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The putative benefits to seeds in myrmecochory (ant‐mediated seed dispersal) are often cast in a reward context. However, microbes have been mostly overlooked as seed mortality agents in myrmecochory, as have potential treatments provided by ant‐handling.We investigated the effects of ant handling on the diversity of seed coat fungal communities of three myrmecochorous plant species.Ant‐handling altered measures of both alpha and beta diversity of fungal communities. Ant‐handled seeds harboured different overall fungal communities and plant pathogen communities than non‐ant‐handled seeds. The myrmecochore pathogenic fungal community showed high dissimilarity (high pairwise community turnover) between ant‐handled and control seeds, while beta diversity measures for ant‐handled seeds and seeds with manually removed elaiosomes were less dissimilar.Ant handling may offer an additional benefit to myrmecochorous seeds via the reduction in the seed coat pathogenic community, which may be driven by elaiosome removal or as a by‐product of ant cleaning behaviours and chemical secretions. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]

It is often difficult to determine the relative importance of different sorts of species interactions in shaping community structure or how communities function because we lack basic information on patterns of occurrence of biotic interactions. Here we determine the geographic distribution of seed-dispersal mutualisms across North America, and then test the hypotheses that those patterns are correlated with mean annual precipitation and latitude. We analyze the floras of 197 sites across North America to identify which species of native seed plants are dispersed by animals in one of three types of plant-animal mutualisms: frugivory, scatter hoarding, and ants. We identified 1655 plant species that are involved in these seed-dispersal mutualisms. 16.5 ± 6.5% of all seed plants across North America are dispersed by animals; 10.0 ± 4.2% by frugivores, 3.7 ± 1.7% by scatter hoarders, and 3.9 ± 2.2% by ants. Secondary dispersal by a different mode and vector (e.g., wind dispersal followed by scatter hoarding, or ballistic dispersal followed by myrmecochory) occurred in 16.8% of all plant mutualist records. Although each mode of dispersal showed a different pattern, the prevalence of seed-dispersal mutualisms increased with mean annual precipitation. The prevalence of seed dispersal by frugivory and scatter-hoarding decreased with increasing latitude. The prevalence of seed-dispersal interactions varies dramatically across North America. The center of greatest diversity for all three types of seed-dispersal mutualisms is the eastern United States, roughly coincident with the eastern deciduous forest. Knowing the distribution of species interactions improves our understanding of how the structure and functioning of communities varies across environmental gradients. [ABSTRACT FROM AUTHOR]

Aim We determine the prevalence of mutualistic seed-dispersal interactions across the North American landscape and then test the hypothesis that patterns in interaction diversity are correlated with latitude, longitude, precipitation, midpoint elevation and the elevational range of sites. Location North America north of the Mexican border. Methods We used regional plant lists to determine the diversity of animal seed-dispersal interactions across North America (over more than 48° of latitude). For each plant list ( n = 197 sites, 12,424 terrestrial plant species and 123,519 plant records), we assigned plant species to one of four seed-dispersal modes (i.e. frugivory, scatter hoarding, myrmecochory or non-mutualist) and to an animal vector (e.g. bird, carnivorous mammal, rodent, ant). Results We identified 14 types of animal-mediated seed dispersal. Plants with seed-dispersal mutualists are most diverse in the south-eastern portion of the continent. Dispersal by frugivores and scatter hoarders is strongly negatively correlated with latitude but myrmecochory is not. The diversity of interaction types is significantly correlated with precipitation and elevational range and negatively correlated with latitude, longitude and midpoint elevation. Main conclusions The diversity of seed-dispersal mutualisms varies dramatically across the continent, suggesting that the co-evolutionary processes that produce these interactions are stronger in certain regions and vegetation types and weaker in others. Elucidation of these patterns and their causes will help us to better understand the co-evolutionary processes that shape communities. [ABSTRACT FROM AUTHOR]

