Search Results (23)

High-severity wildfires create heterogeneous patterns of vegetation across burned landscapes. While these spatial patterns are well-documented, less is known about the short- and long-term effects of large-scale high-severity wildfires on insect community assemblages and dynamics. Ants are bottom-up indicators of ecosystem health and function that are sensitive to disturbance and fill a variety of roles in their ecosystems, including altering soil chemistry, dispersing seeds, and serving as a key food resource for many species, including the federally endangered Jemez Mountain salamander (Plethodon neomexicanus). We examined the post-fire effects of the 2011 Las Conchas Wildfire on ant communities in the Valles Caldera National Preserve (Sandoval County, New Mexico, USA). We collected ants via pitfall traps in replicated burned and unburned sites across three habitats: ponderosa pine forests, mixed-conifer forests, and montane grassland. We analyzed trends in species richness, abundance, recruitment, loss, turnover, and composition over five sequential years of post-fire succession (2011–2015). Ant foraging assemblage was influenced by burn presence, season of sampling, and macrohabitat. We also found strong seasonal trends and decreases over time since fire in ant species richness and ant abundance. However, habitat and seasonal effects may be a stronger predictor of ant species richness than the presence of fire or post-fire successional patterns. Full article

Human-driven changes in land cover and use can significantly impact species ants community structures, often leading to a decline in taxonomic diversity or species homogenization. Ant morphology, used as a proxy for ecological function, offers a valuable framework for understanding the effects of anthropogenic disturbances on ant diversity. This study explored the morphological diversity of ant assemblages in agricultural ecosystems and secondary forests in Italy and the Brazilian Amazon, analyzing how these communities are structured and adapted to different environments. The research aims to understand the ecological interactions and the role of ants in maintaining biodiversity in these contexts. The study was conducted in the Ticino River Natural Park, Italy, and the Paragominas mosaic in Pará, Brazil. The ants were sampled using epigean pitfall traps at 15 agricultural and 13 forest sites. In the secondary forests, the species richness was significantly higher in both countries compared to agricultural areas. In general, the Community Weighted Mean (CWM) of the selected traits (head length, head width, interocular distance, mandible length, eye width, Weber’s length, and tibia length) of Brazilian ants was higher than those of Italian. However, the CWM of agricultural areas of the two countries was more similar. We noticed the convex hull (i.e., the volume of an assemblage in the morphological space) of Brazilian secondary forests was still larger than Italian secondary forests when both assemblages have the same number of species. Morphological homogenization was more pronounced in agricultural settings, whereas secondary forests showed more variability, highlighting the role of environmental filtering in shaping ant communities across land use types. Full article

Ant evolutionary success depends mainly on the coordination of colony members, who recognize nestmates based on the cuticular hydrocarbon (CHC) profile of their epicuticle. While several studies have examined variations in this crucial factor for colony identity, few have investigated the anthropic impact on CHC profiles, and none have focused on Lasius paralienus. Here, we surveyed the changes in L. paralienus CHC assemblages across agroecosystems and assessed whether different vineyard management influences these profiles. Soil sampling within ant nests and in close surroundings was performed to measure microhabitat variations. Our results show that the cuticular chemical composition of Lasius paralienus is mainly affected by the differences between areas, with an existing but unclear anthropic influence on them. Normalized soil respiration partially explains these interarea variations. Irrespective of the conventional or organic management, human activities in agroecosystems mostly impacted L. paralienus linear alkanes, a specific class of CHCs known to play a major role against dehydration, but also affected the abundance of compounds that can be pivotal for maintaining the colony identity. Our findings suggest that vineyard practices primarily affect features of the ant cuticle, potentially enhancing microclimate adaptations. Still, the potential effects as disruptive factors need further investigation through the implementation of behavioral bioassays. Full article

