Diurnal Temperature Variation and Plants Drive Latitudinal Patterns in Seasonal Dynamics of Soil Microbial Community

Abstract

Seasonality, an exogenous driver, motivates the biological and ecological temporal dynamics of animal and plant communities. Underexplored microbial temporal endogenous dynamics hinders the prediction of microbial response to climate change. To elucidate temporal dynamics of microbial communities, temporal turnover rates, phylogenetic relatedness, and species interactions were integrated to compare those of a series of forest ecosystems along latitudinal gradients. The seasonal turnover rhythm of microbial communities, estimated by the slope ( w value) of similarity-time decay relationship, was spatially structured across the latitudinal gradient, which may be caused by a mixture of both diurnal temperature variation and seasonal patterns of plants. Statistical analyses revealed that diurnal temperature variation instead of average temperature imposed a positive and considerable effect alone and also jointly with plants. Due to higher diurnal temperature variation with more climatic niches, microbial communities might evolutionarily adapt into more dispersed phylogenetic assembly based on the standardized effect size of MNTD metric, and ecologically form higher community resistance and resiliency with stronger network interactions among species. Archaea and the bacterial groups of Chloroflexi, Alphaproteobacteria , and Deltaproteobacteria were sensitive to diurnal temperature variation with greater turnover rates at higher latitudes, indicating that greater diurnal temperature fluctuation imposes stronger selective pressure on thermal specialists, because bacteria and archaea, single-celled organisms, have extreme short generation period compared to animal and plant. Our findings thus illustrate that the dynamics of microbial community and species interactions are crucial to assess ecosystem stability to climate variations in an increased climatic variability era.

Moderate grazing increased alpine meadow soils bacterial abundance and diversity index on the Tibetan Plateau

“…Microbes played a vital role in nitrogen transformation and organic carbon decomposition (Park et al., 2012). The resistance and resilience of grassland ecosystems to grazing may be estimated in relation to the microbial community (Hu, Nie, et al, 2019). In addition, domestic herbivore grazing significantly influences the grassland soil bacterial community (Qu et al., 2018).…”

“…This study analyzed soil genes abundance and diversity index, and these results did not represent bacterial activity (Che et al., 2018). Microbial nitrification was detected even in frozen soils by the 15 N isotope dilution method in an alpine meadow (Hu, Nie, et al, 2019; Kato et al., 2013). Nitrogen‐cycling genes of nirS were negatively correlated with soil inorganic nitrogen in alpine meadows (Che et al., 2018).…”

“…In this study, grasslands pH and bulk density significantly influenced microbial classes community by Monte Carlo test. Soils pH took a vital role in driving soil microorganism's communities (Du, Shu, et al, 2019; Hu, Nie, et al, 2019). Soils bulk affected grasslands soil porosity and oxygen contents, and it is positive correlated with soil bacterial richness on the Tibetan Plateau (Che et al., 2018; Chu et al., 2016).…”

“…Moreover, grassland degradation drastically decreases the soil organic carbon and total nitrogen contents (Babel et al, 2014; Du, Ke, et al, 2019). Microbial abundance has an indirect impact on the grassland nitrogen and carbon turnover process (Chu et al., 2016; Hu, Nie, et al, 2019). There has been a growing interest in relating grassland bacterial community and abundance to grazing intensity.…”

“…Gene copy numbers were widely used to indicate microbial abundance (Batten, Scow, & Espel, 2008; Chu et al., 2016; Hu, Nie, et al, 2019). The 16S rDNA gene copy numbers of wetlands were much smaller than upland grassland soils (Park et al., 2012).…”