Interactions between ants and plants vary from being occasionally beneficial to neutral and negative. Ant-mediated dispersal of obligatory myrmecochorous plants is considered mutualistic interaction, providing benefits to plants in terms of seed dispersal. Ants are rewarded by providing elaiosome, sugar, lipid and protein-rich appendages attached to seeds (diaspores). We experimentally examine rates of diaspore removal rates among three species of plants (snowdrop Galanthus nivalis, hollow root Corydalis cava and European wild ginger Asarum europaeum) under field conditions in two study sites in Central Europe. Diaspore morphology is altered by manipulating both elaiosome and seed size. The small-sized acorn ant Temnothorax crassispinus interacts with the snowdrop and hollow root and the moderately-sized red ant Myrmica ruginodis interacts with European wild ginger. Experimental manipulation with elaiosomes yields largely non-significant results. Diaspore removal rates are generally low (snowdrop 10%, hollow root 26%, European wild ginger 34%) probably due to the small size of ants relative to heavy diaspores. Many ants are observed to consume elaiosomes in situ (cheating). We conclude that ant–plant relationships in this case are not mutualistic but rather neutral/slightly negative, because the plants do not obtain any apparent benefits from their interactions with ants.

We update the global assessment of seed dispersal by ants and test the hypothesis that the body size of seed-dispersing ant species varies with latitude in the same way as dispersal distance. We compiled all published data about seed dispersal distance by myrmecochory through March, 2011. We then broke the data down by vegetation type, geography and taxonomy. We also compiled data on body size (body length) of the seed-dispersing ant species from the studies consulted. Based on 7889 observations, the mean dispersal distance was 1.99 m, although the curve has a long tail extending to 180 m. Considering the mean dispersal distance by ant species and study as independent data, the mean dispersal distance was 2.24 ± 7.19 m (n = 183). Shorter distances are associated with smaller ant species, while the tail of the dispersal curve is due to larger ant species. The mean dispersal distance of myrmecochorous seeds dispersed by ants decreased with increasing latitude, but there was no significant relationship between the body size of dispersing ant species and latitude (i.e. myrmecochorous seed-dispersing ant species do not follow Bergmann's rule). In 1998 we made three predictions: 1) the dispersal distances of the Southern Hemisphere will decrease with as more data from mesophyllous vegetation are obtained; 2) assuming that ant nest density is higher at lower latitudes, the differences in distances between hemispheres would probably decrease with more data; and 3) numerical differences between dispersal distances in mesophyllous and sclerophyllous vegetation zones would increase with more data. The results obtained since 1998 support the only the third prediction. The dispersal distances in mesophyllous vegetation zones are shorter than in the sclerophyllous vegetation zones, and the difference between 1998 have increased. The differences in dispersal distances between hemispheres are consistent with the avoidance of parent-offspring competition (escape hypothesis). [ABSTRACT FROM AUTHOR]

Both rewards and signals are important in mutualisms. In myrmecochory, or seed dispersal by ants, the benefits to plants are relatively well studied, but less is known about why ants pick up and move seeds. We examined seed dispersal by the ant Aphaenogaster rudis of four co-occurring species of plants, and tested whether morphology, chemical signaling, or the nutritional quality of fatty seed appendages called elaiosomes influenced dispersal rates. In removal trials, ants quickly collected diaspores (seeds plus elaiosomes) of Asarum canadense, Trillium grandiflorum, and Sanguinaria canadensis, but largely neglected those of T. erectum. This discrepancy was not explained by differences in the bulk cost-benefit ratio, as assessed by the ratio of seed to elaiosome mass. We also provisioned colonies with diaspores from one of these four plant species or no diaspores as a control. Colonies performed best when fed S. canadensis diaspores, worst when fed T. grandiflorum, and intermediately when fed A. canadense, T. erectum, or no diaspores. Thus, the nutritional rewards in elaiosomes affected colony performance, but did not completely predict seed removal. Instead, high levels of oleic acid in T. grandiflorum elaiosomes may explain why ants disperse these diaspores even though they reduce ant colony performance. We show for the first time that different elaiosome-bearing plants provide rewards of different quality to ant colonies, but also that ants appear unable to accurately assess reward quality when encountering seeds. Instead, we suggest that signals can trump rewards as attractants of ants to seeds. [ABSTRACT FROM AUTHOR]

