Ant Diversity Research Articles

Effects of park size, peri-urban forest spillover, and environmental filtering on diversity, structure, and morphology of ant assemblages in urban park

Urban parks are likely the last green areas to preserve fauna diversity in urban ecosystems. We predicted that 1) species richness and ant diversity would increase with increasing park size, and species richness and ant diversity would be inversely related to distance from a peri-urban forest. 2) Larger ants would be predictably prevalent in less-complex habitats but the reverse should be true for small ants. The study was conducted in 47 parks of varying size located in Taichung City, Taiwan. In total, 14,324 ant individuals from 50 morphospecies and 22 genera were collected. No relationship between ant diversity and distance from a peri-urban forest. No significant clustering in functional composition with increasing park size and distance from a peri-urban forest. However, urban ant diversity marginally increased with increasing park size. Larger parks, characterize by heterogeneous fine-scale habitats, had the highest ant species and abundance of ants. The prevalences of opportunist, generalised myrmicinae (GM), and cryptic ant species were linked to increased soil moisture, number of tree species, and leaf litter depth. The positive association between GM and the number of trash bins. Our finding disproved the size-grain hypothesis, but hotter ground surface favored the presence of long-legged ants. The significant association between head width, inter-eye distance, eye width, and environmental variables such as understory vegetation cover, leaf litter depth, and soil temperature suggest that predaceous ants might be prevalent in heterogeneous fine-scale local microhabitats. In conclusion, our study evidenced the importance of heterogeneous fine-scale habitats in urban park to biodiversity.

What can ants tell us about ecological restoration? A global meta-analysis

The development of easily observable measures of restoration success is essential for monitoring of the ambitious proposed global restoration targets (e.g. The Bonn Challenge; New York Declaration on Forests). Systematic reviews with meta-analyses are a good way to evaluate the performance of different organisms in the monitoring of ecological restoration. Among the arthropods, ants have a long history in environmental monitoring. We compiled a data set and performed a global meta-analysis encompassing studies conducted in different ecosystems around the world to investigate whether richness and composition of species or functional groups (FG) of ant communities can be predicted during the restoration process. Moreover, we aimed to understand the influence of restoration technique (natural regeneration or active restoration), ecosystem type (temperate or tropical), and past land use (mining or pasture) on ant communities in areas undergoing restoration processes. Notwithstanding the varied conditions in which the studies were carried out, our meta-analysis showed that reestablishment of ant FG takes place more quickly than species richness. The recovery of ant diversity is faster in tropical ecosystems and areas under natural regeneration can have higher ant diversity than the reference areas. In temperate ecosystems, mined areas under restoration are less likely to recover the number of species than FG richness. Both species and FG composition were less predictable in our meta-analysis. As the publication of new datasets is increasing, we hope that future meta-analyses can build on the present study to further describe and understand the patterns in ant communities to be used as indicators of ecosystem restoration.

Tree diversity increases robustness of multi-trophic interactions.

Multi-trophic interactions maintain critical ecosystem functions. Biodiversity is declining globally, while responses of trophic interactions to biodiversity change are largely unclear. Thus, studying responses of multi-trophic interaction robustness to biodiversity change is crucial for understanding ecosystem functioning and persistence. We investigate plant-Hemiptera (antagonism) and Hemiptera-ant (mutualism) interaction networks in response to experimental manipulation of tree diversity. We show increased diversity at both higher trophic levels (Hemiptera and ants) and increased robustness through redundancy of lower level species of multi-trophic interactions when tree diversity increased. Hemiptera and ant diversity increased with tree diversity through non-additive diversity effects. Network analyses identified that tree diversity also increased the number of tree and Hemiptera species used by Hemiptera and ant species, and decreased the specialization on lower trophic level species in both mutualistic and antagonist interactions. Our results demonstrate that bottom-up effects of tree diversity ascend through trophic levels regardless of interaction type. Thus, local tree diversity is a key driver of multi-trophic community diversity and interaction robustness in forests.

