U.S.-Australia Cooperative Research: A Study of the Effect of Soil Nitrogen on Water-Use Efficiency in Eucalypts from Contrasting Habitats (Long-Term Visit)

该奖项将支持爱达荷州立大学生物科学系Jay E.Anderson教授对澳大利亚国立大学(ANU)的长期研究访问。这次访问是在美澳合作科学计划下进行的。在澳大利亚期间，安德森教授将与澳大利亚国立大学生物科学研究学院的Graham D.Farquhar教授和英联邦科学与工业研究组织(CSIRO)的Michael P.Austin博士合作。该项目的目标是(1)确定在澳大利亚东南部观察到的三种桉树的分布是否与不同物种利用水分效率的差异有关，以及(2)确定物种之间水分利用效率的差异是否源于涉及叶片的光合作用或其他生理过程(包括气孔)的内在差异，或者获取养分的能力差异，尤其是氮素，来自土壤是有责任的。研究结果与农业和营林选择计划有关，这些计划旨在确定水分利用效率更高的植物物种和基因类型，以及努力了解物种自然分布的基础机制。安德森教授将在爱达荷州立大学休假期间进行这项研究。他将研究澳大利亚的桉树，这些桉树受到年平均气温和年平均降雨量的影响。研究氮素水平对植物生长、光合作用能力、气孔导度、羧化效率、水分利用效率和氮素利用效率的影响。美国和澳大利亚的研究小组都有这方面的研究经验。安德森教授和他在爱达荷州的团队之前的工作表明，氮肥提高了本地物种的水分利用效率。法夸尔教授和他在澳大利亚国立大学的同事们在理解植物水分利用效率方面取得了许多进展，并提供了将光合作用过程中的碳同位素差异与水分利用效率联系起来的理论模型和经验证据。奥斯汀博士是CSIRO野生动物和生态部的一名国际领先的植被科学家，他研究了桉树在温度和降雨梯度中的分布。ANU的实验设施，包括一个进行同位素和其他分析的分析实验室，将极大地促进这一研究项目的开展。

This award will support a Long-Term Research Visit to the Australian National University (ANU) by Professor Jay E. Anderson, Department of Biological Sciences, Idaho State University. The visit takes place under the U.S.-Australia Cooperative Science Program. While in Australia, Professor Anderson will collaborate with Professor Graham D. Farquhar, Research School of Biological Sciences, ANU, and Dr. Michael P. Austin, Commonwealth Scientific and Industrial Research Organization (CSIRO). The objectives of the project are (1) to determine whether the observed distributions of three species of Eucalyptus in southeastern Australia are related to differences in the efficiency with which the different species use water, and (2) to resolve whether variation in water use efficiency among species results from inherent differences in photosynthetic or other physiological processes (including stomatal) involving the leaf, or whether differences in ability to acquire nutrients, especially nitrogen, from the soil are responsible. The results are relevant to agricultural and silvicultural selection programs aimed at identifying plant species and genotypes that are superior in water use efficiency, as well as to efforts to understand mechanisms that underlie the natural distribution of species. Professor Anderson will carry out this research while on sabbatical leave from Idaho State University. He will study eucalypts in Australia subjected to gradients in mean annual temperature and in mean annual rainfall. The effect of nitrogen level on plant growth, photosynthetic capacity, stomatal conductance, carboxylation efficiency, water use efficiency, and nitrogen use efficiency will be studied. Both the U.S. and Australian groups have experience in this area of research. Previous work by Professor Anderson and his group in Idaho has shown that nitrogen fertilization improves water use efficiency among native species. Professor Farquhar and his colleagues at ANU have been responsible for many advances in the understanding of the efficiency of water use by plants, and have provided both theoretical models and empirical evidence relating carbon isotope discrimination in the photosynthetic process to water use efficiency. Dr. Austin, of CSIRO's Division of Wildlife and Ecology, is a leading international vegetation scientist who has studied eucalypt distributions in gradients of temperature and rainfall. Experimental facilities at ANU, including an analytical laboratory for performing isotopic and other analyses, will greatly facilitate the carrying out of this research project.