Functional extinction of once abundant species has frequently preceded understanding of their ecological roles. Consequently, our understanding of ecosystems is prone to shifting baselines because it often relies on observations made on depauperate species assemblages. In Australian deserts, current paradigms are that ants are the dominant granivores, mammals are unimportant seed predators and that myrmecochory in many Australian shrubs is an adaptation to increase dispersal distance and direct seeds to favourable germination sites. Here, we ask whether these paradigms could be artefacts of mammal extinction. We take advantage of a predator-proof reserve within which locally extinct native mammals have been reintroduced to compare seed removal by ants and mammals. Using foraging trays that selectively excluded mammals and ants we show that a reintroduced mammal, the woylie (Bettongia penicillata) was at least as important as ants in the removal of seeds of two shrub species (Dodonaea viscosa and Acacia ligulata). Our results provide evidence that the dominance of ants as granivores and current understanding of the adaptive benefit of myrmecochory in arid Australia may be artefacts of the functional extinction of mammals. Our study shows how reversing functional extinction can provide the opportunity to rethink contemporary understanding of ecological processes.

Myrmecochory, or ant-mediated seed dispersal, is an important ecological interaction in which ants benefit by gaining nutrition from lipid-rich elaiosomes attached to seeds and plants benefit from having their seeds dispersed away from parent plants. Most research on the benefits of myrmecochory focuses on primary dispersal, in which ants move seeds to nests, or secondary dispersal, in which ants deposit intact seeds in middens after consuming elaiosomes. Less is known about how ants handle seeds inside nests and if handling influences plant fitness., The seed handling behaviours of a native 'keystone disperser', Aphaenogaster rudis s.l., and an invasive seed-disperser, Myrmica rubra L., on an introduced herb, Chelidonium majus L., were compared. We conducted a greenhouse experiment to test if handling by ants, manual removal of elaiosomes, or no handling (controls) influenced seedling emergence. Colony-level differences in handling behaviours and plant responses were also examined., Aphaenogaster rudis retained seeds inside nests longer than M. rubra, but there was no difference in the amount of elaiosome removed by the two species. There was no difference in the proportion of seedlings that emerged among treatments, but seedlings emerged earlier when handled by A. rudis. Additionally, more seedlings emerged and seedlings emerged earlier the longer seeds were retained inside ant nests., This study suggests that handling by ants may be a benefit of myrmecochory. This is probably not due to elaiosome removal; rather favourable nest conditions may enhance emergence. Also, functional differences in ant species may result in different outcomes for plant partners. [ABSTRACT FROM AUTHOR]

Seed dispersal is a key process for the invasion of new areas by exotic species. Introduced plants often take advantage of native generalist dispersers. Australian acacias are primarily dispersed by ants in their native range and produce seeds bearing a protein and lipid rich reward for ant mutualists (elaiosome). Nevertheless, the role of myrmecochory in the expansion of Australian acacias in European invaded areas is still not clear. We selected one European population of Acacia dealbata and another of A. longifolia and offered elaiosome-bearing and elaiosome-removed seeds to local ant communities. For each species, seeds were offered both in high-density acacia stands and in low-density invasion edges. For both acacia species, seed removal was significantly higher at the low-density edges. For A. longifolia, manual elimination of elaiosomes reduced the chance of seed removal by 80% in the low-density edges, whereas it made no difference on the high-density stands. For A. dealbata, the absence of elaiosome reduced seed removal rate by 52 %, independently of the acacia density. Our data suggests that invasive acacias have found effective ant seed dispersers in Europe and that the importance of such dispersers is higher at the invasion edges. [ABSTRACT FROM AUTHOR]

Ant-mediated seed dispersal, also known as myrmecochory, is a widespread and important mutualism that structures both plant and ant communities. However, the extent to which ant functional types (e.g., granivorous generalists vs. myrmecochorous ants) across environmental gradients affect seed removal rates is not fully understood. We used a replicated, standardized seed removal experiment along elevation gradients in four mountain ranges in the southwestern United States to test predictions that: (1) seed removal rates would be greater at lower elevations, and (2) seed species identity influences seed removal rates (i.e., seeds from their native elevation range would be removed at higher rates than seeds outside of their native elevation range). Both predictions were supported. Seed removal rates were ∼25% higher at lower elevation sites than at higher elevation sites. The low elevation Datura and high elevation Iris were removed at higher rates in their respective native ranges. We attribute observed differences in dispersal rates to changes in ant community composition, functional diversity, and abundance. We also suggest that temperature variation along the elevation gradient may explain these differences in seed removal rates.

