Treves D S, Xia B, Zhou J, Tiedje J M
Center for Microbial Ecology, Michigan State University, East Lansing, MI 48824, USA.
Microb Ecol. 2003 Jan;45(1):20-8. doi: 10.1007/s00248-002-1044-x. Epub 2002 Nov 6.
The hypothesis that spatial isolation is a key determinant of microbial community structure in soils was evaluated by examining the competitive dynamics of two species growing on a single resource in a uniform sand matrix under varied moisture content. One species dominated the community under highly connected, saturated treatments, suggesting that these conditions allow competitive interactions to structure the community. As moisture content decreased, however, the less competitive species became established in the community. This effect was most pronounced at a matric water potential of -0.14 MPa where estimates of final population density and species fitness were equal. A second but more closely related species pair exhibited a similar response to decreasing moisture, suggesting that the effects of spatial isolation we observed are not simply a species-pair-specific phenomenon. These findings indicate that spatial isolation, created by low moisture content, plays an important role in structuring soil microbial communities.
通过研究在不同含水量的均匀砂质基质中单一资源上生长的两个物种的竞争动态，评估了空间隔离是土壤中微生物群落结构关键决定因素这一假设。在高度连通的饱和处理条件下，一个物种在群落中占主导地位，这表明这些条件允许竞争相互作用构建群落结构。然而，随着含水量降低，竞争力较弱的物种在群落中得以确立。这种效应在基质水势为-0.14 MPa时最为明显，此时最终种群密度和物种适合度的估计值相等。第二组但关系更密切的物种对表现出对含水量降低的类似反应，表明我们观察到的空间隔离效应并非简单的物种对特异性现象。这些发现表明，低含水量造成的空间隔离在构建土壤微生物群落中起着重要作用。
