Ant Functional Groups Research Articles

Ant functional groups and their effects on other insects in organic and conventional cropping areas

The present research aimed to study the functional groups of ants in organic and conventional cropping areas and assess their influence on the abundance of other insects in agroecosystems. Sampling was carried out in eight rural properties with organic, and eight with conventional crops in Paraíba do Sul, state of Rio de Janeiro, Brazil. Fifteen pitfall soil traps were installed to collect ants in each property, in April and May 2016. The ants collected were dry-mounted and identified. The insect abundances of the orders Coleoptera, Hemiptera, and Orthoptera were also obtained. Ants were classified into seven functional groups. The functional group with the largest number of species was “omnivores that inhabit the soil and the leaf litter,” followed by “omnivores that inhabit the soil, the leaf litter, and the plants.” The group “omnivores that inhabit the soil and the leaf litter” showed the highest abundance of ants in both types of crops. The mean richness of functional groups was significantly higher in organic than in conventional crops. We only observed the effect of the abundance of ants of the group “omnivores that inhabit the soil, the leaf litter, and the plants” on the abundance of coleopterans in conventional crops. Hence, areas with organic crops are more favorable for maintaining an ant fauna with higher functional diversity than areas using the conventional cropping system.

Does the Ant Functional Group Classification Really Work? A Validation in Two Contrasting Habitats from Central Mexico

Abstract Ants have historically been classified into “functional groups” (FGs) to facilitate their interpretation as bioindicators. A particularly popular classification scheme is the one proposed by Andersen, based on the Australian myrmecofauna. These classification criteria suggest that ant abundance is linked to stress and disturbance, such that their affinity to and tolerance of particular conditions enables them to inhabit specific ecological contexts. Herein, we aimed to validate whether the climatic affinity postulated by the FG approximation can suggest FG composition and abundances in Mexican ant communities, such as has been previously evaluated by studies in other regions worldwide. In a protected natural area with a history of anthropogenic pressure, we evaluated the variation in temperature and humidity of two habitat types during consecutive years: a native oak forest and an induced grassland. The ant communities of the two sites were monitored using three collected methods (baits, pitfalls, and direct observations) and classified into FGs under Andersen’s criteria. We found 34 ant species. The induced grassland site (28 species) was more species rich, more diverse, and had higher ant abundance than the oak site (21 species). There was a similarity in species composition between the sites (44.78%). In the oak forest, FGs related to cold temperatures were the most abundant, while in the induced grassland, heat-tolerant FGs were most abundant. Our findings support that Andersen’s functional group classification is useful in suggesting habitat use in Mexican ant species. Likewise, our data are in accordance with previous findings that both the presence and abundance of FGs must be considered for an adequate application of this classification scheme.

Changes in the core species of the ant-plant network of oak forest converted to grassland: replacement of its ant functional groups.

Land-use change in terrestrial environments is one of the main threats to biodiversity. The study of ant-plant networks has increased our knowledge of the diversity of interactions and structure of these communities; however, little is known about how land-use change affects ant-plant networks. Here we determine whether the change in land use, from native oak forest to induced grassland, affected the network properties of ant-plant networks in a temperate forest in Mexico. We hypothesize that the disturbed vegetation will be more nested and generalized due to the addition of generalist species to the network. The oak forest network comprises 47 plant species and 11 ant species, while the induced grassland network has 35 and 13, respectively. Floral nectar was the resource used most intensely by the ants in both vegetation types. The ant-plant network of the induced grassland was significantly more nested and generalist than that of the oak forest; however, none of the networks were nested when considering the frequency of interaction. In both vegetation types, the ants were more specialized than the plants, and niche overlap was low. This could be related to the dominant species present in each type of vegetation: Prenolepis imparis in the oak forest and Camponotus rubrithorax in the grassland. The central core of cold climate ant species in the oak forest was replaced by a central core of subordinate Camponotini and tropical specialists in the induced grassland. These results suggest that the increase in nestedness and generalization in the grassland may be related to the loss of the cold climate specialists from the core of the oak forest network. Our findings provide evidence that land-use change increases the level of generalization in the ant-plant interaction networks of temperate forests.