Allmania nodiflora, Celosia argentea var. margaritacea, and Digera muricata are annual herbaceous weeds which reproduce exclusively by seed. The plants appear in June, while flowering time is August-February in agricultural fields and August-October/November in other habitats. The synflorescence is an elongated erect spike in A. nodiflora and C. argentea, while it is a long pedunculate spicate raceme in D. muricata. The flowers anthese acropetally in A. nodiflora and C. argentea var. margaritacea, while there is no such clear-cut anthesis pattern in D. muricata. Allmania nodiflora is functionally hermaphroditic. Digera muricata is partially hermaphroditic because the central flower in three-flowered groups is fertile, while the lateral flowers are sterile. Celosia argentea var. margaritacea is functionally gynodioecious. In A. nodiflora and D. muricata, the flowers facilitate autonomous selfing due to synchrony in maturation of the male and female sex. In C. argentea var. margaritacea also, the flowers facilitate autonomous selfing, but it is precluded by strong protandry. All three species are anemophilous and entomophilous. Allmania nodiflora and D. muricata produce one-seeded fruits, while C. argentea var. margaritacea produces multi-seeded fruits. Allmania nodiflora and C. argentea var. margaritacea dehisce by means of a circumscissile lid and disperse seeds, while D. muricata produces indehiscent fruits. All three species are anemochorous, but A. nodiflora is also myrmecochorous.

The dispersal capacity of plant species that rely on animals to disperse their seeds (biotic dispersal) can alter with changes to the populations of their keystone dispersal vectors. Knowledge on how biotic dispersal systems vary across landscapes allows better understanding of factors driving plant persistence. Myrmecochory, seed dispersal by ants, is a common method of biotic dispersal for many plant species throughout the world. We tested if the seed dispersal system of Acacia terminalis (Fabaceae), a known myrmecochore, differed between two elevations in the Greater Blue Mountains World Heritage Area, in southeastern Australia. We compared ant assemblages, seed removal rates of ants and other vertebrates (bird and mammal) and the dominant seed-dispersing ant genera. At low elevations (c. 200 m a.s.l) seed removal was predominantly by ants, however, at high elevation sites (c. 700 m a.s.l) vertebrate seed dispersers or seed predators were present, removing over 60% of seeds from experimental depots when ants were excluded. We found a switch in the keystone seed-dispersing ant genera from Rhytidoponera at low elevations sites to Aphaenogaster at high elevation sites. This resulted in more seeds being removed faster at low elevation sites compared to high elevation sites, however long-term seed removal rates were equal between elevations. Differences in the keystone seed removalist, and the addition of an alternate dispersal vector or seed predator at high elevations, will result in different dispersal and establishment patterns for A. terminalis at different elevations. These differences in dispersal concur with other global studies that report myrmecochorous dispersal systems alter with elevation. [ABSTRACT FROM AUTHOR]

