Soil health is the foundation for maintaining ecosystem stability and multifunctionality. With biodiversity loss as a global concern, it is important to investigate how soil biodiversity responds to land use intensification and changes in ecosystem function. 

In a study published in Soil Biology and Biochemistry, researchers from the Xishuangbanna Tropical Botanical Garden (XTBG) of the Chinese Academy of Sciences demonstrated the interactive effects of soil multidiversity and plant diversity on the relationships between soil multidiversity and ecosystem multifunctionality (MEF). They showed that multitrophic soil organisms of different body sizes are good predictors of soil biodiversity and are essential to maintain ecosystem multifunctionality in tropical land use systems. 

The researchers conducted an extensive study in rubber plantations with different understory plant diversity levels, including monoculture (MRP), high (RHD) and low (RLD) diversity of other plant species. They assessed soil multidiversity including bacteria, fungi, nematodes (five feeding types), and arthropods (Thripidae, Poduridae, and others), 11 variables of ecosystem function and ecological network stability (reflected by co-occurrence network patterns) in rubber plantations differing in land-use intensity. 

They found that soil multidiversity differed significantly in response to different rubber plantations. Compared to rubber monoculture, the multidiversity, multifunctionality, and soil network stability significantly improved in RHD. High plant diversity improved multidiversity and multifunctionality.

Specifically, they found that the relationship between soil multidiversity and multifunctionality was seasonally dependent on the soil characteristics and the body size of soil organisms. Seasonal differences in multidiversity-multifunctionality relationship depended on the body size of soil organisms. Large size soil organisms contributed to multifunctionality significantly in dry season. Rain season facilitated microbial activities and positively affected multidiversity-multifunctionality relationship. 

Their data supported the relevance of soil multidiversity in determining the soil health capacity, which is essential for ecosystem functioning. Therefore, the researchers suggested considering multidiversity as a bioindicator of soil health to monitor land-use driven impacts on the ecosystem functions. 

"Our study highlights that accurate identification of soil health indicators is an important approach to suggest remedial management strategies to maintain soil health and MEF relationship in managed ecosystems such as rubber plantations,” said YANG Xiaodong of XTBG.