Enhanced rock weathering boosts ecosystem multifunctionality via improving microbial networks complexity in a tropical forest plantation

Afforestation is expected to contribute to mitigate global change by promoting carbon stocks and multiple ecosystem services. However, the success of plantations may be limited by the availability of soil nutrients. This is especially critical for plantations in tropical ecosystems which are known to be nutrient poor ecosystems. Enhanced rock weathering (ERW) represents a promising strategy for improving soil health and carbon sequestration in such ecosystems. We added wollastonite skarn, a calcium silicate rock, to soils in a rubber plantation in Yunnan, China, as part of an ERW strategy aimed at promoting soil functioning and biodiversity. Statistical significance was determined using a linear mixed-effects model, with p-values indicating the level of significance. The addition of wollastonite skarn significantly enhanced key ecosystem functions related to carbon, nitrogen, phosphorous, silicon, biodiversity, and pathogen control. However, it did not significantly affect soil enzyme activity. Some of these responses to the addition of wollastonite skarn may be associated with an increase in soil pH. Microbial network complexity played a critical role in explaining the changes in ecosystem multifunctionality in response to ERW, through both direct and indirect pathways. Synthesis and applications: Our findings suggest that ERW is a viable strategy for improving soil health and ecosystem resilience in tropical plantations, which are limited in nutrients. Thus, ERW has implications for carbon management and climate change mitigation.