Publikationsdatum:
2016-10-15
Beschreibung:
Impacts of long-term CO 2 exposure on environmental processes and microbial populations of near-surface soils are poorly understood. This near-surface long-term CO 2 injection study demonstrated that soil microbiology and geochemistry is influenced more by seasonal parameters than elevated CO 2 . Soil samples were taken during a 3-year field experiment including sampling campaigns before, during and after 24 months of continuous CO 2 injection. CO 2 concentrations within CO 2 -injected plots increased up to 23% during the injection period. No CO 2 impacts on geochemistry were detected over time. In addition, CO 2 -exposed samples did not show significant changes in microbial CO 2 and CH 4 turnover rates compared to reference samples. Likewise, no significant CO 2 -induced variations were detected for the abundance of Bacteria , Archaea (16S rDNA) and gene copy numbers of the mcrA gene, Crenarchaeota and amoA gene. The majority (75%–95%) of the bacterial sequences were assigned to five phyla: Firmicutes , Proteobacteria , Actinobacteria , Acidobacteria and Bacteroidetes . The majority of the archaeal sequences (85%–100%) were assigned to the thaumarchaeotal cluster I.1b (soil group). Univariate and multivariate statistical as well as principal component analyses showed no significant CO 2 -induced variation. Instead, seasonal impacts especially temperature and precipitation were detected.
Print ISSN:
0168-6496
Digitale ISSN:
1574-6941
Thema:
Biologie
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