How do water table drawdown, duration of drainage, and warming influence greenhouse gas emissions from drained peatlands of the Zoige Plateau?

Abstract

Alpine peatlands on the Qinghai‐Tibet Plateau are an important soil carbon pool and are extremely sensitive to global change. Duration of drainage and water table drawdown accelerate peatland degradation because the soil changes from an anaerobic to aerobic environment, and climate warming exacerbates this shift. The objective of the present study was to evaluate the effects of drainage on microbial characteristics and greenhouse gas (GHG) emissions, as well as identify the factors mediating those effects. This study also analyzed whether warming increases the variability of GHG emissions. Watertable drawdown exerted greater influence on microbial communities than duration of drainage did. Watertable drawdown significantly increased the relative abundances of Proteobacteria, Acidobacteria, Actinobacteria, and Basidiomycota, and changes in soil microbiota correlated with differences in GHG emissions across three water‐table treatments. Longer drainage was associated with lower GHG emission; watertable drawdown decreased emissions of CO2 and CH4, but increased emission of N2O. In addition, high temperature increased CO2 emission by 75% and N2O emission by 42%, without significantly affecting CH4 emission. Structural equation modelling showed that microbes, especially prokaryotes (r = 0.79, p < 0.05 for all), were the primary factor affecting GHG emissions from drained peatlands. Overall, this study indicates that the watertable exerts a greater effect on GHG emissions than duration of drainage, and that warming increases variability of GHG emissions.

Effects of stand age and soil organic matter quality on soil bacterial and fungal community composition in Larix gmelinii plantations, Northeast China

“…Using random forest machine learning to discriminate between samples based on microbiota composition (Zhang et al, 2018). The importance of indicator microbiota classes was assessed by 10-fold cross-validation (Xue et al, 2021). A total of 24 OTUs were detected as biomarker fungal taxa and 42 OTUs were detected as biomarker bacterial taxa when the error curve of cross-validation was lowest.…”

The impacts of land‐use and climate change on the Zoige peatland carbon cycle: A review

“…Furthermore, (other mechanisms) such as the addition of fresh plant litter may also prime decomposition rates to a greater extent in drained Zoige peatlands (Yan et al, 2022), while the drainage‐induced succession from peatlands to alpine meadows may reduce CH 4 emissions to the point of becoming CH 4 sinks (Wang et al, 2021). In addition, from a perspective of CO 2 and CH 4 , more recently (3 years) drained Zoige peatlands may have higher emissions than older (48 years) drained sites, (Xue et al, 2021), supporting the case for a cessation of drainage on the Zoige peatlands and restoration of degraded areas (Section 4.3).…”

Effects of stand age and soil organic matter quality on soil bacterial and fungal community composition in Larix gmelinii plantations, Northeast China

“…Using random-forest machine learning to discriminate samples with different samples based upon the microbiota composition (Zhang et al, 2018). The importance of indicator prokaryotic classes was assessed by 10-fold cross-validation (Xue et al, 2021). When the cross-validation error curve was at its lowest, a total of 24 OTUs were detected as biomarker fungi taxa and 42 OTUs as biomarker bacteria taxa.…”