Climatic drivers of hemispheric asymmetry in global patterns of ant species richness

Abstract

Although many taxa show a latitudinal gradient in richness, the relationship between latitude and species richness is often asymmetrical between the northern and southern hemispheres. Here we examine the latitudinal pattern of species richness across 1003 local ant assemblages. We find latitudinal asymmetry, with southern hemisphere sites being more diverse than northern hemisphere sites. Most of this asymmetry could be explained statistically by differences in contemporary climate. Local ant species richness was positively associated with temperature, but negatively (although weakly) associated with temperature range and precipitation. After contemporary climate was accounted for, a modest difference in diversity between hemispheres persisted, suggesting that factors other than contemporary climate contributed to the hemispherical asymmetry. The most parsimonious explanation for this remaining asymmetry is that greater climate change since the Eocene in the northern than in the southern hemisphere has led to more extinctions in the northern hemisphere with consequent effects on local ant species richness.

Dissimilarity of Ant Communities Increases with Precipitation, but not Reduced Land-Use Intensity, in Indonesian Cacao Agroforestry

“…This result is similar to that of Delsinne et al [22], who did not find a relationship between precipitation and local ant species richness in arid ecosystems. In our research, the gradient of precipitation was limited (1032 to 2051 mm/year), which may explain why alpha diversity did not show a positive correlation of precipitation and ant diversity [23,24]. Nevertheless, we found that increasing precipitation decreased similarity of ant communities in the cacao agroforestry systems.…”

Efeitos da distância entre iscas nas estimativas de abundância e riqueza de formigas em uma floresta de terra-firme na Amazônia Central

“…Locais mais secos normalmente comportam menos espécies que locais mais úmidos e locais mais quentes concentram mais espécies por unidade de área que locais mais frios (Dunn et al, 2009;Vasconcelos et al, 2010). É possível que florestas mais secas comportem menos espécies de formigas atraídas por iscas que florestas mais úmidas (Tabela 2).…”

“…Esse método de coleta é amplamente utilizado para investigar a atividade de formigas que vivem no solo e na vegetação (Savolainen e Vepsäläinen, 1988;Porter e Savignano, 1990;Davidson, 1998;Bestelmeyer et al, 2000;Brandão et al, 2000;Albrecht e Gotelli, 2001), mas também pode ser empregado para estimar o número de espécies de formigas (Benson e Harada, 1988;Silva et al, 2004) ou como método complementar em inventários (Vasconcelos et al, 2009). No entanto a coleta com iscas normalmente amostra de forma tendenciosa a composição da comunidade.…”

Strong influence of regional species pools on continent-wide structuring of local communities

“…In addition, the species density of ants (i.e. the number of species per unit of area) among communities did not correlate with the size of the sampling grain in a global study using similar community data for ants [19]. We further excluded studies conducted in highly disturbed anthropogenic habitats (e.g.…”

“…Climate influences many attributes of ant community structure and has been shown to explain a large proportion of geographical variation in ant abundance [21,22], species density [19,21,22] and species composition [23]. Recent global studies have shown that temperature and precipitation account for a large portion of the variation in ant species density, whether among ground foraging ant assemblages [19] or canopy species [24]. One possible explanation is that evolutionary constraints on ecological traits such as cold and/or drought tolerance could play a central role in explaining the relative paucity of ant species in these regions.…”