IMPACT OF HIKING TRAIL DISTURBANCE ON ANTS` DIVERSITY AT MOUNT SINAI, ST. KATHERINE PROTECTORATE, EGYPT

Saint Katherine Protectorate (SKP) is one of the most important regions for biodiversity in Egypt. Tourism and its associated activities has become the main economic driver in SKP which might have negative impacts on biodiversity. Ants are effective biological indicators, since ant species diversity correlates with the assembly of other invertebrate fauna of particular habitats. The current study aimed at assessing the impact of some anthropogenic activities along the touristic hiking trail passing through Mount Sinai area on ants` diversity. A total of 583 individuals belonging to nine ant species, three subfamilies, from (Family: Formicidae; Order: Hymenoptera) were recorded within the study localities in Mount Sinai. Our study showed that the hiking trail disturbance had a negative environmental impact on the species richness and abundance of ants within the study localities in Mount Sinai. Based on our results it is advisable to move the hiking trails to slopes of Mount Sinai away from its current location within the basins (farshs). More studies are needed to assess the impact of hiking trails and associated human activities on other biodiversity elements in SKP

Ant community patterns in highly fragmented Chaco forests of central Argentina

AbstractThe Chaco is the largest dry forest biome in South America and one of the regions most threatened by agricultural intensification. As a consequence, in several areas Chaco forests persist as forest remnants of different sizes embedded in an agricultural matrix. Ants are social insects that have key roles in ecosystem functioning, and the effects of this ongoing land use change process on ant communities are little known for this region. In the present study, we assessed the consequences of land use replacement by monocultures and forest fragmentation on ant communities. Particularly, we assessed whether patch size, patch isolation and edge effect affect species richness and composition of ground‐dwelling ants in fragmented landscapes of Chaco forests. We collected ants by combining hand collecting and pitfall traps in 17 forest fragments and the surrounding matrix from two sites in Córdoba, Argentina. Patch size and patch isolation had no effect on ant richness; however, patch isolation and, to a lesser extent, patch size altered ant species composition. The ant community was not affected by edge but it was negatively affected by the crop matrix, which reduced richness and altered species composition. These results indicate that monoculture matrices severely affect ant communities in the Chaco forests, and that the effects of other indicators of habitat fragmentation (patch size and edge effect) are subtler and less relevant. In the present context of land use change, even small fragments could have an important value for the conservation of ant diversity.

Forest cover drives leaf litter ant diversity in primary rainforest remnants within human-modified tropical landscapes

The main effects of habitat loss and fragmentation have been addressed through changes in diversity patterns at different spatial levels. Species richness and diversity are the most used descriptors to assess the effect of changes in land use on tropical communities. However, other biological responses such as richness and diversity of trophic guilds may also provide a better understanding about the robustness and resilience of tropical environments to disturbance. In this study, we evaluated how changes in local and landscape characteristics associated to habitat loss and fragmentation affect: (i) species richness and Shannon diversity as well as (ii) trophic guild richness and diversity of leaf litter ants in human-modified tropical rainforest landscapes in Mexico. For this, we sampled ants in 16 sampling sites and recorded a series of descriptors at both local (i.e. elevation, temperature, relative humidity, soil pH, canopy cover, litter volume and vegetation structure) and landscape level (i.e. landscape heterogeneity, forest cover and connectivity). Overall, we observed that increasing primary forest cover within the sampling sites positively influenced richness and diversity of species and trophic guilds. In addition, at the local level, we found that only richness and diversity of ant species were negatively associated with tree density (i.e. number of trees, litter volume and canopy cover). These findings suggest that opportunistic species can be favored in environments with low tree density. In short, our complementary approach highlights the importance of environmental variability and primary forest cover in the maintenance of ant biodiversity in primary rainforest remnants.

Distribution and diversity of leaf-cutting ants in Northeastern Argentina: species most associated with forest plantations

Leaf-cutting ants (LCA) are considered one of the main herbivores and one of the most destructive pest insects of the Neotropics. Northeastern Argentina harbors the greatest species richness of these ants and in turn comprises the highest surface with forest plantations. Our aim was to establish which species of leaf-cutting ants are most commonly associated with forest plantations by analyzing their geographic distribution using published and unpublished species occurrence data. Also, estimate their potential areas of distribution along a latitudinal gradient that entirely encompasses northeastern Argentina using Ecological Niche Modeling. Only seven of the 20 species recorded were strongly associated with productive systems along the gradient, but only 2–3 species in each region could be considered high-risk species for forest plantations. High-risk species composition shows a turnover between regions. Our models show the potential distribution areas where LCA could become more abundant and dominant, and possibly causing a detrimental effect on the forest plantations in the studied region. We find that ecological niche models are useful tools to assess the environmental suitability of important LCA.

Boreal Sand Hills are Areas of High Diversity for Boreal Ants (Hymenoptera: Formicidae)

The boreal forest in Canada comprises a wide variety of ecosystems, including stabilized (overgrown) sand dunes, often referred to as sand hills. Globally, sandy soils are known for supporting a high diversity of invertebrates, including ants, but little is known for boreal systems. We used pitfall trap sampling in sand hill, aspen parkland and peatland ecosystems to compare their ant diversity and test the prediction that areas with sandy soils have higher invertebrate diversity compared to more mesic/organic soils. Overall, sand hills had ~45% more ant species compared to other sampled ecosystems from Alberta. Similar to other studies, local canopy cover within sand hills was found to be inversely related to ant species richness and diversity. Although sand hills are rare across the region, they are high biodiversity areas for ants, with the sand hills of north-central Alberta having higher species richness of ants compared to other studied areas in Canada.

