Understanding Bird Responses in Regenerating Agricultural Landscapes

Farmland abandonment plays a significant role in shifting vegetation patterns in
agricultural landscapes and often leads to large increases in vegetation cover. This creates an opportunity for large scale habitat restoration particularly in regions of forest and woodland that have been cleared for agriculture. This process is gaining more attention in post-agricultural landscapes of south-eastern Australia. Whilst there has been extensive research into the effects of agricultural intensification on birds in Australia, there have been few investigations into the benefits of extensive regrowth,
particularly in agricultural areas shifting away from traditional farming.

In this thesis I investigated a region within a transitional agricultural landscape in central Victoria, Australia with evidence of increasing regrowth vegetation. I studied historical aerial photos to map the extent of vegetation change and investigated the habitat value of this vegetation for regional bird diversity. I also constructed a predictive model to explore future trends in vegetation patterns in the landscape. The main focus was to investigate the effects of regrowth in a post agricultural landscape and how the present and future vegetation mosaics influence the regional bird community.

Results indicated that regrowth is changing the landscape from a homogenous pasture dominated composition to a more heterogeneous composition of trees, shrubs and pasture. Regrowth is creating areas with important habitat values, which are complementary to the forest remnant and production pasture. These are supporting bird species of conservation concern and adding to regional bird species diversity. Modelling showed succession patterns of regrowth predicting a future landscape predominantly tree dominated. While this would increase habitat for most woodland birds in the region there would be a reduction of habitat for a group of bird species that require mixed patch types in close proximity.

These results highlight the role of regrowth in landscape restoration in south-eastern Australia and provide valuable insights for achieving conservation goals in transitioning agricultural landscapes where regrowth is increasing vegetation cover lost from prior clearing for agriculture.