Dissertation Research: Is Decomposition in Moist Tropical Forests Phosphorus Limited?

尽管人们普遍认为，磷（P）的可用性对热带森林的生态系统动态构成了强烈的约束，但这种信念的直接测试是罕见的。此外，大多数研究，解决了这个问题，集中在磷限制植物群落，几乎没有解决的可能性，微生物群落是磷限制。克利夫兰先生的论文研究表明，碳在低地热带雨林在哥斯达黎加西南部的分解是P限制，虽然这种限制的程度仍然是未知的。早期的研究结果表明，尽管在这个网站上的微生物过程的明显的P限制，磷酸酶，负责有机P的矿化酶的生产和活性相对较低。这个博士论文改进补助金将支持解决以下两个基本问题的实验：1。在潮湿的热带森林中，磷的有效性是否限制了天然碳的分解？和2.在一个有机磷的矿化在弥补无机磷的不足方面应该是重要的地方，磷酸酶活性是否直接受到另一种元素的限制？

Despite a widespread belief that phosphorus (P) availability poses a strong constraint on ecosystem dynamics in tropical forests, direct tests of this belief are rare. Furthermore, most studies that have addressed this issue have focused on P limitation to the plant community; virtually none have addressed the possibility that the microbial community is P limited. Mr. Cleveland's dissertation research to date suggests that decomposition of carbon in a lowland tropical rainforest in southwestern Costa Rica is P limited, although the extent of this limitation is still unknown. Early findings have revealed that in spite of the apparent P limitation to microbial processes at this site, the production and activity of phosphatases, enzymes responsible for the mineralization of organic P, are relatively low. This Doctoral Dissertation Improvement Grant will support experiments that address the following two basic questions: 1. Does phosphorus availability limit the decomposition of native carbon in moist tropical forests? and 2. At a site where the mineralization of organic P should be important in offsetting deficiencies in available inorganic P, is phosphatase activity directly limited by the availability of another element?