Land tenure and biological communities in dry Chaco forests of northern Argentina

Environmental factors and land use control habitat quality and resources availability, thus regulating species distribution. Land tenure in general, and particularly traditional indigenous properties, strongly influence land use in forest ecosystems, but their association with biodiversity is poorly explored. We surveyed 43 forests in the Northern Argentina Gran Chaco, to (1) compare species diversity and composition of birds, mammals and trees between land tenures across a 17 million-hectares region; and to (2) compare diversity between Wichí indigenous properties and non-indigenous properties, within a more restricted geographic range to control for climatic and soil factors (n = 19). Contrary to our expectations, protected areas did not include higher biodiversity, although they showed higher densities of species specifically targeted for human harvest. Wichí properties were the most original regime in terms of community composition of birds and trees. Every land tenure had particular indicator bird and tree species; thus a territorial conservation strategy could include a combination of all them, with a special focus on indigenous properties. Land tenure differences in biodiversity could be the complex result of different habitat quality derived from land use practices and of different geographic location.