ROW: Timing of Nutrient Mineralization from Leaf Litter: Internal Cycling by Fungi

本研究项目的目的是测试在缺磷热带雨林中分解叶的真菌是否短路磷矿化。计划进行一项微型实验，以确定真菌是否可以将部分分解的树叶中的32P输出到新鲜的凋落物中。老凋落物的真菌运输可以解释先前观察到的在叶片分解早期阶段磷的增加超过初始量的100%。如果由于分解真菌的内部循环而绕过凋落物中磷的矿化，植物根中磷的有效性可能会受到限制。在一些磷和氮退化的生态系统中，当真菌种群崩溃时，真菌生物量中储存的营养物质可能会被高等植物利用。未来的目标将包括从真菌生物量中确定营养矿化的时间，因为它可能受到湿润和干燥循环以及食菌微节肢动物的控制。这项研究的结果应对热带森林生态系统的管理以及对这些系统的基本生态学理解产生影响。首席调查员的积极性很高，并得到了知识渊博的同事的支持。机构设施和住宿条件对研究来说是足够的。

The objective of this research project is to test whether leaf- decomposing fungi short-circuit phosphorus mineralization in a phosphorus-depauperate tropical rainforest. A microcosm experiment is planned to determine if fungi can export 32P from partially decomposed leaves into fresh litter. Fungal transport from old litter could explain previously observed increased in P above 100% of the initial amount during early stages of leaf decomposition. If mineralization of phosphorus from litter is bypassed because of internal recycling by decomposer fungi the availability of P to plant roots may be restricted. In some phosphorus and nitrogen depauperate ecosystems, nutrients sequestered in fungal biomass may become available to higher plants when fungal populations crash. Future objectives will include the determination of timing of nutrient mineralization from fungal biomass as it may be controlled by wetting and drying cycles and fungivorous microarthropods. Results of this research should have implications for the management of tropical forest ecosystems as well as for the fundamental ecological understanding of those systems. The principal investigator is well motivated and supported by knowledgeable colleagues. Institutional facilities and accommodation are adequate to the research.