Abstract/Summary

Southern Brazil's highland Araucaria Forest-Campos grassland mosaic is an ancient and iconic landscape in the globally important Atlantic Forest biodiversity hotspot. Human land use has inflicted significant losses on the region's natural vegetation since the late 19th Century, but these have not been effectively quantified. This study uses land cover maps and forest survey data to assess how much of the mosaic's natural vegetation remains, the quality of this remnant vegetation, how it has changed since 1985, and the extent to which it is protected. Natural vegetation covers 13.9-37.3% of the Araucaria Forest-Campos mosaic’s core regions and 13.0-38.0% of the whole area, depending on the dataset. Most remnant areas are degraded and remaining forests have low average integrity. In only minorities of forest plots are the landscape's characteristic Araucaria angustifolia trees still present (23.5% in the Araucaria Forest region), moderately abundant (11.4%), or >50% of the canopy (0.5%). Major expansions in cropland and forest plantations between 1985 and 2018 drove net/absolute losses of 12.7%/24.1% in the mosaic's natural forest and 38.1%/43.2% in its natural grasslands. Protected Areas and Indigenous Territories cover 4.6% of the core mosaic and 6.5% of the whole region. These conserve important remnant vegetation, though grasslands are under-protected. By analysing and integrating diverse and complementary data sources, we significantly improve on and add nuance to previous estimates of the quantity and quality of Araucaria Forest remnants. This study also provides the first robust, quantitative estimate of remaining highland grassland across southern Brazil.