Toward a fundamental understanding of ecosystem metabolism responses to global warming

Abstract

The complex processing of energy and matter by organisms that live in an ecosystem, known as ecosystem metabolism, determines the carbon sink strength of ecosystems and is fundamental to climate change mitigation strategies. To optimize the strategies, the response of ecosystem metabolism, here quantified as net ecosystem exchange (NEE), to global warming was assessed. Using numerous NEE and meteorological measurements from highly diverse ecosystems around the world, it is shown that NEE rapidly increases with increasing temperature, being predictable by a simple modified Arrhenius equation. Despite a high intra-annual NEE variation, the mean NEE over a few years approached zero at all sites. The results suggest that ecosystem metabolism is generally resilient to warming, which is explained by ecosystem metabolism following light and temperature interactions at the Earth’s surface. However, even if ecosystems might maintain their functioning without climate change mitigation actions, rapid biodiversity changes are likely under global warming.