Unfolding the Roles of Particulate- and Mineral-Associated Organic Carbon in Soil Microbial Communities

Abstract

Forest succession is a rapid approach that can be used to increase soil carbon (C) stocks. It is crucial to understand how forest succession influences microbial community assembly and soil carbon fractions to improve carbon sequestration strategies. This present work analyzed microbial communities in forest succession, and the effects of particulate-associated organic C (POC) and mineral-associated organic C (MAOC) on microbial community structure and assembly in forest succession in Changbai Mountains, China. Compared to cropland, primary forest increased MAOC by 35% and POC by 43%, suggesting the importance of POC for microbial assembly processes, offering insights into forest restoration practices to enhance soil carbon sequestration. As succession proceeds, weak environmental selection facilitated the reduced deterministic processes, whereas local ecological and dispersal drift were elevated. Such shifts in fungal and bacterial communities could be mostly triggered by soil pH. Considering that POC was important, shifts in assembly processes can be determined by resource availability rather than succession sequences. Such findings conform to the neutral hypothesis, suggesting that POC exerts a negligible effect on analyzing microbial community assembly in forest succession. Overall, this present work sheds more light on the important effects of POC and MAOC on modeling different microbial communities and community assembly in forest succession.