Deforestation to boost agricultural production for the Earth's growing human population is considered one of the main threats to the world's biodiversity. However, its impact varies from region to region. A study involving 71 bird communities with a total 2,647 species from around the world, led by authors from Peking University, looked at factors that would explain this variability. The results, in which Federico Morelli from the Department of Ecology also participated, have now been published by the journal Nature Ecology & Evolution in early 2024.
Scientists have found that the main filters that determine how species are present in agricultural areas today are natural environmental conditions and human influences in the past. For example, birds living in seasonally changing forests and areas farmed for thousands of years are more resistant to deforestation. Furthermore, individual bird species tend to be filtered based on "functional" characteristics such as body size, habitat preference, and diet. The results show that deforestation-tolerant species tended to be smaller and more migratory, less dependent on natural forests, and less specialized for food than birds highly sensitive to deforestation. At the same time, these traits were also more common in birds found in areas with more variable natural environments and a longer agricultural history.
Morelli surveyed several croplands, in Central Italy, and for published research collected complete data on the occurrence of breeding bird species together with a detailed description of the environment regarding landscape composition, land use, or reforestation. “The main importance of this study is related to intrinsic implications for the conservation of nature. By examining and highlighting which factors — species traits, climate variations, natural disturbance and agricultural history — can determine changes in species assemblages when facing forest loss and fragmentation, we can predict which bird communities could be more vulnerable in the future,” explained Morelli.
Citation:
Hua, F., Wang, W., Nakagawa, S., Liu, S., Miao, X., Yu, L., ... & Elsen, P. R. (2024). Ecological filtering shapes the impacts of agricultural deforestation on biodiversity. Nature Ecology & Evolution, 1-16. https://doi.org/10.1038/s41559-023-02280-w