Ant Diversity Research Articles

Struktur Komunitas Semut (Hymenoptera : Formicidae) di Lahan Pertanian Organik dan Anorganik Desa Batur, Kecamatan Getasan, Kabupaten Semarang

Ants play an important role in terrestrial ecosystems, including in organic and inorganic farmland, as predators, scavengers, and their interaction with other organism. The objectives of this study were to compare the community structure and the role of the ant in organic and inorganic farmland, and also to determine soil abiotic factors in both farmland. The study was conducted in organic and inorganic chili crop land at Batur village, Getasan, Semarang. The sampling of ants was performed using pitfall traps and bait traps, and then the ants were identified. Data analysis used is an abundance index, diversity index, evenness index, Hutchinson test and similarity index. The results showed that the number of species and the number of individual of ants in organic farm were higher (45 individuals, 8 species) than inorganic farm (35 individuals, 6 species). Diversity index of ant species in both farmlands were categorized moderate with the index value of 1.92 and 1.42. Statistically, there were no significant differences in species diversity of ants in organic and inorganic farmland. There were five dominant species in organic field and three dominant species in inorganic field. Ants that predominate in both farmlands were Iridomyrmexsp, Tetramorium sp, Solenopsisgeminata, Odontoponeradenticulata and Diacammasp. The similarity of ant communities between organic and inorganic farmland showed high value of similarity index (IS) which was 85.7%. Statistically, abiotic factors showed that there were significantly different of some abiotic factors in both farmlands, the content of carbon, phospor, organic matter and c / n ratio. Keywords: community structure of ants, agricultural ecosystems

External immunity in ant societies: sociality and colony size do not predict investment in antimicrobials.

Social insects live in dense groups with a high probability of disease transmission and have therefore faced strong pressures to develop defences against pathogens. For this reason, social insects have been hypothesized to invest in antimicrobial secretions as a mechanism of external immunity to prevent the spread of disease. However, empirical studies linking the evolution of sociality with increased investment in antimicrobials have been relatively few. Here we quantify the strength of antimicrobial secretions among 20 ant species that cover a broad spectrum of ant diversity and colony sizes. We extracted external compounds from ant workers to test whether they inhibited the growth of the bacterium Staphylococcus epidermidis. Because all ant species are highly social, we predicted that all species would exhibit some antimicrobial activity and that species that form the largest colonies would exhibit the strongest antimicrobial response. Our comparative approach revealed that strong surface antimicrobials are common to particular ant clades, but 40% of species exhibited no antimicrobial activity at all. We also found no correlation between antimicrobial activity and colony size. Rather than relying on antimicrobial secretions as external immunity to control pathogen spread, many ant species have probably developed alternative strategies to defend against disease pressure.

Keanekaragaman dan Kelimpahan Semut sebagai Predator Hama Tanaman Padi di Lahan Sawah Organik dan Anorganik Kecamatan Karanganom Kabupaten Klaten

Ants potentially as predators that become natural enemies of insect pests in rice fields with paddy cultivation. This study aims to know the diversity and abundance of ants, the role of ants, the population of ants, and the influence of physical and chemical factors in organic and inorganic rice fields. The ants were collected using pit fall trap method with insect bait, fish meat, and sugar solution. The results showed that the number of species and the number of individuals in organic rice fields was higher (429 individuals, 11 species) than inorganic rice fields (193 individuals, 10 species). In general, the index of diversity in organic rice fields was higher (ranging from 0.73 to 1.65) compared to inorganic rice fields (ranging from 0 to 1.28). The index of evenness in organic rice fields ranged from 0.63 to 0.99 (evenly distributed), whereas in inorganic rice fields ranged from 0 to 0.99 (uneven until evenly distributed). The dominant ants in organic rice fields were Camponotus sp, Solenopsis geminata, Anoplolepis gracilipes, and Paratrechina longicornis, whereas in the inorganic rice fields were Tapinoma sp, Solenopsis geminata, and Camponotus sp. The index of similarity between organic and inorganic rice fields showed a high and very high degree of similarity based on the type of feed. Physical factors of high soil and air humidity environment, high soil and air temperature increased the diversity and abundance of ants in the rice fields ecosystem. Factors soil pH in accordance with the growth of soil Arthropods were neutral or slightly acidic. Chemical factors of organic matter content, Nitrogen (N), the content of C organic, and a high P total content increased the diversity and abundance of ants. Keywords: diversity and abundance, ants, organic and inorganic rice fields

