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

暂时性非结构性碳储量在北方林动态中的作用

• 批准号: 238461-2011
• 负责人: Landhäusser, Simon
• 金额: $ 2.33万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=570428
• 关键词: Role; transitory; non; structural; carbon

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. I propose to test the overarching hypothesis that during times of stress when C assimilation is limited, C reserves in tissues will play a critical role in the performance and mortality of seedlings and mature trees. Further, I will investigate various aspects of C reserve allocation to the crown, stem, and root system during and after periods of C limitation in field and controlled growth chamber studies. I will also monitor C limitation effects on processes related to regeneration and mortality. My research program will provide training for HQP in ecophysiology and forest ecology in a collaborative environment. Understanding the role of C reserves in trees could lead to the use of stored C reserves as an early indicator of stress in trees thereby serving as a risk assessment tool for determining forests' health, resiliency, and adaptability to climatic change; thus providing research vital to Canada's forests and its associated economy.

对树木死亡率和森林衰落的潜在机制的国家和国际兴趣日益增加，这最近与干旱和气候变化的强度，长度和频率变化有关。树木死亡率的研究主要直接或间接地关注与水分限制及其对水运输的影响有关的过程。 水分限制被认为是切断叶子供水的主要驱动因素，导致这些组织的干燥，并最终导致树木的死亡。但是，干旱并不能完全解释树木的死亡和整体森林的衰落。对这种下降的可能替代解释是碳（C）饥饿。该假设表明，由于关闭的气孔和减少的C同化，树可能会遭受不足和耗尽的C储量，以在高和长时间的压力下保持其基本呼吸需求。该假设尚未经过严格检验，支持或挑战该假设的经验数据很少。 我建议检验总体假设，即在压力同化受到限制时，组织中的储量将在幼苗和成熟树木的性能和死亡率中起关键作用。此外，我将在田间和受控生长室研究中对C储备分配的各个方面分配给牙冠，茎和根系。我还将监控c对与再生和死亡率有关的过程的限制效果。 我的研究计划将在协作环境中为生态生理学和森林生态学的HQP提供培训。 了解储量在树木中的作用可能导致使用储存的C储量作为树木压力的早期指标，从而作为确定森林健康，韧性和适应气候变化的风险评估工具；因此为加拿大森林及其相关经济至关重要的研究提供了研究。