLANDS Farms and croplands have long been recognized as a major habitat of economically important wildlife (Miller and Powell, 19421. One evident reason is the great extent of such land uses. The U.S. Department of Agriculture ( 1962) summarized this situation for the year 1959: A fifth of the land in the United States is used as cropland. Somewhat over one- fourth is grassland pasture and range. One-third is in forest. If grassland and forest land used for grazing are included, about 60 percent of all land in the United States is in crop and livestock production. Even a secondary value may be expected to have economic and social importance on such a large area. The nature of wildlife habitats is largely determined by the major land-use industry-as noted in the foregoing sections on forest and grazing ranges. This is equally true of extensive croplands, and also of diversified farms where all three of these uses combine to form a mosaic of vegetation types. As mentioned previously, the widely varied habitat pattern on lands of irregular to- pography has its own peculiar characteristics favorable to certain birds and mammals commonly known as farm wildlife. Typical of such spe- cies are the cottontail rabbits, fox squirrels, doves, bobwhite quail, and pheasant. Featuring game animals in this connection does not in any sense discount the importance of songbirds and other nonhunted crea- tures. Nearly all farm lands are privately owned, and this vitally affects public use of the wildlife resource, which by law and precedent is public property. Cropped land has important qualities influencing its capacity to sup- port living things of all kinds. This is a man-made habitat, largely a de- sign of artificially managed monocultures, that may be highly produc- tive of wild creatures under some conditions. The extent to which it does produce depends on how well it fulfills the year-round life re- quirements of the most closely adapted species. This means, of course,
124 Land Use and Wildlife Resources the degree to which it simulates the functioning of a natural ecosystem. Agricultural soils are basically favorable to living organisms in that usually they are fertile and have reasonably good moisture relationships. Cultivated lands commonly abound in weed-seed and grain-residue foods (Baumgras, 1943; Allen, 1949) that support, at once, the often undesirable rodents and the usually desirable game birds. In an eco- logical sense, the agricultural habitat is a disturbance community, sometimes an extensive single vegetation type, at other times a com- plex of conditions-bare soil, row crops, annual fortes and grasses, meadowlands, perennial herb and brush stages, and other early phases of forest or grassland succession. Such types and the terms used to describe them overlap broadly. Graham, a long-time student of wildlife and land-use relationships, described succinctly the logical and necessary emphasis that must be employed in nearly any cropping program for human benefits. He recognized initially ( 1944, p. 1 1 ) that: . . . the capacity of the land to produce varies not only from region to region, but within small areas, in accordance with soil conditions, vegetation, slope, exposure, degree of accelerated erosion, and other physical characteristics. Consequently, . . . In a very general way it may be said that farm land comparatively level may best be devoted to corn, cotton, and cultivated crops; gentle slopes to pasture; steep slopes to trees; and odd corners, and infertile and eroded spots to the pro- duction of useful wild plants and animals. This general statement of land-use capability applies alike to regions, farms, and fields. We may assume that primary uses-such as cash crops on level fertile soils-may have additional worth in their contribution to wildlife by-products. In the extensive corn lands of midwest prairies, for example, or in wheat-and-fallow areas farther west, the secondary values are likely to be minor. On the other hand, where an appreciable portion of the farm is unsuited to tillage, wildlife can be much more important as an accessory product. Policies affecting wildlife and the recreational benefits deriving from it cannot be the same for all agri- cultural areas. Intensively Managed Farms The growing trend toward large intensively managed cropping units has been described (Chapter 31. This trend accompanies increasing mecha- nization, the operation of farms with bigbusiness efficiency, a higher degree of crop specialization, the employment of less labor, and fre- quently absentee ownership. Continuous blocks of relatively level and
Influence of Land Management on Wildlife 125 productive lands are best adapted to such use, with resulting extensive monotypes (e.g., corn, beans, wheat, cotton, sorghum) on what once were prairies, or specialty crops occupying irrigated or drained flats. On these areas, intensive culture is the rule, and the total acreage has high value for this primary purpose. There is little economic basis for giving consideration to wildlife, and there are few sites where it is fea- sible to favor its production. As noted by Allen (1952) In some areas agricultural lands are so well adapted to intensive farming that almost every square foot will yield cash income. Little, if any, wildlife management is practicable in these situations; in truck crop areas such animals as pheasants and rabbits may be more of a nuisance than anything else. The land-use association that Bennitt ( 1939) reported for Missouri prairie chickens has general significance. He found none of these birds on the best prairie soils, since such areas had been totally converted to the cultivation of corn, sorghum, and other crops. "There was almost none... on the next best.... Nearly all the birds were found on the medium to low-grade prairie soils." In the poorest areas cultivation was not extensive and hay meadows and pastures were increasing. There is little reason to doubt that in primitive times the most fertile prairies of Missouri supported the highest populations of these grassland grouse, but such areas had ceased to be "chicken" habitat. Over a period of 14 years, Swanson and Yocum (1958) observed the degradation of habitat and the decline of pheasants and Hungarian par- tridges as the intensity of land use increased in wheat lands of the Washington palouse region. This increased intensity of farming effort has resulted in larger farms, consolidation of fields, more machinery, fewer fence rows, less edge effect, subsidized drainage, elimination of brushy draws, and aerial spraying of insects and weeds. In summary, except for the planting of sweet clover, all factors mentioned have had a tendency to decrease the amount of food and cover in this area. On prairies from Indiana to Iowa are found some of the most pro- ductive agricultural soils in the world. They exemplify the situation of intensively used land as a wildlife habitat. There is, literally, no "waste" space on such farms, except for roadsides and the banks of waterways- ditches that must be accessible to cleaning with a dragline at intervals, and streams in various stages of conversion to ditches. The stabilization of banks with grass and legumes or shrubs is an essential part of land management, and such areas receive heavy use by nesting pheasants, as well as songbirds and rabbits. On intensively used farms an exceptional interest by the landowner
126 Land Use and Wildlife Resources can improve wildlife habitat, even at some expense to cropfield space. Windbreaks (Ferber, 1958) of Russian olive, multiflora rose, or other shrubs provide an agricultural incentive, according to local conditions, and they also introduce durable coverts into blocks of cropland where none is likely to exist otherwise (Wendell, 19483. The response of song- birds (Dambach, 1945), nesting mourning doves, and wintering pheas- ants to such developments may be impressive. Especially on former tallgrass prairie lands, the tolerant, rapid-growing, and easily handled multiflora rose can be used with little concern for its tendency to spread (Scott, 19651. Where the bulk of the land is in short rotations, pioneering by the shrub is automatically controlled That some of these practices are finding at least limited acceptance among farmers is indicated by records of Soil Conservation Districts showing the building of 1,500 miles of windbreaks and 3,700 miles of hedges annually (Anderson and Compton, 1958; see also Fox, 19421. Nelson (1953) described a cooperative program for South Dakota in which windbreaks averaging 7 acres were established at 3-mile intervals with the particular objective of protecting pheasants during winter blizzards. Planting costs were about $42 per acre. While regionally specialized practices may be developed for multiple purposes, it is not realistic to expect measures that will favor wildlife on a large scale. For evident economic reasons major areas of class I land (see Nunns, 1958) will continue to offer the least opportunity for managing this recreational by-product. In effect, this is a natural zoning that commonly allocates the most productive soil to a single efficient use-the antithesis of multiple use. D iversif fed Farms The land-use capability classification of the Soil Conservation Service designates classes I through IV as suitable for cultivated crops, with progressively increasing limitations and need for conservation prac- tices. Classes V through VIII are generally unsuited to cultivation but can be allocated to pasturing, forestry, and wildlife management (Nunns, 19581. Wildlife is the one product to which, in some measure, all of the associated land types contribute For agricultural purposes a "general," or diversified, farm will be valuable in proportion to the high quality cropland it includes. Its usefulness as a wildlife habitat will usually depend on areas of land in classes V to VIII, especially if these are interspersed with fertile cropfields. If this trend of decreasing pro- ductivity is projected to areas submarginal for agriculture, the capacity to support farm wildlife diminishes and the proportion of forest
Influence of Land Management on Wildlife 127 dwelling species increases. Diversified farming has developed frequently on formerly forested lands that are rolling to hilly in topography. Habitat Objectives Leopold (1933), pioneer in wildlife management, recognized "carrying capacity" as a universal characteristic of habitat (see also Errington, 19451. This is to say that for a given species a particular range has defi- nite limitations in the number of animals it will support at a given time. A population could theoretically expand indefinitely if habitat re- sources were infinite. In reality, every population is held in check by the operation of density-dependent environmental or behavioral factors (see Lack, 1954; Dasmann, 1964: 153 et seq.~. Logically, in any habitat a single condition of some kind or other is likely to be more effectively limiting than all others and for management purposes may be desig- nated conveniently as the "critical" factor (see Taylor, 1934; Allen, 1954: 46 et seq.~. As would be expected, critical factors may be quite different from one species to another, even in the same habitat; from one region to another they may vary for an individual species. On a year-to-year basis, weather is a universally influential variable for nearly all birds and mammals (see especially Lehmann, 1953, and Jackson, 1962), yet its effects are conditioned by the kinds and pattern of vegetation. Wild- life biologists are learning to recognize the basic environmental require- ments of many species, especially in terms of seasonal combinations of vegetation types that serve as food and cover. The word "combination" is not to be passed over lightly, since it is the close association of life essentials that permits an animal to satisfy its requirement with a mini- mum of movement and thus a maximum of security. The more various cover types are broken up and mixed together-creating the character- istic condition known as edge effect or interspersion (Leopold, 1933)- the more individual "home ranges" (Burt, 1940) there will be where animals can survive. In other words, the higher will be the habitat carrying capacity. Contour Agriculture In the contiguous 48 states, many farms were laid out originally to conform with section lines, producing a pattern of quadrangular fields, sometimes with little reference to surface features.* Under these con- ditions, cropping laid bare large continuous blocks of land at one *The rectangular system of surveying land, initiated in 1785, applies generally in the states west of the Ohio and Mississippi Rivers and in Alabama, Florida, and Mississippi.
