Forests out of balance: The impacts of drought-induced tree mortality on carbon and water cycling

森林失衡：干旱引起的树木死亡对碳和水循环的影响

• 批准号: 286857303
• 负责人: Professorin Dr. Nadine Katrin Rühr
• 金额: --
• 依托单位: Department Atmosphärische Umweltforschung (IMK-IFU)
• 依托单位国家: 德国
• 项目类别: Independent Junior Research Groups
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2022-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/286857303?language=en
• 关键词: Forests; out; balance; impacts; drought

Climate change is increasing the severity and frequency of drought events. Particularly detrimental to trees and forests are prolonged drought periods alongside co-occurring heatwaves. These so-called hot drought events have been observed to trigger tree mortality in many regions world-wide, including Central Europe. Alongside climate change, atmospheric CO2 concentrations are increasing, which may potentially mitigate tree physiological responses to drought events. Here, models can help to tackle the complexity of multiple environmental change, but current model developments lack critical interactions between tree hydraulic conductivity, photosynthesis, tissue senescence and tree mortality. Therefore, we want to enhance a process-based model with a novel state-of-the-art hydraulic description for several tree species that will be linked to other critical plant physiological processes. This will allow us to address how an increased frequency of drought events will alter tree mortality rates and forest carbon uptake under future atmospheric conditions. For parametrization and evaluation across scales, a wealth of data will be used reaching from own experimental results of leaf gas-exchange to tree mortality data from remote sensing studies and forest monitoring networks. The main aim of the project is to assess the carbon sink potential of European forest stands under potential future, more extreme climate conditions.

气候变化正在增加干旱事件的严重性和频率。对树木和森林特别有害的是长期干旱和同时发生的热浪。据观察，这些所谓的热干旱事件引发了包括中欧在内的世界许多地区的树木死亡。随着气候变化，大气中的CO2浓度正在增加，这可能会减轻树木对干旱事件的生理反应。在这里，模型可以帮助解决多种环境变化的复杂性，但目前的模型发展缺乏树木导水率，光合作用，组织衰老和树木死亡率之间的关键相互作用。因此，我们希望增强一个基于过程的模型与一个新的国家的最先进的水力描述的几个树种，将链接到其他关键的植物生理过程。这将使我们能够解决干旱事件的频率增加将如何改变树木死亡率和未来大气条件下的森林碳吸收。对于参数化和跨尺度评价，将使用大量的数据，从自己的叶片气体交换实验结果到遥感研究和森林监测网络的树木死亡率数据。该项目的主要目的是评估欧洲森林在未来潜在的、更极端的气候条件下的碳汇潜力。