Dynamics of non-structural carbohydrates in three Mediterranean woody species following long-term experimental drought
Open Access
- 1 January 2013
- journal article
- Published by Frontiers Media SA in Frontiers in Plant Science
- Vol. 4, 400
- https://doi.org/10.3389/fpls.2013.00400
Abstract
Stored non-structural carbohydrates (NSC) have been proposed as a key determinant of drought resistance in plants. However, the evidence for this role is controversial, as it comes mostly from observational, short-term studies. Here, we take advantage of a long-term experimental throughfall reduction to elucidate the response of NSC to increased drought 14 years after the beginning of the treatment in three Mediterranean resprouter trees (Quercus ilex L., Arbutus unedo L. and Phillyrea latifolia L.). In addition, we selected 20 Q. ilex individuals outside the experimental plots to directly assess the relationship between defoliation and NSC at the individual level. We measured the seasonal course of NSC concentrations in leaves, branches and lignotuber in late winter, late spring, summer, and autumn 2012. Total concentrations of NSC were highest in the lignotuber for all species. In the long-term drought experiment we found significant depletion in concentrations of total NSC in treatment plots only in the lignotuber of A. unedo. At the same time, A. unedo was the only species showing a significant reduction in BAI under the drought treatment during the 14 years of the experiment. By contrast, Q. ilex just reduced stem growth only during the first 4 years of treatment and P. latifolia remained unaffected over the whole study period. However, we found a clear association between the concentrations of NSC and defoliation in Q. ilex individuals sampled outside the experimental plots, with lower total concentrations of NSC and lower proportion of starch in defoliated individuals. Taken together, our results suggest that stabilizing processes, probably at the stand level, may have been operating in the long-term to mitigate any impact of drought on NSC levels, and highlight the necessity to incorporate long-term experimental studies of plant responses to drought.Keywords
This publication has 38 references indexed in Scilit:
- Nonstructural leaf carbohydrate dynamics of Pinus edulis during drought‐induced tree mortality reveal role for carbon metabolism in mortality mechanismNew Phytologist, 2013
- Linking definitions, mechanisms, and modeling of drought-induced tree deathTrends in Plant Science, 2012
- The roles of hydraulic and carbon stress in a widespread climate-induced forest die-offProceedings of the National Academy of Sciences of the United States of America, 2011
- No evidence for depletion of carbohydrate pools in Scots pine (Pinus sylvestris L.) under drought stressPlant Biology, 2011
- Carbon reserves and canopy defoliation determine the recovery of Scots pine 4 yr after a drought episodeNew Phytologist, 2011
- Mechanisms Linking Drought, Hydraulics, Carbon Metabolism, and Vegetation MortalityPlant Physiology, 2011
- Poor methodology for predicting large-scale tree die-offProceedings of the National Academy of Sciences of the United States of America, 2009
- Lack of direct evidence for the carbon-starvation hypothesis to explain drought-induced mortality in treesProceedings of the National Academy of Sciences of the United States of America, 2009
- Temperature sensitivity of drought-induced tree mortality portends increased regional die-off under global-change-type droughtProceedings of the National Academy of Sciences of the United States of America, 2009
- Mechanisms of plant survival and mortality during drought: why do some plants survive while others succumb to drought?New Phytologist, 2008