128 Land Use and Wildlife Resources time. According to Soil Conservation Service estimates, some 61 per- cent of cultivated land in the United States is sufficiently rolling to erode when not protected by vegetation (Kell, 19381. The system of contour agriculture, which received great impetus during the thirties, was aimed particularly at stabilizing the soil and promoting the infil- tration of water where it falls. It commonly results in fields of irregular shape, with sloping croplands laid out in narrow alternating strips of cultivated ground and close-growing grain or hay. The map of a farm planned on the basis of soil capability typically shows a markedly in- creased interspersion of cover types and resulting edge (Graham, 1941a; Hedge and Klingebiel, 19571. The conversion of an agricultural area from rectangular fields to a completely revised farm plan often results in the removal of old brushy fencerows and borders and an initial degradation of wildlife habitat. However, establishment of the new system will feature permanent vege- tation in critical sites and develop a pattern of coverts that may be as good as the old, or better. On a series of selected Ohio farms, the changeover to modern land- use plans made by the Soil Conservation Service was appraised for its effects on breeding bird populations (Good and Dambach, 19431. Lim- iting their observations to areas in crops, pastures, and woodland (i.e., no specific wildlife management measures), the authors concluded that soil-conserving practices had increased bird populations on two areas by approximately 38 and 45 percent, respectively, and that the most influential factors in bringing about this change were: 1. Fewer acres clean-tilled and in small grains (which support small populations of breeding birds) and a corresponding increase in the acreage with permanent vegetation. 2. More acres in meadow, which support higher populations of breeding birds. 3. Breaking large crop fields into narrow, alternative strips of different crops, resulting in an increase in the number of acceptable territories for field-nesting birds. 4. Increased acreage of managed pastures which support higher populations of breeding birds than poor pastures. 5. Material increase in acreage of protected woodlands, which support about twice as many birds as grazed woods. Cultural Practices While the basic agricultural design is of vital importance to wildlife, so also are the methods of tillage and crop management. The mowing ma- chine is a particularly well known threat to nesting birds and other
Influence of Land Management on Wildlife 129 wildlife-one that has grown steadily in importance since the advent of the first horse-drawn mechanical mower. In Wood County, Ohio, the destruction of pheasants in hay mowing increased about 60 percent from 1938 to 1946 as a result of the grow- ing use of high-speed power mowers (Lee dy and Dustman, 19479. Night mowing of alfalfa for dehydrating mills was especially destruc- tive to pheasants. In a sample of 590 acres cut for mills in 1946, the kill of pheasants was 106 hens and 74 juveniles. Other vertebrates killed totaled 193, including 37 cottontails. In many states during the past 30 years, wildlife workers have ex- perimented with various types of "flushing bars," with some measure of success. However, the encouragement vanishes 'es mowers become more efficient. No easily used device seems to have been perfected for avoiding the cutter bar problem. Where the time of mowing can be controlled, late mowing results in diminished mortality for some spe- cies. Leedy ~ 1949) found that first cuttings of alfalfa in Ohio had six times as many pheasant nests per unit area as second cuttings. The pro- ductivity of nests in stands of small grain was considerably better than in alfalfa, because of the later mowing (Leedy, 19401. The development of early-maturing grasses and legumes will be an increasing liability to such species as the pheasant. That there are situations in which an awareness of the mowing prob- lem can be used to advantage is evident in a news release of the Iowa State Game Commission dated July 1, 1967. The chairman of the Iowa Agricultural Stabilization and Conservation Committee gave full sup- port to the Game Commission's request that farmers raise their mower blades 8 to 10 inches in clipping "government" acres. Intensified land use commonly involves more frequent tillage and more thorough weed control. On prairie wheat fields the spring burning of stubble has long been practiced-to the disadvantage of both soil fer- tility and wildlife. To avoid this result, subsidy payments were used in eastern Washington to encourage farmers to disc their stubblefields in the fall. However, this procedure and summer fallowing for weed con- trol'contributed to the total area of bare soil and the reduction of wild- life cover (Swanson and Yocum, 19581. In Colorado, Sandfort (1952) recommended that fallow discing in wheat stubble be delayed until the second week in June to avoid destroying pheasant nests. Combine har- vesting of grain leaves tall stubble that is relatively good bird cover as long as it stands. Clipping reduces this value, as well as the weed-seed foods produced in such fields. Anderson ~ 1949, 1965) classified as favorable or unfavorable various
130 Land Use and Wildlife Resources farming practices that affect wildlife on lands primarily used for crops, pasture, and woods. Among beneficial farming methods in tilled fields are rotations that include grass-legume meadow, liming and fertilizing, strip cropping, cover crops, stubble mulching, leaving unharvested grain or spreading manure near winter cover, and delayed mowing of road- sides, watercourses, and headlands. Similarly, pasture improvement, through fertilization and reseeding, and grazing within carrying capacity, are considered to be in keeping with good wildlife management (Anderson, 1949, 19651. Burning, overgrazing, and early clean mowing have the opposite effect. Wood- lots function best as wildlife habitat when protected from fire and grazing, when selectively cut (in the case of hardwoods), when brush cuttings are piled and left unburned, and when den trees, mast trees, and hollow logs are preserved. It is evident that nearly all of the practices desirable for the produc- tion of wild creatures are either necessary for good land management or at least are not inimical to it. It is clear also that improvements in the engineering of agricultural implements are a part of increased ef- ficiency on the farm. This is true not only of faster mowers, but of harvesters that leave less grain residue and less cover on the ground. These trends indicate a future need for effective alternatives in favoring the wildlife crop. Problem Sites and Wildlife Plantings A modern land-use plan for a farm in a region of forest climax may in- clude a wide variety of soils and sites ranging from the most level and fertile crop fields on the one hand to the "problem" topography that must be allocated to woodlot on the other. The map of site capabilities will show many locations where an informed landowner can provide for wildlife coverts. In terms of space, such coverts typically cost little or nothing; the cost of establishing and maintaining them will hinge on the problem of developing "practical" techniques and achieving worth- while results. These aspects vary greatly. The Biology Division of the Soil Conservation Service was concerned with problems and opportu- nities of this kind as early as the 1 930's, and experimentation with methods has gone forward on a broad scale since then (Dambach, 1940, 1945, 1948a;Edminster, 1941;Graham, 1941a, 1947;Van Dersal and Graham, 1 946; Allen, 1949; Edminister and May, 1 95 1; Anderson and Compton, 1958;Anderson, 1949,19654. Improvements made specifically for wildlife usually feature the establishment of relatively permanent vegetation on areas where the
