Interannual dynamics of stemwood nonstructural carbohydrates in temperate forest trees surrounding drought
Interannual dynamics of stemwood nonstructural carbohydrates in temperate forest trees surrounding drought
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DOI：
10.1007/s11676-022-01566-2
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发表时间：
2022-11-16
影响因子：
3
通讯作者：
Furze, Morgan E.
中科院分区：
文献类型：
--
作者：
Blumstein, Meghan J.;Furze, Morgan E.
水和碳动态之间的相互作用是与干旱有关的树木死亡的基础。虽然整个树的水分关系在干旱响应和恢复中发挥了关键作用，但非结构性碳水化合物（NSC）的作用及其在干旱事件中的储存和分配变化值得进一步关注，对了解树木的生存至关重要。在这里，我们量化了美国东北部温带森林树木对2016年干旱的原位NSC响应。从2014年到2019年，我们测量了五种树种茎秆中的糖和淀粉浓度，这使我们能够监测NSCs与自然干旱之前、期间和之后的气候条件的关系。我们发现干旱之后，茎木的NSC浓度立即下降。然而，NSC浓度在三年内迅速反弹。值得注意的是，在2016年干旱之后，树木分配给淀粉的比例高于糖。2017年冬季，淀粉占总茎材储量的45%，而在其他年份，淀粉仅占1-2%。此外，我们模拟并评估了茎中NSC总浓度的气候驱动因素。前一年的温度、降水和标准化降水-蒸散指数（SPEI）显著预测了NSC总浓度的变化，茎材浓度在炎热、干燥期下降，在凉爽、潮湿期增加。总的来说，我们的工作提供了对NSC储存的气候驱动因素的见解，并强调了树木的碳经济在其对环境压力的响应和恢复中可能发挥的重要作用。
Interactions between water and carbon dynamics underlie drought-related tree mortality. While whole-tree water relations have been shown to play a key role in the response to and recovery from drought, the role of nonstructural carbohydrates (NSC) and how their storage and allocation changes surrounding drought events deserves further attention and is critical for understanding tree survival. Here, we quantified in situ NSC responses of temperate forest trees to the 2016 drought in the northeastern United States. Sugar and starch concentrations were measured in the stemwood of five tree species from 2014 to 2019, which allowed us to monitor NSCs in relation to climatic conditions before, during, and after the natural drought. We found that immediately following the drought, measured stemwood NSC concentrations decreased. However, NSC concentrations rebounded quickly within three years. Notably, trees allocated proportionally more to starch than to sugars following the 2016 drought. In winter 2017, starch comprised 45% of total stemwood stores, whereas starch made up only 1-2% in other years. Further, we modeled and assessed the climatic drivers of total NSC concentrations in the stem. Variation in total NSC concentrations was significantly predicted by the previous year's temperature, precipitation, and standardized precipitation-evapotranspiration index (SPEI), with stemwood concentrations decreasing following hotter, drier periods and increasing following cooler, wetter periods. Overall, our work provides insight into the climatic drivers of NSC storage and highlights the important role that a tree's carbon economy may play in its response and recovery to environmental stress.