The Mono Basin Ecosystem Effects of Changing Lake Level (1987) / Chapter Skim
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5. Shoreline and Upland Systems
5. Shoreline and Upland Systems
Pages 121-178
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From page 121... ...
The interface between the land and the air, controlling aerosol production from the alkali flats, and the interface between the land and the water, controlling the tufa formations and shoreline erosion, are also discussed. PHYSICAL COMPONENTS Topography The Mono Basin lies on the border of two major physiographic provinces -- the Sierra Nevada and the Great Basin-121
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From page 122... ...
The elevations within the basin range from 13,000 ft to about 6,380 ft. the current level of Mono Lake.
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From page 123... ...
~ ~~ ~Ntb Lop J c~vsN COWTRACK MT ` 8875 123 'it ~ 'of ~ "A ~ MEND - Y 3,145 °~ Solon ~~ 'N \~_/ 13,055 * 'I \ ~ \ %~ Chummy I WHITE MrN \ 14,_ 14 242 FIGURE 5.1 Topographic and other features of area surrounding Mono Lake.
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From page 124... ...
Black Point and Negit Island are both of volcanic origin, but the material is darker (basalt) anc chemically distinct from the rhyolitic Mono Craters.
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From page 125... ...
The ash and cinder plains along both east and west sides of the Mono Craters to the south of the lake have developed Dystric Xerorthent, Typic Xeropsamments, Xeric Torripsamments, and Xeric Torriorthent soils (Table 5.
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From page 126... ...
Xeric Torripsamments are the most widespread soils in the area, but Xeric Torriorthents and Typic Xeropsamments are also widespread. The commonest soils on the north and east shores of Mono Lake are Haplaquents, Durorthidic Xeric Torripsamments, Durorthidic Xeric Torriorthents, Aeric Haplaquents, Typic Psammaquents, and Typic Haplaquents (Table 5.
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From page 127... ...
The data demonstrate that for most variables, the soils derived from rhyolitic ash contain significantly smaller amounts of elements essential for biological systems than those formed from granitic and metasedimentary parent materials. Both of those Mono Basin parent materials produce soils that are highly impoverished in phosphorus and exchangeable bases relative to the common soils of uplands in the Bonneville Basin (Table 5.2~.
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From page 129... ...
The most widespread and destructive avalanches in recent years occurred throughout the Sierra in February 1986. Damage to vegetation was extensive over a wide range of elevation from mountain hemlock and lodgepole pines near Tioga Pass to aspen and pinyon pines near Mono Lake.
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From page 130... ...
for many years after a fire. In the upland shrublands of the pumice flats south of Mono Lake, neither of the dominant shrubs (Artemisia trid~entata and Purshia trid~entata)
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From page 131... ...
At that site, organic matter in the surface 15 cm of soil was only about 20 percent less than that of adjacent areas that were unaffected by fire. It would thus appear that upland fires produce few erosional events that would significantly affect Mono Lake chemistry directly.
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From page 132... ...
About 30 separate domes occur along the north-south axis of the Mono Craters, with the domes becoming progressively younger from south to north. Rhyolitic plugs, cin ders, and ash are associated with each eruption.
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From page 133... ...
The volcanic plug at Black Point is about 13,500 years old (Lajoie, 1968~. The foregoing volcanic events have lain down dozens of ash layers that lend a distinctively banded aspect to cross sections of sediments underlying Mono Lake.
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From page 134... ...
The town of Lee Vining was one of several communities to supply such demands of the mining industry in the 1 850s. Lumber mills were built on several of the streams that terminate in Mono Lake.
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From page 135... ...
An additional 2,000 acres of irrigated pastureland adjacent to Mono Lake are owned by the city and are leased to private operators each year. The city supplies about 8,700 acre-ft/yr of water for irrigation of leased pastures.
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From page 136... ...
As early as 1881, Israel Russell, a pioneer interpreter of the geologic history of Mono Lake, concluded that the wet meadows had been "nearly ruined" by domestic grazers. It is also apparent today that much of the vegetated land between the Pole Line Road and the north shore of the lake has been heavily affected by grazing.
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From page 137... ...
395 just west of Mono Lake, Route 120 over Tioga Pass, which passes near the Mono Craters, and the Pole Line Road to Hawthorne. There are many dirt roads in the basin, most of which are used mainly for exploration and recreation.
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From page 138... ...
The timber industry is still active. In the proposed forest plan for the Inyo National Forest, several large areas are designated for timber harvesting.
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From page 139... ...
Shoreline Vegetation Description of Vegetation Types. the land exposed as Mono Lake mosaic of herbaceous and shrub communities (Figure 5.31.