Influence of Land Management on Wildlife 131 common purpose of erosion control and wildlife management will be served. Some of the sites used to advantage and appropriate cover types are: ( 1 ) grassed terraces and waterways, (2) contour hedges and windbreaks-especially in strip-cropped fields, (3) field borders along woodlots, where soil is sapped of moisture and fertility by the tree roots, (4) plantings of perennial legumes, shrubs, and trees around old gullies and on critical slopes and "odd areas." Living fences of multiflora rose have shown great promise; however, limited use of this species is now recommended to avoid its spreading into pastures and idle areas. Originally, many planting materials were recognized as potentially useful in wildlife management (McAtee, 1941), and extensive trials have been made to screen out those regionally adapted to specific purposes (Davison, 1941, 1945; Graham, 1941b, 1942; Dambach, 1948a; Edminster and May, 1951; Borell, 19621. To have general value in such a program, a plant species needs to serve important needs for wildlife (either as cover or food or both) and to have a broad tolerance of climatic, soil, and moisture conditions. It should survive under indifferent handling and have good soil-binding qualities. The vast majority of plant species tried have proven to have im- portant deficiencies of one kind or another. Among those sufficiently promising to receive widespread use are multiflora rose, autumn olive, bicolor lespedeza, sericea lespedeza, and several species of viburnum, honeysuckle, and dogwood. All of these have fleshy fruits except the lespedezas; autumn olive is particularly tolerant of dry conditions. Pines and other conifers are popular with landowners for ease of handling and landscaping value. In early years of growth they form good ground cover. The lespedezas merit particular mention, since they have been fea- tured in many wildlife programs in the eastern United States south of the Great Lakes region (Davison, 1945~. As a plant easily seeded, site tolerant, and with superior erosion control and wildlife cover charac- teristics, sericea lespedeza (Lespedeza curleata) is outstanding. Well- distributed winter cover is a primary need of the cottontail, and this perennial legume serves the purpose in many situations. Other lespedezas are more useful in quail management, which is an important wildlife interest of landowners in the central and southern states. Introduced annual lespedezas, especially Korean (L. stipulacea), reseed extensively as federals and frequently provide abundant food for the bobwhite. The greatest effort to this end, however, has been made with "bicolor" lespedeza (L. bicolor). The seed of this plant has
132 Land Use and Wildlife Resources high palatability. The plant forms the open type of cover favored by the bobwhite. Over the past 20 years, seed and plants of this species have been extensively distributed by southeastern states as part of their farm wildlife management programs. The planting of food strips on private shooting preserves has become standard practice. It has long been evident that quail make much use of "bicolor patches," and it has been widely assumed that such a program produced more birds. Management Appraise/ Rosene (1956) reported on a 7-year study covering nine hunting pre- serves in Alabama and South Carolina where more than half a million plants of bicolor lespedeza had been used for quail management. The work involved paired experimental and control tracts (with and without bicolor); information was obtained on 1,924 coveys. Rosene found that on each of the experimental areas bicolor formed not less than 32 percent of the food used by quail. In hunting season the coveys were most commonly to be found in the food strips, which made shooting easier-a desirable feature on quail preserves, where the kill is under control. As to the critical question-whether bicolor plantings produce more quail-the increase was less than one covey of quail per 1,000 acres on the developed areas, not a statistically significant difference. Evidently bicolor has value in producing excellent hunting (the dogs go from one planting to another), but it cannot be depended upon to produce more quail on areas where there is sufficient food of other kinds. On the areas studied, food was not a critical limiting factor. As a measure of the success of more general farm game habitat pro- grams, Marshall (1953) made a field reconnaissance of 15 states and carried out a qualitative appraisal of wildlife management practices- primarily plantings in small plots. In order of importance, the plants used were shrub lespedeza, multiflora rose, several other deciduous shrubs, conifers, sericea lespedeza, and various annuals such as Korean lespedeza and partridge pea (Chamaecrista fasciculata). Marshall found that several factors militated against the effectiveness of such developments. Natural plant successions tended to invade the artificial plantings and alter their character. The actual need for small food and cover plantings by wildlife varied greatly from one area to another, and benefits frequently were uncertain. Incentives for a land- owner to invest time and effort in careful establishment and mainte- nance of plantings were largely lacking. Planting failures and inferior stands were common. No reliable research appraisal was made to deter- mine what had been accomplished.
I nfluence of Land Management on Wildlife 133 Such results do not constitute a disavowal of the effectiveness of habitat management; they probably do indicate that "blanket" specifi- cations and large-scale programs are likely to become indiscriminate and ineffective. There is no question that the numbers of a desirable wildlife species can be increased by food and cover manipulations on an area where site and climate are favorable but where the vegetation pattern is deficient. Outstanding examples can be cited where this has been done with the bobwhite and California quails (Hawbecker and Bond, 1942; Rosene, 1950; Steen, 1950; Burger and Linduska, 19671. In each of these management operations, the basis was a soil conserva- tion plan into which quail food and cover types were fitted, especially on edges and unused areas. The striking results of such developments at Remington Farms on Maryland's Eastern Shore (Burger and Linduska, 1967) were achieved in 8 years. Quail coveys increased from 5 to 38 in this period on a 3,00~acre management area, and a substantial buildup of rabbits accompanied the program. The principal practices utilized were: (1) creation and seeding of waterways and diversion terraces, (2) retirement and seeding under federal programs of headlands and borders of cropfields, and (3) establishment of plantings designed to improve farm-game habitat. Through 1964, these practices included seeding 49.4 acres to grass and 8.5 miles of 30-ft strips to sericea lespedeza (Lespedeza cuneata), and planting 7.1 miles of multiflora rose (Rosa multiflora) hedges and 14 acres of food-producing shrubs. Land-use changes dictated by practical farming considerations, primarily fallowing odd areas and reducing grazing intensity, also improved quail habitat. Any reviewer of literature on habitat improvement will conclude that projects carried out with ecological realism are very often success- ful, and that those contrived in other contexts are likely to fail. Such expedients as large-scale artificial feeding, game stocking, and predator control were among the first putative cure-alls questioned and largely discredited by the biologist as a means of managing wildlife on a pub- lic basis (we do not question bird feeding as a private recreational use of the wildlife resource). Now the biologist must remind the profes- sional manager that solving wildlife problems on the land is com- monly a technical business and that a diagnosis of ecological ills should nr~r~rlP the. ~.llr~. A re.nlilv to he faced is that "game is a thin crop." r -~ _ HA At, ~ Where a fair-to-good population of a species already is present, the in- stallation of a few plantings is not likely to produce an increase that can be measured. But under extreme conditions of habitat degradation, an intensive management program may have unmistakable good effects.
