The role of diversity, body size and climate in dung removal: a correlative and experimental approach

The mechanisms by which climatic changes influence ecosystem functions, i.e. by a direct climatic control of ecosystem processes or by modifying richness and trait compositions of species communities, remain unresolved. This study is a contribution to this discourse by elucidating the linkages between climate, land use, biodiversity, body size and ecosystem functions. We disentangled direct climatic from biodiversity-mediated effects by using dung removal by dung beetles as a model system and by combining correlative field data and exclosure experiments along an extensive elevational gradient on Mt. Kilimanjaro, Tanzania. Dung removal declined with increasing elevation, being associated with a strong reduction in the richness and body size traits of dung beetle communities. Climate influenced dung removal rates by modifying biodiversity rather than by direct effects. The biodiversity-ecosystem effect was driven by a change in the mean body size of dung beetles. Dung removal rates were s...

气候变化对生态系统功能的影响机制尚未阐明，其具体途径可分为两类：一是通过气候因子直接调控生态系统过程，二是通过改变物种群落的丰富度与功能性状组成。本研究通过厘清气候、土地利用、生物多样性、体型大小与生态系统功能之间的关联，为该研究议题提供了新的探索视角。我们以坦桑尼亚乞力马扎罗山沿广泛海拔梯度的蜣螂（dung beetle）粪便移除服务作为模式系统，结合相关性野外调查数据与围栏排除实验，区分了直接气候效应与生物多样性介导的效应。粪便移除率随海拔升高而降低，这与蜣螂群落的丰富度及体型大小性状的显著下降密切相关。气候对粪便移除率的影响是通过改变生物多样性实现的，而非直接作用于生态系统过程。生物多样性-生态系统功能效应由蜣螂群落的平均体型大小变化所驱动。粪便移除率为……