Congruent spatial patterns of ant and tree diversity in Neotropical savannas

The strength of plant–animal diversity relationships tends to be idiosyncratic and, in many cases, its mechanisms are poorly understood. Consequently, the relevance of plant diversity patterns as surrogates of animal diversity patterns is still debated. We evaluated if ants and trees show congruent patterns of species richness and turnover at a regional scale, and the extent to which cross-taxon congruence can be attributed to direct interactions between the two taxa. We surveyed the ant and tree communities in 31 sites scattered over the world’s largest tropical savanna (the Cerrado), and found that tree and ant species richness are positively correlated. Furthermore, the greater the dissimilarity in tree community composition (turnover) between any two sites the greater the dissimilarity in ant community composition between these same sites. However, most of the explained variation in ant species richness and turnover was due to the joint influences of the environmental and spatial factors on tree species richness and turnover. Ants and trees shared similar environmental correlates of species richness and turnover, including especially net primary productivity, which in our study region is positively correlated with latitude. Congruent patterns of ant and tree diversity thus appear to have aroused because these two taxa are influenced similarly by environmental and spatial gradients. Nevertheless, we caution against the use of trees as surrogate of ant diversity patterns in Neotropical savannas, given that the observed spatial covariation in species richness and turnover was not strong to the point that tree diversity can reliably predict ant diversity patterns.

Grazing by large savanna herbivores indirectly alters ant diversity and promotes resource monopolisation.

In savannas, grazing is an important disturbance that modifies the grass layer structure and composition. Habitat structural complexity influences species diversity and assemblage functioning. By using a combination of natural sites and manipulated experiments, we explored how habitat structure (grazing lawns and adjacent bunch grass) affects ant diversity and foraging behaviour, specifically the efficiency of resource acquisition, resource monopolisation and ant body size. We found that in the natural sites there was no difference in the amount of time ants took to locate resources, but in the manipulated experiments, ants were faster at locating resources and were more abundant in the simple treatments than in the more complex treatments. Ant body size was only affected by the manipulated experiments, with smaller ants found in the more complex treatments. In both the grazing lawn and bunch grass habitats there were differences in assemblage patterns of ants discovering resources and those dominating them. Seasonality, which was predicted to affect the speed at which ants discovered resources and the intensity of resource monopolisation, also played a role. We show that ants in winter monopolised more baits and discovered resources at a slower rate, but only at certain times within the experiment. Grazing in conjunction with season thus had a significant effect on ant diversity and foraging behaviour, with dominant ants promoted where habitat complexity was simplified when temperatures were low. Our results indicate that structural complexity plays a major role in determining ant assemblage structure and function in African savannas.

Community structure and ant species diversity across select sites of Western Ghats, India

Information available on species composition, richness and diversity of ant communities of Western Ghats is limited. Recognizing this, the study (2010−2013) was undertaken to evaluate richness and diversity of ants in eight sites of Western Ghats, India, with added notes on how it varies on elevation gradient. Spanning across broad altitudinal and latitudinal gradient, selected sites differed greatly for various micro-habitat variables. Using standard collection protocols and employing five collection techniques, 173 species belonging to 65 genera in 10 subfamilies were collected including twenty species published as new to science and two genera and six species reported for the first time from India. Varying among sites, species richness was recorded lowest (S = 29) at Manalar and highest (S = 116) at Periyar Tiger Reserve. With little but significant variations among sites, the Shannon-Wiener's species diversity index (H′) was recorded highest (H′ = 2.60) at Periyar Tiger Reserve and lowest (H′ = 2.11) at Idukki Wildlife Sanctuary connoting that sites with lower richness were not necessarily less diverse. Beta diversity (β-diversity) was lowest (19%) between contiguous sites like Thattekkad Bird Sanctuary and Idukki Wildlife Sanctuary and highest between site Manalar and Periyar Tiger Reserve at 68% suggesting that ant species composition distinctly varied in these sites. Our results indicated that only few species were adapted to full spectrum of environmental variation along altitudinal gradient studied and both species richness and diversity peaked at mid-elevations as against higher elevations wherein it underwent rapid decline. Such behavior is presumably due to favorable ecological conditions at middle altitudes. Our findings rank high as they not only provide baseline data against which futuristic faunal changes could be assessed with respect to perturbations in a biodiversity hotspot but they also could be used to designate ecological sensitivities to various regions of Western Ghats for future conservation programs.

