Ant community structure under Retama sphaerocarpa shrubs in a semi‐arid environment

Abstract

The Tabernas Desert (Spain) is an emblematic area as it constitutes, strictly speaking, the only European desert. Under the canopy of one of the dominant shrub species, Retama sphaerocarpa, there are different microhabitat conditions that encourage the growing of a dense understory of herbs (fertile islands). However, these changes may not be enough to be also reflected in the fauna. Studying ants as bioindicators, we found higher densities of individuals and species richness below the canopy than outside it. However, while the density of individuals increased from outside the canopy to the inner position under the shrubs, species richness increased from the inner to the border position under the canopy and abruptly decreased outside it. This is because the inner positions were usually monopolized by dominant ants with populous nests that feed on aphid honeydew, such as Monomorium subopacum or Tapinoma nigerrimum. Granivorous species (genus Messor) were usually found in intermediate positions under the canopy, taking advantage of the better microclimatic conditions but close to the grass for feeding. Among the most abundant species, the only one found mainly outside the influence of the retama shrubs was the thermophilic insectivorous Cataglyphis ibericus.

Heterogeneity of soil surface temperature induced by xerophytic shrub in a revegetated desert ecosystem, northwestern China

“…These results suggest that maximum temperatures or diurnal temperature variations can be used as cues to detect safe sites for the biota under the canopy. For example, Retana and Cerda (2000) noticed that ant communities track spatial and temporal variability in the thermal environment and reached the similar conclusions as above Carpintero et al (2011). Accordingly, the amelioration of the thermal environment produced by the patchy shrubs plays an important role in the under-canopy biota in desert ecosystems.…”

“…Additionally, shading by shrubs provides shelter for insects, reptiles and other organisms in hot summer months. For instance, by studying ants as bioindicators in the Tabernas Desert, Carpintero et al (2011) reported higher densities of individuals and species richness under shrub canopy than in the interspaces, and pointed out that lower soil temperature beneath canopy may be the main factor. The soil surface temperature measurements made in the present study also showed that aspect of shrub strongly affected soil surface temperature heterogeneity around the shrub.…”

“…Shrubs produce ecologically important microclimates (soil and air temperature, humidity, wind speed, solar radiation, soil evaporation, etc.) under their canopies in desert ecosystems (Vetaas 1992;Moro et al 1997;Tracol et al 2011), which greatly affects near-surface biological processes including seed germination (Valientebanuet and Ezcurra 1991;FrancoPizana et al 1996;Mayor et al 2007), soil seed banks (Price and Reichman 1987;Wang et al 2010), seedling establishment, survival and growth (Franco and Nobel 1989;Moro et al 1997;Ludwig et al 2001;Schumacher et al 2008;Griffith 2010), microbial activities (Goberna et al 2007;Jia et al 2010), root growth (Macduff et al 1986), insects population dynamics (Shelef and Groner 2011;Carpintero et al 2011), etc.…”

Ant community structure and response to disturbances on coastal dunes of Gulf of Mexico

“…These structures may provide increased niche availability, a more stable environment, and increased moisture retention that all strongly influence the distributions of many other organisms (Pollet and Grootaert 1996;Sarig et al 1999;Finke and Snyder 2008;Carpintero et al 2011;Schirmel and Buchholz 2011). All known functional groups of ants can be found in the coastal dunes with the exception of Specialist Predators.…”

Ant Guild Identity Determines Seed Fate at the Post-Removal Seed Dispersal Stages of a Desert Perennial

“…Large scavenging ants, such as Cataglyphis spp. , locate their nests in open sites, which reduces competition with more dominant ant species [ 68 , 69 ]. In our study site, M. ebeninus and some dominant omnivorous ant species ( Tapinoma and Monomorium spp.…”