Unravelling resilience mechanisms in forests: role of non-structural carbohydrates in responding to extreme weather events
Unravelling resilience mechanisms in forests: role of non-structural carbohydrates in responding to extreme weather events
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DOI：
10.1093/treephys/tpab044
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发表时间：
2021-04-05
期刊：
影响因子：
4
通讯作者：
Moscatello, Stefano
中科院分区：
文献类型：
--
作者：
D'Andrea, Ettore;Scartazza, Andrea;Moscatello, Stefano
由于全球气候变化，极端天气事件的频率和强度正在增加。我们假设，树木的碳储量是至关重要的恢复力山毛榉，缓冲源-汇的不平衡，由于晚霜和夏季干旱，以及不同成分的非结构性碳水化合物（NSC）在应对压力的情况下发挥特定的作用。为了评估两种极端天气事件对成熟树木的复合影响，首先是2016年春季的晚霜，然后是2017年夏季的干旱，我们监测了地中海山毛榉林的物候，径向生长以及淀粉和可溶性糖的动态。85%的增长减少后，观察到春季晚霜，但没有干旱事件后。我们观察到一个强大的影响，晚霜淀粉，这也影响了它的动态在随后的营养季节开始。2017年，与淀粉水解相关的可溶性糖的增加在应对严重的夏季干旱中发挥了至关重要的作用。非结构性碳水化合物有助于抵消这两个事件的负面影响，支持植物生存和缓冲压力条件下的源-库失衡。我们的研究结果表明，在树木的生长和NSC存储之间存在很强的权衡。总的来说，我们的研究结果突出了神经干细胞对山毛榉树的关键作用，对极端天气事件的反应，证实了这个物种对高度应激事件的适应能力。这些见解有助于评估森林如何应对气候变化对地中海地区生态系统进程的潜在影响。
Extreme weather events are increasing in frequency and intensity due to global climate change. We hypothesized that tree carbon reserves are crucial for resilience of beech, buffering the source-sink imbalance due to late frosts and summer droughts, and that different components of non-structural carbohydrates (NSCs) play specific roles in coping with stressful situations. To assess the compound effects on mature trees of two extreme weather events, first a late frost in spring 2016 and then a drought in summer 2017, we monitored the phenology, radial growth and the dynamics of starch and soluble sugars in a Mediterranean beech forest. A growth reduction of 85% was observed after the spring late frost, yet not after the drought event. We observed a strong impact of late frost on starch, which also affected its dynamic at the beginning of the subsequent vegetative season. In 2017, the increase of soluble sugars, associated with starch hydrolysis, played a crucial role in coping with the severe summer drought. Non-structural carbohydrates helped to counteract the negative effects of both events, supporting plant survival and buffering source-sink imbalances under stressful conditions. Our findings indicate a strong trade-off between growth and NSC storage in trees. Overall, our results highlight the key role of NSCs on beech trees, response to extreme weather events, confirming the resilience of this species to highly stressful events. These insights are useful for assessing how forests may respond to the potential impacts of climate change on ecosystem processes in the Mediterranean area.