Forest understory ant (Hymenoptera: Formicidae) assemblage in a Meridional Amazonian landscape, Brazil

Las hormigas habitan y explotan los hábitats más variados desde el subsuelo hasta el dosel del bosque. Sin embargo, los estudios sobre la diversidad de hormigas de la vegetación son menos frecuentes en el Amazonas. En este artículo enumeramos las especies de hormigas recogidas en el sotobosque de un remanente de bosque en un paisaje del sur de la Amazonia. La lista incluye 32 especies, de las cuales tres (9 %) son nuevos registros para el estado de Mato Grosso, Brasil, siendo una de estas especies muestreadas por primera vez en Brasil.

Importance of Nesting Resources and Soil Conditions for the Recovery of Ant Diversity During Secondary Succession in a Tropical Rainforest

The secondary succession of tropical rainforest in abandoned agricultural fields modifies components of species diversity and processes of species colonization and replacement. In general, knowledge on invertebrate reassembly is lacking, even though invertebrate assemblages directly influence the maturation of forests. Ants are especially useful for testing hypotheses about the effects of resource diversity and microhabitat conditions. We experimentally assessed the effects of different successional stages on nest colonization. Then, we assessed whether nesting resources and microhabitat conditions (i.e., abiotic conditions) are potential mechanisms that influence the colonization pattern of twig-dwelling ants along a natural chronosequence for 1 year in the Lacandon region, Mexico. We found that ant species richness in twigs is correlated with total species found in leaf litter. The nest occupancy increased as succession progressed, but species richness did not change. Nests occupation increased to greater artificial nesting resource decomposition rates and lower soil pH. Meanwhile, species richness was increased only with lower soil compaction. Species composition changes among successional categories; the changes were greater with greater soil compaction and soil pH. The diversity of nesting resources did not drive twig-dwelling ant assembly. We conclude that the natural maturation of tropical forest enables greater colonization of twig-dwelling ants, but recovery of the species composition of assemblages after 30 years is incomplete, although it shows a recovery trend.

Richness and structure of ant assemblies (Hymenoptera: Formicidae) in Atlantic forest in southern Brazil.

Ant diversity is influenced by the structural complexity of the environment. Ants are thus an ecologically important group due to their potential to serve as indicators of environmental quality. The objective of this study was to evaluate ant diversity in areas with different land use histories and thus, within different stages of regeneration in the Permanent Preservation Area of the Foz do Chapecó Hydroelectric Plant reservoir. Ant assemblies among sample sites were compared using rarefaction analysis, and estimated richness, frequency of occurrence, and relative abundance were calculated. Associations between species and sample sites were evaluated using Principal Component Analysis (PCA). We identified 55 species in total from 24 genera, distributed among seven subfamilies. Eight species had positive associations with sample sites. Estimates indicated that ant richness may be up to 21.4% greater than that observed. This study presents an inventory of species capable of colonizing environments undergoing natural regeneration processes, and aids our understanding of ecological recovery dynamics in protected areas near hydroelectric plant reservoirs southern Brazil.

