How much Araucaria Mixed Forest remains? Novel perspectives on conservation status based on satellite imagery and policy review

• Published in: Biological conservation Vol. 296; p. 110723
• Main Authors: Zorek, Bruna Eliz, Biswas, Sumalika, Brum, Fernanda Thiesen, Leimgruber, Peter, Carlucci, Marcos Bergmann
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2024
• Subjects: Araucaria angustifolia; Atlantic Forest; conservation status; deforestation; Forest cover change; issues and policy; keystone species; mixed forests; Protected area; Remote sensing; satellites; Vegetation mapping; Araucaria angustifolia; Forest cover change; Atlantic Forest; Protected area; Vegetation mapping; Remote sensing
• DOI: 10.1016/j.biocon.2024.110723
• ISSN: 0006-3207

The Araucaria Mixed Forest (AMF) is a highly endangered component of the Atlantic Forest, but detailed information about its conservation status across its entire historical range is lacking. In particular, there is a lack of updated information on the remaining area of AMF, how fragmented it is, and how much is currently protected. Moreover, it is still unclear how the history of deforestation is related to the creation of policies focused on AMF conservation through time. To fill these gaps, we used Sentinel-2 satellite imagery and machine learning focusing on the prominent presence of the keystone species Araucaria angustifolia (araucaria) to map AMF. The remaining AMF extends only 4.3% (~1.2 million ha) of its original range, of which only 13.5% are inside protected areas. AMF is highly fragmented, with 99% of patches <50 ha, making it vulnerable to further declines. Our analysis suggests that policies and conservation measures were insufficient to curb the AMF decline over time. Renewed actions are urgently needed to promote 1) formal protection of the largest AMF patches; 2) strengthening of existing protected areas; 3) integration of (private-owned) Legal Reserves into conservation strategies; and 4) continued and improved range-wide monitoring of AMF via satellite remote sensing. Finally, our approach to mapping AMF based on the prominent presence of araucaria provides a novel way to frequently update forest mapping with a robust proxy.