Drought stress, growth and nonstructural carbohydrate dynamics of pine trees in a semi-arid forest
Drought stress, growth and nonstructural carbohydrate dynamics of pine trees in a semi-arid forest
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DOI：
10.1093/treephys/tpu071
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发表时间：
2014-09-01
期刊：
影响因子：
4
通讯作者：
Koerner, Christian
中科院分区：
文献类型：
--
作者：
Klein, Tamir;Hoch, Guenter;Koerner, Christian
在长期干旱的树木中，碳吸收（C源）和生长（C汇）通常都会下降。这种相关性提出了两个重要的问题：（i）C可用性在多大程度上限制了树的生长;以及（ii）并发C存储限制了树的生长（例如，非结构性碳水化合物（NSC）？为了检验干旱、生长和碳储量之间的关系，我们监测了生长在以色列Yatir森林的3种干旱胁迫水平下的成熟黑松（Pinus halepensis）米勒（Miller）树的NSC水平的变化，并构建了树干生长年表。2012年，中度胁迫和胁迫树木的茎生长分别为34%和14%，液流密度分别为71%和31%，最终针叶长度分别为健康树木的79%和66%。尽管这些大幅度减少的增长和液流，淀粉和可溶性糖的浓度在这些树木的分支是相似的，在所有树木在整个旱季（2-4%干质量）。同时，中度胁迫和胁迫树的根系淀粉浓度分别为健康树的47%和58%，但从不
In trees exposed to prolonged drought, both carbon uptake (C source) and growth (C sink) typically decrease. This correlation raises two important questions: (i) to what degree is tree growth limited by C availability; and (ii) is growth limited by concurrent C storage (e.g., as nonstructural carbohydrates, NSC)? To test the relationships between drought, growth and C reserves, we monitored the changes in NSC levels and constructed stem growth chronologies of mature Pinus halepensis Miller trees of three drought stress levels growing in Yatir forest, Israel, at the dry distribution limit of forests. Moderately stressed and stressed trees showed 34 and 14% of the stem growth, 71 and 31% of the sap flux density, and 79 and 66% of the final needle length of healthy trees in 2012. In spite of these large reductions in growth and sap flow, both starch and soluble sugar concentrations in the branches of these trees were similar in all trees throughout the dry season (2-4% dry mass). At the same time, the root starch concentrations of moderately stressed and stressed trees were 47 and 58% of those of healthy trees, but never