Island Biogeography and Glacier The Extinction Vortex Conserving Plant Diversity in Glacier Global Climate Change Monitoring Glacier's Health Island Biogeography and Glacier Human-caused habitat modification and destruction pose the single largest threat to the survival of biological diversity on earth. Agriculture, urban development, road building, deforestation, dam building, pollution, and many other activities all serve to reduce the total amount of habitat that is available and suitable for species to live in and to break up remaining habitats into small fragments that are isolated as islands in a sea of human development. Biogeography is the study of the geographical and historical distributions of plants and animals.
Island biogeography is the study of the distribution of plants and animals on islands.
The equilibrium theory of island biogeography holds that the number of species living on an island is a function of extinction and immigration rates on the island. As some populations go extinct through natural processes, other populations are established by organisms which migrate to the island and colonize it. Over time these two processes balance each other out. Although the actual species living on the island constantly change, the total number of species remains relatively constant. An island that is far from the mainland will receive fewer immigrants than an island that is nearby, because fewer organisms will be able to cross the large barrier of water to get to the island.