Massaccesi L, Bardgett R D, Agnelli A, Ostle N, Wilby A, Orwin K H
Department of Agricultural, Food and Environmental Science, University of Perugia, Borgo XX Giugno 72, 06121, Perugia, Italy.
Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, UK.
Oecologia. 2015 Mar;177(3):747-759. doi: 10.1007/s00442-014-3135-z. Epub 2014 Nov 19.
Plant communities, through species richness and composition, strongly influence soil microorganisms and the ecosystem processes they drive. To test the effects of other plant community attributes, such as the identity of dominant plant species, evenness, and spatial arrangement, we set up a model mesocosm experiment that manipulated these three attributes in a full factorial design, using three grassland plant species (Anthoxanthum odoratum, Plantago lanceolata, and Lotus corniculatus). The impact of the three community attributes on the soil microbial community structure and functioning was evaluated after two growing seasons by ester-linked phospholipid fatty-acids analysis, substrate-induced respiration, basal respiration, and nitrogen mineralization and nitrification rates. Our results suggested that the dominant species identity had the most prevalent influence of the three community attributes, with significant effects on most of the measured aspects of microbial biomass, composition and functioning. Evenness had no effects on microbial community structure, but independently influenced basal respiration. Its effects on nitrogen cycling depended on the identity of the dominant plant species, indicating that interactions among species and their effects on functioning can vary with their relative abundance. Systems with an aggregated spatial arrangement had a different microbial community composition and a higher microbial biomass compared to those with a random spatial arrangement, but rarely differed in their functioning. Overall, it appears that dominant species identity was the main driver of soil microorganisms and functioning in these model grassland communities, but that other plant community attributes such as evenness and spatial arrangement can also be important.
植物群落通过物种丰富度和组成，对土壤微生物及其驱动的生态系统过程产生强烈影响。为了测试其他植物群落属性的影响，如优势植物物种的身份、均匀度和空间排列，我们建立了一个模型中宇宙实验，采用全因子设计对这三个属性进行操控，使用了三种草地植物物种（香茅、窄叶车前和百脉根）。在两个生长季节后，通过酯连接磷脂脂肪酸分析、底物诱导呼吸、基础呼吸以及氮矿化和硝化速率，评估了这三个群落属性对土壤微生物群落结构和功能的影响。我们的结果表明，优势物种身份在这三个群落属性中具有最普遍的影响，对微生物生物量、组成和功能的大多数测量方面都有显著影响。均匀度对微生物群落结构没有影响，但独立影响基础呼吸。其对氮循环的影响取决于优势植物物种的身份，这表明物种之间的相互作用及其对功能的影响会因其相对丰度而有所不同。与随机空间排列的系统相比，聚集空间排列的系统具有不同的微生物群落组成和更高的微生物生物量，但在功能上很少有差异。总体而言，优势物种身份似乎是这些模型草地群落中土壤微生物和功能的主要驱动因素，但均匀度和空间排列等其他植物群落属性也可能很重要。
