Collaborative RUI Proposal: Effects of Contrasting Cloud Regimes on Plant Carbon/Water Relations at Treeline

全球变暖导致的云模式的潜在变化至关重要，因为它们对植物群落经历的阳光、温度和降水有很大的影响。植物对云层的变化特别敏感，因为阳光、温度和水分供应是影响光合作用碳获取、生长、繁殖和空间分布格局的重要因素。目前以云层频繁覆盖为特征的植物群落(如山地云雾林、温带雨林和热带雨林)预计将对云模式变化作出最戏剧性的反应。该项目的目的是利用对阿巴拉契亚山脉南部(美国东部)和落基山脉(美国西部)在一系列自然云层条件下的光合作用、水分胁迫、叶温和本地树种生长的实地测量。根据这些数据，将开发一个模型，预测云覆盖模式变化对未来增长和生存的长期影响。这些森林生态系统代表了全球发现的两种常见的山脉云系--分别是上午的浸云和下午的碎云。这些森林树种在生理上适应了它们目前的气候条件，预计云量的预测变化可能会导致水分、阳光和树叶温度胁迫的增加，最终导致地理和海拔迁移和/或灭绝。这些高山森林的丧失或减少将对木材生产、积雪以及相应的农业和城市用水供应等重要特征产生重大影响。该项目将涉及拥有强大研究生课程的大学(维克森林大学)和缺乏促进本科生研究的设施和设备的当地文理学院(高点大学)之间的合作努力。来自HPU的三名本科生(来自科学界代表性不足的群体)致力于该项目，并非常有动力成为研究生。

Potential changes in cloud patterns due to global warming are of critical importance because of their strong influence on sunlight, temperature, and precipitation experienced by plant communities. Plants are especially sensitive to changes in cloud cover because sunlight, temperature, and water availability are important factors driving photosynthetic carbon gain, growth, reproduction, and spatial distribution patterns. The most dramatic response to changes in cloud patterns are projected for plant communities currently characterized by frequent cloud cover (e.g. mountain cloud forests, temperate and tropical rainforests). The purpose of this project is to use field measurements of photosynthesis, water stress, leaf temperature, and growth of native tree species in the Southern Appalachians Mountains (eastern US) and the Rocky Mountains (western US) under a range of naturally-occurring cloud regimes. From these data, a model will be developed that predicts long term effects of changing cloud-cover patterns on future growth and survival. These forest ecosystems represent two common types of mountain cloud regimes found across the globe?morning cloud-immersion and afternoon broken clouds, respectively. These forest tree species are physiologically adapted to their current climactic conditions, and it is anticipated that predicted changes in cloud cover may result in increased water, sunlight, and leaf temperature stress, leading ultimately to geographic and altitudinal migration, and/or extinction. Loss or decline of these high-mountain forests would have major impacts on such important features as timber production, snow accumulation, and corresponding water supply for agricultural and municipal use. This project will involve a collaborative effort between a university with a strong graduate program (Wake Forest University) and a local liberal arts college lacking the facilities and equipment to facilitate undergraduate research (High Point University). Three undergraduates from HPU (from underrepresented groups in science) have committed to the project and are highly motivated to become graduate students.