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，生活在其他植物上的植物，在热带山地云雾林（TMCF）中达到其多样性和丰富性的顶峰。在这一生态系统中，附生植物发挥着重要的生态系统作用，因为它们从雨水和薄雾中拦截和保持营养物质和水分，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获得土壤和水，它们特别容易受到气候变化的影响，包括云层高度增加和干旱。这项研究将确定真菌群落在多大程度上容易受到降水或云量减少以及森林破碎化加剧的影响。该项目还将为哥斯达黎加蒙特韦尔德的生态旅游经营者制定林冠生态学培训方案。该地区每年有超过10万人参加林冠探险运动，但很少有游客或导游了解TMCF的重要性，特别是真菌群落。该小组还将向蒙特韦尔德地区的当地研究和教育机构提供培训和演讲，包括蒙特韦尔德保护区、蒙特韦尔德研究所和当地高中。尽管有证据表明，林冠群落作为一个整体对生态系统过程很重要，但关于该群落承受预计气候变化和/或因森林砍伐而增加暴露的能力的信息却很少。在TMCF，有很大的变化，在冠层中的生长形式，可能会在他们的脆弱性不同，减少降水或增加云底高度。虽然已作出努力，以了解个别物种对干旱胁迫的反应，很少有人知道干旱胁迫反应的变化和植物的能力，以科普预计未来的干旱条件。通过在这个高度多样化但相对研究不足的系统中工作，这项研究将增加对植物生态生理学基本主题的理解：植物对干旱的不同反应方式。六个地点的小气候变化提供了一个独特的机会，以确定跨功能组的干旱胁迫反应套件，并确定这些特征是否不同，或可塑性反应，在环境中的变化。功能形态特征，水的关系，水的利用和干旱的脆弱性将在整个梯度测量，以记录暴露于不同的小气候的植物的生理生态策略的变化。还将使用稳定同位素沿沿着评价光合作用策略。还将研究露天牧场树木的树冠群落，因为这些裸露的群落在给定的降水条件下往往会经历更大的水分压力，并可能提供关于树冠群落如何可能受到干旱压力增加或森林破碎化影响的见解。为了评估功能性状对抗旱性的作用，将对森林和牧场三个地点（最潮湿，中间，最干燥）的一组常见物种进行操纵性干旱实验。