Response of dark respiration to temperature in Eriophorum vaginatum from a 30-year-old transplant experiment in Alaska

Abstract

Background: In the Arctic region, temperature increases are expected to be greater under anticipated climate change than the global average. Understanding how dark respiration (Rd) of common Arctic plant species acclimates to changes in the environment is therefore important for predicting changes to the Arctic carbon balance.

Aims: The aim of this study is to investigate the influence of genotype and growing environment on Rd, the temperature response (Q10) of Rd, and foliar N (Nleaf) of the Arctic sedge Eriophorum vaginatum.

Methods: We measured Rd, and determined its Q10 and Nleaf of E. vaginatum populations that were reciprocally transplanted 30 years previously along a latitudinal transect of 370 km in northern Alaska.

Results: Rd and Q10 did not differ among populations (ecotypes) of E. vaginatum, but the local environment had a significant effect on both variables. Rd as well as Nleaf was higher in northern, colder sites, while Q10 was lower there.

Conclusions: Rd in the different populations of E. vaginatum is a very plastic trait and controlled by growing environment, as is Nleaf. The lower Q10 values in the northern sites were most likely a consequence of substrate inhibition of Rd at higher temperatures.