Patterns of taxonomic and functional diversity of birds in riparian forests with natural and agricultural matrices in the Argentine Austral Yungas

Abstract

Birds represent a diverse group that responds markedly to changes in the structural characteristics of their habitat. In this study, we evaluated the response of birds to changes generated by the landscape anthropization in riparian forests of the Austral Yungas. These forests are vulnerable to unnatural disturbances and are within an ecoregion that has a high risk of degradation due to historical and current land use changes. Based on the hypothesis of environmental heterogeneity, we investigated how taxonomic and functional diversity of bird assemblages were related to structural variables of riparian forests and the matrix type (native forest or crop) in which they are immersed. Through direct observations and captures using mist‐nets, we determined bird species richness and abundance, and measured quantitative functional traits in eight riparian forests in the piedmont forest of the Austral Yungas in Argentina. We also calculated four functional diversity indexes and measured structural variables of the forests. Bird species occupied a functional space in a uniform way, particularly in riparian forests immersed in a crop matrix, which tend to be structurally homogeneous; that is, in riparian forests where there is an increase in disturbances, the Functional Evenness values are higher. Changes in land use determine changes in the composition of bird assemblages and may result in the non‐random loss of functionally unique species.

Longitudinal multidiversity pattern and the environmental drivers of riparian bird communities along submontane rivers of Changbai Mountains, China

“…Bird taxonomic diversity indices (species richness and Shannon diversity) were positively related to forest cover, vegetation height variation, and land cover patches. The available forest areas along bodies of water, which serve as habitats and important ecological corridors, support some of the most individual‐ and species‐rich avian communities, although riparian forests are often just a small part of the landscape (Gomez et al, 2021 ; Groom & Grubb, 2004 ; Hsu et al, 2010 ). Continuous and large areas of riparian forests could meet the requirements of various bird species with regard to habitat size and certain special resources, such as nest holes for birds that inhabit forest or river habitats, thus allowing abundant bird species to coexist (Lees & Peres, 2007 ; Magdaleno & Martinez, 2014 ).…”

“…Bird taxonomic diversity indices (species richness and Shannon diversity) were positively related to forest cover, vegetation height variation, and land cover patches. The available forest areas along bodies of water, which serve as habitats and important ecological corridors, support some of the most individual-and species-rich avian communities, although riparian forests are often just a small part of the landscape (Gomez et al, 2021;Groom & Grubb, 2004;Hsu et al, 2010).…”