科研之友
微信
新浪微博
Facebook
分享链接
摘要
A complex set of variables may explain biodiversity patterns both locally and regionally. Evidence exists that greater plant species richness can be associated with localised areas containing a greater percentage of rock exposure. Here, we test whether this is the case at the landscape scale, using semi-natural Afro-montane grassland in southern Africa. Plants were inventoried, percentage rock exposure calculated, and each site graded according to three levels of rockiness. Soil samples from each site were then analysed for particle size, as well as for levels of carbon, nitrogen and available phosphorus. Species richness and the compositional similarity of assemblages were compared between the three rockiness categories. Plants were then categorised into their respective growth forms, and species richness within each group compared across the rockiness categories. Greater species richness in rockier landscapes was driven by two particular plant growth forms, geophytes and perennial grasses. However, no overall plant assemblage compositional changes were recorded between the various rockiness categories, indicating that very few species are not associated with rocky areas in some way in this landscape. This shows that plant species within certain functional groups are naturally more responsive to certain abiotic ecosystem elements than others across a landscape. In turn, this highlights the significance of high habitat heterogeneity in structuring plant communities. Consequently, when an abiotic feature such as rockiness is observed across a landscape, it provides a surrogate for the spatial heterogeneity of certain plant communities.
- 出版日期2013-9
