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Ant Communities (ant + community)
Terms modified by Ant Communities Selected AbstractsPost-fire recovery of ant communities in Submediterranean Pinus nigra forestsECOGRAPHY, Issue 2 2006Anselm Rodrigo This study analyzes the variations in the structure and composition of ant communities in burned Pinus nigra forests in central Catalonia (NE Spain). Pinus nigra forests do not recover after fire, changing to shrublands and oak coppices. For this reason, we suggest that ant communities of burned P. nigra forests will change after fire, because the post-fire scenario, in particular with the increase of open areas, is different to the unburned one, and more favourable for some species than for others. In four locations previously occupied by P. nigra forests where different fires occurred 1, 5, 13 and 19 yr before the sampling, we sampled the structure and composition of ant communities with pitfall traps, tree traps and net sweeping in unburned plots and in plots affected by canopy and understory fire. The results obtained suggest that canopy and understory fire had little effect on the structure of ant communities. Thus, many variables concerning ant communities were not modified either by fire type (understory or canopy fire) or by time since fire. However, a number of particular species were affected, either positively or negatively, by canopy fire: three species characteristic of forest habitats decreased after fire, while eight species characteristic of open habitats increased in areas affected by canopy fire, especially in the first few years after fire. These differences in ant community composition between burned and unburned plots imply that the maximum richness is achieved when there is a mixture of unburned forests and areas burned with canopy fire. Moreover, as canopy cover in P. nigra forests burned with canopy fire is not completed in the period of time studied, the presence of the species that are characteristic of burned areas remains along the chronosequence studied, while the species that disappear after fire do not recover in the period of time considered. Overall, the results obtained indicate that there is a persistent replacement of ant species in burned P. nigra forests, as is also the case with vegetation. [source] Resource discovery in ant communities: do food type and quantity matter?ECOLOGICAL ENTOMOLOGY, Issue 5 2010JESSICA M. C. PEARCE-DUVET 1. Omnivorous woodland ant species trade off between the ability to find and behaviourally control food resources. Dominant species can limit the ability of subordinates to harvest certain food items. However, subordinate species, by being faster discoverers, could gain access to such food items by arriving at them first. 2. In this study, we tested the hypothesis that resource-directed discovery occurs in ant communities and that good discoverers preferentially discover high value resources. We did this by measuring time to discovery and the number of discoveries of high and low levels of two resource types, crickets and honey, for species occurring in Texas and Arizona woodland ant communities. 3. Ants discovered resources roughly 10 times faster in Texas than in Arizona. They discovered crickets more rapidly than honey in both communities, but there was no difference in the discovery of different resource levels. We also found that species were not biased in their discovery of different resource types or levels. 4. These results provide indirect evidence that discovery is directed by resource stimuli but that such directedness does not impact interspecific exploitative competition. [source] Biogeographic effects of red fire ant invasionECOLOGY LETTERS, Issue 4 2000N.J. Gotelli The red imported fire ant, Solenopsis invicta, was accidentally introduced to North America over 60 years ago and has spread throughout the southeastern United States. We document the biogeographic consequences of this invasion. We censused ground-foraging ant communities on a 2000 km transect from Florida through New York that passed through invaded and intact biotas. Native ant species density peaks at mid-latitudes in the eastern United States, and the location of this peak corresponds to the range limit of S. invicta. In uninvaded sites, ant species co-occur less often than expected by chance. In the presence of S. invicta, community structure converges to a random pattern. Our results suggest that the effects of S. invicta on native ant communities are pervasive: not only does the presence of S. invicta reduce species density at local scales, it alters the co-occurrence patterns of surviving species at a biogeographic scale. [source] Army ants in four forests: geographic variation in raid rates and species compositionJOURNAL OF ANIMAL ECOLOGY, Issue 3 2007SEAN O'DONNELL Summary 1The New World army ants are top predators in the litter of tropical forest, but no comprehensive studies exist on variation in assemblage-wide activity and species composition. We used standardized protocols to estimate foraging raid rates and species composition of army ant communities in four Neotropical forests. The study sites spanned approximately 10° latitude, with two sites each in Central and South America. 