Conservation-relevant lands in Australia have higher farmland values

Agricultural land conversion is a major driver of global environmental degradation, contributing to habitat loss for threatened species and climate change when carbon-rich native vegetation is replaced with crops. Conversely, agricultural production remains a necessary land use to ensure food security, support regional employment, and generate foreign income. Hence, conservation interventions and nature-based solutions must compete with-and be balanced against-agricultural production, with careful consideration of the opportunity costs associated with provisioning land from agriculture to environmentally-focused purposes. Information on agricultural land value and opportunity costs are therefore important factors in land use planning, but such data is often limited. We developed a model of farmland value for Australia using socioeconomic and biophysical data and three years of farm sales records across 316 local government areas (LGAs). We then examined the relationships between farmland value alongside conservation values represented by threatened species habitat and carbon storage potential. Farmland value was primarily driven by population density, soil attributes, and rainfall amount, along with travel time to nearest city and forest productivity. Our modelled farmland value layers were strongly correlated with both threatened species richness and maximum woody biomass. Threatened species with higher mean farmland values also had lower mean habitat condition. These results demonstrate that areas in Australia with high importance for conservation and climate mitigation have higher economic and opportunity costs. Therefore, conservation interventions cannot simply focus on low-cost lands, and biodiversity and carbon financing schemes (such as carbon credits) must be sufficiently high to counter economic disincentives.