Ant Biodiversity Research Articles

Short term response of ants to the removal of ground cover in organic olive orchards

Ants are the most abundant group of soil arthropods in olive groves where they are involved in various trophic relation- ships of great importance for crops. The system of soil management is one agricultural practice that has a great effect on ants, so the objective of this study was to compare ant populations in organic olive orchards with a ground cover of natural vegetation and others where this natural vegetation is mechanically removed at the beginning of June. Ants were sampled using pitfall traps at 14, 30, 70 and 90 days after the removal of the ground vegetation. Overall, ant biodiversity did not change. However, changes were observed in the abundance of ant species, in particular, in those species that build shallow nests in the soil, both between the rows of trees and under the canopy of olive trees. In contrast, deep nesting species, such as Messor barbarus, were not affected. The response also dif- fered between the various genera: the abundance of Cataglyphis increased, due to there being more of the species C. rosenhaueri, while there was a significant fall in Aphaenogaster, due to the decline in abundance of A. senilis. Thirty days after the removal of vegetation, the response of most of the genera was clearly noticeable, due to the increased activity of workers, and in some cases there were still differences after 90 days.

Forecasting the future of biodiversity: a test of single- and multi-species models for ants in North America

The geographic distributions of many taxonomic groups remain mostly unknown, hindering attempts to investigate the response of the majority of species on Earth to climate change using species distributions models (SDMs). Multi-species models can incorporate data for rare or poorly-sampled species, but their application to forecasting climate change impacts on biodiversity has been limited. Here we compare forecasts of changes in patterns of ant biodiversity in North America derived from ensembles of single-species models to those from a multi-species modeling approach, Generalized Dissimilarity Modeling (GDM). We found that both single- and multi-species models forecasted large changes in ant community composition in relatively warm environments. GDM predicted higher turnover than SDMs and across a larger contiguous area, including the southern third of North America and notably Central America, where the proportion of ants with relatively small ranges is high and where data limitations are most likely to impede the application of SDMs. Differences between approaches were also influenced by assumptions regarding dispersal, with forecasts being more similar if no-dispersal was assumed. When full-dispersal was assumed, SDMs predicted higher turnover in southern Canada than did GDM. Taken together, our results suggest that 1) warm rather than cold regions potentially could experience the greatest changes in ant fauna under climate change and that 2) multi-species models may represent an important complement to SDMs, particularly in analyses involving large numbers of rare or poorly-sampled species. Comparisons of the ability of single- and multi-species models to predict observed changes in community composition are needed in order to draw definitive conclusions regarding their application to investigating climate change impacts on biodiversity.

Avaliação rápida da diversidade de formigas em sistemas de uso do solo no sul da Bahia

We aimed to compare the soil ant diversity in different land use systems from Atlantic Forest area, in Southern Bahia state, Brazil. The ants were sampled in 16 sites: two primary forest sites (un-logged forest); three young secondary forests (<8 years old); three intermediate secondary forests (8-20 years old); three old secondary forests (>20 years old); three Eucalyptus grandis plantations (3-7 years old), and two introduced pastures. Each site was sampled in three sampling points 15 m apart, and distant over 50 m from the site edge. In each sampling point we gathered the litter from a 1 m² and extracted the ants with Winkler extractors during 48h. We found 103 ant species from 29 genera and eight subfamilies. The five richest genera were Pheidole (19 species), Solenopsis (8), Apterostigma (10), Hypoponera (7) e Paratrechina (5). The highest ant richness density was found in the primary forest (7.4 species/sample; S = 37; n = 5); followed by the old secondary forest (5.33 species/sample; S = 48; n = 9); young secondary forest (5.25 species/sample; S = 42, n = 8); eucalyptus plantation (4.22 species/sample; S = 38, n = 9), intermediate secondary forest (3.5 species/sample; S = 35, n = 10, and introduced pasture (2.67 species/sample; S = 16, n = 6). The ecosystems with higher structural complexity showed the highest ant richness density by sample. Therefore, in the Atlantic Forest region, the eucalyptus plantation is a better alternative of land use to conserve the ant biodiversity than pastures, and quite similar to native secondary forests in ant community characteristics.