Magnetic material diversity in Brazilian ants: displacement behaviour and environmental adaptability.

How geomagnetic field information is collected and processed by insects for orientation and navigation remains elusive. In social insects, magnetic particles are well accepted as magnetic sensors. Ants have the ability to home and hunt, and some migratory and nomadic species can migrate or move over long distances for which magnetoreception is an important mechanism. It was shown previously that ferromagnetic resonance (FMR) spectral parameters of one migratory and one nomadic ant could be distinguished from Brazilian Solenopsis ant species and that these parameters correlate to the local geomagnetic field. The present work focuses on genera engaged in long-distance group raids and emigration collected mainly in the Amazon rainforest. A diversity of specimens of the genus was individually measured by FMR. Cluster analysis of the occurrence of the FMR Low Field component, associated with large or aggregated nanoparticles, and their spectral angular dependence resulted in a phylogenetic dendrogram of the genera of ants, principally from the North Brazilian region. The magnetic material characteristics of ants of the Invertebrate Collection from the Museum Paraense Emilio Goeldi were tested looking for their relation to ant genera and the local geomagnetic field. The observed spectral differences of the magnetic particles suggest that they are related to their capacity for adaptation to their environment and/or to displacement behaviour.

Asian needle ant (Brachyponera chinensis) and woodland ant responses to repeated applications of fuel reduction methods

AbstractAnts (Formicidae: Hymenoptera) are important components of forest ecosystems and can be affected by fuel reduction forest management practices. We assessed the impact of repeated applications of fuel reduction treatments on abundance and diversity of ants within upland mixed‐hardwood forests in the Southern Appalachian Mountains in North Carolina, USA. We established three replicate blocks (~56 ha each) and split each block into four fuel reduction treatments, which included prescribed burning (B), mechanical felling (M), a combination of prescribed burning and mechanical felling (MB), and a control (C; i.e., no treatment). We implemented treatments multiple times (two mechanical thinnings and four prescribed burns) over the course of a 15‐yr period. Due to tree mortality and resultant canopy gaps from high‐severity burns, forest structure was dramatically altered in MB. Over a 3‐yr period (2014–2016), we captured 54,219 ants comprised of 23 genera using pitfall and colored pan traps. Prenolepis imparis was the most common ant species collected, and it was significantly lower in abundance in MB than all other treatments. However, the non‐native species Brachyponera chinensis was more abundant in MB than all other treatments. Thus, some fuel reduction treatments may have consequences for invasive ant colonization in forests. Most ant taxa did not differ in abundance among treatments, suggesting that some fuel reduction practices may affect some, but not all ant species. Our results indicate that some fuel reduction treatments can alter forest ant communities, thus contributing to changing forest ecosystem dynamics. Monitoring of ants and other bioindicators after repeated rounds of fuel reduction treatments could provide useful knowledge that can be used to help balance forest management and biological diversity.

Diversity and Guilds of Ants in Different Land-Use Systems in Rio de Janeiro State, Brazil

ABSTRACT This study aimed to evaluate the ant fauna in three different land-use systems: pasture, eucalyptus plantation and secondary forest, in southeastern Brazil. The ant fauna was collected with standardized pitfall traps. Forty-seven ant species were collected, belonging to 24 genera and six subfamilies. The total ant species richness was significantly higher in secondary forest (29 species) and eucalyptus plantation (25 species) when compared to the pasture (17 species), with no significant difference between the secondary forest and eucalyptus plantation. The species composition differed significantly between the three land-use systems. The frequency distributions of ant guilds in eucalyptus plantation and secondary forest differed significantly from the frequency in the pasture. The results demonstrated the importance of natural forests for the conservation of biological diversity of the Atlantic Forest, but they also indicated that eucalyptus plantations, with native understory plants, can harbor considerable ant diversity.

Idiosyncrasies in cities: evaluating patterns and drivers of ant biodiversity along urbanization gradients

Abstract Urbanization is expected to reduce biodiversity. However, an increasing number of studies report urban biodiversity comparable to that of surrounding nonurban areas, leaving open the question: what maintains biodiversity in cities? We characterized patterns of ant biodiversity across urbanization gradients of three major cities in the Midwestern United States and evaluated the support for two mechanisms underlying the maintenance of biodiversity in cities, specifically via introduced non-native species and differential phenology of communities along each urbanization gradient. We observed idiosyncrasies in ant species diversity such that each city displayed either increased, decreased or no change in biodiversity across the urbanization gradient. We found partial support (one of the three cities) for the hypothesis that non-native species can contribute positively to overall species diversity in cities, though even with introduced species removed from consideration, native ant biodiversity was maintained along the urbanization gradient. We found no support for systematic differential phenology across urbanization gradients, although species diversity did vary over time across all sites. Our results further challenge the assumption of biodiversity loss in cities, as two of our three cities exhibited maintained species diversity along the urbanization gradient. Most importantly, our study demonstrates that urban biodiversity can be maintained entirely by native communities.

