Postdoctoral Fellowship: CREST-PRP: Ecophysiological response of tidal freshwater tree ecosystem engineers to chronic thermal, hydric, and salinity stressors in the Caribbean.

在热带生态系统中，天气通常是稳定和温暖的，但在过去十年中，气候变化导致沿海湿地的温度变化以及降雨和海平面的变化，影响了热带植物群和动物群。由于缺乏适应这些变化的工具，热带植物可能难以生存。本研究将探讨两个树种，紫檀和降香，如何科普温度和供水的变化，以及这些变化如何影响他们的生理。该研究地点位于科雷多尔-Noreste生态保护区，这是加勒比地区的一个自然保护区，代表着淡水沿海湿地。与自然资源管理人员，社区和科学家合作，将收集数据来描述气候变化对这些树木的影响，目的是提前了解可用于通知沿海湿地恢复管理决策的知识。在过去的十年中，波多黎各和更广泛的加勒比地区见证了气温的历史性上升。趋势表明，这种变暖轨迹将持续下去，并伴有其他极端气候，包括海平面上升、极端降水事件和大气扰动加剧。沿海热带植被处于危险的境地，在地球变暖和海平面上升的背景下，植被可能没有适应的生理机制。本研究的目的是评估在相同的中气候条件下，在应对温度升高和盐度增加的潮汐淡水湿地固氮物种的生理生态反应。该研究将调查1）气候变暖和盐度增加如何影响光合作用和渗透平衡的调节，以及2）这些环境变化如何影响固氮活性和效率。该研究采用涉及植物生理学、生态学、气候变化科学和代谢组学的跨学科方法，将包括对两个树种-Pterocarpus officinalis和Dalbergia ecastaphyllum-进行实地观察，这两个树种具有相同的中气候，但水文条件不同，还将进行温室实验，改变空气温度和盐分条件。检查的数据将包括光和温度响应曲线，以评估叶片的耐热性，植物形态特征，水力传导，渗透势，13 C和15 N同位素分析固氮，以及营养分析和非目标代谢组学分析，以创建一个配置文件的代谢产物与盐胁迫和温度变化。综合的方法将适用于通知植物的保护管理工作的选择，从而提高这些关键的生态系统provided.This奖项反映了NSF的法定使命的潜在利益，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

In tropical ecosystems the weather is typically stable and warm but in the past decade climate change has been causing changes in temperature and shifts in rain and sea level in coastal wetlands that are impacting tropical flora and fauna. Lacking tools to adjust to these changes, tropical plants might struggle to survive. This study will investigate how two tree species, Pterocarpus officinalis and Dalbergia ecastaphyllum, cope with changes in temperatures and water supply and how these changes are affecting their physiology. The study site is located in the Corredor Ecológico del Noreste, a natural reserve in the Caribbean that represents freshwater coastal wetlands. Working with natural resource managers, community, and scientists, data will be collected to characterize the effects of climate change on these trees with the goal of advance knowledging that can be applied to inform management decisions about coastal wetlands restoration.In the past decade, Puerto Rico and the broader Caribbean region have witnessed a historical increase in temperature. Trends suggest that this warming trajectory will continue, accompanied by other climatic extremes, including rising sea levels, extreme precipitation events, and intensified atmospheric disturbances. Coastal tropical vegetation is in a perilous situation, where in the context of a warmer planet and rising sea levels, vegetation might not have the physiological mechanisms for acclimation. This study’s goal is to assess the ecophysiological responses of nitrogen-fixing species in tidal freshwater wetlands in response to warmer temperatures and increased salinity under the same mesoclimate conditions. The research will investigate 1) how warmer climate and increased salinity affects photosynthesis and regulation of osmotic balance, and 2) how these environmental changes affect activity and efficiency of nitrogen fixation. Using an interdisciplinary approach involving plant physiology, ecology, climate change science and metabolomics, the study will include field observations of two tree species, Pterocarpus officinalis and Dalbergia ecastaphyllum, that share the same mesoclimate but different hydrologic conditions, and greenhouse experiments in which air temperature and saline conditions will be modified. Data examined will include light and temperature response curves to assess leaf thermal tolerance, plant morphological traits, hydraulic conductance, osmotic potential, 13C and 15N isotopic analyses for nitrogen fixation, as well as nutrient analysis and non-targeted metabolomic analyses to create a profile of metabolites related to salt stress and temperature changes. The combined approach will be applicable to informing plant selection in conservation management efforts, thus enhancing the potential benefits these critical ecosystems provide.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.