The role of thermal acclimation of plant respiration under climate warming : putting the brakes on a runaway train?

Respiration represents a large flux of carbon from terrestrial vegetation to the atmosphere. Of the total amount of carbon fixed in gross primary production (GPP), perhaps up to one half is returned to the atmosphere through respiration at the soil surface (Hopkins et al., 2013), with the remainder accumulating in new plant biomass or lost via respiratory costs associated with the growth of plant tissues and maintenance of metabolic function, including roots. Consequently, disentangling the sources of respiratory carbon losses from ecosystems, particularly respiration of roots from soils, is important in elucidating the underlying sensitivity of component processes to environmental drivers, especially temperature. In this issue of Plant, Cell and Environment, Jarvi and Burton report findings of a soil warming experiment in a temperate forest in North America that describes temporal dynamics in fine root respiration and elucidates a mechanism of metabolic control that, in part, constrains respiratory responses under changing environmental conditions.