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In November 2015 occurred the largest environmental disaster in the world mining industry – the collapse of the Fundão tailings dam in Mariana, Minas Gerais state, Brazil. The dam's tailings buried and contaminated large areas of the Doce River catchment, its estuary, and the surrounding Atlantic Rainforest. Despite the severity and extent of this disturbance, our knowledge about tailings dam failure impacts in terrestrial invertebrate biodiversity and their ecosystem functions remain limited. We investigated the impacts of the dam failure on surrounding Atlantic Rainforest ant communities and their interactions with seeds, two years and four months after the failure. Ant composition changed, as some species were lost and replaced by others. While species richness and number of individuals remained unaffected, 26 species were lost from the affected communities, leading to the phylogenetic impoverishment of the community. The tailings also altered ant-seed interactions, increasing the time ants took to locate a seed and the distance of seed removal. As ants are well-established bioindicators, these impacts likely extend to other faunal groups. The cascading effects of such impacts on forest regeneration are still unclear, as are the potential effects of the observed changes in ant communities on other ecosystem functions ants perform. Implications for insect conservation: Our study shows how a large-scale human-induced impact can affect ant communities and their key role in seed dispersal. Understanding how severe and extensive disturbances affect biological communities is key for devising remediation and recovery strategies in disturbed areas. This knowledge aids in restoring the native flora and fauna in these ecosystems. [ABSTRACT FROM AUTHOR]

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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]

Seed dispersal by ants plays a major role globally in plant dynamics for many angiosperms and can be influenced by multiple factors. One of those factors is competition between ants and other organisms for gaining access to seeds. A habitat with high abundance of potential competitors for ants is forests in marine coast ecosystem, where there is a high abundance of terrestrial crabs that functionally act as seed predators. In a coastal forest on Coiba Island, Panama, we measured seed removal rates at increasing intervals from the coast towards the interior of the forest, representing a decreasing gradient in ant–crab competition. We found that seed removal was dominated by hermit crabs near the coast, and while ants moved more seeds as the distance from the coast increased. We expect that this differential removal should generate varying levels of seed predation and seedling establishment, with crabs acting mainly as seed and seedling predators. This study provides insights into how ant–crab dynamics may play a role in maintaining the vegetation gradients in coastal ecosystems. [ABSTRACT FROM AUTHOR]

Myrmecochory is a common mutualism between ants and plants benefiting both partners: ants obtain a nutrient-rich food source, while plants enjoy a host of benefits ranging from enhanced dispersal to protected germination sites. However, this mutualism can be exploited by invasive myrmecochores, where native ants spread invasive plant seeds, possibly to the detriment of native plant assemblages. With the recent introduction of a potentially invasive myrmecochorous plant (Thesium ramosum) in Alberta, Canada, we tested ant interest in T. ramosum. To evaluate both general interest in T. ramosum as a food source, and preference for T. ramosum over other food sources, we collected colonies of four commonly occurring native Formica species and conducted seed removal trials and food preference trials. We then evaluated interest in and preference for T. ramosum seeds through assessing mean rate of seed removal and food item removal, total number of seeds and food items removed, and trends in seed and food item removal through time. We found that while all ant species tested showed interest in T. ramosum, interest level varied among species, and additional factors such as colony size and presence of host species in socially parasitic species influenced interest in T. ramosum. Considering native ant interest in T. ramosum as a food source, it seems plausible that Formica species may act as a dispersal vector for T. ramosum, potentially enhancing its invasiveness. [ABSTRACT FROM AUTHOR]

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]

Having a wide geographical distribution and, as an engineering species, actively transforming the landscapes they inhabit, ants have a significant impact on the environment, creating new biogenic landforms and changing a number of its parameters, including biotic ones. This review is devoted to the consideration of the diverse environment-forming activities of ants in different regions of the world. An analysis of the scientific literature carried out in this context revealed a clear disproportion between the fairly good knowledge of tropical regions and the insufficient knowledge of temperate latitudes. The environment-forming activity of ants actively populating grasslands removed from agricultural use: steppes, continental and floodplain meadows of temperate latitudes has been especially poorly studied, which determines the undoubted priority of this area of research.

