Shelterbelt bioindicators (terrestrial invertebrates)

Clearing of land for agricultural activities has been an ongoing process for the past 200 years. However, it has now been suggested that remnant native vegetation will provide habitat for beneficial invertebrates that may be able to control pest species without the application of pesticides. Remnant habitats (e.g. shelterbelts or windbreaks) may also provide habitat for a number of ecological processes required for sustainability of agro-ecosystems. These processes include predation (e.g. spiders, predatory beetles), parasitism (e.g. wasps), pollination (e.g. bees, wasps, beetles) and soil turnover and enrichment (e.g. earthworms, isopods, ants, spiders), which aid in pest control, increase crop yields, and improve soil quality. Some other potential benefits of shelterbelts include: salinity control; the provision of land for endangered species (both plants and animals), improvement of aesthetic value and biodiversity; the provision of shade for livestock; and the provision of secondary (economic) benefits to land managers such as firewood, building timber and food (e.g. nuts, fruit, etc).

This project, a collaboration between the Corangamite Catchment Management Authority and CESAR, aims to document the invertebrate (insect and arachnid) fauna within shelterbelts established across four farms near Colac in southwestern Victoria. Through this project we have found a number of invertebrate indicators of shelterbelt size, and composition, which will enable the Corangamite Catchment Management Authority to measure the success of revegetation projects within its catchment. A set of criteria are being formulated that will allow the Catchment management officials to assess future revegetation strategies. Future decisions to financially assist projects will also be based on these criteria. These biological indicators are proving successful in measuring farm management options and sustainable land practices.