Influences of horizontal and vertical aspects of land cover and their interactions with regional factors on patterns of avian species-richness

Brian M Napoletano,John B Dunning,Bryan C Pijanowski,Serge Wich

doi:10.1080/23311843.2017.1296604

Brian M Napoletano, John B Dunning + Show 2 more

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https://doi.org/10.1080/23311843.2017.1296604

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Abstract

We examined how both horizontal and vertical aspects of land-cover diversity influence patterns of avian species-richness across North America. Using count data from Breeding Bird Survey routes wit...

Highlights

The spatial variation in biological communities is a major research topic in applied geography, landscape ecology, biogeography, and community ecology (Costanza, Moody, & Peet, 2011; Elton, 2001; de Roos & Sabelis, 1995; Wilson, 2000), and spatial variation is believed to be as important as temporal variation to the regulation of ecosystem processes (Ma, Zuckerberg, Porter, & Zhang, 2012; Turner & Cardille, 2007)
Analytical methods To test the hypothesized relationship between avian species-richness and landscape factors using diversity and vegetative strata as indirect indicators of habitat-level diversity, we focused on two principal questions in our statistical analysis: (1) Do increasing proportions of multi-strata vegetation correspond to higher levels of species richness in a manner analogous to the effects of increasing land-cover diversity? and (2) Does the importance of vegetation strata decrease as overall landscape diversity increases? To determine the importance of these landscape-level variables and the habitat-level factors they indirectly reflect at the regional scale, we asked whether their influence could be detected across the study region and remain statistically significant even when modeled against regional factors
The findings in this study indicating that landscape factors remain statistically significant even alongside regional factors across the conterminous USA are consistent with other regional studies (e.g. Culbert et al, 2013; Pekin & Pijanowski, 2012; Rahbek et al, 2007) demonstrating that models that purport to explain spatial patterns of species-richness using only one or a few regional factors (Currie (2007) “strong constraints family” of explanation in biogeography) are necessarily incomplete

Summary

Introduction

The spatial variation in biological communities is a major research topic in applied geography, landscape ecology, biogeography, and community ecology (Costanza, Moody, & Peet, 2011; Elton, 2001; de Roos & Sabelis, 1995; Wilson, 2000), and spatial variation is believed to be as important as temporal variation to the regulation of ecosystem processes (Ma, Zuckerberg, Porter, & Zhang, 2012; Turner & Cardille, 2007). Avian species-richness as a measure of biodiversity Avian species-richness, typically considered an α-level variable in the traditional biodiversity hierarchy (MacArthur, 2004; Whittaker, 1972; Whittaker, Willis, & Field, 2001), is commonly used in studies of biodiversity patterns over macro-scales (Gaston & Williams, 1993) because it tracks well with other dominant biodiversity factors at these scales (Gaston & Blackburn, 1995) It does not capture sub-species variations—which may be declining at a rate three orders of magnitude greater than that of species extinctions (Rands et al, 2010)—and is neutral in regards to species composition and attributes (e.g. evenness, rarity, endemism) that may be important in other studies (e.g. trophic structures, sink-source delineation, predator-prey models) and to conservation and management (Storch, Marquet, & Brown, 2007; Wilson, 2000). Species richness is best considered as a widely used, basic indicator of biodiversity that is, necessarily incomplete (Lévêque & Mounolou, 2003)

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