Complex aspen forest carbon and root dynamics during drought A letter
Complex aspen forest carbon and root dynamics during drought A letter
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DOI：
10.1007/s10584-012-0421-9
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发表时间：
2012-04-01
期刊：
影响因子：
4.8
通讯作者：
Anderegg, William R. L.
中科院分区：
文献类型：
--
作者：
Anderegg, William R. L.
近几十年来，在每一个有植被的大陆都有记录表明干旱引起的植被死亡，这是气候变化对陆地生态系统和碳循环反馈影响的一个主要不确定因素。虽然最近的研究集中在干旱引起的森林死亡的具体故障机制，更广泛地了解干旱下的树木的生理，特别是在生长和碳分配的变化，需要确定森林对干旱的敏感性和森林死亡期间的相互作用机制。我在这里提出的多组织和高分辨率的时间动态的树木碳资源在中度实验和自然干旱颤抖的白杨（杨树tremuloides）森林，在北美西部的一个主要森林类型，最近经历了广泛的干旱引起的死亡。干旱导致推断的碳吸收量大幅下降。树碳水化合物的浓度，但是，大大增加了音乐会大幅下降的增长和严重下降的根生物量。这些研究结果强调，生长下降，特别是在细根，这是重要的水分吸收，并增加碳分配到根非结构性碳水化合物的干旱在白杨的关键反应，并可能发挥重要作用，在广泛的死亡。它们表明了干旱和碳-水力相互联系的多年后果。他们强调，需要一个更综合的多组织，多过程，多年的角度来看气候引起的森林死亡率。
Drought-induced vegetation mortality has been documented on every vegetated continent in recent decades and constitutes a major uncertainty in climate change impacts on terrestrial ecosystems and carbon cycle feedbacks. While recent research has focused on specific failure mechanisms during drought-induced forest die-off, a broader understanding of the physiology of trees under drought, especially changes in growth and carbon allocation, is needed for determining the sensitivity of forests to drought and interacting mechanisms during forest mortality. I present here multi-tissue and high-resolution temporal dynamics of tree carbon resources during moderate experimental and natural drought in trembling aspen (Populus tremuloides) forests, a major forest type in western North America that recently experienced widespread drought-induced die-off. Drought led to substantial declines in inferred carbon uptake. Tree carbohydrate concentrations, however, largely increased in concert with substantial decreases in growth and severe declines in root biomass. These findings highlight that growth declines, especially in fine roots which are important to water uptake, and increased carbon allocation to root non-structural carbohydrates are key responses to drought in aspen and could play an important role in widespread die-off. They suggest multi-year consequences of drought and carbon-hydraulic interconnections. They underscore the need for a more integrated multi-tissue, multi-process, and multi-year perspective of climate-induced forest mortality.