Myrmecochorous plants produce seeds with lipid-rich appendages (elaiosomes) which act as a reward for seed-dispersing ants. Seed dispersal is important for exotic species, which often need to establish new mutualistic interactions in order to colonize new non-native habitats. However, little is known about the importance of elaiosomes for seed removal in many of their non-native ranges. We studied ant-seed interactions of elaiosome-bearing and elaiosome-removed seeds of the Australian trees Acacia dealbata and Acacia longifolia in order to assess the relative importance of elaiosomes for seed removal between their native (Australia) and non-native (Portugal) ranges. In Portugal, we also studied the co-occurring native plant species with myrmecochorous seeds, Pterospartum tridentatum and Ulex europaeus, across three contiguous levels of acacia invasion: control (i.e. no acacia), low, and high acacia tree density. Acacia seeds were successfully removed by ants in their non-native region by a diversified assemblage of ant species, even in sites where native plants interacted with only one specialized ant species. In the invaded range, diminishing relative importance of elaiosomes was associated with changes in the ant community due to acacia invasion, and for A. dealbata, ant species richness decreased with increasing acacia tree density. Although seed removal was high for both acacia species, the importance of elaiosomes was proportionally lower for A. dealbata in the non-native region. Native plant species experienced significant reductions in seed removal in areas highly invaded by acacia, identifying another mechanism of displacement of native plants by acacias. [ABSTRACT FROM AUTHOR]

This article reports that seeds of many plant species are carried away by ants. In many cases this is simply predation and most seeds are eaten, although a few may survive after being accidentally dropped. But in other cases plants have evolved to use the ants for dispersal; this is called myrmecochory. Several studies in North America have investigated the ecology of single myrmecochore species or genera. These have shown that myrmecochory provides various benefits to plants in predator avoidance or microsite selection. The study presented in this article examines the incidence of myrmecochory within an area of species-rich sclerophyll vegetation in Australia.

A critical and common, but much ignored, plant-animal interaction is primary seed dispersal by ants (myrmecochory). Ants are ubiquitous across many landscapes, so it may not be surprising that many plants have evolved to utilize them to move their seeds. In fact, myrmecochory has independently evolved over 100 times. Myrmecochory carries all the usual benefits of biotic seed dispersal, such as reduction of competition with siblings, as well as a few more (notably, escape from fire). Seeds dispersed by ants generally possess an attached food body (elaiosome), which attracts and rewards ants. Elaiosomes are commonly described as fat bodies comprising lipids. However, their nutritional and chemical composition can vary widely, with some plant species producing elaiosomes with higher concentrations of protein or carbohydrates than of lipids. Elaiosomes of even quite closely related plant species can vary in chemical composition. Once ants encounter a seed with an elaiosome, they generally return to the nest with that seed, remove the elaiosome, and consume it, although which individuals within the nest consume the elaiosome is in many cases unclear. Once the elaiosomes have been removed, seeds are then disposed of either within the nest or outside of the nest, where they can be potentially secondarily dispersed by wind, water, or animals, including other ant species. This primer will focus on primary dispersal, the initial movement of seeds away from a parent plant. This primer defines myrmecochory, provides an overview of elaiosome traits, summarizes how ants choose and interact with elaiosome-bearing seeds, describes the current understanding of how elaiosomes evolved, and touches on how ant seed dispersal may respond to anthropogenic changes, such as the introduction of invasive species and climate change. This primer is guided by five major questions: (i) What is seed dispersal and myrmecochory? (ii) What are the benefits of myrmecochory? (iii) What is an elaiosome? (iv) How do ants choose and interact with seeds? (v) How did elaiosomes and myrmecochory evolve? [ABSTRACT FROM AUTHOR]

Myrmecochory—seed dispersal by ants—is a mutualistic interaction in which ants attracted by seed appendices take them away from the parental plant location, where seeds usually have better development odds. Not all ant species benefit plants, and the mechanisms of those divergent outcomes are still unclear, especially from the perspective of microbial third parties. Here, we explore the effects of seed manipulation on fungi communities promoted by two ant species with contrasting effects on seed germination and antimicrobial cleaning strategies. We hypothesize that: i) fungi richness is higher in seeds manipulated by Acromyrmex subterraneus (species that negatively affect seed germination), followed by unmanipulated seeds and seeds manipulated by Atta sexdens (ant species that increase seed germination) and ii) seeds manipulated by A. sexdens, Ac. subterraneus and unmanipulated seeds present dissimilar fungi compositions. We identified fungal morphotypes in three groups of seeds: i) manipulated by A. sexdens; ii) manipulated by Ac. subterraneus; iii) unmanipulated. Seeds manipulated by Ac. subterraneus exhibited higher fungal richness than those manipulated by A. sexdens and unmanipulated seeds, indicating that the ant species known to impair germination increases the fungal load on seeds. Additionally, we found that A. sexdens ants were unable to reduce fungal richness compared to unmanipulated seeds. Furthermore, fungal composition differed among all three treatments. Our results underscore the significance of ant species identity in shaping the fungal communities associated with myrmecochorous seeds. Given the potential influence of microbial infection on seed fate, we suggest considering manipulation strategies when evaluating the overall quality of an ant as a seed disperser. [ABSTRACT FROM AUTHOR]