Conservation value of low fire frequency in tropical savannas: Ants in monsoonal northern Australia

The conservation values of ‘old-growth’ forests in landscapes subject to repeated disturbance by fire or logging have received considerable conservation attention. However, little is known of the conservation values of old-growth sites in ecosystems with an evolutionary history of highly frequent disturbance. Here we address the value of low fire frequency (<1 fire/10 years) in tropical savannas, the world's most fire-prone biome, in terms of ant biodiversity. We do this by comparing savanna ant communities within the Territory Wildlife Park (TWP) near Darwin in the Australian monsoonal tropics, which has experienced a low incidence of fire over 25 years due to active fire exclusion, with those of adjacent (outside) sites experiencing the ambient fire regime of burning every 2–5 years. Ants were sampled using terrestrial and arboreal pitfall traps at 16 sites, eight each inside and outside TWP. More than 16 000 ants were recorded during the study, representing a total of 98 ant species from 30 genera. More species in total were recorded outside (90) than inside (74) TWP, but there was no difference in mean site species richness or abundance, and overall species composition was similar. All species recorded inside TWP are common and widespread throughout the savanna landscapes of the broader region, in the absence of active fire exclusion. Low fire frequency at the Territory Wildlife Park therefore does not appear to have enhanced regional ant conservation values. Our findings reinforce the importance of targeting fire regimes that are clearly linked to positive conservation outcomes, rather than assuming a need for maximum ‘pyrodiversity’.

Oil palm expansion into rain forest greatly reduces ant biodiversity in canopy, epiphytes and leaf-litter

Oil palm cultivation is expanding rapidly into many of the world’s most biodiverse tropical regions. One of the most functionally important and ecologically dominant animal groups in these environments is the ants. Here, we quantify the overall impacts of clear-felling lowland dipterocarp rainforest and conversion into oil palm plantation on ant diversity. At study sites in Sabah, Malaysia we collected ants from three microhabitats: 1 – the canopy, 2 – bird’s nest ferns (Asplenium nidus complex, a common epiphyte in forest and oil palm), and 3 – leaf litter. We also measured temperature, humidity and light at collection sites to assess their impacts on ant community composition. Total ant species richness decreased from 309 to 110 (−64%) between forest and oil palm plantation. However, this impact was not the same across all microhabitats, with bird’s nest ferns maintaining almost the same number of ant species in oil palm compared to forest (forest-oil palm, ferns: 36–35 (3% loss), canopy: 120–58 (52% loss), leaf litter: 216–56 (74% loss)). Relative abundance distributions remained the same for fern-dwelling ants, but became less even for oil palm ants in both the canopy and the leaf litter. These differences may be due in part to the ability of bird’s nest ferns to provide a stable microclimate in hot, dry plantations. We also found that non-native ant species were more abundant in oil palm than in forest, and few forest ant species survived in plantations in any of the microhabitats. Only 59 of the 309 forest species persisted in oil palm plantations, corresponding to an 81% loss of forest species resulting from habitat conversion. Although oil palm supports many more ant species than has been previously reported, converting forest into plantation still leads to a dramatic reduction in species richness. The maintenance of forested areas is therefore vital for the conservation of ant biodiversity.

Baseline study of the leaf‐litter ant fauna in a French Guianese forest

Abstract. 1. Leaf‐litter ants represent a major component of biodiversity and are excellent bioindicators reflecting the health of terrestrial ecosystems. This study, conducted in an unspoiled forest near the Nouragues Research Station, represents the first inventory of leaf‐litter ant diversity conducted in French Guiana, and so can be considered as the baseline dataset for ants in this country.2. Ants were extracted from the leaf‐litter using the Ants of the Leaf Litter Protocol, along an altitudinal gradient at four forest sites, including an inselberg.3. A total of 196 ant species representing 46 genera distributed over eight subfamilies were collected. Four distinct communities spread over a gradient of diversity were thus identified: the liana forest was the most species‐rich (140 species) followed by the forested plateau (102 species), the transition forest (87 species) and the forest at the top of the inselberg (71 species).4. The discovery of species new to science plus several species recorded for the first time in French Guiana, coupled with the particular context of this area, suggests that the Nouragues Research Station might represent a centre of endemism. Once completed, this leaf‐litter ant dataset will contribute greatly to the knowledge of ant biodiversity in French Guiana, and has the potential to progressively become an indispensable tool for country‐wide conservation planning programmes.

