Dissertation Research: Consequences and Implications of Leaf-Level N Versus P Limitation

9701899 Goldstein这项拟议的研究侧重于氮和磷这两种最普遍和最重要的限制营养物质对光合作用、森林生长和生态系统过程造成的叶水平营养限制的后果和影响。研究人员建议在夏威夷群岛非常明确和有限的年龄序列中确定叶水平N与P限制的后果和含义。这些地点都是由单一树种主导的天然林，环境条件非常稳定，实验表明，N限制了年轻地点的产量，P限制了最老的地点的产量。长期的肥料试验正在这些地点进行，因此我们可以评估养分有限的地块和解除N或P限制的后果。这项研究的结果将加强并与地下过程、林分水平特征和生态系统水平的养分循环的调查相结合，以更好地了解热带森林的动态。这些信息将对森林对变化的反应以及森林生态系统的恢复和管理产生重大影响。

9701899 Goldstein This proposed research focuses on the consequences and implications of leaf level nutrient limitation to photosynthesis, forest growth, and ecosystem processes caused by nitrogen versus phosphorus, the two most widespread and important limiting nutrients. The researchers propose to determine the consequences and implications of leaf level N versus P limitation in a very well-defined and constrained age sequence of sites in the Hawaiian Islands. The sites are all natural forests dominated by a single tree species, with remarkably constant environmental conditions, along which experiments have demonstrated that N limits production in young sites, and P limits the oldest site. Long-term fertilizer experiments are ongoing in these sites, so we can evaluate both nutrient-limited plots and the consequences of removing limitation by N or P. Results from this study will both augment and be integrated with investigations of belowground processes, stand-level characteristics, and ecosystem-level nutrient cycling to better understand tropical forest dynamics. Such information will have substantial implications for both the responsiveness of forests to change, and the restoration and management of forest ecosystems.