2We recorded a total of 22 species of army ants. The four sites varied in observed and estimated species richness. Species overlap was highest between the Central American sites, and lowest between the South American sites. 3Raid activity varied significantly among sites. Raid activity per kilometre of trail walks was over four times higher at the most active site (Sta. Maria, Venezuela) than at the least active site (Barro Colorado Island, Panama). Furthermore, each site showed a different diel pattern of activity. For example, raid activity was higher during daylight hours in Costa Rica, and higher at night in Venezuela. Raid activity relationships with ambient temperature also varied significantly among sites. 4The overall rate of army ant raids passing through 1 m2 plots was 0·73 raids per day, but varied among sites, from 0 raids per day (Panama) to 1·2 raids per day (Venezuela). 5Primarily subterranean species were significantly more abundant in Venezuela, and above-ground foragers that form large swarm fronts were least abundant in Panama. The site heterogeneity in species abundance and diel activity patterns has implications for army ant symbionts, including ant-following birds, and for the animals hunted by these top predators. [source] Should we use proportional sampling for species,area studies?JOURNAL OF BIOGEOGRAPHY, Issue 8 2004José H. Schoereder Abstract Aim, In this paper we aim to show that proportional sampling can detect species,area relationships (SARs) more effectively than uniform sampling. We tested the contribution of alpha and beta diversity in ant communities as explanations for the SAR. Location, Tropical forest remnants in Viçosa, Minas Gerais, Brazil (20 °45, S, 42 °50, W). Methods, We sampled 17 forest remnants with proportional sampling. To disentangle sampling effects from other mechanisms, species richness was fitted in a model with remnant size, number of samples (sampling effects) and an interaction term. Results, A SAR was observed independent of the number of samples, discarding sampling effects. Alpha diversity was not influenced by remnant size, and beta diversity increased with remnant size; evidence to the fact that habitat diversity within remnants could be the dominant cause of the SAR. Such a relationship between beta diversity and remnant area may have also arisen due to the combined effects of territoriality and aggregation of ant species. Main conclusions, The proposed model, together with proportional sampling, allowed the distinction between sampling effects and other mechanisms. [source] Community organization and species richness of ants (Hymenoptera/Formicidae) in Mongolia along an ecological gradient from steppe to Gobi desertJOURNAL OF BIOGEOGRAPHY, Issue 12 2003Martin Pfeiffer Abstract Aim, Ants (Hymenoptera/Formicidae) have strong influences on ecosystems especially in arid regions. However, little is known about ants of the vast steppe and desert regions of Central Asia. Here we provide the first comprehensive study of ant communities in Mongolia, conducted along a north-to-south gradient in climate. We examined ants' distribution patterns, assessed the impact of climatic parameters on community structure and species diversity and investigated the influence of the corresponding communities of plants. Location, Mongolia (Central Asia). Methods, We observed 31,956 ants at seed baits at 11 study sites along a transect from steppe to Gobi desert for which we attained meteorological data (mean yearly precipitation: 197 to 84 mm). Extra sampling was conducted at sugar and protein baits and by the inspection of different microhabitats. Vegetation patterns of each plot were recorded. Statistical evaluation comprised ordination and correlation. Results, We observed 15 species of ants at seed baits. Three faunal complexes of ants could be distinguished by detrended correspondence analysis (DCA): (1) in steppe baits were dominated by Formica - and Myrmica -species, (2) in semi desert we found mostly species of Tetramorium, Myrmica, Proformica, Plagiolepis, and Leptothorax, and (3) in desert Cataglyphis aenescens and Messor aciculatus dominated, and Lasius was exclusively found there. Another 11 rare ant species were sampled by hand and at sugar baits. Altogether five ant species were new to the Mongolian fauna: Cardiocondyla koshewnikovi, Myrmica koreana, Myrmica pisarskii, Polyergus nigerrimus, and Proformica kaszabi. Assignment of taxa to functional groups showed that in steppe cold climate specialists dominated, in semi desert we found mainly opportunists, and in desert hot climate specialists. Several functional groups know from arid zones in other parts of the world were missing. In desert certain species were highly dominant. First DCA scores of ant- and plant-communities were highly correlated with each other and with climatic parameters. While plant species diversity was positively correlated with increasing northern latitude, ant diversity and ant species richness were not correlated with latitude and responded neither to precipitation, nor to any other climatic parameter. Semi desert was a transition zone between steppe and desert, with high species richness. Ant genus composition of the ecotone overlapped with both other regions. However, beta diversity between pairs of plots within