Comparison of fertility and seasonal effects on grassland microbial communities

Birgander, Johanna; Rousk, Johannes; Olsson, Pål Axel (2014). Comparison of fertility and seasonal effects on grassland microbial communities. Soil Biology & Biochemistry, 76,, 80 - 89
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DOI:
| Published | English
Authors:
Birgander, Johanna ; Rousk, Johannes ; Olsson, Pål Axel
Department:
Biodiversity
MEMEG
Microbial Ecology
BECC: Biodiversity and Ecosystem services in a Changing Climate
Plant Biology
Project:
Effect of environmental factors on fungal and bacterial growth in soil
Research Group:
Microbial Ecology
Plant Biology
Abstract:
The activity of saprotrophic fungi and bacteria, and the balance between them, can affect decomposition. Arbuscular mycorrhizal (AM) fungi are also important for the nutrient and energy transfer in soil. Microbial community composition and activity are believed to have seasonal patterns, and are known to be highly influenced by environmental factors such as pH and nutrient conditions. To evaluate the importance of season for the variation in microbial decomposer community in a context of well-known environmental factor variation, we studied microbial growth, biomass and community structure along a fertility gradient (pH 5.9-8.1; NH4-N 3-19 mu g g(-1) soil, f.w.) in a sandy grassland during one year. The microbial community structure (phospholipid fatty acid (PLFA) composition) and biomass (PLFA and neutral lipid fatty acid (NLFA) signatures) as well as fungal (acetate incorporation in ergosterol) and bacterial (leucine incorporation) growth rates were investigated at eight seasonal time points during one year. The environmental factors pH and NH4 concentrations explained a larger share of the variation in the microbial community structure. Together they explained 37% of the variation, while season (proxied by temperature) only explained 6% of the variation in PLFA composition. Bacterial and fungal biomass were both highest in early spring, while AM fungal biomass peaked in early summer. Bacterial growth rate, on the other hand, was highest during the autumn, while fungal growth rate showed no clear seasonal pattern. In conclusion, the influence of seasonal variation on microbial communities proved to be relatively small compared to that which could be assigned to pH and NH4 in the studied ranges. (C) 2014 Elsevier Ltd. All rights reserved.
Keywords:
PLFA/NLFA ; Microbial community composition ; Bacterial growth ; Fungal ; growth ; Temperate grassland soil ; Arbuscular mycorrhizal fungi (AMF) ; Biological Sciences ; Ecology
ISSN:
0038-0717
LUP-ID:
623cf08c-aee3-42da-8394-da9dfac20a1d | Link: https://lup.lub.lu.se/record/623cf08c-aee3-42da-8394-da9dfac20a1d | Statistics

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