Collaborative research: Linking Heterogeneity of Above-Ground and Subsurface Processes at the Gap-Canopy Patch Scales to Ecosystem Level Dynamics

树木通过根部吸收水分并将其蒸发到空气中来控制土壤湿度。它们还会产生相反的效果，通过遮蔽地面和降低地表附近的风速，减少从土壤到空气的蒸发。目前的流域模型在区域尺度（几十到几百公里）上模拟土壤湿度，并使用极其简化的植被和土壤湿度之间相互作用的表示。不同冠层间的差异和冠层结构的影响在这些模型中没有得到体现。本项目旨在提高对非均质林冠层蒸发、蒸腾与土壤水分之间关系的认识，以及这些关系如何影响从树木尺度到生态系统尺度和区域尺度的土壤水分异质性。该项目将利用密歇根大学生物站现有的丰富数据和正在进行的各种观测。将使用详细观测和最先进的高分辨率建模工具相结合的方法。新的基于雷达的土壤湿度体积观测，以及冠层内和冠层以上的微气象测量，以及一种新的综合建模方法将被使用。该项目将提高我们在多个尺度上预测生态系统结构对能量、水和二氧化碳与大气的交换以及区域流域功能的影响的能力。在气候变化和人类对森林的干扰增加的情况下，这种进展尤其重要，因为预计这将增加森林和其他重要自然资源的空间异质性。它还将创建一个建模工具，在水文和生态科学中具有真正的变革价值。俄亥俄州立大学和密歇根大学的研究生将通过这个合作项目得到支持。本科生将参与拟进行的研究。“植物与水”是一项教育性的K-12社区外展项目，旨在阐明土壤-植物-大气连续体中水流的基本原理，并将培训和雇用本科生作为俄亥俄州中部Oty'Okwa大兄弟大姐妹住宿营地的讲师，这是美国农业部森林服务局“更多的孩子在森林里”倡议的一部分，该计划针对俄亥俄州中部服务不足的小学年龄儿童。

Trees control soil moisture by drawing water through the roots and transpiring them to the air. They also lead to an opposite effect of reducing evaporation from the soil to the air by shading the ground and reducing the wind speed near the surface. Current watershed models simulate soil moisture at regional scales (tens to hundreds of km) and use extremely simplified representations of the interactions between vegetation and soil moisture. The differences between individual crowns and the effects of the canopy structure are not represented in these models. This project aims to improve understanding of the relationships between evaporation, transpiration and soil moisture in heterogeneous forest canopies, and how these relationships affect soil moisture heterogeneity from the tree scale to the ecosystem and regional scales. The project will capitalize on the existing wealth of data and on-going diverse observations at the University of Michigan Biological Station. A combination of detailed observations and state-of-the-art high-resolution modeling tools will be used. Novel radar-based volumetric observation of soil moisture, and in and above canopy micrometeorological measurements will be used, along with a novel integrated modeling approach. The project will advance our capability to predict the effects of ecosystem structure at multiple scales on the exchanges of energy water and CO2 with the atmosphere, and on the functioning of the regional watershed. Such advancement is particularly important in conditions of changing climate and increased human disturbance to forests, which are expected to increase the spatial heterogeneity of forests and other important natural resources. It will also create a modeling tool that will have a truly transformative value in the hydrological and ecological sciences. Graduate students at Ohio State University and the University of Michigan will be supported through this collaborative project. Undergraduate students will be engaged in the proposed research. "Plant and Water", an educational K-12 community-outreach program will be developed to illustrate the underlying principles of water flow in soil-plant-atmosphere continuum and will train and employ undergraduate students as instructors at Big-Brothers Big-Sisters of Central Ohio Residental Camp Oty'Okwa, as part of the USDA Forest Service's "More Kids in the Woods" initiative, a program for underserved elementary-aged children within central Ohio.