Collaborative research: Cascade “Ecohydromics” in the Amazonian Headwater System

合作研究：亚马逊河源头系统的级联“生态水文学”

• 批准号: 2106540
• 负责人: Loren Albert
• 金额: $ 15.26万
• 依托单位: West Virginia University Research Corporation
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2023-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2106540&HistoricalAwards=false
• 关键词: Collaborative; research; Cascade; Ecohydromics; Amazonian

Water movement through landscapes supports plant, animal, and human life, and through evaporation affects cloud processes and large-scale atmospheric circulation. The Amazon Basin cycles more water through streamflow and evaporation than any other contiguous forest in the world, and transpiration by trees – water taken up by roots and released to the atmosphere – is a critical part of this cycle. Understanding how plant roots, stems, and leaves interact with soil water to jointly regulate forest transpiration across landscapes is a critical knowledge gap, especially as climate changes. Forests are likely adapted to distinct soil moisture conditions in different parts of Amazonian landscapes. Specifically, forests on elevated plateaus with deep groundwater use water conservatively in order to tolerate drought, while those in wet valleys with shallow groundwater use water freely but may be poorly prepared for droughts of the future caused by the climate change. To understand landscape hydrology, rainforest compositions, and their susceptibility to global change, an integrated understanding of how water flows are regulated from upstream-to-downstream by plants and soil is required. This understanding is also critical for Earth-system modeling used to project the fate of Amazonian rainforests and quantify their future influence on climate. This project links diverse disciplines – plant physiology, ecology, hydrology – and integrates them into a model of landscape function. This project will also help train the next generation of scientists, both in the U.S. and Brazil, on interdisciplinary approaches in research, and through a summer school on computer modeling of vegetation and hydrologic processes. The project will develop a novel science outreach program connecting K-12 students to real-time Amazon tree data as well as a short class curriculum and a series of videos that teach students how to interpret data, understand the broader scientific context, and build a personal connection with scientists and real-time “talking trees” from the world’s most famous tropical forest.This project characterizes landscape variation in physiological and hydrological processes, and integrate observations with watershed modeling and hypothesis testing. Project activities focus on the spatially intricate mosaic of plateaus and valleys characteristic of central Amazonian headwater catchments. This research hypothesizes that: (H1) strong landscape variation in forest transpiration capacity arises from distinct characteristics of trees residing on plateaus (no root access to groundwater) and valleys (root access to groundwater) zones; (H2) previously unquantified “hybrid” soil hydraulics govern soil water fluxes and transit times connecting plateaus and valleys; and (H3) plateau forests influence the composition and function of valley forests by regulating subsurface water flows from higher to lower landscape areas. Study sites are located in the Brazilian Amazon: “KM34” near Manaus contains an instrumented watershed with more historical data and research on hillslope hydrology than any other watershed in a pristine wet tropical forest, and “KM67” near Santarém sits on a broad plateau with previously deployed deep soil moisture pits, allowing the isolation of processes typical for flat, elevated plateaus. Both sites contain eddy flux towers, canopy access walkways, and a rich history of ecological research and available datasets. A new valley subsite near KM67 will serve as an independent replicate of KM34 observations in valleys. Process-based models of vegetation ecophysiology, subsurface hydrology, and groundwater will be parameterized with observations of leaf physiology, tree morphological traits, soil moisture and physical properties, water table, and streamflow. These models will be integrated employing novel tools in probabilistic learning and uncertainty quantification for proper parameterization and validated with independent observations of tree sapflow, and ecosystem gas exchange and energy balance.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

水分通过景观支持植物、动物和人类的生命，并通过蒸发影响云过程和大范围大气环流。亚马逊盆地通过溪流和蒸发循环的水分比世界上任何其他毗连的森林都要多，而树木的蒸腾--被树根吸收并释放到大气中的水分--是这种循环的关键部分。了解植物的根、茎和叶如何与土壤水分相互作用，共同调节不同景观的森林蒸腾是一个关键的知识缺口，特别是在气候变化的情况下。森林可能适应亚马孙流域不同地区不同的土壤水分条件。具体地说，地下水位较深的高原上的森林为了抵御干旱而节约用水，而地下水较浅的潮湿山谷中的森林可以自由用水，但可能对气候变化造成的未来干旱没有做好充分准备。为了了解景观水文学、热带雨林的组成及其对全球变化的敏感性，需要对植物和土壤如何从上游向下游调节水流有一个综合的了解。这一理解对于用于预测亚马逊雨林命运和量化其未来对气候影响的地球系统建模也是至关重要的。该项目将不同的学科--植物生理学、生态学、水文学--联系在一起，并将它们整合成一个景观功能模型。该项目还将帮助培训美国和巴西的下一代科学家，了解研究中的跨学科方法，并通过一个关于植被和水文过程的计算机建模的暑期班。该项目将开发一个新颖的科学推广计划，将K-12年级的学生与亚马逊实时树木数据联系起来，并推出一个简短的课程和一系列视频，教会学生如何解释数据，了解更广泛的科学背景，并与科学家和来自世界上最著名的热带森林的实时“会说话的树”建立个人联系。该项目描述了生理和水文过程中的景观变化，并将观察与流域建模和假设检验相结合。项目活动的重点是空间上错综复杂的高原和山谷马赛克，这些高原和山谷具有亚马逊中部源头集水区的特点。这项研究假设：(H1)森林蒸腾能力的强烈景观变化源于栖息在高原(没有根进入地下水)和山谷(根进入地下水)地带的树木的不同特征；(H2)以前未量化的“混合”土壤水力控制着土壤水分通量和连接高原和山谷的过渡时间；以及(H3)高原森林通过调节地下水流从景观较高的地区向景观较低的地区影响山谷森林的组成和功能。研究地点位于巴西亚马逊：马瑙斯附近的“KM34”包含一个仪器分水岭，拥有比原始潮湿热带森林中的任何其他流域更多的历史数据和山坡水文研究，而圣塔伦附近的“KM67”位于宽阔的高原上，以前部署了深土壤水分坑，使平坦、隆起的高原的典型过程得以隔离。这两个地点都有涡流通量塔、树冠通道，以及丰富的生态研究历史和可用的数据集。Km67附近的一个新的山谷子站点将作为山谷中km34观测的独立副本。基于过程的植被生态生理学、地下水文学和地下水模型将通过观察树叶生理、树木形态特征、土壤水分和物理性质、地下水位和径流来进行参数化。这些模型将使用概率学习和不确定性量化方面的新工具进行集成，以实现适当的参数化，并通过对树木树干径流、生态系统气体交换和能量平衡的独立观测进行验证。该奖项反映了NSF的法定使命，并已通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。