U.S.-Brazil Cooperative Research: Resource Partitioning Among Woody Plants of a Species-Rich Cerrado

9415987戈尔茨坦美国-巴西合作科学项目支持与博士访问相关的差旅费。夏威夷大学的G. Goldstein，夏威夷糖业种植者协会的F. Meinzer，以及加州大学洛杉矶分校的P. Rundel和P. Jackson，前往巴西。他们将与巴西利亚大学（university of Brasilia）的a . Franco博士及其学生合作，确定巴西中部塞拉多地区代表性木本植物物种土壤水分和养分资源的时空分配程度。他们还建议研究相关的地上过程，如长期水利用效率、氮利用效率和其他生态生理参数，作为资源利用和竞争的衡量标准。稳定氢同位素技术将用于解决土壤水资源分配问题。稳定的氮同位素将用于区分物种之间的氮获取模式（即固氮生物和非固氮生物）。为了整合地下和地上的过程，将使用稳定的碳同位素来评估长期内在的水利用效率。气体交换测量将用于确定实现水利用效率变化的机制。选取具有代表性的木本植物物种进行研究，这些木本植物具有不同的产叶模式和其他特征。＊＊＊

9415987 Goldstein This U.S.-Brazil Cooperative Science Program supports travel expenses related to the visits of Drs. G. Goldstein, Univ. of Hawaii, F. Meinzer, Hawaiian Sugar Planters Association, and P. Rundel and P. Jackson, Univ. of California Los Angeles, to Brazil. They will be working with Dr. A. Franco, of the Univ. of Brasilia and his students, on determining the extent of temporal and spatial partitioning of soil water and nutrient resources among representative woody plant species of a cerrado of central Brazil. They also propose to examine related above ground processes, such as long term water use efficiency, nitrogen use efficiency, and other ecophysiological parameters as measures of resource use and competition. Stable hydrogen isotope techniques will be used to address the question of soil water resource partitioning. Stable nitrogen isotopes will be used to distinguish modes of nitrogen acquisition among species (i.e. nitrogen fixers from non fixers). To integrate below ground and above ground processes, stable carbon isotopes will be used to assess long-term intrinsic water-use efficiency. Gas exchange measurements will be used to determine the mechanisms by which variation in water use efficiency is achieved. Representative woody plant species with different patterns of leaf production and other characteristics will be selected for the study. ***