Effects of Urban Development on Ant Communities: Implications for Ecosystem Services and Management

Research that connects the effects of urbanization on biodiversity and ecosystem services is lacking. Ants perform multifarious ecological functions that stabilize ecosystems and contribute to a number of ecosystem services. We studied responses of ant communities to urbanization in the Lake Tahoe basin by sampling sites along a gradient of urban land development. We sampled ant communities, measured vegetation characteristics, quantified human activities, and evaluated ant-community responses by grouping ants into service-providing units (SPUs), defined as a group of organisms and their populations that perform specific ecosystem services, to provide an understanding of urbanization impacts on biodiversity and their delivery of ecosystem services. Species richness and abundance peaked at intermediate levels of urban development, as did the richness of 3 types of ant SPUs (aerators, decomposers, and compilers). With increasing land development aerator and decomposer ants significantly declined in abundance, whereas compiler ants significantly increased in abundance. Competing models demonstrated that precipitation was frequently among the strongest influences on ant community structure; however, urban development and human activities also had a strong, negative influence on ants, appearing in most models with DeltaAIC(c) < 2 for species richness and abundance patterns of SPUs and generalists. Response diversity was observed within SPUs, which suggests that the corresponding ecosystem services were maintained until development reached 30-40%. Our data provide evidence that ecosystem functions, such as water infiltration and soil productivity, may be diminished at sites subject to greater levels of urbanization and that conserving ant communities and the ecosystem services they provide could be an important target in land-use planning and conservation efforts.

Ants and people: a test of two mechanisms potentially responsible for the large‐scale human population–biodiversity correlation for Formicidae in Europe

AbstractAim: Recent coarse‐scale studies have shown positive relationships between the biodiversity of plants/vertebrates and the human population. Little is known about the generality of the pattern for invertebrates. Moreover, biodiversity and human population might correlate because they both covary with other factors such as energy availability and habitat heterogeneity. Here we test these two non‐mutually exclusive mechanisms with ant species‐richness data from the Fauna Europaea.Location Forty‐three European countries/regions.Methods We derived mixed models of total, native and exotic ant species richness as a function of human population size/density, controlling for country area, plant species richness (as a proxy for habitat heterogeneity), and mean annual temperature and precipitation (variables related to energy availability).Results Ant species richness increased significantly with increasing human population. This result was confirmed when controlling for variations in country area. Both for human population size/density and for ant species richness, there were positive correlations with temperature but not with precipitation. This finding is in agreement with the energy‐availability hypothesis. However, we observed a negative latitudinal gradient in ant and plant species richness, although not in human population size/density. Plant species richness was positively correlated with ant species richness but not with human population size/density. Thus, there is evidence that this type of habitat heterogeneity can play a role in the observed latitudinal gradient of ant species richness, but not in the positive correlation between ant species richness and human population. The results were confirmed for the 545 native and the 32 exotic ant species reported, and we observed a good correlation between exotic and native ant species richness.Main conclusions Ant species richness in European countries conforms to six macroecological patterns: (1) a negative latitudinal gradient; and a positive (2) species–energy relationship, (3) species–area relationship, (4) correlation with plant species richness, (5) exotic–native species richness correlation, and (6) species–people correlation. There is some evidence for the energy‐availability hypothesis, but little evidence for habitat heterogeneity as an explanation of the large‐scale human population–ant biodiversity correlation. This correlation has implications for the conservation of ant diversity in Europe.

