Page 699 - Geosystems An Introduction to Physical Geography 4th Canadian Edition

Chapter 20 Terrestrial Biomes 663
F cus Study 20.1 Environmental Restoration Global Conservation Strategies
One goal of conservation biogeography, restoration ecology, and other related scientific fields is the preservation of biodiversity through habitat conserva- tion. Habitat fragmentation is a major cause of species decline and extinction, and protecting and restoring habitat has become a conservation focus. Climate change is an important variable to con- sider in setting aside protected areas, since temperature and precipitation re- gimes in parks and reserves could even- tually end up outside the natural range of the species in question.
Several concepts are used as the basis for conservation strategies for maintain- ing biodiversity. First implemented by Conservation International in 1989, the idea of biodiversity “hotspots” has pro- vided a focus for conservation efforts and has received scientific attention and financial support. To qualify as a hotspot, a community or ecosystem must contain at least 1500 endemic (native) plant spe- cies, and it must have lost at least 70%
of its original habitat (more information
is at www.conservation.org/How/Pages/ Hotspots.aspx).
The World Wildlife Fund (WWF) uses the concept of ecoregions as the basis for its conservation strategies, with the goal of implementing conservation
on the scale of large natural habitats similar to biomes. In 2000, a team of WWF-sponsored scientists identified
238 ecoregions, known as the “global 200,” as the focus of conservation efforts. The protection of these representative habitats could save a broad diversity of Earth’s species (Figure 20.1.1).
The Man and the Biosphere Program, launched in 1971 by the United Nations Educational, Scientific, and Cultural Organization, establishes biosphere reserves with the goal of preserving bio- diversity as well as promoting economic and social development and maintain- ing the cultural values of local com- munities. This integrated approach to species conservation attempts to mesh biological assets with human activity. Its world network of reserves ranges from relatively undisturbed ecosystems, such as glacier Bay in Alaska, to the mixed towns and green space of southern germany.
The intent of the biosphere reserves in the UN program is to promote sus- tainable development by establishing
a core in which natural features are protected from outside disturbances, surrounded by zones of local develop- ment, natural and cultural resource management, and scientific experimen- tation. Some reserves remain in the planning stage, although they are of- ficially designated. In the United States, several biosphere reserves include na- tional parks, such as Everglades National Park in Florida and Olympic National Park in Washington, both established in the 1970s.
The ultimate goal, about half achieved, is to create at least one reserve in each of the 194 distinctive biogeographic com- munities presently identified. Scientists predict that by about 2025, designating new, undisturbed reserves may no longer be possible because pristine areas will be gone. More than 621 biosphere reserves now exist in 117 countries (see www .unesco.org/new/en/natural-sciences/ environment/ecological-sciences/ man-and-biosphere-programme/).
▶Figure 20.1.1 Biomes containing the WWF “Global 200” ecoregions important for biodiver- sity preservation. The
14 biomes shown, plus
the freshwater and marine biomes, are the broad divi- sions containing a total of 238 specific ecoregions that, if protected, could preserve a large percent- age of Earth’s biodiversity. [World Wildlife Fund; www .worldwildlife.org/science/ ecoregions/global200.html.]
Tropical & subtropical moist broadleaf forests Tropical & subtropical dry broadleaf forests Tropical & subtropical coniferous forests Temperate broadleaf & mixed forests Temperate conifer forests
Boreal forests/taiga
Tropical & subtropical grasslands, savannas & shrublands Temperate grasslands, savannas & shrublands
Wooded grasslands & savannas
Montane grasslands & shrublands
Tundra
Mediterranean forests, woodlands & scrub Deserts & xeric shrublands
Mangroves Freshwater Marine