The potential of subdominant ants of the Formica fusca group and their role in forests are still underestimated. Since ant behaviour is dependent on colony size, studying the functional organisation of nest complexes (NC) is most promising for a more accurate assessment of species capabilities. The study focused on the main ecological and ethological issues of the life activity of Formica lemani Bondroit within large NC (>150 nests) and beyond. After preliminary mapping of the F. lemani NC (main nests, trails, foraging trees), off-nest activity, aggressiveness, and trophobiotic relationships with aphids in and outside the NC territory were studied. Within the NC, the dynamic density, the intensity of movement on trails, and aggressiveness of F. lemani were significantly higher than beyond; the range of symbiont aphids was twice as small, with aphids on birches playing a key role in carbohydrate nutrition of F. lemani. The latter ensures accelerated restoration of trophobiotic interactions in spring and stability of the food supply until autumn. Combined with the lack of pressure from F. rufa group ants, this allowed F. lemani to maintain high population densities, and significantly increased its competitiveness, and role in plant protection against phytophages. Full article

Species traits often vary in a coordinated manner, making up an ecological strategy comprised of suites of interrelated traits. Environmental gradients, such as those along elevational gradients, provide an ideal venue in which to examine variation in ecological strategies with the environment. We examined variation in the morphological strategies of ants along elevational gradients on thirteen mountains across three mountain ranges in central and south-eastern Australia. We pitfall-trapped ants, counted and identified workers and measured morphological traits. Most species showed a hump-shaped relationship between occurrence and elevation, and several responded to microhabitat variables. Morphological traits varied along two key axes: “gracility”, where high values indicated longer-legged species with dorsally positioned eyes and smooth, bare cuticles; and “size and darkness”, where species with high values were larger and darker. Analysis of assemblage-weighted means revealed that gracility decreased with temperature and increased with precipitation, suggesting links with desiccation tolerance. Size and darkness increased with UV-B, declined with increasing canopy cover and peaked at mid-temperatures. We thus detected strong shifts in dominant morphological strategies along our elevational gradients. However, the multifunctionality and interrelatedness of traits and the covariance of climatic factors may make isolation of the function of individual traits difficult. Further, the predictive power of our models may be limited in the context of novel environments predicted under global change. Full article

In northern Alberta, Canada, much of treed boreal peatlands are fragmented by seismic lines—linear disturbances where trees and shrubs are cleared for the exploration of fossil fuel reserves. Seismic lines have been shown to have slow tree regeneration, likely due to the loss of microtopography during the creation of seismic lines. Inverted soil mounding is one of the treatments commonly applied in Alberta to restore seismic lines and mitigate the use of these corridors by wildlife and humans. We assessed the effects of mounding on understory plants and arthropod assemblages three years after treatment application. We sampled five mounded and five untreated seismic lines and their adjacent treed fens (reference fens). Compared to reference fens, mounded seismic lines showed on average lower bryophyte (6.5% vs. 98.1%) and total understory cover (47.2% vs. 149.8%), ground-dwelling spider abundance (226.0 vs. 383 individuals), richness (87.2 vs. 106.4 species) and diversity (19.0 vs. 24.6 species), rove beetle abundance (35.2 vs. 84.8 individuals), and ant richness (9.0 vs. 12.9 species). In contrast, rove beetle and ground beetle richness (39.0 and 14.5 species, respectively) and diversity (16.8 and 7.8 species, respectively) were higher on mounded seismic lines compared to reference fens (richness: 18.0 and 7.5 species, respectively; diversity: 7.0 and 3.8 species, respectively). This is one of the first studies to assess arthropod responses to restoration efforts in the context of oil and gas disturbances in North America, and our results highlight the need to incorporate multiple taxa when examining the impact of such treatments. Full article

