Koranda Marianne, Rinnan Riikka, Michelsen Anders
Division of Terrestrial Ecosystem Research, Centre for Microbiology and Environmental Systems Science, University of Vienna, Djerassiplatz 1, 1030 Vienna, Austria.
Terrestrial Ecology Section, Department of Biology, University of Copenhagen, 2100 Copenhagen, Denmark.
Plant Soil. 2023;488(1-2):551-572. doi: 10.1007/s11104-023-05993-w. Epub 2023 Mar 27.
This study aimed at elucidating divergent effects of two dominant plant functional types (PFTs) in tundra heath, dwarf shrubs and mosses, on soil microbial processes and soil carbon (C) and nutrient availability, and thereby to enhance our understanding of the complex interactions between PFTs, soil microbes and soil functioning.
Samples of organic soil were collected under three dwarf shrub species (of distinct mycorrhizal association and life form) and three moss species in early and late growing season. We analysed soil C and nutrient pools, extracellular enzyme activities and phospholipid fatty acid profiles, together with a range of plant traits, soil and abiotic site characteristics.
Shrub soils were characterised by high microbial biomass C and phosphorus and phosphatase activity, which was linked with a fungal-dominated microbial community, while moss soils were characterised by high soil nitrogen availability, peptidase and peroxidase activity associated with a bacterial-dominated microbial community. The variation in soil microbial community structure was explained by mycorrhizal association, root morphology, litter and soil organic matter quality and soil pH-value. Furthermore, we found that the seasonal variation in microbial biomass and enzyme activities over the growing season, likely driven by plant belowground C allocation, was most pronounced under the tallest shrub .
Our study demonstrates a close coupling of PFTs with soil microbial communities, microbial decomposition processes and soil nutrient availability in tundra heath, which suggests potential strong impacts of global change-induced shifts in plant community composition on carbon and nutrient cycling in high-latitude ecosystems.
The online version contains supplementary material available at 10.1007/s11104-023-05993-w.
本研究旨在阐明苔原荒地中两种主要植物功能类型（PFTs），即矮灌木和苔藓，对土壤微生物过程以及土壤碳（C）和养分有效性的不同影响，从而增进我们对PFTs、土壤微生物和土壤功能之间复杂相互作用的理解。
在生长季节的早期和晚期，采集了三种矮灌木物种（具有不同的菌根关联和生活型）和三种苔藓物种下的有机土壤样本。我们分析了土壤碳和养分库、细胞外酶活性和磷脂脂肪酸谱，以及一系列植物性状、土壤和非生物场地特征。
灌木土壤的特征是微生物生物量碳、磷和磷酸酶活性较高，这与以真菌为主导的微生物群落有关，而苔藓土壤的特征是土壤氮有效性高、肽酶和过氧化物酶活性与以细菌为主导的微生物群落有关。土壤微生物群落结构的变化可以通过菌根关联、根系形态、凋落物和土壤有机质质量以及土壤pH值来解释。此外，我们发现生长季节微生物生物量和酶活性的季节变化可能由植物地下碳分配驱动，在最高的灌木下最为明显。
我们的研究表明，在苔原荒地中，PFTs与土壤微生物群落、微生物分解过程和土壤养分有效性密切相关，这表明全球变化引起的植物群落组成变化可能对高纬度生态系统中的碳和养分循环产生潜在的强烈影响。
在线版本包含可在10.1007/s11104-023-05993-w获取的补充材料。