Effects of isolation on ant assemblages depend on microhabitat

AbstractHow isolation affects biological communities is a fundamental question in ecology and conservation biology. Local diversity (α) and regional diversity (γ) are consistently lower in insular areas. The pattern of species turnover (β diversity) and the influence of isolation on competitive interactions are less predictable. Differences in communities across microhabitats within an isolated patch could contribute to the variability in patterns related to isolation. Trees form characteristically dense and sparse patches (low vs. high isolation) in floating marshes in coastal Louisiana, and canopy and root areas around these trees could support distinct ant communities. Consequently, trees in floating marshes provide an ideal environment to study the effects of isolation on community assemblages in different microhabitats. We sampled ant communities in 120 trees during the summer of 2016. We found ant α diversity was not different between the canopy and roots, and the magnitude and directional effects of isolation on ants were inconsistent between the canopy and root areas. In the roots of sparse sites, ant diversity (α, β, and γ) was lower, species composition was changed, and the signature of interspecific competition was more prominent compared to dense sites. In the canopy, however, significant differences between dense and sparse sites were only detected in α and γ diversity, and ant species co‐occurrence was not significantly different from a random distribution. The inconsistent responses of ants in canopy and root areas to isolation may be due to the differences of species pool size, environmental harshness, and species interactions between strata. In addition, these findings indicate that communities in distinct microenvironments can respond differentially to habitat isolation. We suggest incorporating organisms from different microhabitats into future research to better understand the influence of isolation on the assembly of biological communities.

Richness and Composition of Ground-dwelling Ants in Tropical Rainforest and Surrounding Landscapes in the Colombian Inter-Andean Valley.

Tropical rainforests are characterized by having high structural complexity, stratification, and species diversity. In Colombia, tropical rainforests are critically endangered with only 24% of their area remaining. Forest fragments are often valued based on the presence of vertebrate taxa despite that small habitat remnants may still harbor diverse invertebrate communities. We surveyed the ant fauna associated with rainforest fragments and their surrounding landscape elements (including mature forests, flooded forests, gallery forests, live fences, and pastures) in the Magdalena River watershed. Pitfall traps and litter samples were used to estimate ant richness and diversity, and to compare ant composition among landscape elements. We found 135 species from 42 genera, representing 16% of the species and 43% of the genera known for Colombia. Our surveys also uncovered 11 new ant records for the Colombian inter-Andean region and 2 new records for the country of Colombia: Mycocepurus curvispinosus (Mackay) and Rhopalothrix isthmica (Weber). The highest species richness was found in forest-covered sites, and richness and diversity was lower in the disturbed landscapes surrounding the forest patches. Species composition varied significantly between all habitat types, but was most similar between forest types suggesting that a loss of structural complexity has the greatest effect on ant communities. Across our study sites, ten species showed the greatest response to habitat type and could qualify as indicator taxa for this region. We conclude by discussing the value of conserving even small forests in this landscape due to their ability to retain high diversity of ants.

Changes in landuse alter ant diversity, assemblage composition and dominant functional groups in African savannas

Africa’s savannas are undergoing rapid conversion from rangelands into villages and croplands. Despite limited research, and evidence of deleterious effects to biodiversity, international organisations have earmarked this system for cropland. Invertebrates, and ants in particular, are sensitive indicators of habitat fragmentation, and contribute to ecosystem services at a range of scales. We investigated how rangelands, villages and croplands differ in ant species and functional diversity, and assemblage composition. We sampled ants using pitfall traps at 42 sites (14 replicates each in rangeland, cropland, and village) in northern South African savannas. We investigated the impact of landuse, season, and multiple soil and vegetation habitat variables on ant species diversity, assemblages and functional diversity. Rangelands had the greatest ant species richness, particularly in the wet season. Richness declined with increasing soil clay content. Ant assemblages were distinctly different between landuse types. Rangeland harboured the widest diversity of indicator species, and contained greatest functional diversity. Rangelands accommodated more scavengers, granivores, and plant-matter feeders than cropland, and representation of these groups varied with season. Ants play essential roles in soil nutrient cycling, plant and seedling recruitment, and impact other arthropods through predation and aphidoculous behaviour that in turn influences entire food webs. Thus, the reduced species richness, changes in assemblage composition and the loss of functional groups in ant assemblages found in cropland and villages is potentially problematic. Left unchallenged, these new forms of landuse threaten to characterise the entire African savanna system, impacting not only future ecological, but possibly also human wellbeing.