Industrial production of olive oil generates large amounts of solid waste called ‘alperujo’. Its compost can fertilize many crops, especially olives. Furthermore, superintensive orchards are increasing their surface globally due to higher production and savings in different costs. Ants are considered an important part of the arthropod community in olive orchards and could even play a significant role in pest control. The tree canopy and ground were sampled to compare the ant assemblage in plots fertilized with compost and mineral products in two groves with different types of crop management (superintensive and traditional) over two years. The numbers of ants in both types of fertilization in each grove were not statistically different (p > 0.05), indicating that the type of fertilization did not have a significant impact on its populations in the ground or in the canopy, but the number of individuals was significantly higher in the superintensive grove than in the traditional grove (both in the ground and in the canopy, p < 0.01). The most frequent species in the ground were Pheidole pallidula, Plagiolepis smitzii and Aphaenogaster senilis (superintensive grove) and Pheidole pallidula, Tetramorium gr semilaeve, Plagiolepis pygmaea, and Tapinoma nigerrimum (traditional grove). In the canopy, the most frequent species were Plagiolepis spp. in both groves. Differences in ant densities and species between the groves could be due to the different management, especially of the soil, but it must be confirmed using more replicas and longer periods of study. Full article

Ecological disturbance is fundamental for grassland management and the maintenance of its biodiversity. Fire and grazing are the primary habitat disturbances influencing the structure and composition of grassland ecosystems, both acting to remove grass biomass. Little is known about the effects of such grass biomass removal on grassland ants, an ecologically dominant faunal group. Our study assesses the response of ant communities to long-term experimental burning and mowing treatments in a South African mesic grassland. The study’s main objectives were (i) to assess the effect of frequency and season of burning and mowing on ant species richness and composition and (ii) to identify indicator species associated with the various grassland management treatments. The experiment included two fully crossed fire treatments: frequency (annual, biennial, and triennial) and season (late winter and after spring rains), along with annual mowing and an undisturbed control. Ants were sampled using pitfall traps in 27 plots, comprising 18 burnt, 6 mown, and 3 controls. The mean species richness in the burnt plots (22.38 ± 3.71) was far higher than in the control (23 ± 2.0) or mown (21.0 ± 2.28) plots. However, the total richness (combining plots) did not vary among treatments. Four of the nine most common species showed a statistically significant response to experimental treatment, but there were no significant treatment effects on overall species composition. Three indicator species (IndVal > 70%) were identified for the control plots, and detector species (IndVal 50–70%) were identified for annual, biennial, and triennial burning treatments. Our findings demonstrate that ant communities in this grassland system are highly resilient to burning and mowing, and that fire promotes diversity at the plot scale. Our identified indicator and detector species can be used as a focus for ongoing monitoring of biodiversity change in our grassland system, including in response to woody expansion. Full article

Spatial and temporal variation in the diversity of ants in four urban fragments of the tropical dry forest in the city of Santa Marta was evaluated. The fragments were sampled four times in the dry and rainy season, from October 2019 to January 2020, using pitfall traps, mini-Winkler bags, baits, and manual collection. Both alpha and beta taxonomic diversity and their components were quantified. The functional groups were established based on proposals for Neotropical ant species. A total of 7 subfamilies, 37 genera, and 84 species were collected. Richness varied spatially from 33 to 61 species, but between the two seasons it was 72 and 76 species. Sites N01 and N02 had greater diversity than N03 and N04. In all the fragments, soil ants were dominated by Ectatomma ruidum, but litter ants showed a structure with less dominant species. The dissimilarity between fragments was 60–80%, attributable mainly to turnover (50–70%) but not to nestedness (10%). Seventeen functional groups were identified. Taxonomic diversity of ants in urban fragments in Santa Marta showed marked spatial variation, without influence from the seasons. Despite taxonomic turnover, there was broad similarity in functional groups between the fragments, indicating ecological equivalence of species between the ant assemblages. Full article

