Species richness is more important for ecosystem functioning than species turnover along an elevational gradient

Area of Science:

• Ecology
• Environmental Science

Background:

• Biodiversity is known to enhance ecosystem functioning.
• The influence of environmental heterogeneity on this relationship and the roles of species richness and turnover remain unclear.

Purpose of the Study:

• To quantify the diversity effect and its components (species richness and turnover) on ecosystem functions.
• To assess how environmental heterogeneity shapes the diversity-ecosystem functioning relationship across diverse taxa and ecosystems.

Main Methods:

• Quantified diversity effects for 22 ecosystem functions across 13 ecosystem types on Mt Kilimanjaro.
• Analyzed the contributions of species richness and species turnover to ecosystem functioning variation.

Main Results:

• Environmental heterogeneity increased the diversity effect, explaining 49% to 72% of variation in ecosystem functions.
• Species richness, rather than species turnover, was the stronger mediator of the diversity effect on ecosystem functioning.

Conclusions:

• Environmental heterogeneity strengthens the link between biodiversity and ecosystem functioning.
• Species richness is a more significant driver of ecosystem functioning than species turnover.
• Conserving biodiversity is crucial for maintaining ecosystem functions, aligning with biodiversity experiment predictions.