99th ESA Annual Meeting (August 10 -- 15, 2014)

IGN 13

Tree Survival Under Stress: Does Storage of Labile Carbon Matter?

The most abundant constituent of the biomass of trees is carbon, which is assimilated via photosynthesis. During periods of stress, carbon supply via photosynthesis may become insufficient to meet demand for respiration, growth and other functions. Under these circumstances, trees rely on stored non-structural carbon compounds (NSC) to meet the difference. From these basic principles, one may assume that: 1) NSC storage increases tree survival under stress, and 2) tree growth depends in large part on carbon supply via photosynthesis (i.e. higher supply leads to higher growth rates). However, there is currently a strong debate on the validity of these assumptions, which have profound implications on our understanding and modeling of forest responses to climate change. The goal of this IGNITE proposal is to synthesize what is known and not known about the role and regulation of NSC storage in woody plants. The session is organized to address four main related questions: 1) Does NSC storage increases tree survival under stress? From correlative to experimental data 2) Is NSC storage an overflow of carbon or is it a regulated sink? 3) What methodological approaches can be used to assess NSC storage and dynamics? 4) Do NSC dynamics matter for modeling forest responses to stress? Our ultimate goal is to arrive at some consensus and identify the importance and knowledge voids on a critical but poorly understood aspect of the physiology of trees (see justification).