Dissertation Research: Climate Change, Hydraulic Function, and Ecotypic Variation in Spatially Isolated Ponderosa Pine Populations

德鲁西亚9800932气候变化预计在下世纪将对树木适应更高的温度和干旱的能力提出挑战。干燥的大气条件和气候增加了植物叶表面的蒸发量(蒸腾作用)，增加了水分需求。PI使用了生长在气候梯度上的黄皮松种群的地理比较，作为当前和未来气候之间的差异的替代。PI发现，与凉爽潮湿的气候相比，生长在温暖干燥气候中的树木增加了边材(导水组织)相对于树叶的生物量分配。为了确定树木结构的这些变化是否可能是对气候和气候的生理和进化适应，我们建议检查四个研究问题。首先，边材相对于树叶的分配增加是否会增加树木的蒸腾作用？第二，增加对边材的分配是否会减少夏季长期干旱期间脱水的可能性？第三，增加边材的分配是否能提供更大的树木水分储备？第四，黄皮松对干旱的生理和结构反应是否有潜在的遗传基础？拟议的研究将在树木结构和功能之间建立直接联系，并允许对黄皮松应对气候变化的生理和进化潜力进行预测。

DeLucia 9800932 The change in climate expected in the next century will challenge the capacity of trees to acclimate to increased temperatures and aridity. The dry atmospheric conditions of an and climate increase evaporation from the leaf surfaces of a plant (transpiration), increasing moisture requirements. The PIs used a geographic comparison of Ponderosa pine populations growing on a climate gradient as a proxy for differences between the current and future climate. The PIs found that trees growing in a warm, dry versus a cool, moist climate increased biomass allocation to sapwood (water conducting tissue) relative to leaves. To determine if these changes in tree structure may be physiological and evolutionary adaptations to an and climate, we propose to examine four research questions. First, does increased allocation to sapwood relative to leaves increase transpiration in and trees? Second, does increased allocation to sapwood reduce the probability of dehydration during prolonged summer droughts? Third, does increased allocation to sapwood provide greater water storage in and trees? Fourth, does the physiological and structural response of Ponderosa pine to aridity have an underlying genetic basis? The proposed research will establish direct links between tree structure and function and permit predictions to be made about the physiological and evolutionary potential of Ponderosa pine to respond to climate change.