Kate M. Buckeridge Samiran Banerjee Steven D. Siciliano Paul Grogan. The seasonal pattern of soil microbial community structure in mesic low arctic tundra.Soil Biology and BiochemistryVolume 65 October 2013 Pages 338–347
Abstract
Soil microorganisms are critical to carbon and nutrient fluxes in terrestrial ecosystems. Understanding the annual pattern of soil microbial community structure and how it corresponds to soil nutrient availability and plant production is a fundamental first step towards being able to predict impacts of environmental change on ecosystem functioning. We investigated the composition structure and nutrient stoichiometry of the soil microbial community in mesic arctic tundra on 9 sample dates in 6 months from winter to fall using phospholipid fatty acid analysis (PLFA) quantitative polymerase chain reaction (qPCR) epifluorescent microscopy and chloroform-fumigation–extraction (CFE). PLFA analysis indicates that the winter microbial community was fungal-dominated cold-adapted and associated with high C N and P in the soil solution and microbial biomass. The microscopy data suggest that both bacteria and fungi were active and growing in soils between −5 °C and 0 °C. A significant shift occurred in the PLFA data qPCR patterns microscopy and microbial biogeochemistry after the thaw period resulting in a distinct community that persisted through our spring summer and fall sample dates despite large changes in plant productivity. This shift was characterised by increasing relative abundances of certain bacteria (especially Gram +ves) as well as a decline in fungal biomass and corresponded with decreasing C N and P in the soil solution. The summer period of low substrate availability (plant–microbe competition) was associated with microbial indicators of nutritional stress. Overall our results indicate that tundra microbial communities are clearly differentiated according to the changes in soil nutrient status and environmental conditions that occur between winter and post-thaw and that those changes reflect functionally important adaptations to those conditions.
【土壤呼吸和微生物生物量对盐渍土EC变化的响应】Nan YanPetra Marschner. Response of soil respiration and microbial biomass to changing EC in saline soils.