Can Acacia mangium and Acacia auriculiformis hinder restoration efforts in the Brazilian Atlantic Forest under current and future climate conditions?
Climate change and biological invasions are two of the most cited factors that may affect species diversity in the coming decades. Here we used five climate scenarios to investigate the potential distribution of two invasive tree species, Acacia mangium and A. auriculiformis, in the Atlantic Forest hotspot. Additionally, we used expansion-contraction maps and maps of potential areas for forest restoration to investigate whether biological invasion could affect restoration efforts. We found A. mangium has a large suitable area in all scenarios (average 268,010.1 km2±25,292.4 SD), while A auriculiformis is confined to a relatively small region (average 13,123.1 km2±361.7 SD). In the low greenhouse gas emissions scenario (RCP 2.6), the suitable area for A. mangium varied from the current scenario of 24.8% of the Atlantic Forest to 26.2% and 25.4% in the years 2050 and 2070, respectively. In the high greenhouse gas emission scenario (RCP 8.5), the suitable area contracted to 23.1% and 20.5% in 2050 and 2070, respectively. Approximately 30.8% of the potential area for restoration currently overlaps the suitable area for A. mangium, and this overlap reaches at least 23.8% of the potential areas for restoration in the future scenarios (RCP 8.5 in 2070). A. mangium has a large suitable area in the Atlantic Forest and can become a barrier to restoration efforts in the coming decades. Expansion-contraction maps should be used to establish environmental policies that promote both forest restoration and prevention of biological invasion in suitable areas.