Private reserves suffer from the same location biases of public protected areas

Setting aside private land is an essential component of the biodiversity crisis response. In Brazil, landowners are required to have Legal Reserves (LR) (20%-80% of their property set aside for native vegetation) which, if degraded, need to be restored. Alternatively, landowners can compensate for an LR deficit by purchasing surplus credits. Each landowner can define the location and spatial arrangement of their LR, affecting the reserve's ability to maintain biodiversity and provide ecosystem services (ES). We used hierarchical models to determine drivers for the amount and location of those LR in 3622 farms. The likelihood of setting aside part of the farm as LR (avoiding off-farm compensation) increased with farm size and extent of native vegetation cover, particularly for riparian areas and steep slopes, where conserving vegetation is also mandated in what are called Areas of Permanent Protection (APP). Properties with APP were more likely to meet the full LR requirement within their areas if located in areas of higher transportation costs and lower agricultural suitability. Within properties, the location of LR was mostly in areas with low agricultural suitability, high transportation cost, and close to APP. Landowners' decisions intend to maximize property income and reduce restoration costs, resulting in a spatial pattern similar to public protected areas - usually located on marginal land for agriculture. These areas do not necessarily provide the greatest biodiversity and ES benefits, suggesting that government interventions may be needed to encourage landowners to set aside native vegetation in ways that maximize conservation and ES outcomes.