Does organic management of agroecosystems contribute to the maintenance of the richness of ants?

Does organic management of agroecosystems contribute to the maintenance of the richness of ants? This study assessed the richness of ant species in organically farmed crop agroecosystems of different ages located in the southern state of Paraná, Brazil. During the sampling, the pitfalls that were active during May/August 2009 and from October 2009 to February 2010 were used. A total of 11,874 ants belonging to five subfamilies was sampled, comprising 18 genera and 48 species. The subfamily Myrmicinae (S = 27) had the highest richness, followed by the genera Pheidole (S = 10), Solenopsis (S = 7), Formicinae (S = 3), Camponotus (S = 5), and Brachymyrmex (S = 5). The average difference between the observed richness (Sobs) and the estimated richness (Chao2) was 10.9%. Ant assemblages belonging to agroecosystems under organic management for long times presented the greatest richness, indicating that this system contributes to the maintenance of ant diversity.

Taxonomic and functional ant diversity along a secondary successional gradient in a tropical forest

AbstractThe taxonomic diversity (TD) of tropical flora and fauna tends to increase during secondary succession. This increase may be accompanied by changes in functional diversity (FD), although the relationship between TD and FD is not well understood. To explore this relationship, we examined the correlations between the TD and FD of ants and forest age in secondary forests at the α‐ and β‐diversity levels using single‐ and multi‐trait‐based approaches. Our objectives were to understand ant diversity patterns and to evaluate the role of secondary forests in the conservation of biodiversity and in the resilience of tropical forests. Ant assemblages were sampled across a chronosequence in the Lacandon region, Mexico. All species were characterized according to 12 functional ecomorphological traits relevant to their feeding behavior. We found that TD and FD were related to forest age at the alpha level, but not at the beta level. α‐functional richness and divergence increased linearly with species richness and diversity, respectively. Also, the relationship between taxonomic and functional turnover was linear and positive. Our results indicated that functional traits were complementary across the chronosequence. The increase in FD was mainly driven by the addition of rare species with relevant traits. The older secondary forests did not recover all of the functions of old growth forest but did show a tendency to recovery. Because older successional stages support more TD and FD, we suggest developing agriculture and forestry management practices that facilitate rapid post‐agricultural succession and thereby better preserve the functionality of tropical forests.

An assessment of leaf-litter and epigaeic ants (Hymenoptera: Formicidae) living in different landscapes of the Atlantic Forest Biome in the State of Bahia, Brazil

The Brazilian Atlantic Forest has a rich biodiversity increasingly threatened by human activities. Since the colonial period, the coast of the state of Bahia is among the most affected regions of Brazil by anthropic pressure. Bahia encloses Atlantic Forest remnants distributed in an area reaching 100-200 km along the east-west axis, by 1,000 km along the north-south axis, parallel to the coast of the Atlantic Ocean. We report hereafter the results of an intensive field survey of leaf litter and epigaeic ants realized in forest remnants of the Atlantic Forest landscapes within the original extension of the biome in 11 localities distributed along four degrees of latitude in the state of Bahia. In each site, 16 plots were collected using pitfall and eight using Winkler traps. We identified 391 ant species belonging to 71 genera and nine subfamilies. Among all species recorded, 21 were common to the whole 11 localities, while 98 species were recorded in a single locality. This study highlights the richness and diversity of epigaeic and leaf-litter ants living in the northern part of the Brazilian Atlantic Forest, and is one of the most representative soil ants’ inventories ever done in this biome for a single state of Brazil.

Mind the gap! Integrating taxonomic approaches to assess ant diversity at the southern extreme of the Atlantic Forest.

