Forest sensitivity to a changing climate: Investigating the role of bedrock water storage

森林健康和河流水质受到气候持续变化的威胁，这导致积雪减少，干旱增加，树木死亡和河流干涸。深层地下（包括土壤下的基岩）的作用已成为决定水资源可用性以及森林和溪流命运的关键因素。然而，我们对地下生态系统何时、何地以及如何从气候变化中缓冲生态系统的理解却知之甚少。这项研究计划的首要长期目标是量化气候和地下风化模式之间的相互作用如何调节水的储存和释放到植物和河流。这使我们能够更好地了解当今的水储存动态以及在更温暖，更干燥的气候下的未来动态。短期目标是：（1）提高我们对季节性水储存敏感性的理解，特别是在冬季潮湿，夏季干燥的气候中（例如，这些沿着北美中西部海岸），包括雨雪过渡区;（2）揭示了植物生物群落和径流恢复干旱的后果。这将通过在岩石类型、气候和构造历史的梯度上设置野外观测站来实现。我们将监测相关空间尺度的生态水文过程，并开发可用于预测未来森林和河流状态并解释古记录的机械模型。我们预计，这项工作将使我们能够了解和预测植物依靠风化基岩中的水储存来度过干旱的情景，以及积雪减少将如何影响夏季河流低流量的大小。我们的研究结果还将导致深层地下水储存过程的新发展和纳入地球系统模型，用于预测水和碳循环对气候变化的耦合响应。

Forest health and stream water quality are threatened by ongoing shifts in climate, which have resulted in decreased snowpack, increased drought, dead trees, and dry rivers. The role of the deep subsurface (including bedrock below the soil) has emerged as a key factor in determining water availability and therefore the fate of forests and streams. However, our understanding of when, where, and how the subsurface buffers ecosystems from climate shifts is poorly understood. The overarching, long-term goal of this research program is to quantify how the interaction between climate and subsurface weathering patterns regulates water storage and release to plants and streams. This enables us to better understand present-day water storage dynamics as well as future dynamics under a warmer, drier climate. The short-term objectives are to: (1) advance our understanding of seasonal water storage sensitivity to year-to-year precipitation variability in winter-wet, summer-dry climates in particular (e.g., those along the central west coast of North America), including rain-snow transition areas; and (2) reveal the consequences for plant biome and streamflow resilience to drought. This will be achieved by instrumenting field observatories located across gradients of rock type, climate, and tectonic history. We will monitor eco-hydrologic processes at relevant spatial scales and develop mechanistic models that can be used to predict future forest and stream states and interpret paleo-records. We anticipate that this work will enable us to understand and predict the scenarios in which plants rely on water storage in weathered bedrock to survive drought and how declining snowpacks will impact the magnitude of summer low flows in streams. Our findings will also result in the novel development and incorporation of deep subsurface water storage processes into Earth system models, which are used to predict the coupled response of the water and carbon cycles to a shifting climate.