Interactions and information: exploring task allocation in ant colonies using network analysis

In animal societies, individuals may take on different roles to fulfil their own needs and the needs of their group. Ant colonies display high levels of organizational complexity, with ants fulfilling different roles at different timescales (what is known as task allocation). Factors affecting task allocation can be at the individual level (e.g. physiology), or at the group level (e.g. the network of interactions). We focus on group level processes by exploring the relationship between interaction networks, task allocation and task switching using a previously published data set (Mersch et al., 2013, Science, 340 (6136), 1090–1093) tracking the behaviour of six Camponotus fellah colonies over 41 days. In our new analyses, our goal was to better explain the noisy process of task switching beyond simple age polyethism. First, we investigated the architecture of interaction networks using node (individual) level network measures and their relation to the individual's task – foraging, cleaning or nursing – and whether or not the ant switched tasks. We then explored how noisy information propagation was among ants, as a function of the colony composition (how many ants carried out which tasks), through the information-theoretic metric of ‘effective information’. Our results show that interaction history is tied to task allocation: ants that switched to a task were more likely to have interacted with other ants carrying out that task. The degree to which interactions related to task allocation, as well as the noise in those interactions, depended on which groups of ants were interacting. Overall, we found that colony cohesion was stable even as ant level network measures varied more for ants when they switched functional groups; thus, ant colonies maintained a high level of information flow as determined by network analysis, and ant functional groups played different roles in maintaining colony cohesion through varied information flows. • We analysed the interaction networks of six C. fellah colonies. • We tested how centrality and information flow are tied to task switching. • Node metrics and effective information explained functional group differences. • Interactions were correlated with task switching. • The strength of this correlation, however, differed across functional groups.

Congruent responses of vascular plant and ant communities to pastoral land-use abandonment in mountain areas throughout different biogeographic regions

BackgroundThere is a long-term trend towards the abandonment of agro-pastoral activities in the mountain areas of Europe: the following encroachment process of semi-natural grasslands by shrubs is one of the main severe threats to the conservation of biodiversity in mountain environments. To better understand the impact of land abandonment, we analysed the reliability of plant functional groups, ant traits, and ant functional groups as indicators of land use changes. We carried out the research in Italy at four sites along a latitudinal/altitudinal gradient in three biogeographic regions (Mediterranean, Continental, Alpine). We identified three stages of a chronosequence at each site as representative of the plant succession in response to pastoral land-use abandonment.ResultsAs expected, both the plant and ant assemblages considerably differed across sites at the species level and, within each site, among the three stages. This trend was found also using ant traits, functional groups of ants, and plant functional groups. Ant and plant communities were related in terms of composition and functionality. Harvester ants and ants with collective foraging strategy were associated with annual legumes and grasses (Therophytes); ants with a strictly individual foraging strategy with Phanerophytes. Ant traits and plant functional groups indicated significant differences among the three stages of the chronosequence. However, ant functional groups could not discriminate between the stages represented by secondary grasslands currently grazed and shrub-encroached grasslands ungrazed.ConclusionDespite some limitations of ant functional groups in explaining the succession stages of land abandonment, our results suggest that ants are a good surrogate taxon and might be used as bioindicators of land-use changes and ecosystem functioning. Furthermore, our findings indicate that the functional group approach should be applied to other European ecosystems. Finally, reducing the taxonomic complexity could contribute to developing predictive models to detect early environmental changes and biodiversity loss in mountain habitats.

