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

Ant biodiversity and its relationship to ecosystem functioning: a review

The role of DNA barcoding as a tool to accelerate the inventory and analysis of diversity for hyperdiverse arthropods is tested using ants in Madagascar. We demonstrate how DNA barcoding helps address the failure of current inventory methods to rapidly respond to pressing biodiversity needs, specifically in the assessment of richness and turnover across landscapes with hyperdiverse taxa. In a comparison of inventories at four localities in northern Madagascar, patterns of richness were not significantly different when richness was determined using morphological taxonomy (morphospecies) or sequence divergence thresholds (Molecular Operational Taxonomic Unit(s); MOTU). However, sequence-based methods tended to yield greater richness and significantly lower indices of similarity than morphological taxonomy. MOTU determined using our molecular technique were a remarkably local phenomenon—indicative of highly restricted dispersal and/or long-term isolation. In cases where molecular and morphological methods differed in their assignment of individuals to categories, the morphological estimate was always more conservative than the molecular estimate. In those cases where morphospecies descriptions collapsed distinct molecular groups, sequence divergences of 16% (on average) were contained within the same morphospecies. Such high divergences highlight taxa for further detailed genetic, morphological, life history, and behavioral studies.

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DNA barcoding for effective biodiversity assessment of a hyperdiverse arthropod group: the ants of Madagascar

Processes acting on different spatial and temporal scales may influence local species richness. Ant communities are usually described as interactive and therefore determined by local processes. In this paper we tested two hypotheses linked to the question of why there is local variation in arboreal ant species richness in the Brazilian savanna ('cerrado'). The hypotheses are: (i) there is a positive relationship between ant species richness and tree species richness, used as a surrogate of heterogeneity; and (ii) there is a positive relationship between ant species richness and tree density, used as a surrogate of resource availability. Arboreal ants were sampled in two cerrado sites in Brazil using baited pitfall traps and manual sampling, in quadrats of 20 m � 50 m. Ant species richness in each quadrat was used as the response variable in regression tests, using tree species richness and tree density as explanatory variables. Ant species richness responded positively to tree species richness and density. Sampling site also influenced ant species richness, and the relationship between tree density and tree species richness was also positive and significant. Tree species richness may have influenced ant species richness through three processes: (i) increasing the variety of resources and allowing the existence of a higher number of specialist species; (ii) increasing the amount of resources to generalist species; and (iii) some other unmeasured factor may have influenced both ant and tree species richness. Tree density may also have influenced ant species richness through three processes: (i) increasing the amount of resources and allowing a higher ant species richness; (ii) changing habitat conditions and dominance hierarchies in ant communities; and (iii) increasing the area and causing a species-area pattern. Processes acting on larger scales, such as disturbance, altitude and evolutionary histories, as well as sampling effect may have caused the difference between sites.

Tree heterogeneity, resource availability, and larger scale processes regulating arboreal ant species richness

This study evaluates biotic responses, using ants as bio-indicators, to relatively recent anthropogenic disturbances to mature forest in central Amazonia. The structure of the ground-foraging ant community was compared in four habitats that represented a gradient of disturbance associated with differences in land use. Ants were collected in undisturbed, mature forest, in an abandoned pasture, in a young regrowth forest (situated in a former pasture area), and in an old regrowth forest (established where mature forest was just cleared and abandoned). More ant species were found in mature and old regrowth forest than in the abandoned pasture. By contrast, ant abundance tended to decrease with forest maturity. Both pasture and young regrowth forest exhibited a distinct ant species composition compared to mature forest, whereas species composition in the old regrowth forest showed greater similarity to that of mature forest. In spite of differences in fallow time between former pasture areas and non-pasture areas, there is evidence that different land-management practices do result in different rates of recovery of the ant forest fauna after land abandonment. In any case, recuperation of the ground-foraging ant fauna appears to be faster than regeneration of the woody-plant community. In this sense, regrowth forests may be valuable for the conservation of ground-foraging ants and perhaps for other components of mature-forest leaf-litter fauna within the context of a fragmented landscape.

Effects of forest disturbance on the structure of ground-foraging ant communities in central Amazonia

The tribal and generic classification of the diverse ant subfamily Ponerinae (Hymenoptera: Formicidae) is revised to reflect recent molecular phylogenetic information and a reappraisal of ponerine morphological diversity. The monogeneric tribe Thaumatomyrmecini ( Thaumatomyrmex ) is newly synonymized under Ponerini (syn. nov.), and the diverse genus Pachycondyla is fragmented into 19 genera, largely along the lines of its junior synonyms: Bothroponera , Brachyponera (gen. rev.) , Ectomomyrmex (gen. rev.) , Euponera (gen. rev.) , Hagensia (gen. rev.) , Megaponera (gen. rev.) , Mesoponera (gen. rev.) , Neoponera (gen. rev.) , Ophthalmopone (gen. rev.) , Pachycondyla, Paltothyreus (gen. rev.) , Pseudoneoponera (gen. rev.) , Pseudoponera (gen. rev.), and 6 new genera: Austroponera (gen. nov.), Buniapone (gen. nov.), Fisheropone (gen. nov.), Mayaponera (gen. nov.), Parvaponera (gen. nov.) and Rasopone (gen. nov.). Some junior synonyms of Pachycondyla are transferred to junior synonym status under other genera: Wadeura as a junior synonym of Cryptopone (syn. nov.), and both Termitopone and Syntermitopone as junior synonyms of Neoponera (syn. nov.). A new genus, Iroponera (gen. nov.), based on the new species Iroponera odax (sp. nov.) , is described from Australia. Molecular and morphological justifications for these taxonomic changes are given alongside discussions of phylogenetic relationships. Keys to the world genera of Ponerinae are provided, and morphological diagnoses and species lists are given for each genus. Finally, the available information on ponerine ecology and behavior is reviewed and synthesized.

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The Higher Classification of the Ant Subfamily Ponerinae (Hymenoptera: Formicidae), with a Review of Ponerine Ecology and Behavior.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-3113.1995.tb00102.x

Ruth Levy

Papers

Identification guide to the ant genera of the world