Ants and other insects are often a source of localized secondary dispersal for wind‐dispersed plants and thus play an important ecological role in their spatial dynamics, but there is limited information on how climate change will affect such dispersal processes. Here, we use field experiments to investigate how climate warming affects seed removal, as this initiation of movement represents the first step in insect‐driven secondary dispersal. Our results indicate that for the invasive thistles Carduus nutans and Carduus acanthoides, increased growing temperature influences seed attractiveness to insect dispersers, with seeds from maternal plants grown at temperatures 0.6°C above ambient removed by insect dispersers at higher rates than their unwarmed counterparts. We also observe that seed elaiosomes in these two species play an important role in dispersal, as seeds without elaiosomes were significantly less likely to be removed over the same period. Significant interactions between elaiosome presence/absence and warming treatment were also observed, though only for C. acanthoides, with the boost in seed removal from warming dampened when the elaiosome was present compared to when it was absent. These findings provide evidence that climate warming may alter aspects of dispersal such as seed removal by secondary dispersers, with potential ramifications for dispersal in future climates since seed‐bearing plants around the world may be subject to increased growing temperatures, and many of these plant species bear elaiosomes and experience seed dispersal by insects. [ABSTRACT FROM AUTHOR]

Ants are one of the most ubiquitous, widespread and abundant groups of animals on Earth. They are eusocial and are well noted for their important ecosystem services such as nutrient recycling, seed dispersal, engaging in mutualistic associations with other organisms, as well as serving as predators and scavengers. Although Africa has been recognised as a global hotspot for ant diversity, African ant genera are not as well-known when compared with other regions. The last checklist of Nigerian ants was compiled and published in the 1970s. To contribute to new knowledge on West African ant genera and Nigeria in particular, we conducted a review of the ant species of Nigeria using 132 scientific publications mostly compiled in the database www.antmaps.org, along with a survey of ant species of Lagos and Oyo States in Nigeria which was conducted between 2018 and 2020. The study aimed to ascertain the diversity of Nigerian ant genera, as well as to confirm the presence of previously recorded species and add new species to the current checklist of Nigerian ants, based on the 1970 survey. New information As many as 106 species were recorded from the survey in the current study, of which 28 are new to Nigeria and additional 28 are identified to the morphospecies level. In total, 317 species from 10 subfamilies and 64 genera are now recorded from Nigeria, including 11 invasive ants, of which six are new to Nigeria. The following eleven species that were included in the 1970 checklist were excluded from the current list, mostly due to previous misidentifications: Aenictus rotundatus Mayr, 1901; Anochetus jonesi Arnold, 1926; Camponotus barbarossa micipsa Wheeler, 1992; Camponotus foraminosus dorsalis Santschi, 1926; Camponotus rufoglaucus (Jerdon, 1851); Cardiocondyla zoserka Bolton, 1982; Messor barbarus (Linnaeus, 1767); Odontomachus haematodus (Linnaeus, 1758); Technomyrmex albipes (Smith, 1861); Tetramorium decem Forel, 1913 and Tetraponera penzigi (Mayr, 1907). [ABSTRACT FROM AUTHOR]

Viola pendulipes (Violaceae), a new myrmecochous species from Baiwan Nature Reserve of Guangdong Province in China, is described and illustrated. Morphologically the new species is most similar to V. nanlingensis, but it is easily distinguished by having truncate or cuneate leaf base (versus cordate leaf base), robust rhizome with short internodes (versus slender rhizome with long internodes), curved and drooping peduncles in fruit (versus erect peduncles in fruit), and oblong anterior petals (versus spatulate to rhombic anterior petals). Our phylogenetic analysis, based on ITS sequences, confirms that the new species belongs to V. subsect. Diffusae, and is most closely related to V. yunnanensis. [ABSTRACT FROM AUTHOR]

Ants disperse seeds of many plant species adapted to myrmecochory. While advantages of this ant–plant mutualism for myrmecochorous plants (myrmecochores) have been previously studied in temperate region mostly in forests, our study system was a pasture. Moreover, we used a unique combination of observing the effect of ant‐activity suppression on ant dispersal and comparison of the contribution of ant and unassisted dispersal to the distance from mother plant. We established plots without and with ant‐activity suppression (enclosures). We offered diaspores of a myrmecochorous (Knautia arvensis), and a non‐myrmecochorous (Plantago lanceolata) species in a choice test and followed ants carrying diaspores during days and nights (focus of previous studies was on diurnal dispersal). We measured frequency and distances of ant dispersal and compared them with unassisted dispersal recorded using sticky trap method. The dispersal frequency was lower in enclosures (3.16 times). Ants strongly preferred diaspores of the myrmecochore to non‐myrmecochore with 586 and 42 dispersal events, respectively (out of 6400 diaspores of each species offered). Ant dispersal resulted in more even and on average longer distances (maximum almost tenfold longer, 994 cm) in comparison to unassisted dispersal. Ant dispersal altered the distribution of distances of the myrmecochore from roughly symmetric for unassisted dispersal to positively skewed. Ants dispersed heavier diaspores farther. Ants dropped the majority of diaspores during the dispersal (which reduces clustering of seeds), while several (11%) were carried into anthills. Anthills are disturbed microsites presumably favorable for germination in competitive habitats. Ants provided non‐negligible dispersal services to myrmecochorous K. arvensis but also, to a lesser extent, of non‐myrmecochorous P. lanceolata. [ABSTRACT FROM AUTHOR]