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From page 140... ...
r..;` ,\~Isi { .:- ~ to of. .~ ~ The Mono Basin Ecosystem
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From page 141... ...
SAore~e ~~d ~/~d S>~'e~~ 141 FIGURE S.] Vege1atlon map of the hlstorlca1 shorelands of Mono Lake.
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From page 142... ...
For example, some transects passed through springs that had been exposed by the receding lake, while others extended across broad expanses of barren, saline exposed lake bed and the vegetated strand and ultimately terminated in an upland shrub community. Except for the rabbi/brush-dominated communities occurring on the raised terraces of the alluvial fans of Lee Vining and Rush creeks, the transects represent most gradients occurring around the lake.
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From page 143... ...
These cross sections do not represent actual vegetation gradients but are representative of existing vegetational gradients that demonstrate the relationship of vegetation types to the lake edge, topography, and groundwater. At least seven types of associated vegetation occur on Mann Lake shorelines and ad iacent upland areas.
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From page 144... ...
near four representative locations at Mono Lake. Lake level (v)
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From page 145... ...
I ~ I 1 1 1200 1600 2000 2400 2800 3200 3600 HORIZONTAL DISTANCE (if) face is a solid line, water table is a dashed line, and soil water EC (pmhos)
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From page 146... ...
stands of upland vegetation. A brief discussion of each of the four transects both gives a picture of the different gradients from lake to upland around the lake and helps make possible predictions about how shoreline vegetation will change with fluctuations in lake level.
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From page 147... ...
the terrain is irregular and the water table becomes deeper. The vegetation closest to the barren shoreline is primarily saltgrass, but rapidly grades into dry scrub characterized by rabbitbrush and big sagebrush.
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From page 148... ...
The annual plant zone was dominated by Psathyrotes annua and Mentzelia torreyi, while saltgrass was the primary species in its zone. Environmental Factors Inf luencing Shoreline Vegetation.
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From page 149... ...
The upland dry scrub vegetation is generally found on soils with the lowest pH and EC observed in the area; dry open, wet marsh, and wet shrub associations have intermediate values; while transition marsh/dry and alkaline herbs associations tend to occur on soils of higher pH and EC. However, local conditions may strongly influence soil chemistry.
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From page 150... ...
This habitat type grades into Pinus contorta-Populus tremutoid~es vegetation above about 2200-m elevation mostly along low-gradient sections of streams in glacial valleys (e.g., Lee Vining Creek) where soils are well drained.
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From page 151... ...
This type can be seen in the glacial valley along Lee Vining Creek at 2200 m. Carex praegracitis- Juncus baZticus: This habitat type occurs in outwash meadows along low grade streams.
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From page 152... ...
Photographs taken of Rush Creek below Grant Lake Reservoir in 1940 show riparian vegetation to be as well developed as along Lee Vining Creek. The range of riparian vegetation types was also as variable as on Lee Vining Creek, with extensive stands of black cottonwood and quaking aspen along the channel and willow thickets along the streams just above the alluvial fan.
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From page 153... ...
Between the highway and the lake, a fire in the early l950s eliminated most of the woody riparian vegetation along Lee Vining Creek. The quaking aspen strand that had extended almost to the alluvial fan was destroyed.
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From page 154... ...
The riparian vegetation in the Mono Basin occurs along streams from the high elevations of the Sierra Nevada down to the alluvial fans where streams enter the lake. The high-elevation riparian communities are influenced by local precipitation, streamflow, and groundwater.
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From page 155... ...
Temporary or artificial diversions may cause flooding of alluvial fans beyond normal stream channels and permit the establishment of new riparian thickets or meadows. Most riparian vegetation above Mono Lake but below diversions on the creeks that feed the lake is located on alluvial fans or along shallow-gradient streams that flow through deep channels across the fans.
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From page 156... ...
Recently, streamflow in Rush Creek has been maintained at a sufficient level, either through controlled releases or releases of surplus water, to encourage new recruitment or regrowth of some of the depauperate riparian stands. On the lower part of the alluvial fan, however, the combination of heavy releases, depauperate riparian vegetation, and lower lake levels has caused deep downcutting.
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From page 157... ...
Fire: Fire normally is not important in riparian systems because of the moisture in the habitat. However, in the early 1 950s a fire along Lee Vining Creek between the diversion and Mono Lake destroyed a large portion of the riparian vegetation, as discussed earlier.
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From page 158... ...
The juniper-pinyon woodland is usually characterized by Pinus monophylla and Juniperus osteosperma in the eastern portion of the Mono Basin. Artemisia tridentata and Purshia trid~entata are regular members of this association in the Bodie Hills northeast of Mono Lake and along the foothills of the Sierra Nevada west of the lake.
