WCR: Vegetation Control of Ecohydrologic Processes

0233643 Phillips作为陆地生态系统经济中的主要货币，水的获取、保存和花费就像人类经济中的货币一样。 就像人类使用财政资源一样，植被通常不会以相同的瞬时速度吸收和释放水，而是通过将这一关键资源储存在内部储存器官中来缓冲水的供应和需求。 了解植被如何以及何时捕获，存储和运输水从根到叶和叶是至关重要的量化不同的生态水文功能，如流域缓冲的植被径流关系和洪水响应，以及生态系统吸收大气中的二氧化碳。本研究探讨了在马萨诸塞州的哈佛森林，植被对森林大气水分输送的生理控制。 这项建议的具体目标是量化，使用一种新的诊断方法，森林植被如何在水力响应环境刺激的变化。 这里使用的方法施加短暂的干扰的湿度，光照和降雨的树冠和根系，然后跟踪这些扰动通过树木和土壤的传播。 这个...涟漪。影响包含植被内关键水力特性和过程的综合特征，这些特征支配着植被对生态系统水文的总体控制。 这种新的方法是高度可操作的，并产生大的信噪比进行分析，但不会造成不可逆转的生态干扰，如植物根，茎，和分支的损害或破坏。 最重要的是，这种方法将产生基本的见解植被特性和生理，大气强迫和森林蒸发通量之间的动态关系和反馈。 最后，该项目通过将研究与三个现有项目中的重点教育活动相结合，提供了广泛的教育影响：

0233643PhillipsAs a major currency in the economy of terrestrial ecosystems, water is acquired, saved, and spent much like money in human economies. Like human use of financial resources, vegetation does not generally take up and release water at the same instantaneous rate, but rather buffers supply of and demand for water by banking this critical resource in internal storage organs. Understanding how and when vegetation captures, stores, and transports water from roots to and out of foliage is critical to quantifying diverse eco-hydrologic functions such as watershed buffering of rainfall-runoff relationships and flood responses, and ecosystem uptake of atmospheric carbon dioxide. This study examines the physiological controls exerted by vegetation on forest-atmosphere water transport, at Harvard Forest, Massachusetts. The specific objective of this proposal is to quantify, using a novel diagnostic method, how forest vegetation responds hydraulically to variation in environmental stimuli. The methodology used here imposes short-lived disturbances of humidity, light and rainfall on canopies and root systems, and then traces the propagation of these perturbations through trees and soil. This .ripple. effect contains the integrated signature of key hydraulic properties and processes within vegetation, that govern the overall control that vegetation exerts on ecosystem hydrology. This novel methodology is highly manipulative and produces large signal to noise ratios for analysis, but does not cause irreversible ecological disturbances, such as damage or destruction of plant roots, stems, and branches. Most importantly, this methodology will yield fundamental insights into the dynamic relationships and feedbacks among vegetation properties and physiology, atmospheric forcing, and evaporative fluxes from forests. Finally, this project provides broad educational impacts by integrating research with focused educational activities in three existing programs: