Biodiversity and ecosystem functioning: exploring large-scale patterns in mainland China

Relationships between biodiversity and ecosystem functioning are vital to understand ecosystem properties, and have frequently been addressed in smallscale studies. However, interactions and changes differ at large scales, and should be similarly evaluated to monitor biodiversity and ecosystem functional alterations. In the present study, Mainland China was divided into 241 quadrats of 2 degrees latitude by 2 degrees longitude. Ecosystem function was comprehensively assessed using three indicator variables in each quadrat, primary productivity, bird species richness, and relative humidity. Relationships between each ecosystem function variable were regressed against seed plant species richness. All three indicators exhibited the same change model, a linear model when plant species richness was under 5.000 species, and a hump-back/quadratic model when seed plant richness was over 5.000 species, with an increase in seed plant species richness at a larger scale.