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From page 159... ...
ARTR = Artemisia tridentata, PU IK = Purshia tridentata, CHNA = Chrysothamnus nauseosus, SAVE = Sarcobatus vermiculatus, PRAN = Prunus andersonii, GRASS = mixed grasses, CADO = Carex douglasii, JUBA = Juncus balticus, CHVI = Chrysothamnus viscidiflorus, PIJE = Pinus jeffreyi.
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From page 160... ...
Shrubs capable of tolerating both salinity and high water tables become prominent on lake sediments close to the shores of Mono Lake. Sarcobatus vermiculatus and Chrysothamnus nauseosus are the principle species in such a situation.
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From page 161... ...
Abandoned irrigated fields near L ~ ~ support this association of plants as do many floodplains adjacent to the streams that flow into the lake (Figure 5.5~. the lake often Wildlife The Mono Basin supports a diverse community of terrestrial and aquatic vertebrates, many of which do not rely on the resources of Mono Lake itself.
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From page 162... ...
At lower elevations, the most important streams for trout fishing are Rush and Lee Vining creeks; in both streams wild brown trout are the most important contributor to the fishery. In Lee Vining Creek, a small, reproducing brown trout population was maintained for 1 to 2 km below the diversion by leakage from the dam and seasonal input from Log Cabin Creek.
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From page 163... ...
~ ~ , e creeks. The IFIM model has not yet been applied to those streams (it has been applied to Lee Vining Creek above the diversion)
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From page 164... ...
(1983) have found the adult survival and reproductive performance of Mono Lake's snowy plovers to be adequate for intrinsic population maintenance.
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From page 165... ...
A collapse of Mono Lakers invertebrate populations would affect the plover population -- as it would other birds that feed on invertebrates -- but because plovers also feed around spring-fed seeps, they would probably not totally abandon the Mono Basin as a nesting site. Because none of the other shoreline or upland bird populations in the Mono Basin constitute such a large portion of their respective regional or continental populations, the committee only summarizes information of their habitat, their seasonal occurrence in the Mono Basin, their status while in the basin, their approximate population size in the basin, and how they are likely to respond to possible disturbances in the basin.
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From page 166... ...
Another species of concern, the mountain beaver, is dependent on access to fresh water and uses riparian areas with dense brush along the west side of Mono Lake (J. Harris, Mills College, personal communication)
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From page 167... ...
In a recent report, Cahill and Gill (1987) presented the results of a computer model of air quality in the vicinity of Mono Lake in which they predicted the frequency and intensity of particulate levels near Mono Lake for various lake levels and wind velocities.
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From page 168... ...
Out that the worst dust storms in Owens Valley were associated with northerly winds aligned with the axis of the valley (parallel to the Sierra) , and that such storms transport significant quantities of dust for over 100 mi.
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From page 169... ...
It should be noted that the dust problems of Owens Basin are greater and different in kind from those of the Mono Basin. The town of Lee Vining and nearby population centers are rarely physically affected by airborne dust or blowing sand from the playas surrounding Mono Lake.
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From page 170... ...
If the lake level shifts abruptly, otherwise secure towers may be jeopardized. Approximately 24 percent of the changes in tufa formations in the South Tufa Area, one of the most frequently visited tufa areas, appear to have been caused by the wave action from rising lake levels (memo from Dave and Janet Carte, Mono Lake Tufa State Reserve, to Russ Guiney, January 31, 1986~.
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From page 171... ...
No published reports describe these processes in the Mono Basin. Nevertheless, some general observations can be made about the extent of erosion that will occur if lake levels decline.
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From page 172... ...
If lake levels drop, several types of shoreline erosion will occur. Declining lake levels will increase the gradient of streams entering the lake, increasing channel erosion in the vicinity of where the streams enter the lake.
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From page 173... ...
If lake levels rise, the stream will adjust to a new base level, causing aggradation of channel deposits and decreased sediment load to the lake. Lowering lake levels would expose large areas- of lake bed to erosion by wind, abrasion, surface water, and lake wave action.
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From page 174... ...
at Mono Lake, Mono County, California. Great Basin Nat.
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From page 175... ...
Lee Vining, Calif.: Mono Lake Committee. Holmboe, J., and H
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From page 176... ...
1982. Potential Hazards from Future Volcanic Eruptions in the Long Valley-Mono Lake Area, East
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From page 177... ...
1983. Spacing out at Mono Lake: breeding success, nest density, and predation in the snowy plover.
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From page 178... ...
1985. A Water Balance Forecast Model for Mono Lake, California.
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