Hydraulic Limits to Photosynthetic Performance in Tropical Dry Forest Trees

本研究探讨植物的输水能力在多大程度上限制了它们的生产力。具体来说，我们关注的是树干和树枝（“木质部”）的水力特性与叶片的光合能力的关系。我们的目标是了解血管和光合能力之间的生理联系。我们选择通过检查季节性干燥的森林树木来解决这个基本问题。我们的理论基础反映了季节性降水模式在决定这些森林的叶片寿命和生产力方面所起的重要作用。我们将监测在缺水（干旱）期间维管组织受损的程度，以及这对叶片生产力的影响。我们的研究将是第一个直接研究树木维管和光合能力之间联系的研究。这项工作的结果将增加我们对植物如何随着土壤水分有效性的急剧变化而复制的理解，并将有助于我们了解影响季节性干燥热带森林生产力和生态的因素。

This study addresses the degree to which the water transport capacity of plants limits their productivity. Specifically, we focus on the hydraulic properties of tree stems and branches (the "xylem") in relation to the photosynthetic capacity of the leaves. Our goal is to understand the physiological linkages between vascular and photosynthetic capacity. We have chosen to address this fundamental question by examining seasonally dry forest trees. Our rationale for this reflects the important role that seasonal precipitation patterns play in determining the longevity and productivity of leaves in these forests. We will monitor the extent to which vascular tissues become damaged during periods of low water availability (drought) and the effects that this has on the productivity of leaves. Our study will be one of the first to examine directly the link between vascular and photosynthetic capacity in trees. The results of this work will increase our understanding of how plants copy with dramatic changes in soil water availability, and will contribute to our knowledge of factors influencing the productivity and ecology of seasonally dry tropical forests.