Skip to main content

Research to Protect, Restore, and Manage the Environment (1993) / Chapter Skim
Currently Skimming:

Appendix B: Biodiversity
Pages 201-208

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.


From page 201...
... It can refer to such units as the biota of the entire earth, to the biota of some selected region, to the number and magnitude of differences among evolutionary lineages of organisms, or to the genetic variability within a species. Biodiversity is usefully treated at many different levels, because both basic scientific issues and practical problems focus on different measures of biodiversity.
Read the entire page →
From page 202...
... Maintaining genetic diversity is an essential component of successful captive propagation efforts for rare and endangered species, and much valuable biodiversity can be lost when local populations are exterminated, even if the species survives. Another important component of biodiversity is the distinctness of evolving lineages.
Read the entire page →
From page 203...
... In general, the number of species found on islands is inversely correlated with distance from the mainland and positively correlated with island size and topographic diversity. The low species richness on islands is usually attributed to low colonization rates, high extinction rates (because populations are usually small and subject to decimation by local catastrophes and stochastic variation)
Read the entire page →
From page 204...
... We do know that, on the average, terrestrial tropical species have smaller ranges than species of higher latitudes, but there are many exceptions. A key question is whether a given change in physical environmental conditions causes a greater species turnover in tropical environments than in higher-latitude environments.
Read the entire page →
From page 205...
... A much smaller fraction of marine productivity is being co-opted by humans, but co-option of coastal productivity, particularly that of the estuaries on which many marine organisms depend, is extensive. The International Union for the Conservation of Nature and Natural Resources Invertebrate Red Data Book (1983)
Read the entire page →
From page 206...
... INTRODUCTIONS Humans, inadvertently or deliberately, move large numbers of species around the world. Such introduced species have caused major ecologic and economic problems (witness European rabbits in Australia and chestnut blight and Dutch elm disease in North America)
Read the entire page →
From page 207...
... Much of the burden will have to fall on the exploited lands that dominate the landscapes within which parks and reserves are imbedded. Therefore, forests will have to be managed for a diversity of values, rather than for maximization of wood production, and agricultural practices will have to be modified so that agricultural lands play a greater role in providing habitats for species and corridors for their movements between reserves.
Read the entire page →

Key Terms

  • ecologic communities
  • marine organisms
  • extinction rates
  • genetic diversity
  • introduced species

  • ocean barriers
  • major physical
  • endangered species
  • human population
  • marine biodiversity

  • complex communities
  • coral reefs
  • local populations
  • exotic plants
  • tropical regions

  • physical environment
  • positively correlated
  • typical tropical
  • weedy plants
  • square kilometer

  • colonization rates
  • low densities
  • barring major
  • coniferous trees
  • oceanic islands

  • selected region
  • massive changes
  • wet forest
  • providing habitats
  • fewer marine


    • This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
    More information on Chapter Skim is available.