Birdscaping the environment: restoring the woodland systems of the Mt Lofty region, South Australia
David C. Paton, Daniel J. Rogers, Wendy Harris, 2004. "Birdscaping the environment: restoring the woodland systems of the Mt Lofty region, South Australia", Conservation of Australia's Forest Fauna, Daniel Lunney
Download citation file:
The Mount Lofty Ranges and adjacent plains support an isolated woodland and open forest system that has been extensively cleared such that only 7% of the pre-European vegetation remains. The vegetation has been disproportionately cleared from the good quality agricultural land on lower elevations where only 2% remains. Within this region floral resources are more abundant during winter and spring when plants growing on poor quality soils flower. Honeyeaters recruit into these areas during winter and breed before departing as floral resources wane. Honeyeaters regularly move distances of 10-100 km in search of food within the Mt Lofty region. The habitats that provide floral nectar during late summer and autumn, the gum and box woodlands, however, have been disproportionately cleared and honeyeater populations decline during these times. As a consequence, honeyeaters are unable to recruit back in adequate numbers to service fully the pollination requirements of winter- and spring-flowering plants that suffer reduced seed production. These bird-plant systems operate at a regional scale, and restoration should focus on putting back native vegetation on good quality agricultural land, since components of this vegetation provide floral resources during late summer and autumn.
Based on the amount of vegetation that remains, 35-50 predominantly woodland bird species will go regionally extinct in the Mt Lofty region. Consistent with these predictions, 10 species are already considered regionally extinct and another 60 species continue to decline in abundance and or distribution. The critical requirement is to put back substantial amounts of appropriate habitat. Current revegetation efforts, however, are inadequate. The vast majority of revegetation effort produces patches of new vegetation that are too small (often<1ha), linear in shape, on poorer soils, consist of a few plant species planted in rows and at very high densities, and are largely disconnected from other patches of vegetation. These revegetation efforts support small numbers of widespread bird species and are rarely used consistently by declining species. Many of the declining woodland birds, however, use the extensive Monarto plantations, suggesting that larger areas of reconstructed habitat are needed elsewhere in the region. Based on the habitat needed by pairs of some the declining species, minimum patch sizes of the order of 20-100 ha need to be re-established on good quality agricultural lands. Rather than continuing to retire small plots of land on individual properties a different approach is urgently needed. An alternative is to retire whole farms, perhaps one in ten, and concentrate restoration efforts in fewer larger blocks. This will provide large areas (>100 ha) of good quality land for restoration but will need broad community support. Rather than purchasing farms, owners should be paid to remain on the land and do the restoration work.
This restoration program will take a 100 or more years to produce self-sustaining woodland habitats that the birds can use. In the interim the declining species will need to be managed wisely and intensively so that they will still be present in the landscape to colonize the new habitats. At present there is inadequate information about how to construct woodland habitats as opposed to just planting woodland species. There is also inadequate information on the ecology of the birds. Considerable research and adaptive management is needed to address the information gaps and to build the capacity to implement holistic recovery programs. There is an urgency to take action, since the longer we delay the fewer species that will be conserved. Future generations will not have the same opportunity.