134 Land Use and Wildlife Resources In the latter category are changes that can be seen in semiarid lands when a water deficiency is alleviated. An underground tank, the "gallinaceous guzzler," has been used extensively on California ranches to provide water for valley quail during the summer rearing season (Grading, 19431. The installation of a single water source has made possible the support of 200 birds in ranges where previously there were none (True and Glading, 19461. Natural Successions Nearly all wildlife managers recognize the alternative to planting clumps and strips of selected exotic (or native) vegetation specifically for wildlife. In a region of forest climate, an area retired from cultiva- tion will be taken over naturally by successive stages of herbs, brush, and trees. In fact, the vigorous invasion of such species is one of the difficulties with artificial plantings, requiring the cutting out of in- vaders to preserve desirable features of the original stand. In the case of bicolor lespedeza, periodic mowing of the entire planting followed by discing and fertilizing are necessary to maintain the vigor of the legume and eliminate competition (Rosene, 19521. In the eastern United States the early woody invaders of undisturbed sites typically are species whose fleshy fruits are borne by birds- various brambles (Rubus)~ vines (Vitis, Rhus, Celastrus, Solanum), and numerous shrubs. The low-growing woody species are used as perches by birds whose droppings quickly seed such pioneer tree species as cherry, sassafras, and hackberry. This habit also assures the rapid spreading of woody plants in brushpiles placed as wildlife cover around old gullies and odd areas. The adequacy of natural distribution mechan- ics for early shrub and tree stages of succession is evident in late sum- mer when the droppings of omnivorous mammals (especially the fox, raccoon, and opossum) are filled with the seeds or stones of pokeberry, cherry, persimmon, grape, dogwood, rose, and other woody plants. Other trees appearing in unused sites are brought in via wind-borne seeds (elm, ash, maple) or fruits (oak, hickory, walnut) carried by squirrels and other nut-eaters. Over the major portion of the United States there are woody species that will seed naturally into areas set aside and merely left alone. This is true of native shrubs even on central and northern grasslands (nota- bly Prunus, Rosa, Eleagnus, Symphoricarpos, Shepherdia). Thus, sites where the soil can be stabilized with undisturbed seedings of grass and legumes will eventually come to support their natural complement of native woody plants to serve as wildlife cover. This approach is no
Influence of Land Management on Wildlife 135 doubt the "easy way" and the one that will be taken by landowners whose interest in wildlife and landscaping does not lead them into specific investments. The policy for a farmer to follow in this situation is merely to leave woody vegetation alone where it is not in the way. One problem of managing ground cover for wildlife is that it will eventually be invaded and shaded out by trees. This effect is true for both plantings and natural coverts, and calls for periodic maintenance on the small areas where it is impractical to allow a woodlot to develop. The over-topping trees must be killed with chemicals, cut out, or hacked into and broken over-a method that contributes to sprout growth (Allen, 19491. The ecological realities of the "disturbance" agricul- tural community are that no stage except the climax will maintain it- self indefinitely without attention. Sponsored Government Programs It appears to be inherent in most efforts toward the conservation of soil and water that some wildlife benefits also accrue. This is especially true where land use is reduced in intensity; it is frequently not the case where such measures as reclamation drainage bring about a greater intensity of cropping, even though the prevention of erosion may be a mayor Issue. The longstanding Agricultural Conservation Program (ACP) has in- cluded a variety of practices, the most useful to wildlife being those involving the planting of trees and shrubs, the establishment of other kinds of vegetative cover, and the development of water sources (see U.S. Department of Agriculture, 1 9671. Payments for practices involving shrub and weed control and the improvement of woodlands are likely to vary widely, depending on local interpretation and the particular interests of the operators. In some cases, wildlife is not taken into account because biological activi- ties in the Department of Agriculture have been thinly spread, and general specifications or policies may get a largely nonprofessional interpretation at field level. A greater participation by state wildlife agencies in adapting generally approved practices to local conditions can help this situation, and in some states the necessary relationships between state and federal personnel are well established. Some 23 states now have trained wildlife management extension specialists- a type of service for which there is great need. The increasing orientation of many agricultural programs toward wildlife benefits is evident, and there are far-reaching possibilities. The
136 Land Use and Wildlife Resources Appalachian land stabilization and conservation program, initiated in 1966, offers cost sharing for many practices similar to those of ACP. As another example, in 1966 approximately 47 million acres of crop- land were diverted under the feed grain, wheat, and cotton programs. Such areas are converted to vegetation that often provides nesting cover for game birds or otherwise contributes usefully to the wildlife habitat. A notably beneficial requirement is that whenever mowing is undertaken for weed control it be done after the peak of nesting, or otherwise in the manner least damaging to wildlife. Another feature of the Agricultural Stabilization and Conservation Service program is a provision that can make surplus grain owned by the Commodity Credit Corporation available for feeding migratory birds or resident species. Feeding wild species is not a routine practice in state or federal man- agement programs, but it may be useful for limited periods on water- fowl refuges or in connection with crop depredation problems. The introduced pheasant (Phasianus c. torquatus) is well known for its outstanding ability to survive and reproduce on fertile, intensively farmed lands (Allen, 1956 : 4311. However, even this tolerant species is vulnerable to extreme reductions of both nesting and winter cover. On a test area of 12 square miles in east-central Wisconsin, 4.3 percent of the cropland was retired from production under the Department of Agriculture Feed Grain Program from 1961 to 1964. About half the retired acreage became suitable nesting cover, and studies by Gates and Ostrom (1966) indicated that an average of 17 percent of the pheasant nesting in the area was in this undisturbed acreage. An increase of ap- proximately 10 percent in the pheasant population was attributed to the Feed Grain Program. That retired acres can be beneficial to the prairie chicken and sharp- tailed grouse is indicated in Kirsch's (1964) account of the situation on North Dakota's "drift prairie" in the spring of 1964. He writes that: Prairie grouse have probably responded to soil bank habitat "grassed areas] wher- ever remnant populations remained when the Soil Bank Program was begun. Most of the soil bank in this study is scheduled for return to agricultural use in 1968 and 1969. All soil bank lands will be back in such use by 1971. This leaves a few years for development of a program to save some of the prairie grouse using soil bank habitat.... If new grasslands are developed now, they will be suitable for prairie chicken when much of the soil bank is returned to agricultural use. In the Food and Agriculture Act of 1965, the Congress authorized for the first time cropland acreage diversion agreements with farmers "for the preservation of open spaces, natural beauty, the development
Influence of Land Management on Wildlife of wildlife or recreational facilities, or the prevention of air or water pollution...." 137 For furthering this Greenspan program, the Secretary of Agriculture may transfer Cropland Adjustment Program (CAP) funds to federal, state, or local agencies for land acquisition or to share the cost of conservation practices. Significantly, the act included a provision relat- ing to public access: The rate or rates of annual adjustment payments as determined hereunder may be increased by an amount determined by the Secretary to be appropriate in relation to the benefit to the general public of the use of the designated acreage if the producer further agrees to permit without other compensation, access to such acreage by the general public during the agreement period, for hunting, trapping, fishing, and hiking, subject to applicable State and Federal regulations. . . Gambel (1967) stated that by the above authority, under the 1966 CAP, about 5,500 farmers in 30 states placed more than 480 thousand acres of their cropland under these free public access agreements. This has been a significant effort by the government to meet the incentive needs of land holders in promoting public use of outdoor resources largely at the local level. A reality to be reckoned with is that such programs are temporary, and the good they do may be undone at any time. The population outlook implies strongly that in large measure either the public will be required to own and manage lands and waters for recreation, or a stable long-term formula must be discovered to make public use of private facilities profitable and desirable for the owners. Wl LD Ll F E OF U RBAN AR EAS Songbirds, squirrels, and other wild creatures have long been accepted as part of the "landscaping" of city and suburban dooryards and park- ways. However, it is largely in recent years, with the recognition of "natural beauty" as a feature of our environment worth managing, that particular public attention has been given to the wildlife of metro- politan areas. Conditions frequently found in the urban scene may sup- port a wide variety of birds and mammals-particularly in the vicinity of water areas, wooded stream bottoms, and parks. These habitats commonly support a seasonal migration of marsh and shore birds and serve as feeding areas for such larger species as herons and gulls. With proper encouragement, wood ducks, owls, and flying squirrels may
138 Land Use and Wildlife Resources nest in hollows or nest boxes on city lots. Raccoons, opossums, rab- bits, chipmunks, and woodchucks are common where some open space remains; woodchucks may even become a nuisance in flower beds and vegetable gardens. Where cities have had the vision to preserve natural waters or wet- lands, the waterfowl visitation of spring and fall becomes a popular bird-watching feature for the residents. These areas, even in the midst of a populous and built-up environment, attract wildlife because they are closed to shooting and very often someone will practice artificial feeding. Even rare species may be helped in an important way, as was the case when Hanson (1965) "rediscovered" the giant Canada goose (Bran ta canadensis maxima) and found one of its wintering strong- holds to be Silver Lake at Rochester, Minnesota. He stated that: An attempt to establish nesting Canada geese at Silver Lake was made as early as 1936, when six geese were purchased. However, limited success was achieved until 1947, when a flock of 12 large geese from Nebraska was willed to the city by a former patient of the Mayo Clinic who had enjoyed watching the geese at Silver Lake. This pinioned flock was presumably responsible for decoying wild birds to the lake in autumn. The protection this flock subsequently received permitted its rapid buildup. It is of interest that the geese concentrate in an area of the lake kept free of ice as a result of water being used by the city power plant for cooling purposes and then returned, heated, to the lake. Many of the artificial lakes increasingly common in residential devel- opments were at first a part of storm drainage systems. However, in recent years there has been growing recognition of the advantages of scenic water areas in terms of increased environmental amenity and salability of properties. As has been pointed out by Burby (1967), in studies in North Caro- lina, lakes in residential subdividions are not an unmixed blessing. Questions of safety, ownership, and liability arise, as well as questions of water quality and the related public interest in watershed use. Burby pointed out that since every urban area has a finite number of poten- tial sites for impoundments, the expropriation of these sites for private purposes raises questions of the public's interest in the developments. Although, as he indicated, they have a high scenic and recreation value for the residents of the community, in no case were the lakes investi- gated in the study open to "public" use. Burby said, "Whether the public should be adequately compensated for the use of a diminishing resource is a moot question."