Understanding patterns of species diversity relies on accurate taxonomy which can only be achieved by long‐term natural history research and the use of complementary information to establish species boundaries among cryptic taxa. We used DNA barcoding to characterize the ant diversity of Iguazú National Park (INP), a protected area of the Upper Paraná Atlantic Forest ecoregion, located at the southernmost extent of this forest. We assessed ant diversity using both cytochrome c oxidase subunit 1 (COI) sequences and traditional morphological approaches, and compared the results of these two methods. We successfully obtained COI sequences for 312 specimens belonging to 124 species, providing a DNA barcode reference library for nearly 50% of the currently known ant fauna of INP. Our results support a clear barcode gap for all but two species, with a mean intraspecific divergence of 0.72%, and an average congeneric distance of 17.25%. Congruently, the library assembled here was useful for the discrimination of the ants of INP and allowed us to link unidentified males and queens to their worker castes. To detect overlooked diversity, we classified the DNA barcodes into Molecular Operational Taxonomic Units (MOTUs) using three different clustering algorithms, and compared their number and composition to that of reference species identified based on morphology. The MOTU count was always higher than that of reference species regardless of the method, suggesting that the diversity of ants at INP could be between 6% and 10% higher than currently recognized. Lastly, our survey contributed with 78 new barcode clusters to the global DNA barcode reference library, and added 36 new records of ant species for the INP, being 23 of them new citations for Argentina.

Spatial-temporal dynamics of neotropical velvet ant (Hymenoptera: Mutillidae) communities along a forest-savanna gradient

Understanding how and why biological communities are organized over space and time is a major challenge and can aid biodiversity conservation in times of global changes. Herein, spatial-temporal variation in the structure of velvet ant communities was examined along a forest-savanna gradient in the Brazilian Cerrado to assess the roles of environmental filters and interspecific interactions upon community assembly. Velvet ants were sampled using 25 arrays of Y-shaped pitfall traps with drift fences for one year along an environmental gradient from cerrado sensu stricto (open canopy, warmer, drier) to cerradão (closed canopy, cooler, moister). Dataloggers installed on each trap recorded microclimate parameters throughout the study period. The effects of spatial distances, microclimate parameters and shared ancestry on species abundances and turnover were assessed with canonical correspondence analysis, generalized dissimilarity modelling and variance components analysis. Velvet ant diversity and abundance were higher in the cerrado sensu stricto and early in the wet season. There was pronounced compositional turnover along the environmental gradient, and temporal variation in richness and abundance was stronger than spatial variation. The dry season blooming of woody plant species fosters host abundance and, subsequently, velvet ant captures. Species were taxonomically clustered along the gradient with Sphaeropthalmina (especially Traumatomutilla spp.) and Pseudomethocina more associated, respectively, with cerrado sensu stricto and cerradão. This suggests a predominant role of environmental filters on community assemble, with physiological tolerances and host preferences being shared among members of the same lineages. Induced environmental changes in Cerrado can impact communities of wasps and their hosts with unpredictable consequences upon ecosystem functioning and services.

The diversity of ants (Hymenoptera: Formicidae) interacting with the invasive hibiscus mealybug Maconellicoccus hirsutus (Green 1908) (Hemiptera: Pseudococcidae) on ornamental and cultivated plants in Bahia, Brazil

Biological invasions by exotic species are among the major threats to biodiversity worldwide. The pink hibiscus mealybug (PHM) Maconellicoccus hirsutus (Green 1908) (Hemiptera: Pseudococcidae) is an invasive mealybug species that has been reported in Brazil since 2010. This species is sometimes found in mutualistic association with ants, which help spread this pest and also prey on or remove its natural enemies. Here, we describe for the first time the interactions between ants and M. hirsutus in Brazil, focusing on cocoa trees, Theobroma cacao (L., Malvaceae), and on the ornamental species Mimosa caesalpiniifolia Benth (Mimosaceae), and hibiscus Hibiscus rosa-sinensis L. (Malvaceae), all in the state of Bahia, Brazil. We collected M. hirsutus and associated ants on 50 randomly selected plants of these three species at three sites. We found a high diversity of ants (46 species) in trophobiotic interaction with the exotic mealybug. The highest ant species richness was found on hibiscus, with 33 species recorded interacting with the mealybug. Thirty ant species were observed associated with M. hirsutus on cocoa trees. We found significant differences in the ant assemblages according to site and plant species. Mutualisms with exotic species can cause profound alterations in the communities where they are inserted. This description of ant—M. hirsutus associations in Brazil is an initial step towards a better understanding of the mechanisms by which these mutual interactions become structured in the Neotropics and of their impacts on environment and agriculture.

