Nonstructural leaf carbohydrate dynamics of Pinus edulis during drought‐induced tree mortality reveal role for carbon metabolism in mortality mechanism

• DOI: 10.1111/nph.12102
• Publication Date: 2013-01-11T19:01:17Z
• Authors: Henry D. Adams; Matthew J. Germino; David D. Breshears; Greg A. Barron‐Ga...; Maite Guardiola‐C...; Chris B. Zou; Travis E. Huxman
• Keywords: Carbohydrate Metabolism

Summary Vegetation change is expected with global climate change, potentially altering ecosystem function and feedbacks. However, causes of plant mortality, which are central to vegetation understudied, physiological mechanisms remain unclear, particularly the roles carbon metabolism xylem function. We report analysis foliar nonstructural carbohydrates ( NSC s) associated physiology from a previous experiment where earlier drought‐induced mortality P inus edulis at elevated temperatures was greater cumulative respiration. Here, we predicted faster decline for warmed trees than ambient‐temperature trees. Foliar in droughted declined by 30% through lower watered controls. resulted primarily decreased sugar concentrations. Starch initially declined, then increased above pre‐drought concentrations before mortality. Although temperature did not affect sugar, starch ceased declining higher temperatures. Reduced during lethal drought indicates role mechanism. were completely exhausted differences accumulation timing suggest that changes time death. Drought appears be related temperature‐dependent dynamics concurrent increasing hydraulic stress . other similar species.