@article{chick_lessard_dunn_sanders_2020, title={The Coupled Influence of Thermal Physiology and Biotic Interactions on the Distribution and Density of Ant Species along an Elevational Gradient}, volume={12}, ISSN={["1424-2818"]}, DOI={10.3390/d12120456}, abstractNote={A fundamental tenet of biogeography is that abiotic and biotic factors interact to shape the distributions of species and the organization of communities, with interactions being more important in benign environments, and environmental filtering more important in stressful environments. This pattern is often inferred using large databases or phylogenetic signal, but physiological mechanisms underlying such patterns are rarely examined. We focused on 18 ant species at 29 sites along an extensive elevational gradient, coupling experimental data on critical thermal limits, null model analyses, and observational data of density and abundance to elucidate factors governing species’ elevational range limits. Thermal tolerance data showed that environmental conditions were likely to be more important in colder, more stressful environments, where physiology was the most important constraint on the distribution and density of ant species. Conversely, the evidence for species interactions was strongest in warmer, more benign conditions, as indicated by our observational data and null model analyses. Our results provide a strong test that biotic interactions drive the distributions and density of species in warm climates, but that environmental filtering predominates at colder, high-elevation sites. Such a pattern suggests that the responses of species to climate change are likely to be context-dependent and more specifically, geographically-dependent.}, number={12}, journal={DIVERSITY-BASEL}, author={Chick, Lacy D. and Lessard, Jean-Philippe and Dunn, Robert R. and Sanders, Nathan J.}, year={2020}, month={Dec} }
 @article{weiser_sanders_agosti_andersen_ellison_fisher_gibb_gotelli_gove_gross_et al._2010, title={Canopy and litter ant assemblages share similar climate-species density relationships}, volume={6}, ISSN={["1744-9561"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-78649884769&partnerID=MN8TOARS}, DOI={10.1098/rsbl.2010.0151}, abstractNote={Tropical forest canopies house most of the globe's diversity, yet little is known about global patterns and drivers of canopy diversity. Here, we present models of ant species density, using climate, abundance and habitat (i.e. canopy versus litter) as predictors. Ant species density is positively associated with temperature and precipitation, and negatively (or non-significantly) associated with two metrics of seasonality, precipitation seasonality and temperature range. Ant species density was significantly higher in canopy samples, but this difference disappeared once abundance was considered. Thus, apparent differences in species density between canopy and litter samples are probably owing to differences in abundance–diversity relationships, and not differences in climate–diversity relationships. Thus, it appears that canopy and litter ant assemblages share a common abundance–diversity relationship influenced by similar but not identical climatic drivers.}, number={6}, journal={BIOLOGY LETTERS}, author={Weiser, Michael D. and Sanders, Nathan J. and Agosti, Donat and Andersen, Alan N. and Ellison, Aaron M. and Fisher, Brian L. and Gibb, Heloise and Gotelli, Nicholas J. and Gove, Aaron D. and Gross, Kevin and et al.}, year={2010}, month={Dec}, pages={769–772} }
 @article{lessard_dunn_parker_sanders_2007, title={Rarity and diversity in forest ant assemblages of Great Smoky Mountains National Park}, volume={6}, ISSN={["1528-7092"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-37049024789&partnerID=MN8TOARS}, DOI={10.1656/1528-7092(2007)6[215:RADIFA]2.0.CO;2}, abstractNote={Abstract We report on a systematic survey of the ant fauna occurring in hardwood forests in the Great Smoky Mountains National Park. At 22-mixed hardwood sites, we collected leaf-litter ant species using Winkler samplers. At eight of those sites, we also collected ants using pitfall and Malaise traps. In total, we collected 53 ant species. As shown in other studies, ant species richness tended to decline with increasing elevation. Leaf-litter ant assemblages were also highly nested. Several common species were both locally abundant and had broad distributions, while many other species were rarely detected. Winkler samplers, pitfall traps, and Malaise traps yielded samples that differed in composition, but not richness, from one another. Taken together, our work begins to illuminate the factors that govern the diversity, distribution, abundance, and perhaps rarity of ants of forested ecosystems in the Great Smoky Mountains National Park.}, number={SPEC. ISS. 1}, journal={SOUTHEASTERN NATURALIST}, author={Lessard, Jean-Philippe and Dunn, Robert R. and Parker, Charles R. and Sanders, Nathan J.}, year={2007}, pages={215–228} }