Effects of Habitat Conversion on Ant Functional Groups: A Global Review

Conversion of natural to anthropogenic environments affects biodiversity, and the understanding of these impacts may be improved by assessing how different functional groups respond to such land conversion. We studied land conversion impacts on ant functional groups, as ants are ecologically important and respond well to various environmental changes. We hypothesized that conversion of natural to anthropogenic environments modifies the composition of functional groups, fostering generalist and opportunistic groups over specialist ones, with more responses of this type in tropical than in temperate regions. We recovered 412 papers from ISI Web of Science, of which we selected 17 studies, published between 1993 and 2018, that addressed our study’s question. We assessed whether each functional group responded positively or negatively to conversion of natural habitat into anthropogenic land uses and used Monte Carlo tests to assess significance. Ants were affected by natural habitat conversion into monoculture and polyculture and by the conversion of savannas and of tropical and subtropical forests. Land conversion affected six of the 13 functional groups assessed here. In the temperate zone, cryptic species, predators, subordinate Camponotini, cold-climate specialists and tropical-climate specialists were impaired, whereas hot-climate specialists were favored. In the tropics, land conversion negatively impacted fungus-growers and predators. In both climatic zones, several functional groups, mainly those with broad ecological niches, did not respond to land conversion. Our results corroborate that land conversion effects vary among ant functional groups and indicate that the ant fauna of temperate ecosystems may be more susceptible than that of tropical regions.

Ant species richness, abundance and functional groups along an elevation gradient in Central Cameroon Biodiversity Journal, 2021, 12 (1): 179–194

Ant species richness, abundance and functional groups along an elevation gradient in Central Cameroon Biodiversity Journal, 2021, 12 (1): 179–194

An insight into the quality of sacred groves – an island habitat – using leaf-litter ants as an indicator in a context of urbanization

AbstractSacred groves (SGs) of India are islets of forests providing ecosystem and spiritual services to man. Studies suggest that SGs are deteriorating on their quality due to urbanization, invasive species, land-use change, and religious modernization. We explored diversity, community, and abundance of overall and different functional groups of litter ants, including Anoplolepis gracilipes – an invasive ant – on paired SG-neighbouring home garden (HG) sites in rural and urban landscape to (a) assess the quality of SGs and (b) examine whether the variation in ant community of the two habitats was predicted by urbanization and abundance of A. gracilipes. We considered species and local contribution to β-diversity to identify species and sites crucial for conservation of sites. Abundance and richness of overall ants, proportional trap incidence of species, and abundance of A. gracilipes were similar on SG and HG, but species diversity and abundance of certain ant functional groups were higher on SG. Ant community of SG was different from HG, but was not affected by urbanization. A. gracilipes and rural SGs contributed the most to β diversity. A. gracilipes gave little pressure on native ant community. The study concludes that SGs, despite invaded by A. gracilipes, have potential for conserving biodiversity.

Seeking surrogates for taxonomic and functional evaluations of leaf-litter ant faunas

Comprehensive biodiversity inventories are expensive and time-consuming to achieve, especially for groups of megadiverse organisms. One approach to resolve such situations is to utilize biological substitutes, referred to as surrogates. A surrogate should provide meaningful information at a lower cost and/or effort than the original level of resolution. Studies have shown that species richness is often not the best or most appropriate component or predictor of biodiversity. Functional diversity can be used as a measurement of the ecological differentiation between habitats or between biological functions. We evaluated the use of several taxonomic metrics as potential surrogates for leaf-litter ant assemblages distributed in 65 Atlantic rainforest sites. Our goal was to find reliable and economic substitutes for both taxonomic and functional leaf-litter ant diversity and composition. We tested four potential surrogate approaches for taxonomic metrics and three for functional group metrics. Additionally, we also evaluated the time and costs involved. We used a large leaf-litter ant database that comprises 364 ant species, respectively classified into 13 or 26 ant functional groups based on either a general and specific resolution. Subfamily was found to be an unacceptable surrogate for both taxonomic and functional group metrics. Mixed-level and indicator taxa metrics were rated as ‘excellent’ taxonomic surrogates. Mixed-level and genus metrics were rated as ‘excellent’ or ‘acceptable’ functional group surrogates when considering the most general functional resolution, while mixed-level and genus were considered as ‘excellent’ surrogates when considering the more specific resolution. The monetary and time costs to identify ants to genus level were lower than those using indicator taxa and mixed-level metrics. The use of a certain higher taxon functional and taxonomic surrogates allows a reduction of survey and analysis costs while still enabling the analysis of biological diversity from the taxonomic and functional point of view.

