Modelling Plant Species Diversity Pattern in a Local Environmental Space

Abstract

Abstract. The loss of biodiversity is a major concern for conservationists and whole human societies these days. Understanding plant species diversity pattern along local environmental gradients can be very useful for undertaking management and conservation measures. Despite the enormous efforts in the last decades, however, unified theory about the plant diversity pattern has not yet emerged. This study tries to model plant species diversity pattern in the context of four local/indirect environmental gradients. Nonparametric correlation and multiple regression methods have been used. Ecological response surfaces of species richness at the two levels of observation showed similar complex distribution in the local environmental space. Vegetation diversity and evenness also had complex pattern with several peaks. Dividing species into growth forms revealed their specific manner of diversity distribution. Plant diversity correlated positively with elevation, habitat dryness, herb stratum cover and mature forest stands. It correlated negatively with slope convexity and inclination, tree stratum cover and early-successional stands. Alien and rare plant species number were also positively correlated with species richness and diversity. β-diversity variation along moisture gradient was due mainly to herbs. Trees and shrubs showed decreasing β-diversity along moisture gradient with increasing elevation. β-diversity along elevational gradient showed no clear trend. Our results support the idea that diversity pattern is much more complicated than previously thought due to the complex interplay between local environmental gradients, vegetation succession and history. Understanding of diversity pattern in the local environmental space will allow resident managers and conservationist to set more specific goals and to take more applicable actions in order to preserve plant diversity in the area for the future generations.