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

各国和国际社会越来越关注树木死亡和森林衰退的根本机制，最近人们认为这与干旱的强度、持续时间和频率的变化以及气候变化有关。对树木死亡率的研究主要集中在直接或间接地与水分限制及其对水分运输的影响有关的过程上。 水分限制被认为是切断树叶供水的主要驱动力，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森林的整体衰退。这种下降的另一种可能解释是碳（C）饥饿。这一假说表明，由于关闭气孔和减少C同化树可能遭受不足和耗尽的C储备，以维持其基本的呼吸需要在高和长期的压力。这一假设尚未得到严格的检验，支持或质疑这一假设的经验数据很少。

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.