Clues for our missing respiration model

Abstract

Respiration is as essential to plants as it is to animals. Because respiration increases exponentially in response to temperature in the short term, models predict that higher temperatures would lead to higher plant respiration losses, yielding less carbohydrate supply for growth and reproduction. Also because the short-term temperature response is exponential, respiration has been suggested as the cause of slower growth in warmer conditions in field studies (Clark et al., 2003). However, many studies have shown acclimation of respiration, where respiration rates of plant tissues at a common temperature decline after longer exposure to warmer temperatures, becoming close to their original rate before the temperature was increased (Atkin & Tjoelker, 2003). Respiration also shows this acclimation response in roots and soil microbial communities (Luo et al., 2001). Evidence of acclimation is accumulating (Slot & Kitajima, 2015), but questions remain on whether acclimation is a general response for different species, soils, tissues and for the whole plant and the ecosystem. Questions also remain about incomplete acclimation – if the response of respiration to higher temperatures is lower than estimated from short-term responses, but greater than no change at all. We cannot have a useful, powerful model of respiration until these issues are addressed with strong evidence. Obtaining strong evidence depends on the challenging task of precisely measuring the components of the whole-tree carbon (C) balance. In this issue of New Phytologist, Drake et al. (2019a, pp. 1298-1312) present an elegant solution to this challenge to answer questions about partitioning of photosynthesis.

Citation

Ryan, Michael G.; Asao, Shinichi. 2019. Clues for our missing respiration model. New Phytologist. 222(3): 1167-1170.