Spatial patterns and influencing factors of ground ant species diversity on the land-bridge islands in the Thousand Island Lake, China

Spatial patterns and influencing factors of ground ant species diversity on the land-bridge islands in the Thousand Island Lake, China

Ant Occupation of Twigs in the Leaf Litter of the Atlantic Forest: Influence of the Environment and External Twig Structure

Twig cavities are microhabitats that may be used by different ant species for nesting and colony expansion. However, ants do not colonize all twigs available in the leaf litter, pointing to the existence of environmental or twig-related filters. In this study, we analyzed which environmental and twig attributes affected twig occupation by ants. We surveyed seven plots in six Atlantic forest sites in southeastern Brazil. To characterize the environmental filters, we quantified canopy cover and leaf litter moisture and depth. At the twig level, we measured twig length and diameter and the area and circumference of all holes in each twig. Ant colonies occupied 13.42% of the 4,805 twigs surveyed, and we recorded a total of 52 twig-nesting ant species. Brachymyrmex admotus was the most frequent species. Ant species richness increased with canopy cover and leaf litter moisture and with the relative number of occupied twigs. In addition, we found that ant species richness increased with length and diameter of the twigs, and that twigs with smaller holes were more frequently occupied by ants, regardless of the availability of larger diameter holes. Our work demonstrates that both environmental characteristics and twig morphology can structure occupation of twigs by ants. In addition, we demonstrated that certain species show a preference for certain twig types. We highlight the importance of twigs for maintaining ant diversity and for colony expansion of arboreal species and species inhabiting the leaf litter.

Stability of Afromontane ant diversity decreases across an elevation gradient

As the need to better understand the ecology of hotspots of endemism intensifies, the insurance hypothesis is drawing increasing attention from policy-makers and scenario-planners. The hypothesis states that biodiversity increases ecosystem stability. When species numbers fluctuate, there is potential for further perturbation, loss of function and increased opportunity for invasive species to fill vacated niches. Southern Africa is predicted to be disproportionately impacted by global change, and high altitude systems as foci of endemism are particularly vulnerable to warming. Using ants, a group key to ecosystem function, we assess effects of temperature, season, aspect, vegetation and soil conditions on montane ant species richness, stability of ant community composition, and stability of ant species richness across an altitude gradient. Over six consecutive years of bi-annual sampling, we gathered one of the largest standardized data sets to date. We showed for the first time that stability of ant species richness decreases with increasing altitude, whilst compositional similarity of ant communities is higher with increasing altitude. Findings reveal more similar, species-poor, less stable ant communities at high altitude at the same sites over time.

Study of Ant Diversity in Various Localities of Akola, Maharashtra, India

Study of Ant Diversity in Various Localities of Akola, Maharashtra, India

Ant diversity in Muhan Pokhari area of Shivapuri-Nagarjun National Park, Nepal

Ant diversity was studied in Muhan Pokhari area of Shivapuri-Nagarjun National Park (SNNP)at 1,700 m to 1,900 m asl during winter and summer seasons of 2017. Ants were collected using pitfall traps, leaf litter sampling, bait and hand collection methods along a transect of50 m in each of all 5 sites (1,700 m, 1,750 m, 1,800 m, 1,850 m and 1,900 m). Altogether 817individual ants were collected representing 5 sub-families, 16 genera and 23 morpho species. Formicinae (57.67%) was the most abundant sub-family, followed by Myrmicinae (40.39%), Pseudomyrmicinae (0.8%), Ponerinae (0.73%) and Dolichoderinae (0.37%). Camponotus (437individuals) was the most abundant genus followed by Aphaenogaster (287). Species richness was higher in winter (17 morph species) than in spring (14 morph species). Shannon-Wiener diversity index (1.4618) and Evenness index (0.5539) were higher in spring season. Pitfall trap method was found most effective with highest number of individual ants (567) and of 21 species. The Shannon-Weiner diversity index was highest for pitfall method (1.3039) whereas evenness index was highest for the bait method (0.62615). Two genera Pachycondylaand Echinopla were recorded for the first time in Nepal.