Collaborative Research: (RUI): Dry in the sky? Ecophysiological Strategies and Drought Tolerance among Tropical Montane Cloud Forest Canopy Epiphytes

合作研究：（RUI）：天空干燥？

• 批准号: 1556289
• 负责人: Sybil Gotsch
• 金额: $ 40.42万
• 依托单位: Franklin and Marshall College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-05-01 至 2020-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1556289&HistoricalAwards=false
• 关键词: Collaborative; Research; RUI; Dry; sky

Epiphytes, plants that live on other plants, reach their peak of diversity and abundance in Tropical Montane Cloud Forests (TMCF). In this ecosystem, epiphytes play important ecosystem roles because they intercept and hold on to nutrients and water from rain and mist and provide food and resources for many birds, animals and insects. Because these plants do not have access to soils and water from the ground, they are particularly vulnerable to changes in climate, including increases in cloud height and drought. This research will determine the degree to which epiphyte communities are vulnerable to decreases in precipitation or cloud cover, and increased forest fragmentation. This project will also develop a training program in canopy ecology for ecotourism operators in Monteverde, Costa Rica. This region hosts over 100,000 people per year for canopy adventure sports but few tourists or guides get information on the importance of the TMCF in general and the epiphyte community specifically. The team will also provide training and presentations to local research and educational institutions in the Monteverde region including the Monteverde Reserve, the Monteverde Institute and local high schools.Despite evidence that the canopy community as a whole is important to ecosystem processes, there is little information regarding the ability of this community to withstand projected changes in climate and/or increases in exposure due to deforestation. In the TMCF, there is great variation in growth forms in the canopy that may differ in their vulnerability to decreases in precipitation or increases in cloud base heights. Although efforts have been made to understand individual species responses to drought stress, little is known about variability in drought-stress responses and the ability of plants to cope with projected future drought conditions. By working in this hyper-diverse, but relatively understudied system, this research will increase the understanding of a fundamental topic in plant ecophysiology: the diverse ways plants respond to drought. Variability in microclimate across the six sites provides a unique opportunity to identify suites of drought-stress responses across functional groups and determine whether these traits vary, or respond plastically, to changes in the environment. Functional morphological traits, water relations, water use, and vulnerability to drought will be measured across the gradient to document variation in ecophysiological strategies in plants that are exposed to different microclimates. Photosynthetic strategies will also be evaluated along the gradient using stable isotopes. Canopy communities in open pasture trees will also be studied because these exposed communities tend to experience greater water stress within a given precipitation regime and may provide insights on how canopy communities are likely to be affected by increases in drought stress or forest fragmentation. To assess the role of suites of functional traits on drought resistance, a subset of common species from three of the sites (wettest, intermediate, driest) from both forests and pastures will be subjected to a manipulative drought experiment.

附生植物是生活在其他植物上的植物，达到了热带山地云森林（TMCF）的多样性和丰度。在这个生态系统中，附生植物扮演着重要的生态系统角色，因为它们拦截并抓住了雨水和雾气中的营养和水，并为许多鸟类，动物和昆虫提供食物和资源。由于这些植物无法从地面进入土壤和水，因此它们特别容易受到气候变化的影响，包括云高度和干旱的增加。这项研究将确定附生植物群体容易减少降水或云覆盖的程度，并增加森林破碎。该项目还将在哥斯达黎加蒙特维德（Monteverde）为生态旅游运营商开发一项培训计划。该地区每年拥有超过100,000人参加Canopy Adventure运动，但很少有游客或指南获得有关TMCF一般重要性和Epiphyte社区的重要性的信息。该团队还将向蒙特维德地区的当地研究和教育机构提供培训和演讲，包括蒙特维德保护区，蒙特维德研究所和当地高中。在TMCF中，冠层的生长形式存在很大的变化，其脆弱性可能会降低降水量或云碱基高度的增加。尽管已经努力了解单个物种对干旱压力的反应，但关于干旱压力反应的可变性以及植物应对预计未来的干旱状况的能力知之甚少。通过在这个多样性但相对研究的系统中工作，这项研究将增加对植物生态生物学基本话题的理解：植物对干旱的反应方式。六个站点的小气候变异性提供了一个独特的机会，可以识别跨功能组的干旱压力反应套件，并确定这些特征是否会变化或塑料对环境变化的反应。功能形态学特征，水关系，用水和干旱的脆弱性将在整个梯度上进行测量，以记录暴露于不同微气候的植物中生态生理策略的变化。光合策略还将使用稳定的同位素沿梯度进行评估。还将研究开放式牧场树木的树冠社区，因为这些暴露的社区倾向于在给定的降水体内经历更大的水压，并且可能会提供有关冠层社区如何受到干旱压力或森林破碎化的增加影响的见解。为了评估功能性状套件对干旱抗旱性的作用，这是来自森林和牧场的三个地点（最湿，中间，最干燥）的共同物种的一部分，将经过操纵性的干旱实验。