Species loss drives ecosystem function in experiments, but in nature the importance of species loss depends on dominance

Aim: Decades of experimental research have conclusively shown a positive relationship between species richness and ecosystem function. However, authoritative reviews find no consensus on how species loss affects function in natural communities. We analyse experimental and observational data in an identical way and test whether they produce similar results.

Location: North America and Europe (experimental communities); global (natural communities).

Time period: Experimental communities: 1998–2013; natural communities: 1982–2018.

Major taxa studied: 

Experimental communities: temperate grassland plants; natural communities: temperate grassland plants, tropical forest trees, kelp forest producers
and native bees.

Methods: We used an approach inspired by the Price equation to analyse 129 datasets from experimental and natural communities worldwide. We tested how the
effects of species loss on ecosystem function varied with dominance and the nonrandomness
of species loss an...