Degradation of organic matter in Swiss Alpine pasture and forest soils: Microbial community dynamics as a function of soil type and temperature during a one-year experiment.

Abstract

Assessing the sensitivity of soil microbes to climatic variations, this study investigated the impacts of increasing temperatures on soil microbial communities and soil respiration in subalpine forests and pasture soils in Jaun, Switzerland. This research uses phospholipid fatty acid analysis (PLFA) to elucidate the variations in microbial biomass, community structure, and soil carbon dynamics. This study investigated the effects of increasing temperatures on microbial communities and activities, as well as carbon degradation in pasture and forest soils in a subalpine region. The results indicated that increasing temperatures significantly increased soil respiration, enhanced microbial activity and organic matter decomposition, and altered the composition of microbial communities. Furthermore, differences in the composition of microbial communities between forest and pasture soils were observed, with forest soil exhibiting a higher fungi-to-bacteria ratio and a higher proportion of saprotrophic fungi, particularly in scenarios with litter addition. Additionally, an increase in Gram-positive bacteria and a decrease in the total amount of PLFA with rising temperatures were observed in both forest and pasture soils. These findings underscored the critical role of soil microbial responses with increasing temperatures and their potential implications for carbon cycling in subalpine soils under anticipated future climate scenarios.