this zone was low, indicating a small-scale mosaic pattern. Main conclusions, The ant communities in the Mongolian steppe and desert zones were strongly influenced by low temperatures and differed in many aspects from the ant fauna in other arid ecosystems, especially in terms of species richness, diversity of feeding guilds, and richness of functional groups. [source] Are Ants Useful Indicators of Restoration Success in Temperate Grasslands?RESTORATION ECOLOGY, Issue 3 2010Kate C. Fagan Assessments of restoration are usually made through vegetation community surveys, leaving much of the ecosystem underexamined. Invertebrates, and ants in particular, are good candidates for restoration evaluation because they are sensitive to environmental change and are particularly important in ecosystem functioning. The considerable resources currently employed in restoring calcareous grassland on ex-arable land mean that it is important to gather as much information as possible on how ecosystems change through restoration. We compared ant communities from 40 ex-arable sites where some form of restoration work had been implemented between 2 and 60 years previously, with 40 paired reference sites of good quality calcareous grassland with no history of improvement or cultivation. A total of 11 ant species were found, but only two of these were found to be significantly different in abundance between restoration and reference sites: Myrmica sabuleti was more likely to be present in reference sites, whereas Lasius niger was more likely to be found in restoration sites. Myrmica sabuleti abundance was significantly positively correlated with age of restoration sites. The potential number of ant species found in temperate grasslands is small, limiting the information their assemblages can provide about ecosystem change. However, M. sabuleti is a good indicator species for calcareous grassland restoration success and, alongside information from the plant community, could increase the confidence with which restoration success is judged. We found the survey to be quick and simple to carry out and recommend its use. [source] Responses of ant communities to experimental fire regimes on rangelands in the Victoria River District of the Northern TerritoryAUSTRAL ECOLOGY, Issue 2 2003BENJAMIN D. HOFFMANN Abstract Fire is a significant feature of Australia's savannas. Its use is being encouraged for cattle rangeland management, but there is little knowledge of the ecological effects of prescribed fire regimes on native biodiversity. The responses of ant communities to five experimental fire regimes over 2 years are reported from the Victoria River District in the semi-arid tropics of northern Australia. The experiment was stratified at two levels: soil type (red and black) and fire treatment (unburnt; burnt twice in successive years in early (May) or late (October) dry season and unburnt thereafter; and burnt twice, 3 years apart, in early or late dry season). Ants were sampled twice in April, corresponding with the end of the 1997 and 1998 wet seasons. Ant species richness was not responsive to fire treatment, but reduced with time since fire on black soil. Total ant abundance also reduced with time since fire on the black soil, with significant different abundances in burnt versus unburnt plots in the 1998 sample. Soil type and sampling time had the greatest influence on ant community composition in multivariate analysis than did fire regime, although there were moderate gradients of time since fire with the black soil plots. The abundance of 19 species were significantly different between fire regimes in ANOVA, 13 on red soil and six on black soil. The abundance of eight species (four each on red and black soil) changed significantly with time since fire, with seven promoted by burning. Ant functional group profiles changed little with fire. Total ant abundance and richness had significant relationships with key pasture species and vegetative variables. The responses of ants largely recapitulated those of plants, birds and reptiles on the same plots. It is envisaged that ants will have an important role to play in the sustainable management of Australia's rangelands aiding the off-reserve conservation of biodiversity. [source] Australian ant research: fabulous fauna, functional groups, pharmaceuticals, and the FatherhoodAUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 3 2004Jonathan D Majer Abstract Apart from flies, ants are Australia's most noticeable and studied insects. In addition to their sheer abundance and ubiquity in most terrestrial ecosystems, they are also exceptionally diverse. Here, we outline the history of describing the Australian ant fauna and document the resources that are available for identifying and researching them. Unusual patterns in chromosome numbers in individual species are discussed, and the rediscovery of an ancient ant is described. A framework for understanding the dynamics of Australian ant communities is outlined, and the functional groups that fall within this framework are documented. The predictability of responses of ant communities to stress and disturbance has enabled a protocol for using ants as bioindicators of environmental health and integrity to be developed. This has been exported and