Neotropical savanna ants show a reversed latitudinal gradient of species richness, with climatic drivers reflecting the forest origin of the fauna

AbstractAimTo evaluate the extent to which ant species richness in Neotropical savannas varies with macrogeographic variables, and to identify the potential climatic drivers of such variation.LocationThe Cerrado savanna biome of central Brazil, in a region spanning ca. 20° of latitude and 18°of longitude.MethodsStandardized sampling of the arboreal and ground‐dwelling faunas was performed in 29 well‐preserved savanna sites using pitfall traps. Species were classified according to their habitat affinities: open‐savanna specialists, forest‐associated species or habitat generalists. We used generalized linear models to evaluate the importance of geographic (latitude, longitude and elevation) and climatic (mean temperature and three metrics of rainfall) variables as predictors of species richness.ResultsThe total number of species recorded at each site varied more than twofold (from 59 to 144), and latitude was the best geographic correlate of overall species richness. However, contrary to the expected pattern, more species were found at higher than lower latitudes. This reversed latitudinal pattern of diversity occurred for both the arboreal and ground‐dwelling faunas, and for the habitat generalists and forest specialists. The savanna specialists showed a mid‐latitudinal peak in diversity. Overall, there was a significant positive association between rainfall and species richness, but the strength of this relationship varied with ant habitat affinity.Main conclusionsThe Cerrado ant fauna shows a reverse latitudinal gradient in species diversity, and this can be explained by increasing rainfall during the warmest months of the year (and therefore in plant productivity) with increasing latitude. The sensitivity of Cerrado ant diversity to declining rainfall contrasts with the high resilience to aridity of the Australian savanna ant fauna, and this reflects the contrasting evolutionary histories of these faunas. Our findings highlight the importance of historical processes as drivers of intercontinental contrasts in macroecological patterns.

Ant Assemblage Structure in a Secondary Tropical Dry Forest: The Role of Ecological Succession and Seasonality

This study identified the main biological mechanisms governing the diversity of ants on different ecological time scales. Ants were sampled in 15 plots distributed in early, intermediate and late stages of succession (five plots per stage) at the Parque Estadual da Mata Seca, Brazil. At each sample point, unbaited pitfall traps were installed in hypogaeic, epigaeic and arboreal strata. We collected 95 ant species from 26 genera and nine subfamilies. Our results indicated that there was an increase in species richness in advanced stages of succession. We also observed that ant assemblages were different among successional stages. For the arboreal and epigaeic strata, species richness did not change with succession progression, but species composition of these two strata differed among successional stages. Unlike to arboreal and epigaeic ants, hypogaiec ant species richness was higher in the intermediate and late stages of succession and the composition of hypogaeic ants differed among successional stages. Similarity between ant species foraging in arboreal and epigaeic strata decreases with succession progression and β-diversity was higher in advanced successional stages. Additionally, species richness was higher in the dry season, whereas the composition of ant assemblages did not change between seasons. A considerable fraction of the ant assemblage was found only in advanced stages of succession, demonstrating the importance of secondary habitats in maintaining biodiversity in dry forests.

