Vegetation structure drives taxonomic diversity and functional traits of birds in urban private native forest fragments

Abstract

Many studies in urban landscapes have revealed that vegetation structure influences the taxonomic diversity and traits of birds and drives greater bird richness in greenspaces. However, most of these studies have been carried out mainly in public spaces. Private lands represent large components of cityscapes worldwide, and so understanding the role they play in the maintenance of biodiversity, and how vegetation traits drive the ecological attributes of birds, remain poorly known. Here we identified local factors of vegetation related to the bird fauna of urban private native forest fragments in Sorocaba, state of São Paulo, Brazil, with a focus on their ecological attributes. We predicted that increased vegetation structure would select birds that depend on forest environments and the resources they support. We sampled 13 vegetation traits in 28 private urban native forests to evaluate the relationship between vegetation structure and taxonomic diversity and functional traits of birds. Confirming our prediction, vegetation structure shaped the ecological attributes of birds, with five vegetation traits driving bird taxonomic diversity and functional traits, of which the number of standing dead trees was related to more bird ecological attributes. Vegetation structure in urban private native forest fragments may increase habitats and resources, thus supporting habitat-and feeding-specialist species. Our results provide insights for public policies aimed at management and maintaining vegetation structures that benefit bird fauna (e.g. number of standing dead trees, tree richness, canopy cover), in support of the ecological functions they perform in urban landscapes.

Influence of habitat type and distance from source area on bird taxonomic and functional diversity in a Neotropical megacity

“…Urban landscapes may also have high habitat heterogeneity depending on the size of native patches, the ages of urban and native remnants, land and vegetation cover, gray (urban) structures and population densities and socio-economic characteristics (MacGregor-Fors and Schondube 2011;Ramalho and Hobbs 2012;Sacco et al 2015;Pena et al 2017). Distinct management actions in urban areas may benefit habitat heterogeneity and resources for birds (Toledo et al 2012;Beninde et al 2015;MacGregor-Fors et al 2016;Oliveira Hagen et al 2017;Campos-Silva and Piratelli 2020), making them richer and/or functionally more diverse than surrounding ecosystems (Sol et al 2014;Oliveira Hagen et al 2017).…”

“…The size of green (vegetation) patches, habitat structure, vegetation cover (including street trees), and proximity of water bodies are strongly positive predictors of high bird species richness (MacGregor-Fors and Schondube 2011; Sacco et al 2015;Pena et al 2017;de Carmago Barbosa et al 2020;Campos-Silva and Piratelli 2020). Conversely, buildings, impervious surfaces, human density, human activities, bird-window collisions, domestic animals, noise and light pollution negatively with bird species richness and positively with abundance of few habitat and diet generalist species (Leveau and Leveau 2004;Villegas and Garitano-Zavala 2010;Fontana et al 2011a;MacGregor-Fors andSchondube 2011, 2012;Reis et al 2012;Loss et al 2014;Pena et al 2017;Brisque et al 2017;Pedreros et al 2018;Basilio et al 2020;de Carmago Barbosa et al 2020).…”

“…The spatial configuration and interactions among the abovementioned factors may affect bird assemblages in urban ecosystems (Oliveira Hagen et al 2017;Leveau et al 2020). However, there have been some contrasting results regarding how distance of urban greenspaces from source areas (urban-fringe) affects bird species richness, abundance, and functional composition (MacGregor-Fors and Ortega-Álvarez 2011;Puga-Caballero et al 2014;Campos-Silva and Piratelli 2020).…”

“…The Atlantic Forest is recognized for harboring many endemic forest birds with high conservation priorities (Vale et al 2018). However, several forest birds do not find suitable environmental conditions (i.e., habitats, niches, and resources) in urbanized sites (Fontana et al 2011b;Toledo et al 2012;Sol et al 2014;de Carmago Barbosa et al 2020;Campos-Silva and Piratelli 2020), being unable to disperse across distances higher than 0.5 km (Ehlers Smith et al 2018). In this sense, habitats near the urban fringe may play a major role in bird conservation in relation to those further away in Neotropical megacities (Puga-Caballero et al 2014).…”

Characteristics of vegetation as determinant of Timor Friarbird (Philemon inornatus) distribution in Bipolo Lanscape of West Timor Island, Indonesia

“…The point count method is used to record bird encounters in the grid (outside the transect line). This is assessment is achieved when the observers walk to a specific area in all habitat or land cover within the grid, and marks the coordinates of the bird encountered with GPS (Machtans and Latour 2003), and records the number of individuals for 5-10 minutes before moving to the next point (Bibby et al 2000;Campos-Silva and Piratelli 2020). Moreover, line transect method is used to estimate the birds recognized only within the transect line by continuously walking while observing, at a distance of 50 m on both sides (right and left) along the observation path.…”