On the example of 5 species of herbaceous flowering plants of the Ukrainian Carpathians it is shown that they are in close relationships with a number of insects, some of which are involved into pollination and hence in the formation of mature seeds. It was found out that the species composition of insects does not depend on plant species composition, but on the ecological conditions of their habitat. The highest number of insects is connected with Dipsacaceae (30 species) and Asteraceae plants (29 species), less with Apiaceae (21 species), and the least with Boraginaceae (13 species). A significant role of phytophagous insects in the reproduction of plant populations was established. For example, Senecio carpaticus is one of species that depends significantly on the amount of received damage from the leaf beetles (Chrysomelidae) in the higher parts of the Ukrainian Carpathians. By the example of a number of Formicidae species, the role of myrmecochory in plants seeds dissemination is shown. It was confirmed that successful reproduction of Pulmonaria filarszkyana mainly depends on the presence of ants which disperse the species’ seeds over large area. Formica cunicularia, F. lemani, F. cinerea, Myrmica ruginodis, Tetramorium caespitum dominate among the ant species mentioned above.

Ants provide a common dispersal vector for a variety of plants in many environments through a process known as myrmecochory. The efficacy of this dispersal mechanism can largely determine the ability of species to track changes in habitat availability caused by ongoing land-use and associated disturbances, and can be critical for population gene flow and persistence. Field studies were conducted in a typical fragmented agricultural landscape in southern NSW, Australia, to investigate the extent to which dispersal services by ants are influenced by anthropogenic disturbances associated with roadwork activities (i.e., soil disturbance as the result of grading of roads). Observational experiments were performed in road segments that were divided into disturbed and non-disturbed zones, where Acacia pycnantha seeds were offered at multiple bait stations and monitored. For combined species, the mean dispersal distance recorded in the disturbed zone (12.2 m) was almost double that recorded in the non-disturbed zone (5.4 m) for all roadside sites. Our findings show that myrmecochory is an unevenly diffuse mutualism, where few ant species contributed to much of the dispersal of seeds. Iridomyrmex purpureus was responsible for all seed dispersal distances >17 m, where a maximum of 120 m in disturbed, vs. 69 m in non-disturbed zones, was recorded. Rhytidoponera metallica and Melophorus bruneus were important seed dispersers in non-disturbed and disturbed zones, respectively. In general, large bodied ants tended to move more seeds to longer distances in disturbed zones, as opposed to non-disturbed zones, where smaller bodied species carried out a greater percentage of short distance dispersals (

The question of whether species’ origins influence invasion outcomes has been a point of substantial debate in invasion ecology. Theoretically, colonization outcomes can be predicted based on how species’ traits interact with community filters, a process presumably blind to species’ origins. Yet, exotic plant introductions commonly result in monospecific plant densities not commonly seen in native assemblages, suggesting that exotic species may respond to community filters differently than natives. Here, we tested whether exotic and native species differed in their responses to a local community filter by examining how ant seed predation affected recruitment of eighteen native and exotic plant species in central Argentina. Ant seed predation proved to be an important local filter that strongly suppressed plant recruitment, but ants suppressed exotic recruitment far more than natives (89% of exotic species vs. 22% of natives). Seed size predicted ant impacts on recruitment independent of origins, with ant preference for smaller seeds resulting in smaller seeded plant species being heavily suppressed. The disproportionate effects of provenance arose because exotics had generally smaller seeds than natives. Exotics also exhibited greater emergence and earlier peak emergence than natives in the absence of ants. However, when ants had access to seeds, these potential advantages of exotics were negated due to the filtering bias against exotics. The differences in traits we observed between exotics and natives suggest that higher-order introduction filters or regional processes preselected for certain exotic traits that then interacted with the local seed predation filter. Our results suggest that the interactions between local filters and species traits can predict invasion outcomes, but understanding the role of provenance will require quantifying filtering processes at multiple hierarchical scales and evaluating interactions between filters. [ABSTRACT FROM AUTHOR]

