Soil fungi are critical components of microbial communities in terrestrial ecosystems. In recent years, DNA sequence-based methods have been used to survey soil fungi from a range of forests and have revealed an extremely high fungal diversity in soils. However, in contrast to bacterial studies, surveys of soil fungal diversity and composition across large geographic scales remain rare.
Dr. Shi Lingling of Xishuangbanna Tropical Botanical Garden (XTBG) and her teachers conducted a study to investigate the diversity of soil fungi along a latitudinal gradient, encompassing a broad range of forest types, soil types, and climatic zones. They collected soil samples from 17 study sites, consisting of relatively undisturbed forest systems, running along a latitudinal gradient in China. The gradient spanned a latitudinal range from 21°27′ N to 48°45′ N. Forest types included tropical, sub-tropical, temperate and boreal forests, all occurring within national forest reserves. Soil fungal communities were determined using 454 pyrosequencing.
They addressed three main questions: 1) was the diversity of soil fungal communities correlated to the diversity of the above ground vegetation? 2) How did fungal diversity vary along the latitudinal gradient? And 3) what were the primary factors affecting soil fungal community composition?
Their results showed that soil fungal diversity was lowest in the subtropical and tropical forests, slightly higher in boreal forests, and highest in the temperate forests. Fungal assemblages had a spatial structure despite the high capacity for dispersal of the species. Soil fungal diversity was strongly influenced by variations in soil temperature. However, in contrast to temperature, precipitation had only a minor effect on soil fungal diversity.