Direct and Indirect Effects on Community Resilience in Oak Forests

奥斯特费尔德河S. DEB-9615414 PI建议测试直接和间接影响的重要性，在东南部的纽约州的橡树林。 橡树的情景肥大生产似乎会导致啮齿动物种群密度的短暂增加。 反过来，啮齿动物似乎调节低密度的舞毒蛾种群，是携带莱姆病的蜱虫的主要宿主。 PI将模拟肥大产生并测量啮齿动物种群水平的反应。 将确定小鼠种群密度变化对舞毒蛾蛹存活率、卵块密度、蜱虫幼虫寄生率和蜱虫若虫丰度的影响。 PI将进行啮齿动物清除实验，以检验啮齿动物种群密度仅在蛾周期的低阶段调节舞毒蛾种群动态的假设。 相互作用的建模将确定系统行为对啮齿动物捕食和橡子消耗的功能反应变化以及桅杆周期节奏变化的敏感性。 除了有助于更全面地了解决定生态系统结构和动态的因素外，这项研究的结果将适用于落叶林的管理和影响东北生活质量的两个因素-舞毒蛾落叶和莱姆病的快速传播。

Ostfeld, R. S. DEB-9615414 The PIs propose to test the importance of direct and indirect effects in oak forests of southeastern New York State. Episodic mast production by oak trees appears to cause transient increases in the density of rodent populations. Rodents, in turn, appear to regulate low-density gypsy moth populations and are the primary reservoirs of the tick that carries Lyme disease. The PIs will simulate mast production and measure the response in rodent population levels. The effect of changes in mouse population densities will be determined for survival of gypsy moth pupae and density of egg masses, and parasitization rates of larval ticks and nymphal tick abundance. The PIs will conduct rodent removal experiments to test the hypothesis that rodent population density regulates gypsy moth population dynamics only during the low phase of the moth cycle. Modeling of the interaction will determine the sensitivity of system behavior to variation in the functional response of rodent predation and acorn consumption and to variation in the rhythm of the masting cycle. In addition to contributing to a more complete understanding of the factors determining the structure and dynamics of ecological systems, the results of this study will be applicable to the management of deciduous forests and to two factors affecting quality of life in the northeast - gypsy moth defoliation and the rapid spread of Lyme disease.