Dissertation Research: Linking Leaf Lifespan to Distribution and Growth Strategies of Oaks: Implications for Global Change

[801455]本研究将探讨15种栎属共生种叶片寿命与其他植物性状和生境的关系。叶片寿命将用于表征橡树的功能群，这些功能群可能用于预测对二氧化碳升高的反应。这项研究将在佛罗里达州北部的三个试验点的成熟树木和温室试验的幼苗上进行。该研究系统提供了大量在结构和生理上非常相似的近亲物种，它们都发现于同一地理区域，但叶片寿命却截然不同。这允许研究随叶片寿命变化的性状，而不需要由于不同的进化起源或气候差异而产生额外的性状变化。这项研究有三个主要组成部分：1)量化叶片寿命与对栎树碳、养分和水分利用具有重要意义的植物性状之间的关系；2)通过不同土壤水分和养分梯度对栎树物种丰度和覆盖度进行实地调查，以确定叶片寿命是否与土壤性状相关；3)通过温室试验确定叶片寿命是否可作为预测二氧化碳浓度升高下栎树生长增强的有用参数。

9801455 Bazzaz This research will investigate the function of leaf lifespan in relation to other plant traits and to habitat in 15 co-occurring species of the oak genus. Leaf lifespans will be used to characterize oaks into functional groups that may be used to predict responses to elevated CO2. The research will be conducted on mature trees in three field sites in northern Florida and on seedlings in greenhouse experiments. The study system provides a large number of closely related species which are structurally and physiologically very similar, and are all found in the same geographic region, but which have contrasting leaf lifespans. This permits study of traits that vary with leaf lifespan, without additional trait variation due to different evolutionary origins or to climatic differences. The research has three major components: 1) quantification of the relationships between leaf lifespan and plant traits important for carbon, nutrient and water utilization in oaks, 2) a field survey of abundance and percent cover of oak species across soil moisture and nutrient gradients to determine whether leaf lifespan is correlated to soil properties, and 3) a greenhouse experiment to determine whether leaf lifespan is a useful parameter in predicting growth enhancement of oaks under elevated CO2.