Habitat Associations of Ant Species (Hymenoptera: Formicidae) in a Heterogeneous Mississippi Landscape

Community assembly and the factors that influence it have long been a topic of interest to ecologists, but theory has yet to produce unequivocal evidence that communities assemble in predictable ways. The goal of this study was to document the relationship between ant communities and environmental variation between four habitat types. To accomplish this, ant communities and 16 environmental variables were sampled across four different habitat types in the Black Belt Prairie and Flatwoods regions in Mississippi. Furthermore, ant species were placed into functional groups for an analysis of the relationship between the assembly of ecological communities and variation in ecosystem function. A total of 20,916 ants representing 68 species was collected across the four habitat types. Nonmetric multidimensional scaling and analysis of covariance analyses both revealed three distinct ant communities, which can be characterized by habitat type: pasture, prairie, and woodland. Principle components analysis (PCA) simplified the 16 environmental variables into four principle components that explained 78% of the variation among sites. Results of multiple regression using the four PCA axes as predictor variables suggest that regional variation in soil structure, land cover type, and the presence of grazing have had major influences on ant community composition. Variation in flora and habitat architecture had smaller but significant effects on ant species diversity and functional group composition. Our results imply that restoration of native ant communities in disturbed habitats must consider how current disturbance regimens likely interact with the presence of Solenopsis to lower ant biodiversity.

Seed harvester and scavenger ants along roadsides in Northern Israel

Roads and their edges are important factors of human disturbance in natural landscapes. It is generally admitted that roadsides support more scavengers and seed harvester insects than habitats around them. I used ground-nesting ants (Hymenoptera: Formicidae) to test these hypotheses in a Mediterranean region of Israel. Twice in three different habitats (roadsides and range areas of shrub steppe (bata) and open maquis) I looked for ant nests in 90 plots, each of which measured 80 square metres. The dominant species was the seed-harvester Messor semirufus (André, 1883) that built more nests along roads than in the natural habitats. The distances between neighbouring nests were shorter in road verges than in nature. Subdominant species were scavengers Tapinoma israele Forel, 1904 and Tapinoma erraticum (Latreille, 1798) that nested equally in the studied habitats. In total, I found 131 nests of 23 ant species (10 % of species living in Israel). Species richness and Alfa biodiversity index were equal in the three habitats, while species composition was different, and nest number was higher in the roadsides. Beta turnover index of Wilson and Shmida indicated a net contribution of roadsides to general ant biodiversity. In conclusion the results of this research support the hypothesis that seed-harvester ants are more abundant in roadsides than in habitats around them, but they do not support the second hypothesis that scavenger species show the same pattern.

Ant biodiversity and the predatory function (A response to Philpott and Armbrecht, 2006)

Ant biodiversity and the predatory function (A response to Philpott and Armbrecht, 2006)

Biodiversity Analysis of Forest Litter Ant Assemblages in the Wayanad Region of Western Ghats Using Taxonomic and Conventional Diversity Measures

The diversity of litter ant assemblages in evergreen, deciduous and Shola evergreen (Shola) forest vegetation types of the Wayanad region of the Western Ghats was assessed employing conventional and taxonomic diversity indices. Non-dependence on quantitative data and the ability to relate the phylogenetic structure of assemblages with ecological conditions of the habitat, and to ascertain priorities for conservation of habitats, makes non-parametric taxonomic diversity measures, such as variation in taxonomic distinctness Λ+ and average taxonomic distinctness Δ+, highly useful tools for assessment of litter ant biodiversity.Although Δ+ values saturated leading to closer values for the 3 litter ant assemblages, Λ+ proved to be a more dependable index. Evenness in taxonomic spread was high in ant assemblages in deciduous forests and low in evergreen forests compared to the regional master list. Low Λ+ of ant assemblage in deciduous forests indicates that among the 3 forest vegetation types, deciduous forests provided the most favorable habitat conditions for litter ants. Low evenness, as is indicated by Λ+ in evergreen forests, was attributed to the presence of a group of taxonomically closely related ant assemblage more adapted to prevail in moist and wet ecological conditions.