Influence of Land Management on Wildlife 139 Burby mentioned, further, that many lake-oriented subdivisions are designed around pre-existing lakes initially intended for agricultural purposes and that, in most cases, the dams that create these lakes were not designed to withstand the pressure of surrounding urban develop- ment. As a result of more rapid and increased runoff-over that exist- ing in more pastoral periods-as the watershed is developed, there is a constant danger of washout and flooding of downstream areas. At present, according to available information, no public agency in North Carolina has the responsibility for supervising the construction of dams for lakes in residential areas or for converting agricultural lakes to urban use, although various public agencies may be involved or con- cerned in relation to highways, mosquito control, and water quality (Burby, 19671. Adequate control or solution of problems of this kind probably will require coordinated action of federal, state, and local of. . . Ma. .s. Urban lakes can provide fishing and boating opportunities, although hunting is, in general, a nonconforming use and must be prohibited within city limits. However, the hunting season may have its effects in such localities. It is well known that, where pheasants are plentiful in adjacent agricultural lands, they will react to shooting by flying into the outskirts of towns and suburbs. There, in shrubbery and weedy lots, they will be protected from the gun but increasingly exposed to cats and dogs. Beyond the suburban fringe changes are commonly taking place that, at least temporarily, favor small game and other wildlife. Especi- ally where soils are not of the highest quality, such lands tend to be broken up into many small residential farms. As noted by George (1966), management is not intensive, pastures are maintained as "vista" open spaces or for riding horses, erosion scars are repaired, gullies are planted to woody vegetation or used for ponds, and condi- tions generally favorable to wild creatures are maintained. Often these conditions develop without any real consideration being given to the effect on wildlife. Farming, as such, is subordinated or abandoned en- tirely, fields being converted to grassland reserve and often allowed to grow up to brush and trees. Although many species of wildlife have been able to survive in human population centers, the disturbing and limiting influences are many. In these areas, the chief mortality factor for some animals (especially squirrels and rabbits) is often the street traffic. In addition to the concrete, asphalt, walls, and fences that supplant the natural cover of open lands, wildlife must contend with such obstacles as
140 Land Use and Wildlife Resources buildings, panes of glass, and television towers, which produce large numbers of casualties yearly. In the suburbs, homeowners habitually use many kinds of pesticides liberally; in industrial areas, air and water pollution are likely to be local hazards. Airports now constitute a special problem, since danger to human life is directly involved. As Drury observed (1966), many of these spacious, well-grassed areas are so attractive to certain kinds of birds one might think they were designed to be refuges. He remarked: Consider Logan International Airport [Boston] . It was built on many square miles of onetime mudflats and gravel bars, bare at low tide, once a major gathering place for migrating shore birds, and the wintering ground of more than 5 thousand black ducks. Large mussel beds around it are a magnet for herring gulls. Raised runways were built, but between the runways, to hold costs down and help drainage, low areas were left; they are now filled with freshwater. Before 1960, (when a crash of an airplane after colliding with a flock of starlings killed 61 people) the edges of these ponds and most of the low places on the airport were heavily grown up with tall reeds; beyond them on the edges of the runways, were bushes including bayberry and sumac. As Drury pointed out, the area provided a maximum amount and variety of habitat and edge highly attractive to birds and other forms of wildlife. Starlings roosted in the reeds at the edge of the ponds, and gulls were attracted to the garbage that frequently is to be found on or near airports. When the reeds were kept cut, the starlings no longer re- turned in large numbers, but cleaning up the garbage and waste in Boston and other metropolitan areas is more difficult. With respect to problems caused by birds at airports and in connec- tion with the images or "angels" on radar screens, which resemble images created by small fighter aircraft, Drury (1966: 889) concluded: Let me repeat: The problems created by birds at airports and on radar do not seem insurmountable. They would be quite simple were it not for financial or political limitations and motives. We know or can find the biological or political and physical factors and take reasonable steps to remove the basic causes. That is, when we are sensible about where we dump our filth and substitute long-range planning for short-term financial gain. Opportunities for managing wildlife in and around cities and towns are excellent. With a program of grain feeding and a few tame mallards on water areas as decoys, nearly any community can create an out- standing wild bird spectacle during the fall and spring migrations. Resident species of wildlife can be encouraged by such simple mea- sures as the seasonal control of weed burning, of mowing, and of in
Influence of Land Management on Wildlife 141 discriminate use of herbicides. Open spaces can often be handled satis- factorily and can serve as study areas for school groups and outdoor enthusiasts by allowing the native flora and fauna to develop undis- turbed. As stated by Stearns (1967~: Within the boundaries of most urban units, whether small cities or vast megaloptic Esic] complexes, it is still possible to find land with good potential as habitat for wild birds and animals. Such urban wildlife habitat would bring to the city dweller some appreciation of the realities of nature. He could learn about ecological con- cepts such as carrying capacity, territoriality, adaptability, competition, and the interdependence of wildlife and its environment. Davey (1967) noted that the Land and Water Conservation Fund administered by the Bureau of Outdoor Recreation can be used for wildlife-related recreational projects within urban areas and that the Open Space Land Program administered by the Department of Housing and Urban Development has no restriction against incorporating wild- life aspects. It is particularly important in metropolitan districts that construc- tion site standards receive attention as a means of preventing unneces- sary erosion, with resulting siltation and degradation of water areas. In recognition of this problem, as it is associated with road construction, an amendment to the Federal Aid Highway Act of 1966 directs the Secretary of Transportation to consult with the Secretary of Agricul- ture in formulating guidelines to minimize soil erosion. Engineers of the Soil Conservation Service and the Bureau of Public Roads have developed specifications to be followed by state agencies in projects utilizing federal funds. As another provision of the act, advice from wildlife agencies must be sought in developing road construction plans. This should help to minimize the harmful effects of road building on wildlife and, in some cases, result in improved wildlife habitat. A Department of the Interior news release of February 5, 1968, re- fiected a growing optimism concerning the prospects of preserving and managing the open lands and green spaces of the built-up portions of the country: The year 1967 marked another victory for the American people in the continuing effort to preserve undeveloped lands and waters for public conservation and recreation purposes against the encroachment of urban expansion, highways, air- ports, and similar developments, Secretary of the Interior Stewart L. Udall said today. Citing statistics gathered by the Bureau of Outdoor Recreation, Secretary Udall revealed that during 1967 some 1,715,000 acres of land and water were acquired