Interactive effects of urbanization and year on invasive and native ant diversity of sacred groves of South India

Urbanization is a major threat to native biodiversity. Invasion of tramp species is a major consequence of urbanization, which might threaten native species. Ants are established robust ecosystem indicators. We assessed the changes of ant community in sacred groves (SGs) of urban and rural landscapes of south India between 2013 and 2019, and asked, 1) what is the effect of urbanization on ant community? 2) has the population of invasive ants, particularly Anoplolepis gracilipes – a globally notorious tramp species, changed in response to urbanization and year? 3) is species composition of ants in SGs different between landscapes and years? and 4) has the population of native ants or any ant functional groups responded with the population of invasive ants? The richness of overall species, native species, and invasive species was not affected by year or landscape, but the abundance was. In six years, the abundance of ants doubled, but due to A. gracilipes. A. gracilipes, previously restricted only in the urban SGs had established in rural SGs in six years. A significant turnover of native species was observed across years and with the population rise of A. gracilipes. While Generalist Myrmecines and Tropical Climate Specialists increased with the abundance of invasive ants, Cryptic Species decreased. We consider the stability maintained in the native species composition and richness in SGs, the aftermath of the conditions provided by SGs. However, the evident shift in the composition of native ants over the years point out how invasive ants affect the native species composition.

Diversity and Abundance of Ant (Formicidae) Functional Groups in Range of Land Use Systems in Jambi, Sumatra

Kerusakan hutan tropika basah dapat menimbulkan dampak lingkungan berupa penurunan keanekaragaman hayati dan terganggunya fungsi serta stabilitas ekosistem. Tujuan dari penelitian ini adalah untuk mendapatkan bukti apakah perubahan hutan tropika basah menjadi bentuk penggunaan lahan lain berakibat pada penurunan keragaman dan kelimpahan semut, dan untuk menunjukkan apakah semut dapat dijadikan sebagai bio-indikator perubahan sistem penggunaan lahan (SPL). Penelitian ini dilakukan di Jambi Sumatra pada akhir musim penghujan (Mei−Juni) 2004 pada berbagai taraf intensifikasi SPL. Inventarisasi dan koleksi semut dilakukan dengan menggunakan metode “Winkler” pada enam SPL, yaitu: hutan primer, hutan sekunder, perkebunan karet, perkebunan kelapa sawit, ladang ketela pohon, dan padang alang-alang. Hasil penelitian menunjukkan bahwa ditemukan 50 genus semut pada 6 SPL tersebut. SPL tidak berpengaruh secara nyata terhadap keragaman dan kelimpahan seluruh semut tetapi berpengaruh secara nyata terhadap kelompok semut pesaba dan semut predator. Keragaman jenis dan kelimpahan yang tinggi dari semut predator ditemukan pada SPL hutan primer dan hutan sekunder. Keragaman jenis dan kelimpahan menjadi rendah apabila SPL hutan diubah menjadi SPL ladang ketela pohon. Kelimpahan semut pesaba tertinggi diketemukan pada SPL perkebunan kelapa sawit. Data yang diperoleh menunjukkan bahwa semut dapat digunakan sebagai bio-indikator dalam perubahan SPL di kawasan Jambi, Sumatra.

Food resource exploitation and functional resilience in ant communities found in common Mediterranean habitats

Understanding how ecosystems may cope with future environmental change is a key challenge in modern ecology. Ecosystem resilience depends on both functional redundancy (the number of species making a similar contribution to a given ecosystem function) and response diversity (variability in the responses of functionally similar species to disturbance). Ants provide numerous important ecosystem functions that are rooted in their dietary ecology. We focused on food resource exploitation and analyzed how functional redundancy and response diversity changed across common habitats for Mediterranean ant communities. Our aim was to assess the vulnerability of ant-furnished ecosystem functions to future environmental change. We used cafeteria experiments to identify ant functional groups: we offered ants a variety of seeds, insects, and liquid sugars. Then, using more general baits, we estimated ant species richness and abundance. We also examined 12 ant traits (morphological, social, ecobehavioral, and physiological) thought to reflect responses to disturbance. We found that most Mediterranean ant species are dietary generalists. Functional redundancy was highest and lowest for sugar and seed consumers, respectively, a consistent trend across habitats that was unrelated to species richness. Response diversity did not depend on ant functional group. Interestingly, both functional redundancy and response diversity were higher in pine forests and shrublands than in oak forests, a pattern that was consistent regardless of whether the functional groups were examined collectively or individually. Variation in functional redundancy and response diversity was strongly driven by site-specific species richness. Response diversity also varied based on trait type. Ecosystem functions mediated by seed-consuming ants should be the most vulnerable to environmental change, and habitat type and local species richness should affect the vulnerability of any ecosystem functions mediated by ant dietary ecology. Species-poor communities in forests should be the most vulnerable, while species-rich communities in open habitats should be the most resilient.

