Publication Details

Category Text Publication
Reference Category Journals
DOI 10.1111/j.1365-2486.2012.02686.x
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Title (Primary) Microbial communities and their responses to simulated global change fluctuate greatly over multiple years
Author Gutknecht, J.L.M.; Field, C.B.; Balser, T.C.
Journal Global Change Biology
Year 2012
Department BOOEK
Volume 18
Issue 7
Page From 2256
Page To 2269
Language englisch
Keywords Nitrogen deposition; lipid biomarker; mycorrhizal fungi; elevated CO2; climate variation; global change; inter-annual variation

We used microbial lipid analysis to analyze microbial biomass and community structure during six years of experimental treatment at the Jasper Ridge Global Change Experiment (JRGCE), a long-term multi-factor global change experiment in a California annual grassland. The microbial community fingerprint and specific biomarkers varied substantially from year to year, in both control and experimental treatment plots. Possible drivers of the variability included plant growth, soil moisture, and temperature. Surprisingly, background variation in the microbial community was of a larger magnitude than even very significant treatment effects, and this variation appeared to constrain responses to treatment. Microbial communities were mostly not responsive or not consistently responsive to the experimental treatments. Both AMF biomarker abundance (16:1 ω5c) and the fungal to bacterial ratio were lower under nitrogen addition in most years. Bacterial lipid biomarker abundances (15:0 iso and 16:1 ω7c) were higher under nitrogen addition in 2002, the year of largest microbial biomass, suggesting that bacteria could respond more to nitrogen addition in years of better growth conditions. Nitrogen addition and warming led to an interactive effect on the Gram-positive bacterial biomarker and the fungal to bacterial ratio. These patterns indicate that in California grassland ecosystems, microbial communities may not respond substantially to future changes in climate and that nitrogen deposition may be a determinant of the soil response to global change. Further, year-to-year variation in microbial growth or community composition may be important determinants of ecosystem response to global change.
Persistent UFZ Identifier
Gutknecht, J.L.M., Field, C.B., Balser, T.C. (2012):
Microbial communities and their responses to simulated global change fluctuate greatly over multiple years
Glob. Change Biol. 18 (7), 2256 - 2269