142 Land Use and Wildlife Resources for permanent public use in forest, park, open space, fish and game, and multi- purpose reservoir areas, compared with about 750,000 acres converted to urban and highway development. This marks the third successive year, Secretary Udal, noted, that despite rising land prices, the Nation has set aside more undeveloped acres for conservation than for urban and other development. PROSPECT Discussions in this chapter should be considered to deal with a sampling of the broad array of land-use problems that must be faced if we are to preserve and make available for public benefits the wildlife of North America. In most situations, from city to wilderness, management is feasible if enough biological and economic understanding can be brought to bear. The research effort in support of land-use management is well established in public agencies and educational institutions. A reasor~- able level of support will enable this research effort to furnish informa- tion essential to continued progress as populations build and the scene on this continent changes. REFERENCES Allen, D. L. 1949. The farmer and wildlife. Wildl. Manage. Inst. Bull. 84 p. Allen, D. L. 1952. Wildlife and the business of farming. J. Soil Water Conserv. 7(5):223-226, 245. Allen, D. L. 1954. Our wildlife legacy. Funk & Wagnalls, New York. 422 p. Allen, D. L. 1956. The management outlook, p. 431466. In D. L. Allen (ed.), Pheasants in North America. The Stackpole Co., Harrisburg, Pa., and Wildlife Management Institute, Washington, D.C. Alley, H. P. 1965. Big sagebrush control. Wyo. Agr. Exp. Sta. Bull. 354R. Allied, B. W. 1949. Distribution and control of several woody plants in Texas and Oklahoma. J. Range Manage. 2:17-29. Anderson, W. L. 1949. Agronomic practices in relation to wildlife. I. Soil Water Conserv. 4:1 07-116, 1 28. Anderson, W. L. 1965. Making land produce useful wildlife. (rev.) U.S. Dep. Agr. Farmers' Bull. 2035. 30 p. Anderson, L., and V. Compton. 1958. More wildlife through soil and water con servation. Soil Conservation Service, Agr. Inform. Bull. 175. Atkins, A. P. 1956. Report of the president, 1955. J. Range Manage. 9:63-64. Bailey, J. A., and M. M. Alexander. 1960. Use of closed conifer plantations by wildlife, N.Y. Fish & Game J. 7:130-148. Bailey, R. W., G. W. Craddock, and A. R. Croft, 1947. Watershed management for summer flood control in Utah. U.S. Forest Service, Misc. Publ. No. 639.
Influence of Land Management on Wildlife 143 Baumgras, P. 1943. Winter food productivity of agricultural land for seed-eating birds and mammals. J. Wildl. Manage. 7~1~:13-18. Bennitt, R. 1939. Some agricultural characteristics of the Missouri prairie chicken range. 4th N. Amer. Wildl. Conf. Trans. p. 491-500. Biswell, H. H. 1959. Prescribed burning and other methods of deer range improve- ment in ponderosa pine in California. Proc. Soc. Amer. Foresters, p. 102-105. Biswell, H. H. 1961. Manipulation of chemise brush for deer range improvement. Calif. Fish & Game 47:125-144. Biswell, H. lI., R. D. Taber., D. W. Hedricks, and A. M. Schultz. 1952. Manage- ment of chemise brushlands for game in the north coast region of California. Calif. Fish & Game 38 :453484. Borell, A. E. 1962. Russian-olive (Elaeagnus angustifolia) for wildlife and other conservation uses. U.S. Dep. Agr. Leafl.517. 8 p. Boussu, M. F. 1954. Relationships between trout population and cover on a small stream. J. Wildl. Manage. 18:229-239. Box, T. W., and J. Powell. 1965. Brush management techniques for improved forage values in south Texas. Tex. Tech. Coll. Range Manage. Rep. 651. 21 p. Bue, I. G., H. G. Uhlig, and J. D. Smith. 1964. Stock ponds and dugouts, p. 391- 398. In J. P. Linduska and A. L. Nelson (ed.), Waterfowl tomorrow. U.S. Bureau of Sport Fisheries and Wildlife, Washington, D.C. Burby, R. J., III. 1967. Lake-oriented subdivisions in North Carolina: decision factors and policy implications for urban growth patterns. Part I. Developer decisions. Univ. N.C. Rep. No. 9. Water Resources Research Institute. 177 p. Burger, G. V., and J. P. Linduska. 1967. Habitat management related to bobwhite populations at Remington Farms. J. Wildl. Manage. 31~1~: 1-12. Burt, W. H. 1940. Territorial behaviour and populations of small mammals in southern Michigan. Univ. Mich. LIus. Zool. Misc. Publ. 45. 58 p. Carson, R. 1962. Silent spring. Houghton Mifflin Co., New York. Chapman, D. W. 1962. Effects of logging upon fish resources of the West Coast. J. Forest. 60:533-537. Clawson, M., R. B. Held, and C. H. Stoddard. 1960. Land for the future. Johns Hopkins Press, Baltimore, Md. 570 p. Cole, G. F. 1957. A preliminary report on antelope-range relationships in central Montana. 10th Annul Meeting Amer. Soc. Range Manage. Proc. 10 p. Costello, D. F. 1956. Factors to consider in the evaluation of vegetation condition. J. Range Manage. 9:73-74. Cotner, M. L. 1963. Controlling pinyonjuniper on Southwestern rangelands. Ariz. Agr. Exp. Sta. Rep. 210. 28 p. Dambach, C. A. 1945. Some biologic and economic aspects of field border man- agement. 10th N. Amer. Wildl. Conf. Trans. p. 169-184. Dambach, C. A. 1948a. The relative importance of hunting restrictions and land use in maintaining wildlife populations in Ohio. Ohio J. Sci. 48(6~:209-229. Dambach, C. A. 194Sb. New lessons from old plantings. J. Soil Water Conserv. 3~4~: 165-169. Dasmann, R. F. 1964. Wildlife biology. John Wiley & Sons, New York. 231 p. Davey, S. P. 1967. The role of wildlife in an urban environment.32d N. Amer. Wildl. & Natur. Resour. Conf. Trans. p. 50-60. Davison, V. E. 1941. Shrubs for wildlife on farms in the southeast. U.S. Dep. Agr. Leafl. No. 200. 8 p.
144 Land Use and Wildlife Resources Davison, V. E. 1945. Wildlife values of the lespedezas. J. Wildl. Manage. 9~1~: 1-9. Day, A. 1966. Wildlife habitat management as a means of increasing recreation on public lands. U.S. Burl Land Manage. Rep. 73 p. (mimeo). Dixon, J. S. 1934. A study of the life history and food habits of mule deer in California. Calif. Fish & Game 20: 1-146. Driscoll, R. S. 1967. Managing public rangelands. U.S. Dep. Agr. Inform. Bull. 315. Drury, W. H., Jr. 1966. Birds at airports. In A. L. Nelson and A. Stefferud (ad.), Birds in our lives. U.S. Bureau of Sport Fisheries and Wildlife. 561 p. Edminster, F. C.1941. Wildlife management through soil conservation on farms in the northeast. U.S. Dep. Agr. Farmers' Bull. 1868. 53 p. Edminster, F. C., and R. M. May. 1951. Shrub plantings for soil conservation and wildlife cover. U.S. Dep. Agr. Circ.887. 68 p. Einarsen, A. S. 1948. The pronghorn antelope and its management. Wildlife Man- agement Institute, Washington, D.C. 238 p. Erickson, A. W. 1965. The brown-grizzly bear in Alaska. Alaska Dep. Fish & Game, F.A. Proj. W-6-3-5, Work Plan F. Errington, P. L. 1945. Some contributions of a fifteen-year local study of the northern bobwhite to a knowledge of population phenomena. Ecology Monogr. 15~1~: 1-34. Ferber, A. E. 1958. Windbreaks in conservation farming. U.S. Soil Conserv. Serv. Misc. Publ.759.22 p. Ferret, C. M., and H. R. Leach. 1950. Food habits of the pronghorn antelope of California. Calif. Fish & Game 36~1~:21-26. Fox, A. C. 1942. Windbreaks and their value to wildlife. Soil Conserv. 7(10):259- 260. Gambel, E. L. 1967. Greenspan provisions of the cropland adjustment program. 54th Annul Mtg. Ass. So. Agr. Workers.5 p. Gates, I. M., and G. E. Ostrom. 1966. Feed grain program related to pheasant pro- duction in Wisconsin. J. Wildl. Manage.30~3~:612-617. George, J. L. 1966. Farmers and birds, p.396403. In A. L. Nelson and A. Stefferud (ed.), Birds in our lives. U.S. Bureau of Sport Fisheries and Wildlife. 561 p. Good, E. E., and C. A. Dambach. 1943. Effect of some land use practices on breed- ing birds in Ohio. J. Wildl. Manage.7 :291-297. Graham, E. H. 1941a. Wildlife management as a part of soil conservation. U.S. Soil Conserv. Serv. Misc. Publ. 23.50 p. Graham, E. H. 1941b. Legumes for erosion control and wildlife. U.S. Dep. Agr. Misc.Publ.412.153p. Graham, E. H. 1942. Grasses for soil and wildlife conservation. Soil Conserv. 7(10~: 244-247, 250. Graham, E. H. 1944. Natural principles of land use. Oxford University Press, New York. 274 p. Graham, E. H. 1947. The land and wildlife. Oxford University Press, New York. 232p. Griffith, G. K. 1962. Guidelines for antelope management. Interstate Antelope Conf. Trans. p. 102-114. Hanson, H. C. 1965. The giant Canada goose. Southern Illinois University Press, Carbondale. 226 p. Hawbecker, A. C., and R. M. Bond. 1942. Wildlife increased by erosion control practices. Soil Conserv. 7(10): 255-256.