Many remnants of tropical forests are surrounded by deforested areas dominated by successional vegetation. Although secondary dispersal by scatter-hoarding rodents and ants may influence seed predation and seedling recruitment, very little is known about its importance in degraded forest ecosystems., We studied the effects of secondary dispersal on seed predation, germination and seedling recruitment of the primarily bird-dispersed tree Clusia trochiformis in a tropical montane forest in Bolivia. We carried out exclosure experiments that allowed or excluded access to seeds by vertebrates in three habitat types (forest interior, degraded habitat close to and degraded habitat far from the forest margin) in a spatial block design at six sites. We offered a total of 1440 seeds (both with and without an aril) and marked half of them with a thread to follow their fate after 48 h and after 1 month., We found that secondary dispersal by ants was highest in the forest interior but was also frequent in degraded habitats close to and far from the forest edge. Secondary dispersal significantly increased seedling recruitment, particularly in the degraded habitats, probably because seeds were often dispersed to sites beneath the leaf litter. Recruitment success increased significantly with dispersal distance. High recruitment of secondarily dispersed seeds in the degraded habitat was due to the combined effect of reduced predation and increased germination of seeds that had been moved by ants., Synthesis. In the absence of secondary dispersal, seed germination and seedling recruitment were very low in degraded habitats. Seed dispersal by ants substantially increased natural regeneration in the deforested habitats. Our experiments thus demonstrate that the effects of biotic interactions on plant demography can vary across habitat boundaries at small spatial scales and that secondary dispersal is a crucial and overlooked process that can aid the regeneration of deforested habitats in the tropics. [ABSTRACT FROM AUTHOR]

Pogonomyrmex cunicularius pencosensis Forel is the dominant disperser of elaiosome bearing seeds in the northern Monte Desert of semiarid Northwest Argentina. In this study, various aspects of the biology of this ant species were examined and related to its ability to disperse myrmecochorous seeds. Data are presented on P. cunicularius pencosensis nesting habits, colony size, feeding habits and foraging behaviour. Finally, it is discussed how all these aspects of the life history of P. cunicularius pencosensis may positively influence the seed dispersal of native myrmecochorous plants, as well as their ecological and evolutive implications. [ABSTRACT FROM AUTHOR]

In degraded drylands, direct sowing is one of the most widespread revegetation practices, but its efficiency is low and usually seed enhancement techniques are needed to increase its success. We evaluated how to induce seed dispersal by ants (myrmecochory), as this interaction could improve the chances of seed germination and seedling establishment, via seed transport to ants' nests where seeds are protected and the soils enriched. Our objective was to develop seeds with the addition of baits attractive to ants without affecting seed germination. First, we tested the attractiveness of baits of different sizes and ingredients by performing cafeteria experiments in nests of the omnivorous ant Dorymyrmex tener, the most abundant and effective seed disperser ant in the Patagonian steppe. Then, we attached the most preferred baits (small baits containing pate, sugar and clay) to seeds of two native plants species (Acaenasplendens and Oenothera odorata) with relevant characteristics for restoration purposes and tested their attractiveness to ants. We used different strategies to attach the bait to the seeds (e.g. encrusted, agglomerate and seeds on the surface) looking for the most attractive and simplest one. We found that only baited seeds were removed and the interaction was induced regardless of the way the bait was attached. Also, germination of seeds with bait was similar to that of seeds without bait in O. odorata, but reduced in A. splendens. We showed that it is possible to encourage ants to transport previously non‐attractive seeds through the design of baits, potentially improving direct sowing efficiency. [ABSTRACT FROM AUTHOR]