Abstract: Projecting the trajectories of the community structure and function of forests following fire disturbance is an important research area in restoration ecology. There are many uncertainties in above and belowground biological processes during the secondary succession. We monitored species composition and soil physicochemical properties of forests in 2018, along a fire chronosequece, i.e., 2, 3, 9, 15, 31, 50 and 150 years since fire (YSF). The results showed that the temporal pattern of species turnover rate was characterized by a mono-peak curve. The smallest dissimilarity was found between communities in 15 YSF and in 150 YSF, but the total species turnover rate was largest. The abundance of Carex rigescens, Sanguisorba officinalis, Adenophora teraphylla and Ledum palustre increased over time after fire disturbance. The beta diversity of the regenerated communities was codetermined by the soil nutrient content and the stoichiometry of soil microbial biomass, while species composition was controlled by soil microbial biomass N∶P and soil C∶N and varied with successional stages. Similar species composition was found between the communities in 2 and 15 YSF and that in 150 YSF. Soil microbial biomass N∶P was higher in earlier stages of the secondary succession series. There was a positive correlation between soil microbial biomass N∶P and the Bray-Curtis dissimilarity index. The lowest soil C∶N ratio was detected in the community of 9 YSF, which was negatively correlated with the total species turnover rate. The communities of 9 and 15 YSF had comparatively lower species turnover rate under the edaphic conditions with a higher soil C∶N ratio. In general, soil nutrient content and soil microbial biomass stoichiometry are two predominant variables driving the recovery of beta diversity and community structure for the fired forest communities.

Key words: species turnover rate, community similarity, fire succession sequence