The Evaluation of Biodiversity as a Target for Conservation

Summary

One dilemma for conservation biologists is to ponder whether ecological processes are better targets for conservation than are species. In this chapter, we discuss this dilemma under the assumption that not all species are equal in terms of the size, shape, orientation of their geographic range, and their density distribution within the range. Conserving a single species found only in a restricted area (endemic) may not preserve global biodiversity, but on the other hand, conserving an ecosystem and the processes therein may still lead to a reduction in biodiversity within the conservation area, and at the same time leave a large proportion of “rare” species unprotected. Obviously both approaches should be used to maintain global biodiversity, but the question remains how we target those areas that need protection. With a view to setting conservation priorities, we map an ecological unit of measurement henceforth known as M, which for any group of species, at any geographic scale (in this case 1° latitude by 1° longitude), is equal to the sum of the reciprocals of the area of each species’ geographic range.