Herbivores shape plant invasions through impacts on demography and dispersal, yet only demographic mechanisms are well understood. Although herbivores negatively impact demography by definition, they can affect dispersal either negatively (e.g., seed consumption), or positively (e.g., caching). Exploring the nuances of how herbivores influence spatial spread will improve the forecasting of plant movement on the landscape. Here, we aim to understand how herbivores impact how fast plant populations spread through varying impacts on plant demography and dispersal. We strive to determine whether, and under what conditions, we see net positive effects of herbivores, in order to find scenarios where herbivores can help to promote spread. We draw on classic invasion theory to develop a stage-structured integrodifference equation model that incorporates herbivore impacts on plant demography and dispersal. We simulate seven herbivore "syndromes" (combinations of demographic and/or dispersal effects) drawn from the literature to understand how increasing herbivore pressure alters plant spreading speed. We find that herbivores with solely negative effects on plant demography or dispersal always slow plant spreading speed, and that the speed slows monotonically as herbivore pressure increases. However, we also find that plant spreading speed can be hump shaped with respect to herbivore pressure: plants spread faster in the presence of herbivores (for low herbivore pressure) and then slower (for high herbivore pressure). This result is robust, occurring across all syndromes in which herbivores have a positive effect on plant dispersal, and is a sign that the positive effects of herbivores on dispersal can outweigh their negative effects on demography. For all syndromes we find that sufficiently high herbivore pressure results in population collapse. Thus, our findings show that herbivores can speed up or slow down plant spread. These insights allow for a greater understanding of how to slow invasions, facilitate native species recolonization, and shape range shifts with global change. [ABSTRACT FROM AUTHOR]

Abstract Ants disperse seeds of many plant species adapted to myrmecochory. While advantages of this ant–plant mutualism for myrmecochorous plants (myrmecochores) have been previously studied in temperate region mostly in forests, our study system was a pasture. Moreover, we used a unique combination of observing the effect of ant‐activity suppression on ant dispersal and comparison of the contribution of ant and unassisted dispersal to the distance from mother plant. We established plots without and with ant‐activity suppression (enclosures). We offered diaspores of a myrmecochorous (Knautia arvensis), and a non‐myrmecochorous (Plantago lanceolata) species in a choice test and followed ants carrying diaspores during days and nights (focus of previous studies was on diurnal dispersal). We measured frequency and distances of ant dispersal and compared them with unassisted dispersal recorded using sticky trap method. The dispersal frequency was lower in enclosures (3.16 times). Ants strongly preferred diaspores of the myrmecochore to non‐myrmecochore with 586 and 42 dispersal events, respectively (out of 6400 diaspores of each species offered). Ant dispersal resulted in more even and on average longer distances (maximum almost tenfold longer, 994 cm) in comparison to unassisted dispersal. Ant dispersal altered the distribution of distances of the myrmecochore from roughly symmetric for unassisted dispersal to positively skewed. Ants dispersed heavier diaspores farther. Ants dropped the majority of diaspores during the dispersal (which reduces clustering of seeds), while several (11%) were carried into anthills. Anthills are disturbed microsites presumably favorable for germination in competitive habitats. Ants provided non‐negligible dispersal services to myrmecochorous K. arvensis but also, to a lesser extent, of non‐myrmecochorous P. lanceolata.

