Seasonal variations in soil fungal communities and co-occurrence networks along an altitudinal gradient in the cold temperate zone of China: A case study on Oakley Mountain

Abstract

The biogeography of soil fungi has attracted much attention in recent years; however, studies on this topic have mainly focused on mid- and low-altitude regions. The seasonal patterns of soil fungal community structure and diversity along altitudinal gradients under the unique climatic conditions at high latitudes remain unclear, which limits our insight into soil microbial interactions and the mechanisms of community assembly. In this study, Illumina MiSeq sequencing was used to investigate the spatiotemporal changes in soil fungal communities along an altitudinal gradient (from 750 m to 1420 m) on Oakley Mountain in the northern Greater Khingan Mountains. Altitude had significant impacts on the relative abundances of the dominant phyla and classes of soil fungi, and the interaction of altitude and season significantly affected the relative abundances of Ascomycota and Basidiomycota. The number of soil fungal taxa and Faith’s phylogenetic diversity (PD) index tended to monotonically decline with increasing elevation. Soil moisture (SM), soil temperature (ST) and pH were the main factors affecting fungal community structure in May, July and September, respectively. The soil dissolved organic carbon (DOC) content significantly shaped the soil fungal community composition along the altitudinal gradient throughout the growing season. Compared to that in May and July, the soil fungal network in September had more nodes and links, a higher average degree and a higher average clustering coefficient. The nine module nodes in the co-occurrence network were all Ascomycota taxa, and the identities of the keystone taxa of soil fungi in the network showed obvious seasonality. Our results demonstrated that altitude has stronger effects than season on soil fungal community structure and diversity at high latitudes. In addition, the co-occurrence network of soil fungi exhibited obvious seasonal succession, which indicated that the keystone taxa of soil fungi exhibit niche differentiation among seasons.

Seasonal Variations Affect The Ecosystem Functioning And Microbial Assembly Processes In Plantation Forests

“…Furthermore, spring consisted of nodes with high BC values (Supplementary Table 15), indicating the importance of the control potential that an individual node exerts over the interactions of other nodes [82]. These complex interactions in spring might consequently enhance system durability and resistance to adverse environmental conditions such as wet-dry and freeze-thaw cycles with changing seasons [83].…”

Dominant Role of Stochastic Processes in Soil Fungal Communities in Pioneer Forests at a Regional Scale

“…Additional work has shown that the vertical distribution patterns of soil fungal communities observed in these studies were usually explained by environmental factors that change along elevation gradients. These include changes s Submission Template mSystems Submission Template mSystems Submission Template mSystems Submission Template mSystems Submission Template mSystems Submission Te 2 in soil moisture and organic carbon at different elevations, resulting in soil fungal diversity and community composition patterns changing with elevation (34,35). The seasonal patterns of soil fungal communities also appear to be inconsistent, according to recent reports.…”