CREST-PRP: Ecohydrology in the Anthropocene: Hydrometeorological Controls of Physical and Biogeochemical Processes in Chronically Stressed Ecosystems

CREST博士后研究计划(CREST-PRP)为活跃的CREST中心的个人早期职业科学家提供两年的研究、培训和指导经验支持。CREST-PRP奖项的目标是增加STEM劳动力的存在，这些个人是STEM领域代表性不足的群体的成员。CREST-PRP奖项表彰具有巨大潜力的研究人员，并支持他们的研究经验，以拓宽他们的视野，促进跨学科互动，并为CREST-PRP学者在科学界担任领导职位做好准备。该研究项目“CREST-PRP：人类世的生态水文学：长期处于压力下的生态系统的物理和生物地质化学过程的水文气象控制”，与CREST-PRP的目标直接一致。该项目由波多黎各大学CREST环境纳米技术创新、研究和教育中心的一名研究人员提交，旨在研究人类导致的土地利用变化以及天气和气候模式变化对生态系统的影响。位于波多黎各群岛的两个地点将是本研究的地点：蚊子湾，一个世界著名的具有红树林植被的旅游生物发光海湾，在过去三个世纪里在那里进行农业和军事行动；以及Finca Atabey，一个有甘蔗生产历史的多种作物农场。这项研究结合了水文学、生态学、植物生态生理学和气象学的组成部分，旨在回答与气候条件变化有关的复杂问题，评估生态系统对当前和未来压力来源的适应能力。研究成果包括一个模型框架，可用于研究加勒比海盆地和热带地区其他地点的人为和气候压力的影响。这类工作的成果还将帮助社区制定与环境保护做法有关的知情公共政策，使当地经济受益，并在社区努力恢复和发展环境可持续生态系统时支持粮食主权。加勒比区域容易受到气候变化相关因素和人类干扰的影响，这些因素正在考验生态系统的环境可持续性。系统的生物物理量化对于适应可持续性的保护方法至关重要。这项研究研究的基础是以陆地-水-海洋连通性为基础的综合、跨学科的生态水文-生态生理学研究框架。该项目将寻求回答以下主要问题：1)时空变异性和反复的气候变化如何影响生态生理学、植物反应及其对气候条件变化的耐受性？2)天气和气候变异性如何影响波多黎各半干旱地区的水源分布和可用性？3)土壤有机质的过去和现在来源是什么，时空变异性如何影响有机质的起源和分布？4)有人类利用历史的生态系统中人为N输入的时空动态是什么？这项研究将评估位于波多黎各群岛半干旱地区的两个不同生态系统的水文气象对生物地球化学过程和植物耐受性的影响，那里的淡水供应是主要的压力来源。这项研究将使用生态水文和水文气象方法，其中自然丰度的同位素(δD、δ18O、δ15N和δ13C)将作为环境应激源和植物反应的指标。将测量结构(面积、重量、比叶面积)和生态生理叶功能性状(气孔导度、渗透率、渗透势、元素)，以评估植物对氢气和盐分胁迫的生理反应。将对土壤和水进行生物地球化学分析(有机碳、土壤有机质轻组分和重组分、有机质来源和氮源的δ15N和δ13C的自然丰度、pH、盐度、电导率、体积水含量和元素分析)。将对各种水源进行采样，以确定δD和δ18O的自然丰度。将对植物进行采样，以测定δD和δ18O的自然丰度。水利用效率(基于δ13C和δ18O)将每两个月确定一次。将使用基于R的贝叶斯混合模型来确定工厂中水源的相对比例。干旱和潮湿天气在植物水源、可利用性以及植物物理和生理特征方面的差异预计将反映加勒比地区季节性天气变化以及与脉冲事件相关的气候变化。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。

The CREST Postdoctoral Research Program (CREST-PRP) provides two years of support for research, training, and mentoring experiences for individual early career scientists at active CREST Centers. The goal of the CREST-PRP awards is to increase the STEM workforce presence of individuals who are members of groups underrepresented in STEM fields. CREST-PRP awards recognize investigators with significant potential and support their research experiences to broaden their perspectives, facilitate interdisciplinary interactions, and prepare CREST-PRP scholars for positions of leadership within the scientific community. The research project, " CREST-PRP: Ecohydrology in the Anthropocene: Hydrometeorological Controls of Physical and Biogeochemical Processes in Chronically Stressed Ecosystems", is in direct alignment with the CREST-PRP goals. Submitted by a researcher affiliated with the CREST Center for Innovation, Research, and Education in Environmental Nanotechnology at the University of Puerto Rico, the project is designed to study impacts on ecosystems due to the combined effects of human-induced changes in land use and changing weather and climate patterns. Two sites located in the Puerto Rico archipelago with a common semi-arid climate but contrasting land use will be the sites for this study: Mosquito Bay, a world-renowned touristic bioluminescent bay with mangrove vegetation where agriculture and military operations were carried out during the last three centuries, and Finca Atabey, a multi-cropping farm with a previous history of sugar cane production. Combining hydrology, ecology, plant ecophysiology and meteorological components, the research will aim to answer complex questions related to changing climate conditions, assessing ecosystems’ adaptability to present and future stressors. Research outcomes include a model framework that can be used for studying the effects of anthropogenic and climate stressors at other sites in the Caribbean Basin and the Tropics. Findings from this type of work will also assist communities in developing informed public policies related to environmental conservation practices, benefitting local economies, and supporting food sovereignty as communities work to restore and develop environmentally sustainable ecosystems.The Caribbean region is vulnerable to climate change-related factors and anthropic disturbances which are testing the environmental sustainability of ecosystems. Biophysical quantification of the system is crucial for a conservation approach to adaptive sustainability. This research study is based on an integrated, transdisciplinary ecohydrological-ecophysiology research framework within a terrestrial-aquatic-marine connectivity-based matrix. The project will seek to answer the following overarching questions: 1) How does spatiotemporal variability and recurrent climate change impact ecophysiology plant responses and their tolerance to shifting climatic conditions? 2) How does weather and climate variability affect water source distribution and availability in the Puerto Rican semi-arid regions? 3) What are the past and present sources of soil organic matter and how spatiotemporal variability affects organic matter origin and distribution? 4) What are the spatiotemporal dynamics of anthropogenic N inputs in ecosystems with history of anthropogenic use? The research will assess hydrometeorological effects on the biogeochemical processes and plant tolerance in two contrasting ecosystems located in semi-arid regions in the Puerto Rico archipelago, where freshwater availability is the main stressor. The study will use an ecohydrological and hydrometeorological approach where natural abundance of isotopes (δD, δ18O, δ15N and δ13C) will be indicators of environmental stressors and plant response. Structural (area, weight, Specific Leaf Area) and eco-physiological leaf functional traits (stomatal conductance, osmolarity, osmotic potential, elements) will be measured to assess plant physiological responses to hydric and salinity stress. Soil and water will be sampled for biogeochemical analyses (Organic Carbon, SOM light fraction and heavy fraction, natural abundance of δ15N and δ13C for organic matter origin and nitrogen sources, pH, salinity, conductivity, volumetric water content, elemental analyses). A variety of water sources will be sampled to determine the natural abundance of δD and δ18O. Plants will be sampled for natural abundance of δD and δ18O determinations. Water use efficiency (based on δ13C and δ18O) will be determined bi-monthly. An R-based Bayesian mixing model will be used to determine the relative proportions of the water sources in the plants. Differences in plant water source, water availability, and physical and physiological plant characteristics between dry and wet weather are to be expected to reflect seasonal weather variability as well as climate change related to pulsing events in the Caribbean region.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.