Consistency in bird community assembly over medium-term along rural-urban gradients in Argentina

Abstract

Background The analysis of bird community assembly rules is fundamental to understand which mechanisms determine the composition of bird species in urban areas. However, the long-term variation of community assembly rules has not been analyzed yet. The objectives of this study are (1) to analyze the variation of community assembly rules along rural-urban gradients of three cities in central Argentina and (2) to compare the patterns of community assembly between two periods separated by 6 years. Bird surveys were performed along transects in urban, suburban, and rural habitats during 2011 and 2017. Departures from null models that took into account differences in species richness (standardized effect size, SES) were calculated for functional and phylogenetic diversities. Results A total of 57 species were recorded. Bird species richness was higher in suburban than in urban and rural habitats. SES of functional diversity increased over the years and was significantly lower in urban habitats than in rural habitats, showing a pattern of functional clustering in the most urbanized areas and functional randomness in rural ones. Phylogenetic diversity was higher in both suburban and urban habitats than rural ones, and the phylogenetic clustering in rural bird assemblages changed to randomness in suburban and urban habitats. Conclusions Bird communities in urban habitats were phylogenetically random and functionally clustered, evidencing environmental filtering by urbanization. In contrast, bird communities in rural areas tended to be phylogenetically clustered, evidencing that certain clades are adapted to rural areas. The processes structuring bird communities along rural-urban gradients were consistent between the 2 years compared.

Taxonomic, Phylogenetic and Functional Diversity of Bird Assemblages in Urban Green Spaces: Null Model Analyses, Temporal Variation and Ecological Drivers

“…Besides its inherent value, functional and phylogenetic diversity hold conceptual relevance for community ecology since functional and phylogenetic clustering patterns can provide insights into community assembly mechanisms such as the environmental filtering of species from the regional species pool (Weiher, 2011). So far, there is evidence that suggests that urban areas may be acting as filters for some lineages and functional traits (Sol et al, 2017;Leveau, 2021). To test this, departure from randomness is assessed through the comparison of observed values against random expectations obtained from null models that take into account differences in species richness (Swenson, 2014; for an example see Weideman et al, 2020).…”

Species Traits Drive Long-Term Population Trends of Common Breeding Birds in Northern Italy

“…Although species population trends are not directly informative on drivers of population changes [ 21 ], observing a common trend among species with similar ecological or life history traits can provide the foundation to test specific hypotheses about the drivers of the observed population dynamics [ 22 ]. Despite the arising attention of a trait-based approach in community ecology [ 15 , 23 , 24 , 25 , 26 , 27 , 28 , 29 ] and population ecology [ 30 , 31 , 32 , 33 , 34 ], only in the last few years researchers have started to explore the link between traits and population trends in avifauna over long time periods, highlighting the existence of different patterns among distinct functional groups [ 22 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ].…”

Sustainable urban systems: from landscape to ecological processes

“…Hakkoum et al ( 2021 ) found that the input of organic matter and nutrients from the treated wastewater can increase the biodiversity of soil cyanobacteria, but municipal and mining solid wastes lead to decrease of diversity and microalgal biomass. Leveau ( 2021 ) found that environmental filtering by urbanization led to phylogenetical randomness and functional clustering of bird communities in urban habitats. By comparing nutrient cycling and litter decomposition between the litter of a single species and a mixed composition of litter in urban parks in São Paulo City, Brazil, Ferreira et al ( 2021 ) found that both environmental and biogeographic characteristics of the species shall be considered in urban reforestation programs.…”