International Research Fellowship Program: Effects of Soils and Precipitation on Plant and Ecosystem Traits in South African Savanna

国际研究奖学金计划使美国科学家和工程师能够在国外进行三到二十四个月的研究。该计划的奖项提供了联合研究的机会，并利用国外独特或互补的设施、专业知识和实验条件。该奖项将支持约瑟夫·克雷恩博士与南非开普敦大学的威廉·邦德博士和明尼苏达大学的彼得·赖克博士合作18个月的研究奖学金。该项目将结合对克鲁格国家公园几个根和地上部特征(化学、稳定同位素和组织密度)的广泛调查，以与克鲁格国家公园土壤类型和年降雨量的大梯度有关。非洲一些地区的湿润草原有一个动物群落，并没有像其他大陆那样枯竭。沿着克鲁格广泛的降水梯度，PI将描述各种草本植物的根和叶的特征，以及草原的氮循环及其对N和P施肥的响应。这些研究可以作为一个有用的模型系统来理解草原-牧草相互作用和生态系统功能的基本驱动因素。理解为什么放牧动物在较干燥的草原(以及某些土壤类型)达到最高丰度的关键，需要了解根和叶的结构和功能、放牧和养分循环之间的关系。除了了解非洲放牧生态系统本身的重要性外，由于北美许多人试图将野牛、麋鹿、马和其他物种重新引入北美大平原地区，重要的是首先了解仍有充足食草动物的草原的功能。

0301834CraineThe International Research Fellowship Program enables U.S. scientists and engineers to conduct three to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support an eighteen month research fellowship by Dr. Joseph Craine to work with Dr. William Bond at the University of Cape Town in South Africa and with Dr. Peter Reich at the University of Minnesota.This project will combine broad-scale surveys of several root and shoot traits (chemical, stable isotope and tissue densities) to relate to large gradients in soil type and annual precipitation in the Kruger National Park. The humid grasslands in some parts of Africa have a faunal assemblage that has not been depleted like on other continents. Along broad precipitation gradients in Kruger, the PI will characterize traits of roots and leaves of a wide variety of herbaceous species as well as to characterize the nitrogen cycles of the grasslands and their responses to N and P fertilization. These studies may serve as a useful model system for understanding the basic drivers of grassland-grazer interactions and ecosystem function. The key to understanding why grazers reach their highest abundance in the drier grasslands (and on certain soil types) requires understanding relationships among the construction and functioning of roots and leaves, grazing, and nutrient cycling. Aside from the importance of understanding the African grazing ecosystems in and of themselves, as many in North America seek to reintroduce bison, elk, horses and other species to areas of the Great Plains of North America, it is important to first understand the functioning of grasslands that still have a full complement of grazers.