A quantitative biological analysis of the efficiency of Danish nature management with emphasis on biological diversity (in danish)

The Convention on Biological Diversity obliges contracting parties to develop national strategies that will preserve all biodiversity (including species). Denmark ratified the convention in 1994 and a national strategy was outlined in 1995. This strategy relies on red-listed species (those species identified as threatened) to act as focal species in developing management plans for conservation. We investigate the performance of red-listed species to act as surrogates for all biodiversity. We used all available atlas data for Denmark to map the distributions of amphibians, bats, birds, butterflies, click beetles, large moths, and reptiles on a 10 x 10 km grid (n = 468), and examined the ability of priority areas chosen to conserve red-listed species to represent other non-target species. We found that while priority areas for redlisted species are effective at representing non-target species once, they were unable to identify suitable networks of priority areas that would represent all species more than once. More than one representation of each species is required to guarantee that populations are not vulnerable to extinction due to stochastic events and future deterministic actions. Hence, long term fulfillment of the obligations outlined in the Convention on Biological Diversity are unlikely if management is focused exclusively on red-listed species. We also performed a gap analysis on the existing network of protected and other managed natural areas in Denmark to examine the efficiency of these in terms of representing species. The network of managed areas represents species more effectively than random area selection; 99% of non-red-listed species and 85% of red-listed species occur within the managed areas. However, the efficiency is much less than can be achieved using quantitative area selection methods that optimize species representation for a given area. In principal, a number of grid cells similar to that of the existing network of managed areas is sufficient to represent all species four times. -4- In light of these results, the strengths and weaknesses of the existing strategy are discussed and we advocate the development and implementation of an updated biodiversity strategy, which is science-based and data-driven. In addition, to ensure the future performance of nature management in Denmark, it is also essential to develop an investment plan to significantly increase data-collection and compilation. Finally, we advocate science based and data-driven approaches that will guarantee accountability and flexibility within the process of selecting priority areas. This will enable people and decision- makers to assess whether their values, national and international obligations are being applied faithfully when strategies for biodiversity management are developed and implemented.