Dirt roads and fire breaks produce no edge effects on litter-dwelling arthropods in a tropical dry-forest: a case study

Edge effects threaten organisms and ecological processes in habitat remnants, but they have been poorly studied in non-humid forests such as cerradao, a tropical dry forest sometimes derived from fire-suppressed savanna in Brazil. The diverse ecosystem functions performed by arthropods may be disrupted by edge effects, and there is pressing need for more studies on this subject. We sampled fragments of cerradao facing either a road or fire breaks, assessing edge effects in: beta diversity and community composition of epigaeic (litter-dwelling) arthropod orders, ant species, and ant functional groups; ant species richness and diversity; leaf litter depth; and colony residence time of a predatory ground-dwelling ant, Odontomachus chelifer (Ponerinae). None of the variables measured differed between edge and interior of the sites sampled. Dry forests have high micro-climatic variations caused by discontinuities in the canopy cover and, as such, changes in abiotic variables in cerradao edges might not be as clear as those observed in tropical rainforests. Our study demonstrates that edge effects may not be so prevalent in cerradao facing roads or fire breaks, which possibly increases the chances of survival of a higher fraction of the original arthropod fauna compared to rainforest fragments.

Soil surface complexity has a larger effect on food exploitation by ants than a change from grassland to shrubland

1. Changes in vegetation community composition, such as a transition from grassland to shrubland (woody encroachment), are associated with reductions in plant cover and increases in bare ground. Encroachment‐driven changes in surface cover at small spatial scales can alter ant community assemblages by changing their foraging behaviour and their ability to locate and monopolise resources.2. Artificial arenas with three levels of complexity were used to examine changes in ant foraging efficiency, body size and ability to monopolise food. The three levels of complexity included a control (no substrate), low‐complexity treatment (woody debris) and high‐complexity treatment (leaf litter).3. No difference was found in ant species composition within the complexity arenas between grassland and shrubland, but ant functional groups ‘generalised Myrmicinae’ and ‘subordinate Camponotini’ were more abundant in grassland arenas, whereas ‘opportunists’ were more abundant in shrubland arenas. Ants took twice as long to find baits in high‐complexity treatments, and 1.5 times as long in low‐complexity treatments, than in control treatments, which were bare arenas with no substrate. Ant body size declined with increasing surface complexity, suggesting that larger ants are discouraged from foraging in complex habitats.4. There was also significantly greater monopolisation of the protein bait (tuna) in low‐ and high‐complexity treatments, but there were no differences between tuna and carbohydrate (honey) in the control treatment. Consistently, no differences were found in ant behaviour between grasslands and shrublands.5. The present study shows that ants are more responsive to small‐scale alterations in soil surface complexity than to changes in vegetation community composition. Changes in soil surface complexity select for ants based on body size, which in turn influences their foraging success. Changes in vegetation complexity at small spatial scales are therefore likely to influence ant behaviour and abundance of some functional groups, potentially having an effect on the many ecosystem functions carried out by ants.

Effectiveness of Winkler Litter Extraction and Pitfall Traps in Sampling Ant Communities and Functional Groups in a Temperate Forest.

