Phosphorus Regulation of Decomposition, Microbial Dynamics, and Foliar Chemistry in Moist Tropical Forests

潮湿热带森林中磷的分解、微生物动力学和叶化学的调节

• 批准号: 0089447
• 负责人: Alan Townsend
• 金额: $ 57.09万
• 依托单位: University of Colorado at Boulder
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-06-01 至 2005-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0089447&HistoricalAwards=false
• 关键词: Phosphorus; Regulation; Decomposition; Microbial; Dynamics

Despite a widespread belief that low phosphorus (P) availability is a strong constraint on ecosystem dynamics in many tropical forests, direct tests of this belief are rare, and understanding of tropical forest biogeochemistry remains relatively poor. To test this assumption, a phosphorus fertilization experiment will be conducted in lowland moist tropical rainforests located on extremely old soils in southwest Costa Rica. Preliminary work has shown that P availability is poor in these systems, and that low P availability appears to limit the activity of soil microorganisms. This research will follow up on these preliminary data through the use of long-term P fertilization plots which span gradients in soil age and which include at least 3 different dominant canopy trees in these forests. Each individual plot will contain a mature canopy tree at its center, and the trees will contain permanent climbing ropes to provide access to live canopy leaves. In addition to the effects of fertilization on canopy chemistry, the research will monitor processes within the soil and on the forest floor, including soil respiration, litter decomposition, analyses of microbial function and composition, and a suite of soil biogeochemical analyses. This work will advance understanding of how P availability regulates ecosystem processes in lowland tropical forests, with an emphasis on the poorly understood microbial communities. In addition, the investigators seek to maintain these fertilization plots for the long term, and to facilitate collaboration from other scientists interested in using them.

尽管人们普遍认为，在许多热带森林中，低磷（P）的可用性是对生态系统动力学的强烈限制，但对这种信念的直接测试很少见，并且对热带森林生物地球化学的理解仍然相对较差。为了测试这一假设，将在位于西南哥斯达黎加的极旧土壤上的低地潮湿的热带雨林中进行磷肥实验。初步工作表明，P在这些系统中的可用性很差，并且低P的可用性似乎限制了土壤微生物的活性。这项研究将通过使用长期的P受精块来跟进这些初步数据，这些图在土壤年龄层面层面，其中包括这些森林中至少包括3种不同的主要冠层树。每个单独的地块将在其中心包含一个成熟的冠层树，树木将包含永久的攀爬绳索，以提供对活篷叶的通道。除了受精对冠层化学的影响外，该研究还将监测土壤内和森林地面上的过程，包括土壤呼吸，垃圾分解，微生物功能和成分的分析以及一套土壤生物地球化学分析的套件。这项工作将促进对P供应如何调节低地热带森林中生态系统过程的理解，重点是了解的微生物群落。此外，研究人员试图长期维持这些受精地，并促进有兴趣使用它们的其他科学家的合作。