Earthworm composition, diversity and biomass under three land use systems in south-eastern Australia

Abstract

In south-eastern Australia, strips of planted native trees and shrubs (shelterbelts) are frequently established to restore ecosystem services altered by agriculture. Despite their wide use, little is known about the effects of establishing shelterbelts on soil macro invertebrates, especially earthworms, which are of major importance in soil processes. We assessed earthworm composition, diversity and biomass in three land use systems: native shelterbelts dominated by Acacia and Eucalyptus species, agricultural pastures and native remnant woodland fragments dominated by Eucalyptus blakelyi and/or Eucalyptus melliodora. Earthworm communities differed significantly among systems, with abundance, biomass and diversity greatest under pasture. Within shelterbelts we saw a shift from high earthworm biomass and density to low with increasing time after establishment. Soil edaphic variables did not correlate strongly with earthworm biomass or density, but were correlated with earthworm community composition. Overall the introduction of native woody vegetation was associated with a decline in density and biomass of earthworms, including a decrease in the relative abundance of exotic species. As such shelterbelts can be used to promote native earthworm relative abundance, which may be important for local diversity, soil function and landscape connectivity.