adapted to other regions of the world. Australian ant research has also lead to promising sources of biopharmaceuticals. As well as describing these two practical applications of Australian ant research, this review looks at some of the future directions that studies on Australian ants might take. [source] Impact of Flooding on the Species Richness, Density and Composition of Amazonian Litter-Nesting AntsBIOTROPICA, Issue 5 2009Amy L. Mertl ABSTRACT Litter-nesting ants are diverse and abundant in tropical forests, but the factors structuring their communities are poorly known. Here we present results of the first study to examine the impact of natural variation in flooding on a highly diverse (21 genera, 77 species) litter-nesting ant community in a primary Amazonian forest. Fifty-six 3 × 3 m plots experiencing strong variation in flooding and twenty-eight 3 × 3 m terra firme plots were exhaustively searched for litter-nesting ants to determine patterns of density, species richness and species composition. In each plot, flooding, litter depth, twig availability, canopy cover, plant density, percent soil nitrogen, carbon, and phosphorus were measured. Degree of flooding, measured as flood frequency and flood interval, had the strongest impact on ant density in flooded forest. Flooding caused a linear decrease in ant abundance, potentially due to a reduction of suitable nesting sites. However, its influence on species richness varied: low-disturbance habitat had species richness equal to terra firme forest after adjusting for differences in density. The composition of ant genera and species varied among flood categories; some groups known to contain specialist predators were particularly intolerant to flooding. Hypoponera STD10 appeared to be well-adapted to highly flooded habitat. Although flooding did not appear to increase species richness or abundance at the habitat scale, low-flooding habitat contained a mixture of species found in the significantly distinct ant communities of terra firme and highly flooded habitat. [source] Patterns of abundance of fire ants and native ants in a native ecosystemECOLOGICAL ENTOMOLOGY, Issue 4 2009KATHARINE L. STUBLE Abstract 1.,This correlational study examines the relationship between the red imported fire ant (Solenopsis invicta) and native ants in a longleaf pine savanna. Fire ants are frequently associated with a decline in native ants throughout the invaded range, but fire ant invasion is often coupled with habitat disturbance. Invasion of fire ants into the longleaf pine savanna provides an opportunity to examine the structure of the ant community in the absence of habitat disturbance. 2.,Pitfall trapping was conducted within the longleaf pine savanna as well as across a naturally occurring soil moisture gradient, in plots that had been artificially watered. 3.,Species richness did not vary as a function of fire ant density. There was an inverse relationship between native ant density and fire ant density, but this abundance pattern does not necessarily imply a causal link between fire ant invasion and native ant decline. For individual species, fire ant densities were negatively correlated with the densities of only two native ant species, including Solenopsis carolinensis, a native species that potentially limits the invasion of fire ants. Additionally, fire ants and native ants respond differently to soil moisture, with native ants favouring drier conditions than fire ants. 4.,The possible exclusion of fire ants by some native ants, as well as differences in habitat preferences, provide alternative explanations for the frequently observed negative correlation between fire ants and native ants. [source] Microsatellite analysis reveals strong but differential impact of a social parasite on its two host speciesMOLECULAR ECOLOGY, Issue 3 2006BIRGIT FISCHER-BLASS Abstract The speed and the dynamics of the co-evolutionary process strongly depend on the relative strengths of reciprocal selection pressures exerted by the interacting species. Here, we investigate the influence of an obligate social parasite, the slave-making ant Harpagoxenus sublaevis, on populations of the two main host species Leptothorax acervorum and Leptothorax muscorum from a German ant community. A combination of genetic and demographic data allowed us to analyse the consequences of raiding pressure on the hosts' life history and possible host preferences of the parasite. We can demonstrate that slave raids during which the social parasite pillages brood from neighbouring host colonies are both frequent and extremely destructive for both host species. Microsatellite analysis showed that, on average, a single slave-maker colony conducts more than three raids per year and that host colonies mostly perish in the aftermath of these parasite attacks. Only in few cases, surviving nests of previously raided host colonies were found in the surroundings of slave-maker colonies. As a consequence of the high prevalence of parasites and their recurrent and devastating slave raids on host colonies, the life expectancy of host colonies was severely reduced. Combining our results on host-specific parasitic colony founding and raiding frequencies with the post-raid survival rate, we can demonstrate an overall higher