New global study, with MED/CHANGE – University of Évora researchers, finds biodiversity impacts of agricultural deforestation have inherent and predictable geographical differences

A new collaborative study at global scale recently published in Nature Ecology & Evolution journal suggests that regions with more variable natural environments and longer agricultural histories tend to support bird communities that are more tolerant of deforestation. The study was led by Peking University, with the participation of three researchers from MED&CHANGE of the University of Évora.

Agriculture is the foundation of human civilization and a prime example of our impact on Earth. Almost 40% of our planet’s ice-free land surface, most of which was previously forested, is now dedicated to agriculture. As our demand for food increases, so does agricultural deforestation, which is widely viewed as one of the greatest threats to global biodiversity. Yet, the magnitude of agriculture’s impact on biodiversity varies widely across the world. This study found that natural environmental conditions and past human influences have essentially served as filters to determine which species are present in a region’s bird community today, and how tolerant they are to agricultural deforestation.

This also means that biodiversity in some regions is more inherently threatened by agricultural deforestation than in others. Worryingly, many predicted hotspots for future agricultural deforestation are in such ‘high impact’ regions, notably tropical areas with short agricultural histories and less variable environmental conditions. This foreshadows severe biodiversity consequences of future agricultural expansions, and underscores the need to proactively plan agricultural land use to reduce deforestation in these regions.

The example of agroecosystems in southern Portugal: agroecosystems, such as the ‘montado’ system, form a multifunctional landscape, evidence of past human influence. While the heterogeneous matrix has allowed the maintenance of more natural refuges, the extensive management has promoted greater adaptability of bird communities to the system itself, making them more tolerant and resilient to deforestation. The ‘montado’ management system is able to combine production with a high biodiversity value which makes it worthy to preserve.

The study involved 47 researchers from around the world, resulting in a database of 71 regional bird communities and 2,647 bird species which enabled to test, for the first time, whether environmental conditions and agricultural history could explain the global variation of agricultural deforestation on biodiversity.