Short Communication: Ant (Hymenoptera: Formicidae) diversity as bioindicator of agroecosystem health in northern slope of Mount Slamet, Central Java, Indonesia

Widhiono I, Pandhani RD, Darsono, Riwidiharso E, Santoso S, Prayoga L. 2017. Short Communication: Ant (Hymenoptera: Formicidae) diversity as bioindicator of agroecosystem health in northern slope of Mount Slamet, Central Java, Indonesia. Biodiversitas 18: 1475-1480. This study examined the diversity of ant assemblages in two different agroecosystems (organic and intensive farming) with maize as main crops on the northern slope of Mount Slamet, Indonesia from April to August 2015. The response of ant diversity to the different farming systems was evaluated. In total, 359 ants from 17 species in five subfamilies were collected: 13 species from the organic farm and 10 species from the conventional farm. Seven (41%) species were found only on the organic farm, four (23%) species were found only on the conventional farm, and six (35%) species were found on both. The Morisita-Horn similarity index (33%) showed that the similarity of the species composition in the two habitats was low. More individual ants were found on the organic farm than the intensive farm [287 (79.94%) vs. 72 (20.05%) individuals]. The diversity of the ants was affected by the density of weeds with organic farming. Hypoponera sp. had the highest Indicator Value (50.7), followed by Aphaenogaster sp. (28.9), Diacamma sp. (28.2), and Odontoponera sp. (27.6), however only Odontoponera sp can be used as bioindicator. Although the ant diversity was higher with organic farming than with intensive farming, there was no correlation with soil conditions. As a bioindicator, the Indicator Value reflects agroecosystem health better than does ant diversity.

Competence of Litter Ants for Rapid Biodiversity Assessments

Rapid Biodiversity Assessment approaches associated with focusing taxa have overcome many of the problems related to large scale surveys. This study examined the suitability of litter ants as a focusing taxon by checking whether diversity and species assemblages of litter ants reflect the overall picture of arthropod diversity and assemblages in leaf litter in two vegetation types: secondary forest and pine plantation in Upper Hanthana forest reserve, Sri Lanka. In each vegetation type, arthropods were sampled using three sampling methods (Winkler extraction, hand collection, and pitfall traps) along three 100 m line transects. From the two sites, 1887 litter ants (34 species) and 3488 litter arthropods (52 species) were collected. Species assemblages composition of both ants and other arthropods differed significantly between the two sites (ANOSIM,p=0.001) with both groups generating distinct clusters for the two sites (SIMPROF,p=0.001). But there was no significant correlation (p>0.05) between abundance and richness of litter ants and those of other arthropods in both vegetation types. The overall finding suggests that the litter ants do not reflect the holistic picture of arthropod diversity and assemblages in leaf litter, but the quality of the habitat for the survival of all litter arthropods.

Ants as indicators of soil quality in an on-going recovery of riparian forests

The increasing devastation of the Brazilian Atlantic Forest stresses the need to recover areas within this biome, and studies using potential indicator organisms to assess the forest recovery process are important to determine the intensity of human interference during this process. We aimed to evaluate the richness and abundance of ant genera in forests at different stages of recovery, and to identify soil attributes that contribute to differentiate these areas. Four areas with different periods of recovery were studied: one native undisturbed site (NT), and three sites with five (R05), 10 (R10), and 20 (R20) years without human perturbance. In each site, we defined a 10×10m sampling grid with 30 random points (15 Pitfall+15 Monoliths) and collected the ants at a depth of 0–20cm. We also analyzed physical, chemical, and biological properties at each site to correlate them with the ant genera. These variables were used in canonical discriminant analysis (CDA) and canonical correlation analysis (CCA). Leaf litter quality, higher ant genera diversity and abundance correlated with both NT and R20, more than with the other areas evaluated. The ant genera abundance was appropriated for separating the different vegetation recovery stages. The CDA analysis indicated that Atta (0.418) correlated with R05, and Brachymyrmex (0.136) with NT, being genera that contributed to area differentiation, and these genera may serve as indicators to qualify the stages of the recovery gradient. The ant genera correlated with the areas R05 and R10 also are correlated closely with environments defined by little vegetation complexity and with urban areas, while those predominating in NT and R20 are common to areas with more structured floristic composition. These results highlight the strong relationship between ants and some of the physical, chemical, and biological soil properties of the different areas.