Artificial waterbodies can help tackle the ongoing freshwater biodiversity crisis by providing new habitat for aquatic wildlife. Farm dams are among the most abundant artificial waterbodies in agricultural landscapes, yet general guidelines for maximising their ecological potential are yet to emerge. Here we used a continental-scale dataset of frog species near 8,800 Australian farm dams to ask: What characteristics promote higher frog species richness at farm dams? The highest values of species richness were at older (>20 years) farm dams of intermediate sizes (0.1 ha in surface area), with smaller rainfall catchments (<10 ha), and near other freshwater systems or conservation sites. By identifying quantifiable features improving the ecological value of farm dams, this work helps identify “win-win” outcomes for agricultural productivity and conservation. In the future, “biodiversity credit” policies could promote large-scale implementation by rewarding farmers who invest in improving the condition of their farm dams.

We developed a machine learning based meta-model to identify sustainability pathways through rapid scenario generation and defined the safe operating space for achieving them via scenario discovery. We trained a meta-model to replicate the Land-Use Trade-Offs integrated model of the Australian land system. Latin hypercube sampling was used to create many scenarios exploring the impact of uncertainties in key drivers including future socio-economic development, climate change mitigation, and agricultural productivity at a granular level. Economic and environmental impacts were evaluated against nationally downscaled SDG targets. Scenario discovery revealed new pathways to achieving five SDG targets for 2050 which required crop yield increases above 1.78 times, a carbon price above 100 AU$ tCO2-1, a > 9% biodiversity levy on carbon plantings, and carefully regulated land-use policy. Machine learning based meta-modelling teamed with scenario discovery revealed the policy and scenario settings required for a sustainable future for the Australian land sector.