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为期两年的研究，培训和指导经验。CREST-PRP奖项的目标是增加那些在STEM领域代表性不足的团体成员的STEM劳动力。CREST-PRP奖项旨在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，促进跨学科的互动，并为CREST-PRP学者在科学界的领导地位做好准备。研究项目“CREST-PRP：人类世的生态水文学：长期压力生态系统中物理和生物地球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，旨在研究人类引起的土地利用变化和天气气候模式变化的综合影响对生态系统的影响。位于波多黎各群岛的两个地点具有共同的半干旱气候，但土地使用情况截然不同，将作为本研究的地点：Moscow Bay，一个世界著名的旅游生物发光海湾，有红树林植被，在过去三个世纪中进行了农业和军事行动，Finca Atabey，一个多作物农场，以前有甘蔗生产的历史。该研究结合水文学、生态学、植物生态生理学和气象学，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的适应性。研究成果包括一个模型框架，可用于研究加勒比海盆和热带地区其他地点的人为和气候压力的影响。这类工作的结果还将协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的生态系统时支持粮食主权加勒比区域易受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。生物物理量化的系统是至关重要的保护方法，以适应可持续性。 本研究是基于一个综合的，跨学科的生态水文生态生理学研究框架内的陆地-水生-海洋连通性为基础的矩阵。该项目将寻求回答以下首要问题：1）时空变异性和周期性气候变化如何影响生态生理学植物反应及其对不断变化的气候条件的耐受性？2)天气和气候变化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的来源是什么？时空变异如何影响有机质的起源和分布？4)在有人类利用历史的生态系统中，人为氮输入的时空动态是什么？这项研究将评估水文气象对位于波多黎各群岛半干旱地区的两个对比生态系统的水文地球化学过程和植物耐受性的影响，在那里，淡水供应是主要的压力源。该研究将采用生态水文学和水文气象学方法，其中同位素（δD、δ 18 O、δ 15 N和δ 13 C）的天然丰度将作为环境压力和植物反应的指标。将测量结构（面积、重量、比叶面积）和生态生理学叶功能性状（气孔导度、渗透压、渗透势、元素）以评估植物对水分和盐度胁迫的生理响应。将对土壤和水进行采样，以进行土壤地球化学分析（有机碳、有机质轻组分和重组分、有机质来源和氮源的δ 15 N和δ 13 C天然丰度、pH值、盐度、电导率、体积含水量、元素分析）。将对各种水源进行取样，以确定δD和δ 18 O的天然丰度。将对植物进行采样，以测定δD和δ 18 O的天然丰度。将每两个月确定一次水利用效率（基于δ 13 C和δ 18 O）。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。干旱和潮湿天气之间的植物水源、水的可用性以及植物的物理和生理特征的差异，预计将反映季节性天气变化以及与加勒比地区脉动事件相关的气候变化。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的知识价值和更广泛的影响审查标准进行评估来支持。

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.