Altered litter and cellulose decomposition across an anthropogenic habitat modification gradient in Sulawesi, Indonesia

O_LIMany tropical regions in Southeast Asia have experienced extensive habitat modification, creating a mosaic of forested and agricultural land. The capacity of these human-modified tropical landscapes to support biodiversity and ecosystem functions and services is of considerable practical interest. C_LIO_LIDecomposition of plant material is a key process maintaining the nutrient cycle in both natural and agro-ecosystems, but few studies have documented the relative contributions of different guilds of decomposers, acting on different plant substrates, across different tropical land-uses. C_LIO_LIWe measured decomposition of leaf litter and cellulose across a gradient of anthropogenic habitat modification (forest, shrubland, and corn farmland) within Panua Nature Reserve, Sulawesi, Indonesia. The influence of fungi and the litter invertebrate community were investigated experimentally. C_LIO_LIDecomposition of both substrates was significantly lower in corn plantations than in forest sites. Partial exclusion of litter invertebrates, but not fungi, significantly reduced decomposition, but the feeding guild composition of the litter invertebrate community did not differ significantly across habitat types. C_LIO_LIOur results confirm that even small-scale agricultural areas adjacent to forest fragments can experience impaired ecosystem functions. These changes can be linked to reduced invertebrate activity, apparently independent of the functional structure of the litter invertebrate community. Effective management of human-modified landscapes will be needed to maintain nutrient cycling, even in areas where agroecosystems and tropical forests occur in close proximity. C_LI HighlightsO_LIHabitat modification alters litter and cellulose decomposition C_LIO_LISmall-scale agriculture near forest fragments can impair ecosystem functions. C_LIO_LIExclusion of litter invertebrates, but not fungi, significantly reduced decomposition. C_LIO_LIMaintaining nutrient cycling requires effective management of human-altered landscapes. C_LI