Red imported fire ants mounds have been suggested as a potential reservoir for beneficial entomopathogenic fungal species that are vital for more complex roles in the ecosystem aside from infecting the insects. In the current study, the assemblage of fungal symbionts of the red imported fire ants (RIFA) were obtained across five cities in Guangdong Province, China. The sampling areas were selected because of high occurrence of fire ants mounds in the regions. Mound soils, plant debris within mounds, and ants were collected from three sampling locations in each city for potential isolation of entomopathogenic fungal associates of RIFA. All samples were collected during the spring of 2021. Following successful isolation from substrates, the patterns of fungal species composition, and richness were evaluated. In total, 843 isolates were recovered, and based on their phenotypic distinctiveness and molecular characterization based on DNA sequences of multiple loci including the ITS, SSU, and LSU regions, 46 fungal taxa were obtained, including 12 that were unidentified. Species richness and abundance was highest in the mound soils, while the lowest value was recorded from the ant body. As per the different locations, the highest abundance level was recorded in Zhuhai, where 15 fungal taxa were cultivated. The most common taxa across all substrates and locations was Talaromyces diversus. A baseline analysis of the fungal community composition of RIFA would better our understanding on the interactions between these social ants and their associated microbial organisms, and this knowledge in turn would be important for the successful management of the RIFA. Full article

Soil microbes have a wide range of distribution across the world and can be found in different agricultural and forest systems including cultivated soils, ant mounds, decaying trees, leaves, roots, and on insect bodies. Across five counties of Guangdong province of China, the assemblage of bacterial associates of red imported fire ant (RIFA) were examined. The locations were selected based on evidence of high presence of RIFA mounds in these regions. Samples were analyzed from mound soils, plant debris within mounds, and the ant body. The current study analyzed bacterial species composition and richness patterns, where 525 isolates were recovered in total, comprising 44 bacterial taxa. Taxa abundance was highest in the ant body at 35 taxa, while the values were relatively similar across soil substrate and plant debris, where 3 and 6 taxa, respectively, were recorded. The highest bacterial taxa recovery rate was recorded in Guangzhou, where a total of 17 taxa were isolated. Myroides odoratimimus was the most common across all substrates and locations among the bacterial taxa. Others with the highest isolation frequencies includes, Enterobacter cloacae, Vagococcus fluvialis, and Myroides odoratus. The understanding of the bacterial community composition of RIFA is crucial for the development of successful management techniques for these notorious social ants. In order to expand on the findings of the current study, it is imperative to understand if the associated microbial communities of the RIFA form a parasitic, antagonistic, or mutualistic relationship with their host. In this vein, further studies would examine the influence of the characterized bacterial associates of the RIFA on the social behavior, physiology, and the host response to foreign pathogens. Full article

China’s East Asia monsoon zone is undergoing rapid land-use conversion and urbanization. Safeguarding remaining biodiversity requires reducing, mitigating, and/or eliminating the negative impacts of human-induced landscape modification. In this study, we sampled ground-dwelling ants at 40 plots over 12 continuous months in a suburban area in southwestern China to examine whether and how vegetation composition and habitat fragmentation affected species richness and assemblage composition for the general ant community and, specifically, for principal functional groups (including Opportunists and Generalized Myrmicinae). Warmer seasons were associated with a higher capture rate for all functional groups. Patterns of ant species richness among Opportunists were more sensitive to vegetation and fragmentation than for Generalized Myrmicinae, and these effects generally varied with season. Patterns of ant assemblage composition for Opportunists were exclusively sensitive to vegetation, whereas Generalized Myrmicinae were sensitive to both vegetation and fragmentation with variation among seasons. Overall, our findings highlight the important role of seasonality, vegetation composition, and habitat fragmentation in mediating the impacts of human-induced landscape modification on urbanized ant communities, which make an essential functional contribution to biodiversity in the East Asia monsoon zone. Full article