Influence of Land Management on Wildlife Hedge, A. M., and A. A. Klingebiel. 1957. The use of soil maps, p. 400-411. In Soils. The yearbook of agriculture 1955. U.S. Department of Agriculture. U.S. Government Printing Office, Washington, D.C. Hervey, D. F. 1961. Improving sagebrush ranges: progress report of the Great Divide Experimental Range. Colo. Agr. Exp. Sta. Gen. Ser.761. 10 p. Hill, R. R.1956. Forage, food habits, and range management of the mule deer. 145 In W. P. Taylor (ed.), The deer of North America. Wildlife Management Institute, Washington, D.C. 668 p. Hoover, M. D.1962. Water action and water movement in the forest, p. 31-80. In Forest influences. FAG Forest. and Forest Prod. Stud. No. 15. Food and Agri- culture Organization, Rome. Hoover, R. L., C. E. Till, and S. Ogilvie. 1959. The antelope of Colorado. Colo. Game Fish Dep. Tech. Bull. No. 4. Hubbard, R. L. 1962. The place of browse seeding in game range management. 27th N. Amer. Wildl. Natur. Resour. Conf. Trans. p. 394-401. Huss, D. L. 1964. A glossary of terms used in range management. American Society for Range Management, Denver, Colo. Hyatt, S. W. 1966. Sagebrush control: costs, results, and benefits to the rancher. J. Range Manage. 19(1 ~ :4243. Hyder, D. F., and F. A. Sneva. 1958. Herbage response to sagebrush spraying. J. Range Manage. 9~1~:34-38. Jackson, A. S. 1962. A pattern to population oscillations of the bobwhite quail in the lower plains grazing ranges of northwest Texas. S.E. Ass. Game Fish Comm., 16th Annul Conf. Proc., p. 120-126. Johns, W. 1965. Where the livestock, but not the antelope, can play. Conserv. News 30~20~:7-10. Johnson, E. A. 1952. Effect of farm woodland grazing on watershed values in the southern Appalachian Mountains. J. Forest.50: 109-113. Julander, O. 1951. Utah's big game, livestock, and range relationship research project. J. Range Manage. 4:330-334. Julander, O. 1955. Deer and cattle relations in Utah. Forest. Sci. 1: 13Q-139. Julander, O. 1958. Techniques in studying competition between big game and livestock. J. Range Manage. 11: 18-21. Julander, O. 1962. Range management in relation to mule deer habitat and herd productivity in Utah. J. Range Manage. 15:278-281. Julander, O., and D. E. Jeffrey. 1964. Deer, elk and cattle range relations on sum- mer range in Utah. 29th Wildl. ~ Natur. Resour. Conf. Trans. p. 404-413. Julander, O., and W. L. Robinette. 1950. Deer and cattle range relationships on Oak Creek range in Utah. J. Forest. 48:410415. Julander, O., W. L. Robinette, and D. A. Jones. 1961. Relation of summer range condition to mule deer herd productivity. J. Wildl. Manage. 25:54-60. Kell, W. V. 1938. Strip cropping, p. 634-645. In Soil & men. The yearbook of agriculture 1938. U.S. Department of Agriculture. U.S. Government Printing Office, Washington, D.C. Kirsch, L. 1964. The value of soil bank lands to breeding prairie grouse. U.S. Bureau of Sport Fisheries and Wildlife.5 p. Komarek, R. 1966. A discussion of wildlife management, fire, and the wildlife landscape, p.177-194. In 5th Tall Timbers Fire Ecol. Conf. Tall Timbers Re- search Station, Tallahassee, Fla.
146 Land Use and Wildlife Resources K~xchler, A. W. 1964. The potential natural vegetation of the conterminous United States. American Geographical Society, New York. Lack, D. 1954. The natural regulation of animal numbers. Oxford University Press, Cambridge, England. 134 p. Lay, D. S. 1956. Effects of prescribed burning on forage and mast production in southern pine forests. J. Forest.54:582-584. Lay, D. S. 1957. Browse quality and the effects of prescribed burning in southern pine forests. J. Forest.55:342-347. Leach, H. R., and A. L. Hensley. 1954. The sage grouse in California with special reference to food habits. Calif. Fish & Game 40~4~:385-394. Leedy, D. L. 1940. Natural pheasant production in relation to agricultural land-use. Ph.D. Thesis. Ohio State University, Columbus. (Dies. Abstr. 33: 115-124.) Leedy, D. L. 1949. Ohio pheasant nesting surveys based on farmer interviews. J. Wildl. Manage. 13~3~: 274-286. Leedy, D. L., and E. H. Dustman. 1947. The pheasant decline and land-use trends, 1941-1946. 12th N. Amer. Wildl. Conf. Trans. p. 479490. Lehmann, V. W. 1953. Bobwhite population fluctuations and vitamin A. 18th N. Amer. Wildl. Conf. Trans. p. 199-246. Leithead, H. L. 1950. Field methods used to demonstrate range conservation. J. Range Manage. 3:95-99. Leopold, A. 1933. Game management. C. Scribner's Sons, New York, 481 p. Line, L. 1964. The bird worth a forest fire. Audubon Mag. 66:370-375. Longhurst, W. M., A. S. Leopold, and R. F. Dasmann, 1952. A survey of California deer herds. Calif. Dep. Fish Game Bull. No. 6. Lull, H. W. 1959. Soil compaction on forest and range lands. Forest Serv. Misc. Publ. No. 768. Marshall, W. H. 1953. A survey of farm-game habitat restoration programs in fif- teen states. 18th N. Amer. Wildl. Conf. Trans. p.390411. McAtee, W. L. 1941. Plants useful in upland wildlife management. U.S. Fish & Wildl. Serv., U.S. Dep. Interior Conserv. Bull. 7. 50 p. Miller, J. P., and B. B. Powell. 1942. Game and wild-fur production and utilization on agricultural land. U.S. Dep. Agr. Circ. 636. 58 p. Mohler, L. L., J. H. Wampole, and E. Fichter. 1951. Mule deer in Nebraska Na- tional Forest. J. Wildl. Manage. 15: 129-160. Morris, M. S., and J. E. Schwartz. 1957. Mule deer and eLk food habits on the Na- tional Bison Range. J. Wildl. Manage. 21~2~:189-193. Murie, O. J. 1951. The elf of North America. The Stackpole Co., Harrisburg, Pa. 376 p. Nelson, B. A. 1953. Pheasant habitat improvement in South Dakota. 32d Annul Western Ass. State Game Fish Comm. Conf. Proc. p. 123-126. Nunns, F. K. 1958. The classification of rural land, p. 362-370. In Land. The yearbook of agriculture 1958. U.S. Department of Agriculture. U.S. Govern- ment Printing Office, Washington, D.C. Orell, 3. L. 1964. Private responsibilities for resources. 29th N. Amer. Wildl. & Natur. Resour. Conf. Trans. p. 10-16. Parker, K. W. 1954. Application of ecology in determination of range condition and trend. J. Range Manage. 7: 14-21. Parker, K. W., and S. C. Martin. 1952. The mesquite problem on southern Arizona ranges. U.S. Dep. Agr. Circ. 908.