mortality rate for the smaller host species L. muscorum. This might be caused by a preference of H. sublaevis for this secondary host species as demographic data on host species usage indicate. [source] Response of an open-forest ant community to invasion by the introduced ant, Pheidole megacephalaAUSTRAL ECOLOGY, Issue 3 2000C. Vanderwoude Abstract The introduced tramp ant, Pheidole megacephala, is a well-known pest of urban areas and coastal dune ecosystems in eastern Australia. Until recently, establishment and spread of P. megacephala colonies has been regarded as likely only in disturbed areas. Here we describe the extent of an established colony of P. megacephala in a long undisturbed open forest near Maryborough in southeast Queensland and compare ant community structure with those of nearby uninfested sites. Tuna baiting revealed three distinct zones: (i) a zone totally dominated by P. megacephala (at least 10 ha) where few other ant ant species were detected; (ii) a zone where P. megacephala was absent and many other ant species were found; and (iii) a zone where opportunists (species of Ochetellus and Paratrechina) competed with P. megacephala at baits. Pitfall trapping over a 9-month period resulted in 12 species being recorded at the infested site, compared with a mean of 25 species recorded at adjoining uninfested forest. Over 94% of ants recorded in pitfalls at the infested site were P. megacephala. Most notably, P. megacephala had completely displaced dominant Dolichoderines (species of Iridomyrmex), subordinate Camponotini (species of Camponotus, Opisthopsis and Polyrhachis) and other species of Pheidole which are common at forest sites. [source] Twig-Nesting Ants: The Hidden Predators of the Coffee Berry Borer in Chiapas, MexicoBIOTROPICA, Issue 3 2010Ashley Larsen ABSTRACT Coffee is a globally important crop that is subject to numerous pest problems, many of which are partially controlled by predatory ants. Yet several studies have proposed that these ecosystem services may be reduced where agricultural systems are more intensively managed. Here we investigate the predatory ability of twig-nesting ants on the main pest of coffee, the coffee berry borer (Hypothenemus hampei) under different management systems in southwest Chiapas, Mexico. We conducted both laboratory and field experiments to examine which twig-nesting ant species, if any, can prey on free-living borers or can remove borers embedded in coffee fruits and whether the effects of the twig-nesting ant community differ with habitat type. Results indicate that several species of twig-nesting ants are effective predators of both free-living borers and those embedded in coffee fruits. In the lab, Pseudomyrmex ejectus, Pseudomyrmex simplex, and Pseudomyrmex PSW-53 effectively removed free-living and embedded borers. In the field, abundance, but not diversity, of twig-nesting ant colonies was influenced by shade management techniques, with the highest colony abundance present in the sites where shade trees were recently pruned. However, borer removal rates in the field were significant only in the shadiest site, but not in more intensively managed sites. This study provides evidence that twig-nesting ants can act as predators of the coffee berry borer and that the presence of twig-nesting ants may not be strongly linked to shade management intensity, as has been suggested for other arthropod predators of the borer. Abstract in Spanish is available at http://www.blackwell-synergy.com/loi/btp [source] Impact of Flooding on the Species Richness, Density and Composition of Amazonian Litter-Nesting AntsBIOTROPICA, Issue 5 2009Amy L. Mertl ABSTRACT Litter-nesting ants are diverse and abundant in tropical forests, but the factors structuring their communities are poorly known. Here we present results of the first study to examine the impact of natural variation in flooding on a highly diverse (21 genera, 77 species) litter-nesting ant community in a primary Amazonian forest. Fifty-six 3 × 3 m plots experiencing strong variation in flooding and twenty-eight 3 × 3 m terra firme plots were exhaustively searched for litter-nesting ants to determine patterns of density, species richness and species composition. In each plot, flooding, litter depth, twig availability, canopy cover, plant density, percent soil nitrogen, carbon, and phosphorus were measured. Degree of flooding, measured as flood frequency and flood interval, had the strongest impact on ant density in flooded forest. Flooding caused a linear decrease in ant abundance, potentially due to a reduction of suitable nesting sites. However, its influence on species richness varied: low-disturbance habitat had species richness equal to terra firme forest after adjusting for differences in density. The composition of ant genera and species varied among flood categories; some groups known to contain specialist predators were particularly intolerant to flooding. Hypoponera STD10 appeared to be well-adapted to highly flooded habitat. Although flooding did not appear to increase species richness or abundance at the habitat scale, low-flooding habitat contained a mixture of species found in the significantly distinct ant communities of terra firme and highly flooded habitat. [source] | |||||||||||||||||||