Water Relations and Dioecy

从对来自不同生态系统的雌雄异株植物(分离的雄株和雌株)的一些研究中可以清楚地看出，两性在相同的微生境中的分布并不均等。然而，人们对这种分布差异的生理基础知之甚少。这项研究将检验与性别之间可能的水关系差异及其对生产力和生存的影响有关的几个假说。该项目的实验技术之一将是在自然丰度水平下分析水的稳定同位素比(特别是D/H比)，以检测单个树木提取水的深度。这些信息是至关重要的，因为它很大程度上说明了单个树木的生长和存活潜力。由于这些信息也被记录在树木年轮中，随着植物的生长，我们的分析应该提供关于植物所用水源的基本的长期信息，并结合碳同位素比率分析应该提供在这些条件下生产力与水分消耗比率的综合测量。在我们的双子叶树种(如杨树)的应用方面，构成了用于纸浆生产的树种的主要部分。由于这项研究的重点是影响增长、生产率和生存的参数，它们可能会直接应用于这个重要的行业。

It is clear from a number of studies of dioeceous plants (separate male and female plants) from diverse ecosystems that two sexes are not equally distributed in the same microhabitats. Yet little is understood of the physiological bases of the difference in distribution. This study will test several hypotheses relating to the possible differences in water relations between sexes and their implications for productivity and survival. Among the experimental techniques in this project will be the analysis of stable isotope ratios of water (specifically D/H ratios) at natural abundance levels to detect the depths from which individual trees are extracting water. The information is critical as it says much about the potential for growth and survival of individual trees. Since this information is also recorded in tree rings as plants grow, our analysis should provide fundamental long-term information on water sources used by plants and in combination with carbon isotope ratio analysis should provide an integrated measure of the productivity to water consumption ratio under these conditions. Among the applied aspects of our dioeceous species (such as poplars) constitute a major fraction of the tree species used for pulp production. Since this study are focusing on the parameters affecting growth, productivity and survival, they could have direct application to this important industry.