Biodiversity in tropical agroforests and the ecological role of ants and ant diversity in predatory function

Abstract1. Intensive agricultural practices drive biodiversity loss with potentially drastic consequences for ecosystem services. To advance conservation and production goals, agricultural practices should be compatible with biodiversity. Traditional or less intensive systems (i.e. with fewer agrochemicals, less mechanisation, more crop species) such as shaded coffee and cacao agroforests are highlighted for their ability to provide a refuge for biodiversity and may also enhance certain ecosystem functions (i.e. predation).2. Ants are an important predator group in tropical agroforestry systems. Generally, ant biodiversity declines with coffee and cacao intensification yet the literature lacks a summary of the known mechanisms for ant declines and how this diversity loss may affect the role of ants as predators.3. Here, how shaded coffee and cacao agroforestry systems protect biodiversity and may preserve related ecosystem functions is discussed in the context of ants as predators. Specifically, the relationships between biodiversity and predation, links between agriculture and conservation, patterns and mechanisms for ant diversity loss with agricultural intensification, importance of ants as control agents of pests and fungal diseases, and whether ant diversity may influence the functional role of ants as predators are addressed. Furthermore, because of the importance of homopteran‐tending by ants in the ecological and agricultural literature, as well as to the success of ants as predators, the costs and benefits of promoting ants in agroforests are discussed.4. Especially where the diversity of ants and other predators is high, as in traditional agroforestry systems, both agroecosystem function and conservation goals will be advanced by biodiversity protection.

Ant biodiversity in different habitats in Shilin Park, Yunnan Province

Ant biodiversity in different habitats in Shilin Park, Yunnan Province

Las hormigas del suelo en México: diversidad, distribución e importancia (Hymenoptera: Formicidade)

Se presenta la síntesis de la diversidad taxonómica y funcional de tas hormigas del suelo en México, su distribución y principales patrones ecológicos. La formicofauna del suelo comprende 407 especies y subespecies, siendo Myrmicinae la subfamilia más diversa con 53% del total. Myrmicinae domina las áreas tropicales del país, mientras que Formicinae las zonas templadas. Se encuentran especies de géneros neotropicales, neárticos, pantropicales, holárticos y cosmopolitas. Los géneros más diversos son Pheidole (51 spp), Neivamyrmex (37) y Lepthotorax (21). Las comunidades más ricas están en las selvas tropicales altas y medianas y las más pobres en los matorrales áridos y los bosques templados. La región del Este y Sureste es la más diversa con 56% del total de especies, mientras que la Península de Baja California con solamente 30 especies, es la región con mayor número de endemismos (40%). Veracruz es el estado más rico seguido de Chiapas y Nuevo León; los de menor diversidad son el Estado de México, Querétaro y Tlaxcala. El gremio trófico predominante es el de las omnívoras (44% de las especies), ocupando las depredadoras el segundo lugar (30.5%). En los sitios perturbados existe mayor abundancia y biomasa, pero menor diversidad y la comunidad está dominada por unas cuantas especies. Se discute el papel de las hormigas en los agroecosistemas y se enfatiza la necesidad de completar el inventario de las especies de México, de evaluar sus efectos en el suelo y de implementar estudios encaminados a su manejo.

Ant Biodiversity in Semiarid Landscape Mosaics: The Consequences of Grazing vs. Natural Heterogeneity

The conservation of biodiversity in landscape mosaics requires an understanding of the impacts of human land use within mosaic elements and an evaluation of the biological uniqueness of different elements. We address these issues by examining patterns of ant diversity in three semiarid rangeland landscapes used predominantly for grazing. These landscapes lie along a regional gradient from shortgrass steppe through a transitional zone to desert grassland, along which climate and ant species composition vary. Within each landscape, we compared the effects of grazing and natural variation in soils and vegetation on ant diversity and community composition. Grazing had little effect on ant richness, diversity, or composition at the transitional zone or the desert grassland site, but ungrazed areas at the shortgrass steppe site had a higher overall richness and favored the abundance of some species. Some samples of saltbush (Atriplex canescens) shrubland were similar to ungrazed samples in richness and species composition. In both the transitional zone and the desert grassland, creosotebush (Larrea tridentata)-dominated habitats harbored comparatively species-rich and distinct ant communities. In addition, mesquite (Prosopis glandulosa) coppice dunes at the desert grassland site favored the abundance of several species that were rare across the site. Canonical correspondence analysis revealed that variation in soil strength and texture best explained community variation at the shortgrass steppe site, whereas soil texture and associated differences in shrub density best explained differences in composition at the transitional and desert grassland sites. The characterization of habitats based upon vegetation classification did not adequately reflect environmental variation that was important to ants in shortgrass steppe, but reflected important soil textural variation in the transitional and desert grassland sites. These results suggest that ant conservation in these semiarid rangelands should emphasize patterns of variation in soil properties. The results add to a growing consensus that a variety of variables determined by the responses of several focal taxa may be needed to characterize biodiversity patterns.

