Diurnal patterns of gas‐exchange and metabolic pools in tundra plants during three phases of the arctic growing season

Ecology and Evolution

Rajit Patankar¹  Behzad Mortazavi¹  Steven F. Oberbauer² 

[1] Department of Biological Sciences, University of Alabama, Tuscaloosa, Alabama;Department of Biological Sciences, Florida International University, Miami, Florida

关键词: Alaska;    circadian clock;    photoperiod;    photosynthesis;    respiration;    sugars;    total nonstructural carbohydrates;    tussock tundra;   

DOI  :  10.1002/ece3.467

来源: Wiley

【 摘 要 】

Abstract

Arctic tundra plant communities are subject to a short growing season that is the primary period in which carbon is sequestered for growth and survival. This period is often characterized by 24-h photoperiods for several months a year. To compensate for the short growing season tundra plants may extend their carbon uptake capacity on a diurnal basis, but whether this is true remains unknown. Here, we examined in situ diurnal patterns of physiological activity and foliar metabolites during the early, mid, and late growing season in seven arctic species under light-saturated conditions. We found clear diurnal patterns in photosynthesis and respiration, with midday peaks and midnight lulls indicative of circadian regulation. Diurnal patterns in foliar metabolite concentrations were less distinct between the species and across seasons, suggesting that metabolic pools are likely governed by proximate external factors. This understanding of diurnal physiology will also enhance the parameterization of process-based models, which will aid in better predicting future carbon dynamics for the tundra. This becomes even more critical considering the rapid changes that are occurring circumpolarly that are altering plant community structure, function, and ultimately regional and global carbon budgets.

【 授权许可】

Unknown   
© 2013 The Authors. Published by Blackwell Publishing Ltd. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original study is properly cited.