Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
Oecologia. 2012 Jan;168(1):187-97. doi: 10.1007/s00442-011-2067-0. Epub 2011 Jul 17.
Arbuscular mycorrhizal (AM) fungi are ubiquitous and ecologically important microbes in grasslands. Both the host plant species and soil properties have been suggested as potentially important factors structuring AM fungal communities based on studies within local field sites. However, characterizations of the communities in relation to both host plant identity and soil properties in natural plant communities across both local and broader geographic scales are rare. We examined the AM fungal spore communities associated with the same C(4) grasses in two Eastern serpentine grasslands, where soils have elevated heavy metals, and two Iowa tallgrass prairie sites. We compared AM fungal spore communities among host plants within each site, looked for correlations between fungal communities and local soil properties, and then compared communities among sites. Spore communities did not vary with host plant species or correlate with local soil chemical properties at any site. They did not differ between the two serpentine sites or between the two prairie sites, despite geographic separation, but they did differ between serpentine and prairie. Soil characteristics are suggested as a driving force because spore communities were strongly correlated with soil properties when data from all four sites are considered, but climatic differences might also play a role.
丛枝菌根（AM）真菌在草原中广泛存在且具有重要的生态学意义。基于对当地实地研究，宿主植物物种和土壤特性被认为是可能对 AM 真菌群落结构产生重要影响的因素。然而，在自然植物群落中，对与宿主植物身份和土壤特性相关的 AM 真菌群落的特征描述，无论是在本地还是更广泛的地理尺度上，都很少见。我们在两个东部蛇纹石草原中研究了与相同 C（4）草相关的 AM 真菌孢子群落，这些土壤中含有较高水平的重金属，以及两个爱荷华州高草草原地点。我们比较了每个地点内宿主植物之间的 AM 真菌孢子群落，寻找真菌群落与当地土壤特性之间的相关性，然后比较了地点之间的群落。在任何地点，孢子群落都不随宿主植物物种或与当地土壤化学特性相关。尽管地理位置不同，但在两个蛇纹石地点之间以及两个草原地点之间没有差异，但在蛇纹石和草原之间存在差异。土壤特性被认为是一个驱动因素，因为当考虑所有四个地点的数据时，孢子群落与土壤特性强烈相关，但气候差异也可能起作用。
