Shrub density effects on the community structure and composition of a desert animal community

Mario Zuliani,Christopher J Lortie,Nargol Ghazian

doi:10.2981/wlb.00774

Abstract

Positive interactions between shrubs and animals are frequent in desert ecosystems. Shrub canopies can provide refuge to some animal species from predators and shelter from stressful environmental conditions by ameliorating high temperatures through lowering the amplitude of variation. Consequently, there have been many contrasts of shrub versus open effects; however, we extend this approach further by testing these effects on a gradient of shrub densities in the Carrizo National Monument, California. We tested the hypothesis that shrub density is a landscape-level predictor of vertebrate community composition and structure. We used camera traps, transects and focal observations to estimate animal density and composition, alongside the deployment of temperature sensors. Plots were established within shrub patches ranging from 0 to 12 shrubs per 10 m radius. Plots with relatively higher shrub densities had increased abundance and richness of vertebrate animal species. Temperature and residual dry matter were also important mediators of animal density and richness. Shrub cover was also an important driver of animal communities but we propose that shrub density is a more rapid proxy for vegetation effects in deserts relevant to wildlife conservationists, and managers.

Highlights

BioOne Complete is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses
Shrub cover was an important driver of animal communities but we propose that shrub density is a more rapid proxy for vegetation effects in deserts relevant to wildlife conservationists, and managers
The abundance (Table 1, GLM, p-value = 1.34 × 10-08; estimated marginalized means (EMM) −0.3490 ± 0.104, post hoc, p-value = 0.0008) and richness (Table 2, GLM, p-value = 1.22e-0.08; EMM −0.2403 ± 0.0876, post hoc, p-value = 0.0061) of vertebrate communities declined with shrub densities in the open microsites across the shrub-density gradient, while evenness (Table 3, GLM, p-value = 0.3547) was not significantly different between plots

Summary

Introduction

BioOne Complete (complete.BioOne.org) is a full-text database of 200 subscribed and open-access titles in the biological, ecological, and environmental sciences published by nonprofit societies, associations, museums, institutions, and presses. To ameliorate the stressors associated with these changes, positive interactions between these local animal species and foundational shrubs have been reported (Lortie et al 2016, Dangles et al 2018). These positive interactions are defined as non-trophic interactions between species, where at least one of these interacting individuals benefit, while the other is either unaffected or benefits in the process (Bertness and Leonard 1997, Molina-Montenegro et al 2016). The license permits use, distribution and reproduction in any medium, provided the original work is properly cited

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