Legacy effects of European colonialism on hotspots of biocultural diversity threat

Patterns of biological diversity have been shaped by cultural practices in the past, while in turn, cultures and languages have evolved in close interaction with local species and ecosystems. However, in the Anthropocene, human activities are putting increasingly diverse pressures on ecosystems and cultures, resulting in accelerating threat levels on both. Understanding where biological and cultural diversity is threatened globally, and how far current and historical anthropogenic drivers such as colonialism shape their distribution is crucial for pinpointing hotspots and prioritizing efforts to counter these threats. We use global data on biological diversity (using amphibians, birds, mammals and reptile diversity as a proxy) and linguistic diversity (using as a proxy for cultural diversity) to estimate their current threat levels using the Red List Index framework. Using this data, we identify hotspots and coldspots of threat to both biological and linguistic diversity as well as a combined threat (here termed biocultural diversity threat). In a second step, we identify global drivers of biological, linguistic and biocultural diversity threat using beta-regression models. We find that the spatial patterns of the erosion of biological diversity and linguistic diversity are only weakly congruent on a global scale and that they are driven by differential sets of mechanisms. These include the level of urbanization in the case of linguistic diversity threat and roughness, per capita GDP and the proportion of intensive agriculture for biological diversity. The only common driver of biocultural, linguistic and biological diversity threat was the increasing occupation time of European colonial powers. Hence, our results show that the European colonial expansion has left long-lasting imprints on both biological and cultural diversity. This highlights substantial time-lags of human past actions and can be readily translated to today where the globe is more connected than ever, illustrating the importance of understanding and alleviating contemporary anthropogenic pressures. Read the free Plain Language Summary for this article on the Journal blog.