Selection of proper sampling methods for measuring a community of interest is essential whether the study goals are to conduct a species inventory, environmental monitoring, or a manipulative experiment. Insect diversity studies often employ multiple collection methods at the expense of researcher time and funding. Ants (Formicidae) are widely used in environmental monitoring owing to their sensitivity to ecosystem changes. When sampling ant communities, two passive techniques are recommended in combination: pitfall traps and Winkler litter extraction. These recommendations are often based on studies from highly diverse tropical regions or when a species inventory is the goal. Studies in temperate regions often focus on measuring consistent community response along gradients of disturbance or among management regimes; therefore, multiple sampling methods may be unnecessary. We compared the effectiveness of pitfalls and Winkler litter extraction in an eastern temperate forest for measuring ant species richness, composition, and occurrence of ant functional groups in response to experimental manipulations of two key forest ecosystem drivers, white-tailed deer and an invasive shrub (Amur honeysuckle). We found no significant effect of sampling method on the outcome of the ecological experiment; however, we found differences between the two sampling methods in the resulting ant species richness and functional group occurrence. Litter samples approximated the overall combined species richness and composition, but pitfalls were better at sampling large-bodied (Camponotus) species. We conclude that employing both methods is essential only for species inventories or monitoring ants in the Cold-climate Specialists functional group.

Habitat fragmentation, EFN‐bearing trees and ant communities: Ecological cascades in Atlantic Forest of northeastern Brazil

AbstractHabitat fragmentation has a marked impact on the functional composition of tropical forest tree assemblages, and such change is likely to cascade through other trophic levels. Here, we investigate how habitat fragmentation affects extrafloral nectary (EFN)‐bearing plants and ant functional groups known to attend EFNs in a fragmented landscape of the Atlantic Forest. Extrafloral nectary‐bearing trees were identified in 50 0.1‐ha plots located in forest fragments, edge and interior patches. Ants were surveyed in 30 1‐m2 litter samples in each of 17 forest fragments and in forest interior. Extrafloral nectary‐bearing plants accounted for 19.9% of individuals and 10.5% of species and included both pioneer and shade‐tolerant species similarly rich in the three habitat types. However, shade‐tolerant individuals accounted for >80% of EFN‐bearing plants in forest interior, compared with 2% in forest edge and 29% in fragments. Forest edge and fragment plots had a third fewer EFN‐bearing individuals and species compared with forest interior. This appeared to have important implications for local ant communities as the density of EFN‐bearing trees was the most important variable explaining the species richness of arboreal dominant ants. Our results show that plant loser–winner replacements promoted by forest fragmentation can cascade through higher trophic levels, with implications for forest dynamics and biodiversity conservation.

Effects of environmental variation and livestock grazing on ant community structure in temperate eucalypt woodlands

Abstract Grazing by livestock is a major ecological disturbance, with potential effects on vegetation, soil, and insect fauna. Ants are a diverse and functionally important insect group with many associations with the ground layer, yet recent global syntheses question the importance of grazing effects on ant communities relative to vegetation or soil. We examined the effects of vegetation, soil and grazing on the whole ant community, ant functional groups, and abundant species in temperate eucalypt woodlands, southeastern Australia. We found limited influence of grazing on our vegetation and soil measures, except for a positive association between grazing and exotic perennial grass cover. We also found that exotic grass cover had a negative effect on overall ant abundance and richness, but not functional groups or individual species. Soil C:N ratio had a positive effect on the subdominant Camponotini, and leaf litter cover had a positive effect on the abundance of cryptic species. Partial Mantel tests revealed an effect of both environmental and grazing measures on ant assemblage composition, but constrained ordination showed that leaf litter cover, grass biomass, and native and exotic perennial grass cover had stronger correlations with ant community structure than grazing. Our study shows that both environmental variation and grazing play a role in driving ant community structure, but that key environmental variables such as grass biomass and leaf litter cover are particularly important in temperate eucalypt woodlands. Monitoring of ant communities to measure the benefits of changed grazing regimes for biodiversity should consider contemporary grazing pressure as well as the underlying effects of variation in plants and soils.

