Macro-arthropod succession in grassland growing on bauxite residue

Abstract

Ecosystem functions such as nutrient cycling are crucial components of revegetation programmes for bauxite residues and other tailings. Whilst vegetation establishment on bauxite residue is well studied, little is known about the development of the soil-biota. Macro-arthropod assemblages have been used to monitor and evaluate restoration success on a variety of mine spoils, but there is no information on its presence in bauxite residues. In order to understand the colonization and community development of macro-arthropods in revegetated residue, we compared species from two revegetated residues with an unamended site using pitfall and pan trap techniques. Whilst relatively few immobile species were present in the unamended site, high diversity was recorded for the revegetated sites. A number of species representative of predatory and carnivorous trophic structure were identified for the two vegetated sites. Additionally, many species identified are indicative of later stages of succession. These findings indicate that bauxite residues can be successfully restored to a functioning grassland type ecosystem. Monitoring of key arthropod species is recommended as part of the restoration evaluation process.