Sulphur is an essential nutrient for plants, and it plays an important role in nutrient cycles in grassland ecosystems. However, excessive sulphur fertiliser use and atmospheric sulphur deposition may lead to soil acidification in terrestrial ecosystems, which in turn causes soil nutrient imbalance and changes the structure and function of soil biotic communities.  

In the past few decades, a lot of studies have been conducted to examine the impacts of nitrogen deposition on grassland ecosystems and soil acidification, but how sulphur deposition will affect grassland ecosystem biota is poorly understood. 

In September 2019, Prof. JIANG Yong, together with his colleagues from the Institute of Applied Ecology (IAE) of the Chinese Academy of Sciences (CAS), conducted a sample survey on the experimental plots of a sulphur addition experiment, which was established in May 2017 at the Erguna Forest-Steppe Ecotone Research Station of CAS. 

The researchers measured chemical and biological properties of the soil samples and found that sulphur addition had a significant impact on richness and diversity of soil nematodes, but not on total abundance of soil nematodes and the relative abundance of Cervidellus and Aphelenchus (the dominant nematode species).  

In response to sulphur addition, the relative abundance of predator-omnivorous nematodes increased significantly, while the relative abundance of bacterivores decreased. In addition, the Food Web Structural Index increased significantly with the increase of sulphur addition rate. 

The study shows that sulphur deposition affects the soil nematode community structure mainly by affecting the omnivores-predators and thus the top-down pressure.  

Results indicate that sulphur deposition can change the composition of soil nematode community, affect the stability of nematode community structure, and intensify the disturbance to the energy flows between underground organisms at different trophic levels.  

The results were published in an article in Science of the Total Environment entitled "Sulfur deposition changed the community structure of soil nematodes by affecting omnivores-predators."