生物多様性管理と林業ジャーナル

Distribution Range and Pattern of a Species are as much an Expression of Biodiversity

Margaret

While the prevailing focus on the status of threatened species is important and indeed indicates high-priority biodiversity concerns, it does not present the full picture of global biodiversity loss. Equally concerning, but less well-documented, is the steady decline of many “common” and “widespread” species. Abundance, distribution range and pattern of a species are as much an expression of biodiversity (on a genetic level) as the raw number of species itself in a given locality. A great number of species not yet rare enough to qualify for the red list are affected by this process. In Europe, for example, while 8% of the bird species are globally threatened, another 38% are undergoing steady decline, mainly due to changing land-use patterns, especially in relation to agriculture. Biodiversity Management This often overlooked dimension of biodiversity decline, which might be as serious as the increasing number of threatened species, is particularly relevant when looking at local and regional biodiversity issues in connection with land-use activities that involve substantial, but relatively contained, transformation of habitats (as in the case of limestone mining for cement and aggregate production). During the planning phase, the most important biodiversity issue to be examined is the likelihood for the project to have adverse impacts on high-value biodiversity elements (species, habitats, ecosystem services, traditional uses). If the project is in an area where Holcim has no operating experience, there is a risk that significant biodiversity values in the area of interest may not be recognised early enough. As in some cases there might be little available information in the public domain, even desk-based early assessments may not always reveal the presence of important biodiversity issues, and the confidential and rapid timeline of the planning phase studies does not allow for extensive fieldwork to rectify this. Among the potential