Effect of overstory tree species diversity and composition on ground foraging ants (Hymenoptera: Formicidae) in timber plantations in Ghana

ABSTRACTPlantation forests are becoming an increasingly important component of the world’s forested ecosystem. However, relatively little is known about how forest plantation management, overstory tree species composition and diversity impact biodiversity of nontree components of the forest. We assessed changes in ant functional group composition as related to changes in overstory tree diversity (monocultures vs. polycultures), species composition (native African species vs. exotic teak), and time (one and two years after planting). A pitfall trapping scheme was implemented during the summer months of 2006 and 2007. A total of 7473 specimens were collected representing six subfamilies, 22 genera, and 65 species. We found no significant differences in traditional diversity measures or functional group composition between treatments one year after planting. Two years after planting, we found that species richness of ground foraging ants had significantly increased (F = 4.60, d.f. = 4, 15, p = 0.01). Several observed trends may have indicated that these ant communities were in transition and will likely become more distinct over time as the different plantation types recover from disturbance and diverge from each other in overstory structure.EDITED BY Sheila Ward

Multi-century dynamics of ant communities following fire in Mediterranean-climate woodlands: Are changes congruent with vegetation succession?

As vegetation recovers after disturbances such as fire its composition and structure systematically changes, affecting the availability of resources for fauna and mediating physical conditions. According to the habitat accommodation model, these changes drive a succession of animal species, which enter and leave according to their habitat requirements. While the response of ants to fire has been extensively studied, studies of ant communities in biomes with long fire-return intervals have been overwhelmingly short-term in nature. Here, we explore the response of ant species, functional groups and communities to time since fire using a uniquely long-term (>300years) chronosequence in eucalypt woodlands of south-western Australia. Marked non-monotonic vegetation structural changes occur in non-resprouting Eucalyptussalubris-dominated woodlands following fire, with tree and ground fuel cover peaking at intermediate periods post-fire. Hence, we predicted that changes in the occurrence of Dominant Dolichoderinae, Hot-Climate Specialist and Cold-Climate Specialist functional groups would mirror the non-monotonic changes in habitat complexity, as predicted by the habitat accommodation model. Overall ant species richness and composition did not show clear post-fire successional patterns, with extensive spatial turnover a likely factor. However, richness and abundance of ant functional groups broadly responded as predicted, with Dominant Dolichoderinae and Hot-Climate Specialists more prominent in more-open recently-burnt and long-unburnt habitat, and Cold-Climate Specialists more prominent in less open habitat at an intermediate time since fire. This matching, non-monotonic temporal pattern of changes in ant functional groups and vegetation structure suggests that ant functional group occurrence is mediated through changes in habitat, as posited by the habitat accommodation model, and not simply time since disturbance. Current fire management in E. salubris woodlands aims to minimise wildfire occurrence, which is consistent with the maintenance of ant functional diversity at a regional scale given the long time periods over which changes occur post-fire. The combination of recent large wildfires and predicted fire-facilitating climate changes suggest that future shifts in the relative dominance of ant functional groups are likely if fire management is unsuccessful in limiting wildfires occurring in mature woodlands.

Ant community structure and response to disturbances on coastal dunes of Gulf of Mexico

Coastal dunes are complex and fragile ecosystems. The decrease in environmental stressors from sea to inland creates zonation patterns of habitats, which support high biodiversity. Although coastal dunes have been examined in primary succession studies for more than 100 years, invertebrates have received much less attention than other taxa. In this study, we examined ant community composition and its relationship with vegetation structure on dunes, and used ants as indicators to reveal the influence of anthropogenic disturbances on these habitats. Quadrat sampling, hand collecting, and beating plants were used to sample ants on coastal dunes fringing the northern Gulf of Mexico. Ants representing 44 species were found, with diversity and number of functional groups increasing from foredunes to backdunes. Bush areas of the backdunes supported a unique ant community. Ant diversity was correlated with plant richness, stem number, and plant cover, but the correlation was not consistent among habitats. Ant diversity was lower in degraded, young-planted, and re-built but not in old-planted sites. In addition, different types of disturbance changed the ant community and functional groups in different ways. Our study emphasizes the importance of protecting the whole dune system, especially the backdunes, which support high diversity but are often completely destroyed by urban development. Data from this research provides a benchmark to examine trajectories of coastal dune ecosystem degradation or recovery when exposed to natural or anthropogenic disturbances.