Soil biota play a pivotal role in mediating multiple ecosystem services (i.e., multifunctionality) that is of key importance for human well-being. Land use intensification can reduce soil biodiversity, which might weaken ecosystem services that depend on soil biodiversity for their delivery. However, whether intensive land use could impact the relationship between soil biodiversity loss and ecosystem multifunctionality reduction remains unclear. A dilution-to-extinction approach was used to set up soil biodiversity loss by inoculating serially diluted soil suspension (ranging from 100 to 10-8 levels) from two long-term fertilization treatments to the sterilized soil that has never been fertilized. The two fertilization treatments represented two distinct intensification land use including the unfertilized control (NP0) and a fertilized treatment (NP120) amended with (NH4)2HPO4 annually (120 kg ha-1 yr-1) since 2002 in an alpine meadow on the eastern Tibetan Plateau. Soil microcosms of 2 fertilization levels crossing 8 biodiversity levels were incubated for 8 months. Then, soil community and multifunctionality parameters including carbon (C) and nutrient mineralization, enzyme activities, plant growth, and functional stability were determined.
Results/Conclusions
After 8 months of incubation, fertilization aggravated the decreased extent of C utilization potential and enzyme activities particularly at lower biodiversity. Plant biomass and nutrient (nitrogen and phosphorus) uptake were depended on the interactions of biodiversity loss and fertilization. Fertilization decreased the functional stability (measured as the decomposition of dead roots following transient heating stress) for high biodiversity treatments but increased it at lower biodiversity. We conclude that changes in soil community composition and biodiversity by intensive land use can increase the risk of losing biodiversity on multifunctionality reduction. Exploring the response of fertilization-induced consequence to further biodiversity loss would contribute to the understanding of the mechanisms of ecosystem process and sustainable management in alpine meadow ecosystem.