Biodiversity and Decomposition in Mesic Forests: An Across-site Experimental Study of Patterns and Processes

9416819科尔曼关于生态系统分解和养分循环的研究一直是解释生态系统功能的重要过程。它们已成为LTER计划的“Keystone”参数。人们对数百种以枯枝落叶和微生物为食的动物的功能作用越来越感兴趣，这些动物几乎出现在所有陆地地点。这些物种是如何运作和互动的，它们对于系统的最佳运作来说是“必要的”吗？该项目将通过研究导致三个湿润、温暖、阔叶林地点之间显著差异的因素，探索生物多样性和分解过程之间的相互作用，这三个地点都位于相似的土壤类型上。两个热带地点，波多黎各的Luquillo(Luq)和拉斯哥斯达黎加的La Selva，分别具有较低和较高的土壤微节肢动物物种丰富度。考韦塔(Cowetta)位于阿巴拉契亚山脉南部，其微型节肢动物的物种丰富程度接近拉斯维加斯。CWT和LuQ都在Harmon等人目前正在进行的一般底物分解网络研究中。与Harmon等人的相同或相似的凋落物基质。网络，将被装在垃圾袋中的研究与之前的研究相同。该网络将扩大到包括LAS，以检验这一假设：凋落物中含有最多样化的凋落动物的森林将具有最快的分解速度。相反，物种丰富度(LUQ)相对较低的森林，在对水分/温度状况的差异进行校正后，其分解速度将显著较低。CWT的分解速度预计将介于这两个热带地区的分解率之间，因为它的季节循环是温暖潮湿的天气。该项目使用简单、经过验证的技术来比较不同地点的分解速率，并应为更广泛地研究LTER网络中的生物相互作用和过程奠定基础。

9416819 Coleman Studies of decomposition and nutrient cycling in ecosystems have been very important processes for the interpretation of ecosystem function. They have become "keystone" parameters in the LTER program. There has been an increasing interest in the functional roles of hundreds of species of litter- and microbial- feeding fauna which occur in virtually all terrestrial sites. How do these species operate and interact, and are they "necessary' for optimal functioning of the system? This project will explore the interaction between biodiversity and decomposition processes, by studying factors causing marked differences which have been found between three moist, warm, broad-leaved forest sites, all on similar soil types. Two tropical sites, Luquillo (LUQ) in Puerto Rico, and La Selva (LAS Rica, have low and high species richnesses of soil microarthropods, respectively. Cowetta (CWT), in the Southern Appalachian mountains, has a species richness of microarthropods approaching that of LAS. Both CWT and LUQ are in the general substrate decomposition network study currently being conducted by Harmon et al. The same or similar litter substrates to those of the Harmon et al. network, will be contained in litter bags identical to the previous study. The network will be expanded to include LAS, to test the hypothesis: forests with litters containing the most diverse litter faunas will have the most rapid decomposition rates. Conversely, forests with relatively low species richness (LUQ) will have significantly lower rates of decomposition, when corrected for differences in moisture/temperature regimes. CWT is expected to have a decomposition rate intermediate to that of the two tropical sites, because of its seasonal cycles of warm wet weather. This project uses simple, proven techniques to compare decomposition rates across sites and should be the groundwork for more widespread studies of biotic interactions and processes across the LTER network.