Role of transitory non-structural carbon reserves in boreal forest stand dynamics

国家和国际上对树木死亡和森林减少的基本机制越来越感兴趣，这些机制最近与干旱和气候变化的强度、长度和频率的变化有关。对树木死亡率的研究主要直接或间接地集中在与水分限制及其对水运的影响有关的过程上。水分限制被认为是切断叶片供水的主要驱动因素，导致这些组织干燥，最终导致树木死亡。然而，干旱并不能完全解释树木的死亡和整体森林的减少。这种下降的另一个可能的解释是碳(C)饥饿。这一假设表明，由于气孔关闭和碳吸收减少，树木可能在高和长时间的应激下遭受维持其基本呼吸所需的碳储备不足和耗尽。这一假设尚未得到严格的检验，支持或挑战这一假设的经验数据也很少。

There is growing national and international interest in the underlying mechanisms of tree mortality and forest decline which have recently been associated with changes in the intensity, length and frequency of drought and climate change. Research in tree mortality has mainly focused either directly or indirectly on the processes related to moisture limitations and its impact on water transport. Moisture limitation is thought to be the main driver that cuts off the water supply to the foliage, leading to the desiccation of these tissues and ultimately to the death of trees. However, drought does not fully explain the death of trees and overall forest decline. A possible alternative explanation of this decline is carbon (C) starvation. This hypothesis suggests that due to closed stomata and reduced C assimilation trees could suffer from insufficient and depleted C reserves necessary to maintain their basic respiration needs during high and prolonged stress. This hypothesis has not been rigorously tested and empirical data that support or challenge this hypothesis are scarce.