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Unsustainable and widespread agricultural practices often lead to severe degradation of a landscape and significant loss of ecosystem function. Land clearing is a primary cause of habitat fragmentation, monoculture farming leads to nutrient imbalances and increased erosion, and pesticide use has been linked to impaired pollinating abilities of native insect species. When these agrarian activities become more frequent and intense, the gravity and risk of biodiversity loss in related areas increases remarkably. One approach to addressing the negative ecological impacts that agricultural developments bring is restoring a degraded patch of land through landcare strategies such as revegetation and soil nutrient replenishment.

Bush Heritage Australia: who are they, and what do they do?

Bush Heritage Australia (BHA) is an example of a conservation organisation that focuses on restoring degraded landscapes with damaged ecosystems, rather than maintaining an already biodiverse area. They do this by purchasing various patches of land around Australia that have been unsustainably managed in the past – for example, Scottsdale Reserve in the NSW Snowy-Monaro region. With the establishment of Scottsdale, BHA aims to shift the vegetation profile so that it is dominated by native species rather than exotic ones and create a landscape which provides suitable habitats for native species.

BHA’s work at Scottsdale Reserve

In order to redirect the Scottsdale landscape from a fixed state of degradation onto a path of recovery, BHA works on restoring native species populations to pre-agricultural levels by removing the weed-dominated topsoil and directly planting a variety of native grasses, trees and shrubs. In addition to weed removal and direct seeding, BHA manages the population sizes of kangaroos to ensure that they are maintained at a sustainable level and removes introduced wildlife that destroy local ecosystems, for example feral pigs.

During our work experience visit to Scottsdale, we were involved in helping with riparian revegetation activities. This included choosing appropriate native species seedlings grown in the on-site nursery, and planting them on the banks of a creek that ran through the property. To promote healthy growth of the seedling, a multi-nutrient tablet was placed into the soil and temporary guards were erected around every seedling. We also planted native species of riparian grasses very close to the water, which was done to control erosion in the patch, and improve the creek water quality and bring the creek ecosystem back to a healthy state. Finally, we place logs around the site to make it more attractive to native species of birds and insects.

Do these strategies work?

Due to its role in creating healthy habitats, revegetation has shown to have a positive impact on the species richness of native marsupial and bird populations. However, revegetation activities are most effective when they complement remnant vegetation patches rather than replace them. Studies have also found that controlled fire practices can help with ecological restoration due to the capacity of fire to stimulate the soil seed bank, which BHA should consider including as a potential strategy.