Here’s the slides from my presentation at the 27th International Congress for Conservation Biology . Abstract also below.
Deforestation is a major driver of biodiversity loss and environmental degradation worldwide. International and national efforts to combat deforestation have taken a number of forms, ranging from policies which restrict forest clearing, to broader commitments to achieve ‘no net loss’ of vegetation. However, the efficacy of such policies is rarely evaluated. Data limitations and methodological challenges can impede the evaluation of policy impact in the presence of confounding variables, time-lags and misalignment of spatial and temporal data. Such challenges in evaluation must be overcome to ensure policy effectiveness and the delivery of environmental benefits. We combine satellite imagery of forest loss, along with information on key macroeconomic and climatic variables within a novel statistical framework, to evaluate the impact of successive policies aimed at reducing deforestation in Australia. A wealthy nation with strong governance and high institutional capacity, Australia has introduced at least fifteen sub-national policies to combat deforestation since the 1980’s, in addition to an overarching national goal to reverse deforestation by 2020. Despite these efforts, little is known of what effect these policies have had on the rate of forest loss over time. We analyze the change in forest cover across Australia between 1972 and 2012, and model trends in deforestation using a spatially explicit bent-cable regression framework. The bent-cable model provides a more realistic and flexible representation of system changes than traditional regression methods, and has a greater capacity to detect the impact of a policy intervention on the response of interest. We find that the introduction of policies generally had a limited effect on the rate of forest loss, while terms of trade, rainfall and amount of forest remaining had an overall greater influence. Our study provides much needed insight into how societal and environmental goals can effectively be balanced.