Most of the forests of the Amazon basin grow on nutrient-poor soils (Jordan 1982). Despite this, these forests remain productive through a variety of nutrient conservation mechanisms and a very effective system of organic matter decomposition and nutrient cycling (Jordan 1982). When an area of forest is fragmented however, the remaining patches experience modified microclimatic conditions (Camargo & Kapos 1995, Didham & Lawton 1999), and changes in floristic composition (Laurance et al. 1998), which can affect the decomposer community (Didham et al. 1996, Souza & Brown 1994) and consequently the decomposition process.