Indigenous lands and conservation units slow down non-GHG climate change in the Cerrado-Amazon ecotone

Preserving tropical forests by avoiding deforestation and forest degradation is essential for maintaining ecosystem services. Brazilian Conservation Units (CUs) and Indigenous Lands (ILs) have effectively prevented deforestation and supported climate regulation. However, these protected areas face increasing threats from forest fires and droughts across the Amazon and Cerrado biomes. This study assesses how disturbances affect climate regulating factors (surface temperature (LST), evapotranspiration (ET), and albedo) in Mato Grosso state, among different land uses (CUs, ILs, and multiple-use areas - MUs). To do so, we analyzed satellite data collected between 2001 and 2020. Results showed that MUs (outside protected areas) had lower ET (∼10%), higher daytime LST (∼1.5 °C), and higher albedo (∼10%) than CUs and ILs in both biomes in 2001. Over the study period, MUs experienced a greater increase in LST (Amazon: ∼1.4 °C; Cerrado: ∼1.1 °C) and albedo (Amazon: ∼6%; Cerrado: ∼3%) compared to protected areas, regardless of the biome. In contrast, ILs and CUs showed smaller mean changes in LST (∼0.2 °C), ET (∼1.3%), and albedo (∼1.3%). These changes were associated with native vegetation loss, forest fires, and water stress. Our results highlight the important role of protected areas in maintaining climate stability, with higher ET, lower LST, and lower albedo than other land uses. However, the long-term preservation of these services within protected areas depends on interventions in surrounding regions, particularly in the Amazon. Protecting and restoring these natural ecosystems is key for safeguarding ecosystem services and climate regulation in tropical regions.