Material cycling and population interactions in food webs, and the evolutionary dynamics of biological communities

该项目旨在促进生态学研究，分析生物群落和食物网的结构和动态与物质循环、生物体之间的相互作用以及与资源利用和种间相互作用有关的特征的演变。由于水生群落具有生态系统的基本性质，特别是环境斑块，并且是可操纵的小而半封闭的系统，适合野外和实验室研究，因此我们将自然植物群落和实验室微观世界中的水生群落作为模式系统进行研究。在包括树洞、竹桩和猪笼草在内的天然植物群落中，我们发现了几个重要的群落属性。(1)单只植皮藻的碎屑量和水体稳定性与植皮体大小相关，植皮体大小与生物量和物种丰富度相关。因此，当地社区的空间和/或资源有限。(2)物种相互作用(Pr…在当地群落中，受限制的少数物种之间发生了更多的竞争和竞争；每个物种的聚集分布和物种之间的随机关联往往导致种间相互作用减少，这可能会促进物种共存。(3)尽管群落多样性存在局部局限性，但在斑块环境中可以维持区域物种丰富度，这是因为斑块降低了种间相互作用的整体强度，所涉及的环境异质性允许物种之间的生态位分离。(4)生活史和生理特征的进化差异，特别是在栖息地选择和觅食、发育、生长和生存的能量分配方面，可能导致竞争物种的共存。在微观实验中，强调了微生物环的重要性。从摄食行为和营养价值两个方面对甲壳动物利用细菌作为食物资源进行了研究。枝角类对细菌有很好的捕集机制。此外，还研究了细菌对新环境的入侵能力，以及基因工程有用细菌在修复受污染环境中的应用。现在对斑块环境中相互作用的有机体和食物网的数学模型进行分析，以预测群落和食物网结构的进化动态。较少

This project was to promote ecological studies that analyzes the structure and dynamics of biological communities and food webs in relation to material cycling, interactions among organisms, and evolution of traits associated with resource uses and interspecific interactions. We investigated aquatic communities in natural phytotelmata and in laboratory microcosms as model systems because they possess essential properties of ecological systems, especially environmental patchiness, and are manipulable small, semiclosed systems which are suitable to both field and laboratory studies. In natural phytotelmata including treeholes, bamboo stumps, and pitcher plants, we found several important community properties. (1) In individual phytotelmata, the amount of detritus and stability of aquatic site were correlated with phytotelm size, and the phytotelm size was correlated with biomass and species richness. Thus, local communities were space and/or resource limited. (2) Species interactions (pr … More edation and competition) in local communities occurred among restricted small sets of species ; aggregated distribution in each species and random association between species often resulted in reduced interspecific interactions which might promote species coexistence. (3) Despite the local limitation of community diversity, regional species richness could be maintained in patchy environments, because the patchiness reduces overall strength of interspecific interactions and environmental heterogeneity involved allows niche segregation among species. (4) Evolutionary divergence of life-history and physiological traits, especially in habitat selection and the allocation of energy to foraging, development and growth, and survival, could leads to coexistence of competing species. In microcosm experiments, the importance of microbial loop was emphasized. The use of bacteria by crustaceans as food resources was studied in terms of foraging behavior and nutritional value. A cladocera had a fine trapping mechanism for bacteria. Also, invadability of bacteria into novel environments was studied in relation to application of genetically-engineered useful bacteria for restoring polluted environments. Mathematical models of interacting organisms and food webs in patchy environments are now analyzed to predict evolutionary dynamics of community and food web structures. Less