Conservation biology focuses on the application of biological principles to the preservation of biodiversity. Implementation of conservation efforts is largely limited by political problems. While the need for the protection of some species such as the giant panda or the grizzly bear has general support, the protection of more inconspicuous species is limited, primarily for economic reasons. In addition to preserving single species, the conservation of species diversity and genetic diversity is critical for their survival. Concequently , conservation biology is aimed to proctect ecosystems including the species which inhabit it.

• Habitat destruction is a major reason for the decimation and extinction of species.
  In many areas subsistence farming has been replaced by major deforestation. Over 1 million species have been lost through the logging of the rainforest. It is estimated that on a global level 10 % of the existing species could become extinct over the next 20 years, if habitat destruction continues at the present rate.
  Habitat destruction: Fig. 58.1 , historical extiction rates Fig. 58.2

• Habitat requirement : species often require for survival an area that is actuallly larger than their usual range
  Migratory birds require feeding and resting grounds along their migratory path.
  Prudhoe bay pipeline disrupts migratory pattern of caribou. r-strategist require habitat with occational disturbance for clonization.
  Furbish's lousewort : Fig. 58.3 , Edge effect : Fig. 58.9

• Distribution of threatened species in the US : Fig. 58.19 , Fig. 58.7

• Introduction of new species can lead to the extinction of many indigenous species : Fig. 58.13

• Maintaining biodiversity
  environmental considerations: climatic changes, air quality, hydrological changes, diseases , Fig. 58.15
  Economic considerations: rarely include conservation measures
  some conservation measures are cost-effective
  Fig. 58.5

• Preventing species extinction Fig. 58.16 , Fig. 58.17