Abstract

BERDUC, Alfredo; LORENZON, Rodrigo Ezequiel  and  BELTZER, Adolfo Héctor. Bird diversity patterns along a latitudinal gradient of riparian forests from Middle Paraná River, Argentina. Rev. Mex. Biodiv. [online]. 2015, vol.86, n.2, pp.419-430. ISSN 2007-8706.  https://doi.org/10.1016/j.rmb.2015.04.003.

We studied the variation of species richness (alpha diversity), beta diversity, abundance and evenness of bird assemblages along a latitudinal gradient of 500 km of riparian forests. We sampled 5 localities placed in north-south direction through a mixed sampling technique (transects and points count). Species richness decreased as latitude increased, reproducing the pattern of regional species richness reported in a previous study. Since we found a latitudinal pattern of species richness and abundance, results supported the "more individuals hypothesis" as a mechanism that explains the latitudinal pattern of diversity. Beta diversity and evenness did not vary latitudinally. Results showed that alpha component of diversity is more important than beta component in terms of its influence on the negative latitudinal pattern of regional richness of birds in a subtropical area. Despite the exclusive environmental characteristics of riparian corridors, we found a negative latitudinal pattern of alpha diversity which is widespread in upland environments.

Keywords : Alpha diversity; Beta diversity; More individual hypothesis; Riparian corridor.