Understanding where biodiversity is and how it is distributed is crucial to conserving vulnerable and dynamic ecosystems. Although natural forests support greater diversity and are vital for the conservation of organisms, recent studies have argued that monoculture plantations can be used as an alternative habitat for forest species. We investigate how ant diversity patterns and assemblage composition vary between monoculture timber plantations and adjacent natural forests using pitfall traps in the Natal Midlands of South Africa. A total of 326 ants were collected, comprising 4 subfamilies, 13 genera, and 30 species. The blue gum plantations had the highest species diversity compared to other habitats. Although two species were found exclusively in the natural forest, it had the lowest ant diversity. Generally, species assemblages between the compared plantations and the natural forests were distinct. Monoculture plantations affect ant communities, leading to a change in their distribution patterns and assemblage composition. Determining how these rapidly expanding plantations affect biodiversity at different scales is essential for preserving indigenous fauna. Although our findings proposed that blue gum plantations have the potential to conserve ant taxonomic diversity compared to pine plantations, we recommend that future studies investigate the response of ant functional diversity to monoculture timber plantations in the region. Full article

Biodiversity patterns along elevational gradients are generally characterised by monotonic decreases or mid-elevational peaks in species richness, while elevational zones may be characterised by distinct assemblages, or higher zones may be subsets of lowland assemblages. Elevational gradients in diversity have been less studied in the Afrotropical region. This study documents ant diversity patterns in three forest types associated with the tropical mountains of Udzungwa; we hypothesise that: (1) ant diversity and activity will show a monotonic decrease from mid-elevation with increasing elevation and (2) that forests associated with different elevations will have a distinct ant assemblage. Pitfall traps were deployed at three targeted elevations (650–800, 800–1400, and 1400–1500 m a.s.l.). Ant species richness declined with increasing elevation from 650 m a.s.l. and formed three elevational assemblages with lower elevation forests having almost twice as many species as sub-montane forests and three times as many as that of the montane forests. In contrast, overall ant activity peaked at 800–1400 m a.s.l. The ant assemblages associated with the lower elevation forest were very distinct, while assemblages associated with the sub-montane and montane forests shared species. Our study reveals valuable and relevant information for biodiversity monitoring and conservation planning as the species associated with each forest type may be used as indicator species for assessing biodiversity responses to climate change and anthropogenic activities on these mountains. Full article

Temporal changes in soil development were assessed on fluvial terraces of the Little River in the upper Coastal Plain of North Carolina. We examined five profiles from each of six surfaces spanning about 100,000 years. Soil-age relationships were evaluated with inter-surface clay mineral comparisons and regression of chemical properties versus previously reported optically-stimulated luminescence ages using the most developed subsoil horizon per profile. Bases to alumina (Bases/Al₂O₃) ratios have negative correlations with age, whereas dithionite-Fe (Fe_D) concentrations are positively correlated with time and differentiate floodplain (<200 yr BP) from terrace (≥10 ± 2 ka) soils and T4 pedons (75 ± 10 ka) from younger (T1-T3b, 10 ± 2–55 ± 15 ka) and older (T5b, 94 ± 16 ka) profiles. Entisols develop into Ultisols with exponentially decreasing Bases/Al₂O₃ ratios, reflecting rapid weatherable mineral depletion and alumina enrichment during argillic horizon development in the first 13–21 kyr of pedogenesis. Increasing Fe_D represents transformation and illuviation of free Fe inherited from parent sediments. Within ~80–110 kyr, a mixed clay mineral assemblage becomes dominated by kaolinite and gibbsite. Argillic horizons form by illuviation, secondary mineral transformations, and potentially, a bioturbation-translocation mechanism, in which clays distributed within generally sandy deposits are transported to surface horizons by ants and termites and later illuviated to subsoils. T5b profiles have Fe_D concentrations similar to, and gibbsite abundances greater than, those of pedons on 0.6–1.6 Ma terraces along Coastal Plain rivers that also drain the Appalachian Piedmont. This is likely because the greater permeability and lower weatherable mineral contents of sandy, Coastal Plain-sourced Little River alluvium favor more rapid weathering, gibbsite formation, and Fe translocation than the finer-grained, mineralogically mixed sediments of Piedmont-draining rivers. Therefore, recognizing provenance-related textural and mineralogical distinctions is crucial for evaluating regional chronosequences. Full article