When does temperature matter for ecosystem respiration?

Abstract

The temperature response of ecosystem processes is key to understand and predict impacts of climate change.This is especially true for respiration, given its high temperature sensitivity andmajor role in the global carbon cycle.However, similar intrinsic temperature sensitivity for respiration does not mean comparable temperature effects across ecosystems and biomes because non-temperature factors can be more important. Here we analyzed soil and sediment respiration data and found that in temperature ranges corresponding to high latitude mean temperatures, absolute respiration rates aremore sensitive to non-temperature factors than to projected direct temperature effects. However, at higher temperatures (>20 °C) the direct effect of temperaturemediated by temperature sensitivity will likely be more important over changes in non-temperature factors in shaping how respiration change over time.This supports past suggestions that the relatively small projected temperature increase at low(tropical) latitudesmay have a large direct impact on absolute respiration. In contrast, absolute respiration rates at high (boreal/arctic) latitudeswill likely bemore sensitive on the development of the non-temperature factors than on the direct effects of the large projected temperature increase there. Social media abstract.Respirationmay be less dependent to changes in temperature at higher than lower latitudes.