Influence of Land Management on Wildlife 147 Patterson, R. L. 1952. The sage grouse in Wyoming. Sage Brooks, Denver. 341 p. Pechanec, J. F., A. P. Plummer, J. H. Robertson, and A. C. Hull, Jr. 1944. Eradica- tion of big sagebrush. U.S. Forest Serv. Intermountain Forest Range Exp. Sta. Res.PaperNo.10. Pechanec, J. F., G. Stewart, A. P. Plummer, J. H. Robertson, and A. C. Hull. 1954. Controlling sagebrush on rangelands. U.S. Dep. Agr. Farmers' Bull. 2072. 36 p. Pickford, G. D., and E. H. Reid. 1943. Competition of elf and domestic livestock for summer range forage. J. Wildl. Manage. 7~3~:328-332. Plummer, A. P., D. R. Christensen,and S. B. Monson. 1965. Job completion report of game forage revegetation project. Utah State Fish & Game Dep. Inf. Bull. No. 65-10. Read, R. A. 1957. Effects of livestock concentration on surface soil porosity within shelterbelts. J. Forest. 55 :529-530. Renner, F. G., and B. W. Allred. 1962. Classifying rangeland for conservation planning. U.S. Dep. Agr., Soil Conserv. Serv., Agr. Handb. No. 235. Rhoades, E. D., et al. 1964. Water intake on sandy range as affected by 20 years of differential cattle stocking rates. J. Range Manage. 17: 185-190. Ridd, M. F. 1965. Area-oriented multiple use analysis. U.S. Forest Serv. Inter- mountain Forest Exp. Sta. Res. Paper No. 21, 14 p. Riley, C. V. 1952. An evaluation of reclaimed coal strip-mined lands as wildlife habitat. Ph.D. Thesis. Ohio State University, Columbus. (Dies. Abstr. 18:740- 743,1958.) Robinette, W. L., O. Julander, J. S. Gashwiler, and J. G. Smith. 1952. Winter mor- tality of mule deer in Utah in relation to range condition. J. Wildl. Manage. 16:289-299. Rogers, G. E. 1964. Sage grouse investigations in Colorado. Colo. Game, Fish Parks Dep. Tech. Publ. No. 16. Rosene, W., Jr. 1950. Quail studies on a river floodplain. J. Soil Water Conserv. 5~3~: 111-114. Rosene, W., Jr. 1952. Care and maintenance of bicolor lespedeza. Soil Conserv. 17~7~: 151-153. Rosene, W., Jr. 1956. An appraisal of bicolor lespedeza in quail management. J. Wildl. Manage. 20~2~: 104-110. Sampson, A. W., and B. S. Jesperson. 1963. California range and brushlands browse plants. Calif. Agr. Exp. Sta. Ext. Serv. Manual 33. 162 p. Sandfort, W. W. 1952. Ring-necked pheasant production in north-central Colorado. M.S. Thesis. Colorado A&M College, Fort Collins. (Unpublished.) Sayers, W. B. 1966. To tell the truth, 25 years of Amencan Forest Products In- dustries, Inc. J. Forest. 64~10~:657-663. Scott, R. F. 1965. Problems of multiflora rose spread and control. 30th N. Amer. Wildl. Natur. Resour. Conf. Trans. p.360-378. Skeete, G. M. 1966. Can ranchers adjust to fluctuating forage production? J. Range Manage. 19: 258-262. Smith, A. D. 1950. Sagebrush as a winter feed for deer. J. Wildl. Manage. 14(3): 285-289. Smith, A. D. 1959. Adequacy of some important browse species in overwinter- ing of mule deer. J. Range Manage. 12(1): 8-13. Smith, D. R. 1961. Competition between cattle and game on eLk winter range. Univ. Wyo. Agr. Exp. Sta. Bu11.377.
148 Land Use and Wildlife Resources Smith, J. G., and O. Julander. 1953. Deer and sheep competition in Utah. J. Wildl. Manage. 17: 101-112. Society of American Foresters. 1964. Forest terminology. 3d ed. Society of American Foresters, Washington, D.C. 35 p. Stearns, F. W. 1967. Wildlife habitat in urban and suburban environments. 32d N. Amer. Wildl. & Natur. Resour. Conf. Trans. p. 61-69. Steen, M. O. 1950. Road to restoration. 15th N. Amer. Wildl. Conf. Trans. p. 356- 362. Stevens, D. R. 1966. Range relations of elk and livestock, Crow Creek Drainage, Montana. J. Wildl. Manage. 30~2~:349-363. Stoddard, H. L. 1931. The bobwhite quail; its habits, preservation, and increase. C. Scribner's Sons, New York. 559 p. Stoddart, L. A., and A. D. Smith. 1955. Range management, 2d ea., McGraw-Hill Book Co., New York. Swanson, C. V., and C. F. Yocum. 1958. Upland game-bird populations in relation to cover and agriculture in southeastern Washington. 23d N. Amer. Wildl. Conf. Trans. p. 277-290. Taylor, W. P. 1934. Significance of extreme or intermittent conditions in distribu- tion of species and management of natural resources, with a restatement of Liebig's Law of Minimum. Ecology 15:374-379. Taylor, W. P., and H. K. Buechner. 1943. Relationship of game and livestock to range vegetation in Kerr County, Texas. The Cattleman (Starch). True, G. H., Jr., and B. Glading. 1946. Catchment and other devices for supplying water for wildlife in California. 26th Annul Western Ass. State Game & Fish Comm. Conf. Proc. p. 156-160. Twiss, R. H. 1969. Conflicts in forest landscape management. J. Forest. 67: 19-23. U.S. Bureau of the Census. 1960, 1965. Historical statistics of the United States. U.S. Government Printing Office, Washington, D.C. U.S. Department of Agriculture. 1962. Major uses of land and water. Agr. Econ. Rep. No. 13, p. 17. U.S. Department of Agriculture. 1965. Soil and water conservation needs. U.S. Dep. Agr. Misc. Publ. 971. U.S. Department of Agriculture. 1967. Agricultural Conservation Program, sum- mary fiscal year 1966. Agr. Stabilization and Conserv. Service. 133 p. U.S. Department of the Interior. 1960. Project twenty-twelve: A long-term pro- gram for our public lands. U.S Government Printing Office, Washington, D.C. U.S. Forest Service. 1965. Timber trends in the United States. U.S. Dep. Agr. Forest. Res. Rep. No. 17. Van Dersal, W. R., and E. H. Graham.1946. The land renewed. Oxford University Press, New York. 110 p. Wandell, W. N. 1948. Agricultural and wildlife values of habitat improvement plantings on the Illinois Black Prairie. 13th N. Amer. Wildl. Conf. Trans. p. 256-270. Wilbert, D. E. 1963. Some effects of big sagebrush control on eLk distribution. J. Range Manage. 16~2~: 74-78. Workman, D. R., K. R. Tefertiller, and C. L. Leinweber. 1965. Profitability of aerial spraying to control mesquite. Tex. Agr. Exp. Sta. MP-784. 12 p. Yoakum, J. 1962. Interstate antelope range-its research and management needs. Interstate Antelope Conf. Trans. p. 52-58.