Linking tree water status to the carbon budget: identifying mechanisms of drought-induced tree mortality in Pinus nigra and Picea abies

将树木水分状况与碳预算联系起来：确定黑松和冷杉干旱引起的树木死亡机制

• 批准号: 206980852
• 负责人: Privatdozent Dr. Henrik Hartmann
• 金额: --
• 依托单位: Julius Kühn-Institut (JKI) - Bundesforschungsinstitut für Kulturpflanzen
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2011
• 资助国家: 德国
• 起止时间: 2010-12-31 至 2014-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/206980852?language=en
• 关键词: Linking; tree; water; status; carbon

Forest ecosystems foster the bulk of terrestrial biodiversity and are a major driving force of the cycling of life-supporting elements (e.g., carbon, nitrogen). However increasingly frequent occurrences of increasingly intense heat and drought events have led to widespread forest mortality around the globe. Anticipated future increases of drought events may further threaten the survival of forests and hence jeopardize the sustained flow of the life-supporting services they provide. Surprisingly, there are large gaps in the fundamental understanding of how drought kills trees. Current working hypotheses (carbon starvation, impeded carbon translocation, hydraulic/symplastic failure) all lack experimental support but a thorough understanding of these mechanisms is central to predicting impacts on forest ecosystems, future vegetation distribution and element cycling. Here I propose a series of experiments explicitly designed to partition the different mechanisms of drought-induced tree mortality. The experimental design will cover morphological, physiological and functional aspects of the studied trees and will include manipulations of the atmospheric composition. The results of these experiments will improve our understanding of drought-induced tree mortality and will be helpful for developing adaptation and mitigation strategies. Thus they are essential for the conservation of forest ecosystems in a warmer and dryer, CO2-enriched world.

森林生态系统培育了大部分陆地生物多样性，是维持生命要素循环的主要驱动力（例如，碳、氮）。然而，日益频繁的酷热和干旱事件导致地球仪各地的森林普遍死亡。预计未来干旱事件的增加可能进一步威胁森林的生存，从而危及森林提供的维持生命服务的持续流动。令人惊讶的是，在干旱如何杀死树木的基本理解方面存在很大的差距。目前的工作假说（碳饥饿，阻碍碳转运，液压/共质体故障）都缺乏实验支持，但这些机制的透彻理解是预测森林生态系统，未来植被分布和元素循环的影响的核心。在这里，我提出了一系列的实验明确设计分区干旱引起的树木死亡的不同机制。实验设计将涵盖所研究树木的形态、生理和功能方面，并将包括对大气成分的操纵。这些实验的结果将提高我们对干旱引起的树木死亡率的理解，并将有助于制定适应和缓解战略。因此，它们对于在一个更加温暖和干燥、二氧化碳富集的世界中保护森林生态系统至关重要。