Abstract

Oases are key components of arid ecosystems because they concentrate a high species diversity. Anthropogenic activities strongly impact oases, however, the effect of land use change on biodiversity in arid ecosystems have been poorly investigated, limiting the design of conservation strategies. Here we evaluate the effect on birds of anthropization of oasis-valleys in the Atacama Desert of northern Chile. By using transects, we evaluated birds and estimated the Relative Integrated Anthropization Index (INRA) of three oases (Azapa, Chaca and Camarones). We determined the influence of INRA on bird species richness using generalized linear mixed models (GLMM). In addition, we estimated the Shannon diversity index and compared randomized species accumulation curves among oasis-valleys by rarefaction analysis. We compared the composition of the bird community of the oasis-valleys using hierarchical clusters. The Azapa valley exhibited the highest anthropization level (71.8), followed by Chaca (39.9) and Camarones (4.6). Similar values for total bird species richness was found in Azapa (20), Chaca (17) and Camarones (20). We did not find a significant effect of the anthropization level on bird species richness per transect nor Shannon diversity index. Rarefaction analysis found a greater bird species richness in Camarones, the oasis-valley with the lowest anthropization level. Bird community composition differed significantly among valleys, indicating a change in the identity of the species. According to our findings, a better understanding of the effects of land use change on bird communities from arid environments requires to take into consideration species identities.