Seed dispersal by ants is one of the methods of seed dispersal that leads to an increase in plant diversity and plant coexistence at the local scale. This study was conducted with the aim of investigating the number of plant species, plant families transported by ants, and comparing the genus and species of ants transporting seeds, in Teng-e-Sayad area of Chaharmahal va Bakhtiari province. Study areas for collecting ant nest samples include three animal grazing management zones: 1- National Park 2- Protected Area 3- Free Grazing Area. Sampling was done in each study area from the soil related to 3 ant nests in each of the sites from 0 to 5 cm deep. Sampling was done in 2018 during the three months of July, August and Septamber in the study areas. In this experiment, 5 genera and 12 species of ants were identified. The results showed that a total of 62 plant species belonging to 15 plant families were transported by ants, of which 36 plant species were jointly transported by ants in all three regions. The results showed that there is only a significant difference between the ant genera Camponotus and Cataglyphis and also between the two genera Camponotus and Tetramorium (P<0.05). The results showed that the genus Messor, as a predatory ant, has transmitted 19 plant species that have nothing in common with other ant genera, and this ant genus has transmitted a large number of plant species compared to other ant genera. According to the results of this research, Messor can be considered as an ant that transmits a large number of plant species and species seeds and has an important effect on the diversity and presence of species in the vegetation composition. [ABSTRACT FROM AUTHOR]

Background Seed dispersal is a critical process in plant colonisation and demography. Fruits and seeds can be transported by several vectors (typically animals, wind and water), which may have exerted strong selective pressures on plant’s morphological traits. The set of traits that favour dispersal by a specific vector have been historically considered as seed dispersal syndromes. As seed dispersal syndromes have a great potential to predict how seeds move (i.e. the relative importance of the standard mechanisms of seed dispersal), they have attracted the attention of naturalists and researchers for centuries. However, given that observations of actual dispersal events and colonisation are seldom reported, there is still much confusion in current studies failing to properly discriminate between seed dispersal syndromes (i.e. sets of traits that favour a particular mechanism) and actual seed dispersal (i.e. the vector that moves a given seed in one dispersal event). This distinction is important because the presence of any seed dispersal syndrome does not preclude the seed being occasionally dispersed by other non-standard mechanisms (i.e. different from the one predicted). Similarly, the absence of seed dispersal syndromes does not prevent seeds from being dispersed. The correct coding of seed dispersal syndromes thus requires a systematic and evolutive, rather than a phenomenological approach. Unfortunately, such approach has rarely been implemented at a community-level and no comprehensive datasets of seed dispersal syndromes are yet available for any entire flora. New information This database contains categorisation of the native European flora into eight seed dispersal syndromes. Information for a total of 9,874 species retrieved from the volumes of Flora Europaea were analysed. Earlier versions of this database, which only coded for the presence of four long-distance dispersal syndromes (endozoochorous, epizoochorous, thalassochorous and anemochorous diaspores), were used in four previous studies. Here, we present a fully revised and expanded database, including the presence of four additional short-distance dispersal syndromes (myrmecochorous, vertebrate hoarding, freshwater hydrochorous and ballochorous diaspores), a nomenclatural update for all species and the codification of 416 additional species. Roughly half (51.3%) of the native European flora produce diaspores without traits clearly associated with facilitating seed dispersal. The other half (48.7%) of the European plant species produces diaspores with some specialised traits associated with seed dispersal, most of which (79.9%) with a potential to facilitate long-distance dispersal events. The most common diaspores are those with anemochorous (23.5%), epizoochorous (8.0%), endozoochorous (7.8%), myrmecochorous (7.2%), thalassochorous (2.3%), freshwater dispersal (2.1%), ballochorous (4.6%) and vertebrate hoarding associated traits (0.2%). Two-thirds (66.3%) of the European shrub and tree species have diaspores with some specialisation for biotic seed dispersal. [ABSTRACT FROM AUTHOR]

1. Current anthropogenic disturbances have changed natural environments, broadly impacting ecosystem services and functions. Here, the authors focused on the secondary dispersal of diaspores by ants, which serve an important ecological function in the natural regeneration of degraded habitats. 2. The authors experimentally studied the effects of vegetation suppression and soil disturbance on (i) diaspore removal, (ii) the quality of secondary removal, and (iii) the structure of interaction networks between ants and diaspores. The authors tested whether the disturbance affected the species richness of seed removers, diaspore removal rate, removal distance and time, and removal effectiveness. Additionally, the authors tested whether the structure of ant‐diaspore networks, that is, specialisation, modularity and robustness, is altered by soil disturbance. To do that, the authors studied three degraded and three preserved areas in the Brazilian Cerrado. 3. The authors observed 25 ant species interacting with the diaspores. Disturbance did not affect ant species richness, removal distance or removal rate, but ants took twice as long to remove the diaspores in the preserved habitat. The frequency of interaction networks was higher in the preserved habitat, and the effectiveness of species in removing the diaspores differed between habitats. Surprisingly, the authors observed that ants considered effective dispersers mostly occurred in degraded habitats, highlighting the potential of myrmecochory in the regeneration of impacted environments. 4. The findings point to the potential of ants in acting as secondary seed dispersal, improving the restoration of areas highly impacted by soil disturbance. Moreover, this study contributes to understanding the effects of anthropogenic disturbances on ecological interactions and ecosystem functions. [ABSTRACT FROM AUTHOR]

