Microbial Consortia and Disturbance in Sediment Habitats

Deb-0108412-Lovell风暴、火灾和捕食者等因素造成的环境干扰是影响生物群落多样性和组织的一种普遍力量。由于竞争的相互作用，高等生物体的物种多样性通常在中等干扰水平上达到峰值。微生物群落更多地依赖于积极的相互作用而不是竞争，并且是以互惠互利的联盟组织起来的。这些联合体中物种之间的相互作用促进了重要的生态功能，如有机物分解和养分循环，并高度依赖于未受干扰的沉积物的物理结构以及生物对这种结构的修改。其中最戏剧性的变化之一就是生物膜的形成。生物膜稳定了微生物群落，并为其中的微生物提供了动态平衡。我们预测，与高等生物不同，沉积物微生物组合的互惠性质将受到干扰的严重破坏，并将采取几种实验方法来验证这一理论。我们试图将干扰对沉积物微生物区系的影响整合到干扰对高等生物群落影响的理论和经验框架中。这将为微生物生态学的一个重要方面提供亟需的理论基础，从而服务于这两个领域。

DEB-0108412 - LovellEnvironmental disturbance by such factors as storms, fires and predators, is a pervasive force impacting the diversity and organization of organism communities. Because of competitive interactions, higher organism typically have their peak species diversity at intermediate disturbance levels. Microbial communities are much more dependent upon positive interactions than on competition, and are organized in mutualistic consortia. The interactions among species in these consortia facilitate vital ecological functions, such as organic matter decomposition and nutrient cycling, and are highly dependent on the physical structure of undisturbed sediments and on modifications of this structure by the organisms. Among the most dramatic modifications by the resident microbiota is biofilm formation. The biofilms stabilize consortia and provide homeostasis for the microorganisms within them. We predict that unlike higher organisms, the mutualistic nature of sediment microbial assemblages will be seriously disrupted by disturbance and will take several experimental approaches to test this theory. We seek to integrate the impacts of disturbance on sediment microbiota into the theoretical and empirical framework of disturbance effects on higher organism communities. This would serve both fields by providing much needed theoretical underpinnings to an important aspect of microbial ecology.