Spatial species diversity in temperate species-rich forest ecosystems: Revisiting and extending the concept of spatial species mingling

摘要

Species rich woodland communities play an important role in ecosystem functioning at local, regional and global scale. With ongoing climate change and an ever-increasing human world population we certainly cannot take high species diversity for granted. In fact species diversity is a precious and threatened commodity that requires monitoring and conservation. China has a wealth of natural woodlands with high species diversity that stretch over several climate zones and even in the temperate zone tree diversity is considerable in this country. For monitoring species diversity it is crucial to rely on meaningful summary characteristics that offer sufficient information to make correct decisions in conservation. We analysed large, fully mapped plots from ten species-rich temperate forest sites with the new species segregation function as a significantly more meaningful extension of the traditional spatial species mingling index. The new characteristic is a function of distance and we defined a number of auxiliary measures describing its shape for a more effective analysis of spatial species diversity. We could show that these auxiliary characteristics helped to classify species-rich forests as part of a cluster analysis, which supports the view that the species segregation function provides high quality information. We also successfully applied non-parametric modelling through spatial reconstruction for testing the contribution of the species segregation function to a synthesis of observed spatial species diversity patterns. The results demonstrated that the new characteristic described the complex diversity patterns well and has the potential of being a robust and effective characteristic in monitoring species-rich woodland communities.