Frequent fuel‐reduction burning: the role of logs and associated leaf litter in the conservation of ant biodiversity

AbstractFrequent low‐intensity fires are used in management of Australian forests to reduce fuel loads and protect natural resources and human property. Low‐intensity fires are typically patchy and unburned litter microhabitats are often associated with large objects such as logs, which may act as refuges both for vertebrate and for invertebrate fauna. The aim of this study was to determine whether ants were using unburned leaf litter microhabitats associated with logs as a refuge after fire. The study was carried out in Bulls Ground State Forest, New South Wales, Australia, where experimentally burned and unburned sites had previously been established. Species richness and abundance of ants in leaf litter did not differ between habitats adjacent to logs and away from logs, in burned and unburned sites. Fifteen of the 42 ant species were found in all four habitats, and contributed 94% of total ant abundance. Every habitat had a group of unique species, which together made up 30% of the total species richness. There was also a distinct group of species that was not found in the leaf litter associated with the burned/open habitat. However, as 45% of all species were found in low abundance (less than 10 individuals), care must be taken in inferring patterns for these groups. When functional groups were used to assess community structure, ‘cryptic’ species were found to be common in all habitats, whereas ‘subordinate Camponotini’ were found in burned habitats only. This study indicates that in an area where frequent burning is applied on a broad scale, preserving a range of microhabitats, including those associated with retained logs, may make a substantial contribution to conserving ant biodiversity.

Frequent fuel-reduction burning: the role of logs and associated leaf litter in the conservation of ant biodiversity

Frequent fuel-reduction burning: the role of logs and associated leaf litter in the conservation of ant biodiversity

Ants as bioindicators of soil function in rural environments

Farmers are being encouraged to redress the problems of land degradation by implementing a series of changes in their land management. However, there are few tools to monitor soil condition which can reliably inform farmers of the state of their soil. This paper examines ants and their importance in ecosystem functioning, principally their ability to maintain or restore soil quality in rural environments, and their value as bioindicators of soil quality. The reader is provided with a summary of those studies which have recorded the species composition and activity of ant fauna in agricultural soils and naturally vegetated environments. However, it is rare to find studies which sample both environments concurrently. An overview of the types of measures available to assess ant biodiversity is followed by a discussion of the current status of biopedological research into ant–soil relationships and the trends and gaps in current research knowledge, principally in the areas of water and soil movement and nutrient effects. Lastly the paper seeks to forecast the future directions of ant biopedological research, and to identify the type of research required to fully appreciate the value of ants as soil quality indicators to monitor the sustainability of the soil resource. Ants should be considered an important group of soil fauna, yet they have received meagre attention in comparison with other soil fauna such as earthworms. There is a need for specific experiments to test the hypothesis that ants can be used as bioindicators of soil quality.

Ant biodiversity and its relationship to ecosystem functioning: a review

Ants are important components of ecosystems not only because they constitute a great part of the animal biomass but also because they act as ecosystem engineers. Ant biodiversity is incredibly high and these organisms are highly responsive to human impact, which obviously reduces its richness. However, it is not clear how such disturbance damages the maintenance of ant services to the ecosystem. Ants are important in below ground processes through the alteration of the physical and chemical environment and through their effects on plants, microorganisms, and other soil organisms. This review summarizes the information available on ant biodiversity patterns, how it can be quantified, and how biodiversity is affected by human impacts such as land use change, pollution, invasions, and climate change. The role of ants in ecosystems is discussed, mainly from the perspective of the effects of ground-dwelling ants on soil processes and function, emphasizing their role as ecosystem engineers. Some lines of research are suggested after demonstrating the gaps in our current information on ant-soil interactions.