Log Decomposition Processes as Influenced by Heterotroph Community Structure

将对分解原木进行详细的过程级和社区级研究，这些原木是以俄勒冈州H.J.安德鲁斯LTER遗址为中心的长期对数衰变研究的一部分。具体地说，这项研究将集中完成三项研究任务。首先，将完成为期两年的四种腐烂原木的营养动态研究。原木养分含量变化的数据将与通过固氮等过程输入的养分信息以及通过碎裂和淋洗等过程输出的信息结合在一起。其次，将研究1985年田间设置的原木，以确定与分解者群落相关的固氮、真菌群落分布和酶活性。这项工作将完成对原木腐烂季节模式的研究。第三，将完成对1985年开始的原木中萜类和苯酚含量的分析。其中一些化合物被认为是钻木虫的引诱剂和/或分解的抑制剂。这项研究的意义在于，它将有助于我们了解原木腐烂在森林生态系统养分循环中的作用。在太平洋西北部的古老森林中，倒下的原木和其他木质碎屑占地上有机质(活的和死的有机质)的22%，占地上碎屑的81%。这些大量枯死的木质材料很可能成为这些森林系统中养分的重要储存库和养分动态的调节器。肖瓦尔特博士和他的同事们在这一研究领域有着良好的生产力记录。他们所能得到的制度支持是优越的。

Detailed process-level and community-level studies will beconducted on decomposing logs that are part of a long-term logdecay study centered at the H.J. Andrews LTER site in Oregon. Specifically, the research will focus on completing threeresearch tasks. First, a two-year study of nutrient dynamics infour species of decaying logs will be finished. Data on changesin nutrient content of the logs will be integrated withinformation on nutrient inputs through processes such as nitrogenfixation, and outputs through processes such as fragmentation andleaching. Second, logs set in the field 1985, will be studied todetermine nitrogen fixation, fungal community distribution andenzyme activity associated with the decomposer community. Thiseffort will complete a study of seasonal patterns in log decay. And third, analyses of terpene and phenol content of the logs setout in 1985, will be completed. Some of these compounds arethought to serve as attractants for wood-boring insects and/or asinhibitors of decomposition. The significance of this research is that it will help us tounderstand the role of log decay in nutrient cycling in forestecosystem. In old-growth forests of the Pacific Northwest,downed logs and other woody debris comprise up to 22% of above-ground organic mass (live and dead organic matter) and 81% ofaboveground detritus. This large mass of dead woody material maywell serve as an important storehouse of nutrients and regulatorof nutrient dynamics in these forest systems. Dr. Showalter and his colleagues have good records ofproductivity in this research area. The institutional supportavailable to them is superior.