The relative importance of invertebrate and microbial decomposition in a rainforest restoration project

Tropical rainforests are increasingly disturbed by human activities. While restoration projects often succeed in replacing tree cover, they rarely manage to restore soil function. Consequently, there is an urgent need to understand the changes that occur during soil restoration. Model ecosystems such as the Eden Project present an ideal opportunity to investigate these changes. The Eden Project was built 15 years ago, and its plants grown from seedlings, or sown directly into a soil made up of standardized mixtures of recycled organic material. Today, the Eden Project's rainforest biome consists of a diverse community of plants, invertebrates, and microorganisms. Different areas within the biome are managed differently, allowing us to separate the relative contributions of decomposers under differing physical conditions. Litterbag experiments revealed significant differences in decomposition rates in bags of different mesh sizes. Phospholipid fatty acid analysis revealed that microbial biomass and community structure varied under different management regimes. Soil enzyme assays revealed that glucosidase activity increased in soils with more organic matter, whereas phenol oxidase activity increased in more alkaline soils. Our study takes a step toward understanding the interactions between invertebrates and microbes, and the way in which soils function during restoration.