Can revegetation assist in the conservation of biodiversity in agricultural areas?

Abstract

It has been suggested that revegetation in agricultural areas to tackle land degradation problems can also aid in the conservation of biodiversity in these regions. Native biota is restricted to remnant areas, which are mostly small, often unconnected, and subject to a variety of impacts from the surrounding altered landscape. The current remnant network is not sufficient to ensure the long-term persistence of the biota, and requires enhancement. Revegetation provides an opportunity to protect and add to the existing remnant network. However, there are few data available with which to assess the likely impact of revegetation on conservation values, and few guidelines as to how revegetation should be designed for conservation purposes. This paper presents an initial framework for developing revegetation strategies which tie into the existing conservation network. Revegetation can either provide buffer strips around existing remnants to protect them from external impacts, corridors between them to increase connectivity, or additional habitat to increase the area of vegetation available, or can enhance degraded remnant areas. Precise design principles and specifications for these types of revegetation are lacking, and may not be appropriate since they will depend on vegetation types and the requirements of target species. In addition, revegetation will help retain biodiversity indirectly if it helps stabilize an otherwise degrading agricultural landscape. Revegetation in agricultural areas is compared with minesite rehabilitation, where the redevelopment of functioning ecosystems and faunal habitat appears to be possible. The task is harder in the agricultural situation because the scale of modification is greater, soil changes are more difficult to redress, and recolonization by native species is less likely. Increased research effort is needed on the implementation and effects of differing types of revegetation, strategies for increasing rates of adoption of revegetation and methods of integrating conservation considerations into revegetation programmes.