 @article{sanders_lessard_fitzpatrick_dunn_2007, title={Temperature, but not productivity or geometry, predicts elevational diversity gradients in ants across spatial grains}, volume={16}, ISSN={["1466-8238"]}, url={http://www.scopus.com/inward/record.url?eid=2-s2.0-34547997185&partnerID=MN8TOARS}, DOI={10.1111/j.1466-8238.2007.00316.x}, abstractNote={ABSTRACTAim  This research aims to understand the factors that shape elevational diversity gradients and how those factors vary with spatial grain. Specifically, we test the predictions of the species–productivity hypothesis, species–temperature hypothesis, the metabolic theory of ecology and the mid‐domain effects null model. We also examine how the effects of productivity and temperature on richness depend on spatial grain.Location  Deciduous forests along an elevational gradient in Great Smoky Mountains National Park, USA.Methods  We sampled 22 leaf litter ant assemblages at three spatial grains, from 1‐m2 quadrats to 50 × 50 m plots using Winkler samplers.Results  Across spatial grains, warmer sites had more species than did cooler sites, and primary productivity did not predict ant species richness. We found some support for the predictions of the metabolic theory of ecology, but no support for the mid‐domain effects null model. Thus, our data are best explained by some version of a species–temperature hypothesis.Main conclusions  Our results suggest that temperature indirectly affects ant species diversity across spatial grains, perhaps by limiting access to resources. Warmer sites support more species because they support more individuals, thereby reducing the probability of local extinction. Many of our results from this elevational gradient agree with studies at more global scales, suggesting that some mechanisms shaping ant diversity gradients are common across scales.}, number={5}, journal={GLOBAL ECOLOGY AND BIOGEOGRAPHY}, author={Sanders, Nathan J. and Lessard, Jean-Philippe and Fitzpatrick, Matthew C. and Dunn, Robert R.}, year={2007}, month={Sep}, pages={640–649} }
 @article{davidson_lessard_bernau_cook_2007, title={The tropical ant mosaic in a primary Bornean rain forest}, volume={39}, ISSN={["1744-7429"]}, DOI={10.1111/j.1744-7429.2007.00304.x}, abstractNote={ABSTRACTIn primary lowland rain forest in Brunei Darussalam, we studied arboreal ant communities to evaluate whether densities and spacing of spatially territorial taxa along 2.9 km of well‐studied trails are consistent with existence of a continuous mosaic of dominant ants. A median intercolony distance of 24.5 m, about twice or less distances over which colonies of most included species regularly ranged, suggested a relatively continuous mosaic. Despite relying on nesting sites in preformed plant cavities, carpenter ants contributed > 70 percent of mapped colonies. Most belonged to theCamponotus(Colobopsis)cylindricus(COCY) complex, including SE Asia's ‘exploding’ ants. Their lack of aggression against certainPolyrhachisspecies was associated with interspecific territory sharing by members of the two groups, and with a dominance‐discovery trade‐off. Experimental approaches yielded evidence for two putative contributors to positive association. Larger‐bodiedPolyrhachisparasitize food‐finding abilities of smaller, more populousCamponotusworkers, and the two taxa cooperate in territorial defense. Highly territorial and predatory weaver ants (Oecophylla smaragdina) were an important component of the ant mosaic in primary forest, second only to codominant COCY andPolyrhachistaxa. Members of the genusCrematogasterwere significantly associated withOecophyllain baiting censuses and regularly monopolized near‐nest baits to the exclusion of weaver ants. Litter ant abundances differed between territories ofOecophyllaand less predatory COCY species, but direction of difference was inconsistent over time. The densely packed mosaic of spatially territorial, and differentially predatory, taxa in Bornean rain forest likely contributes to spatial variation in ant effects on plant and arthropod communities.}, number={4}, journal={BIOTROPICA}, author={Davidson, Diane W. and Lessard, Jean-Philippe and Bernau, Christopher R. and Cook, Steven C.}, year={2007}, month={Jul}, pages={468–475} }