LTREB: Oak Mast as a Keystone Resource in Forest Community Dynamics

9306641 Wolff在阿巴拉契亚山脉南部的山湖生物站进行的一项为期13年的研究结果表明，mast生产与主要和次要消费者之间存在动态相互作用。间断性的桅杆生产导致了老鼠、花栗鼠和其他桅杆消费者的种群波动。食肉动物，主要是横斑猫头鹰，对啮齿动物的密度表现出数值反应。种子的存活和萌发只发生在桅杆生产的高峰期，幼苗的死亡率与鹿的觅食活动有关。花栗鼠似乎是地面筑巢鸟类的主要捕食者，它们的密度与junco雏鸟的成功成反比。该项目将在两年时间内继续监测这些营养水平上的主要参与者，以确定间歇性生产对阿巴拉契亚南部落叶林群落中选定的初级和次级消费者、种子存活和森林更新以及群落稳定性的直接和间接影响。具体而言，该项目将(1)确定mast生产在调节三种以种子为食的啮齿动物物种（白足鼠，鹿鼠和花栗鼠）的种群密度中的作用，(2)确定波动的啮齿动物密度是否以及如何影响种子存活和发芽率，以及地面筑巢鸟类（主要是juncos）的羽翼成功，(3)测试捕食者-饱食假说。(4)确定鹿食活动对林下植被生存和生长的影响；(5)为舞毒蛾入侵前群落结构和动态提供基线数据。这类研究项目对于理解由森林生态系统组成的种群之间复杂的相互作用尤为重要。这项工作的结果将产生物种相互作用的基本见解，并提供适用于更好地管理森林资源的信息。＊＊＊

9306641 Wolff Results from a 13-year study conducted at the Mountain Lake Biological Station in the southern Appalachian Mountains suggests a dynamic interaction between mast production and primary and secondary consumers. Episodic mast production has resulted in population fluctuations of mice, chipmunks, and other mast consumers. Carnivores, primarily barred owls, exhibit a numerical response to rodent densities. Seed survival and germination occurs only during peak mast production years and seedling mortality is associated with deer browsing activity. Chipmunks appear to be the major predators on ground nesting birds, and their densities are inversely correlated with junco fledgling success. This project will continue the monitoring of the major players in these trophic levels for two years to determine the direct and indirect effects of episodic mast production on selected primary and secondary consumers, seed survival and forest regeneration, and community stability in a southern Appalachian deciduous forest community. Specifically the project will (1) determine the role of mast production in regulating population densities of three seed-eating rodent species, white-footed mice, deer mice, and chipmunks, (2) determine if and how fluctuating rodent densities affect seed survival and germination rates, and fledgling success of ground nesting birds, primarily juncos, (3) test the predator-satiation hypothesis for seed masting in deciduous oaks, (4) determine the role of deer browsing on survival and growth of understory vegetation, and (5) provide baseline data on these aspects of the community structure and dynamics prior to the anticipated invasion of gypsy moths. %%% Research projects of this type are especially important to the understanding of the complex interactions of populations comprised by the forest ecosystem. Results from the work should yield fundamental insights on species interactions as well s provided information applicable to the be tter management of forest resources. ***