Mutualistic interactions provide essential ecosystem functions that contribute to promoting and maintaining diversity in ecosystems. Understanding if functionally important mutualisms are "resilient" (i.e., able to resist or recover) to anthropogenic disturbance is essential for revealing the capacity for diversity to recover. Animal‐mediated seed dispersal supports plant population growth and influences community structure, and disturbance affecting seed dispersal can contribute to low resiliency of plant diversity. Ant–seed dispersal mutualisms are sensitive to anthropogenic disturbance, as they rely on one to a few high‐quality dispersal partners. In North American eastern deciduous forests, ants in the genus Aphaenogaster are "keystone dispersers" of understory forbs adapted to dispersal by ants (myrmecochores), which make up more than one‐third of the understory herbaceous community. The majority of forests within this region have regenerated from previous disturbance in the form of clearing for agriculture. Previous studies have revealed that myrmecochore diversity is not resilient to previous clearing. Here, we ask if seed dispersal mutualisms are resilient to historical forest disturbance and if decreases in mutualistic interactions with partners, Aphaenogaster sp., or increases in antagonistic interactions cause degradation of function. In a large‐scale natural experiment (20 sites), we measured seed removal, the abundance of mutualistic partners and other invertebrates interacting with seeds, myrmecochore cover, and diversity, along with ant habitat and forest structure. We found lower and more variable seed removal in secondary forests compared with remnant forests. A path analysis of all forests revealed that the abundance of mutualists was the primary determinant of the variation in seed removal, and that seed damage by antagonists (invasive slugs) negatively affected dispersal and was higher in secondary forests. In a path analysis of remnant forests, the link between mutualist abundance and seed removal was absent, but present in the secondary forest path, suggesting that seed dispersal is more variable and dependent on the mutualist abundance in secondary forests and is stable and high in remnant forests. Our results suggest that functional resilience to disturbance is variable, where seed dispersal is low in some secondary forests and not others. This work provides key insights into the effects of disturbance on mutualistic interactions and how the resilience of critical ecosystem functions impacts the capacity for diversity resiliency. [ABSTRACT FROM AUTHOR]

The ecology of fear refers to the non-fatal cost that predators and parasites impose on prey populations. These non-consumptive effects (NCEs) can influence animal–plant interactions, but evidence thereof comes mainly from vertebrate systems with less focus on invertebrates. Here, I investigated whether the foraging behaviour of the ant Ectatomma ruidum was influenced by its primary predator, the forest toad Rhinella alata. In field tests, the probability of seed removal by the ants was 25% for seeds placed with the forest toad compared to 32% for control seeds, suggesting that toads reduce ant foraging rates. A further experiment revealed that ants which had previously encountered the predator and its faeces were more likely (59%) than inexperienced ants (50%) to avoid the exit with the predator faeces. This outcome suggests that ants are capable of learning cues associated with predation risk, possibly leading to NCEs. This indicates that predators can exert NCEs on invertebrate prey with potential cascading effects on seed dispersal, extending results previously seen only in vertebrate seed dispersal systems.

Forested landscapes increasingly comprise patches of differing land-use histories that include past stand-replacing anthropogenic disturbances such as logging, fire, or agricultural use. These disturbances affect community composition, and can disrupt trophic interactions among mutualistic guilds that differ in ecological requirements and mobility. However, few studies address the joint effects of past disturbance on spatial distributions of mutualistic guilds across spatial scales. We studied how past land-use history affected regional community patterns of ant-dispersed plants (myrmecochores) and their ant mutualists across a broad climatic gradient in New York State (spanning two ecoregions, 250 km distance, and elevations from 276 to 616 m above sea level). We found that changes in species composition of myrmecochores and ants along the full environmental gradient were closely coupled in residual stands that did not experience stand-replacing disturbance within the last 80 years. In contrast, species compositions of myrmecochores and ants varied independently of each other across this gradient in secondary stands (established after a stand-replacing disturbance ~60–80 years prior to this study), suggesting that past disturbance decoupled species compositions of the two guilds. Importantly, historical land-use diluted the effects of regional climatic gradient in secondary stands at broad scale, but its effect was too weak to observe it within individual ecoregions. Thus, weak hard-to-observe land-use history effects on community composition at local (subregional) scales can scale up to homogenize community composition at broader scales. Consequently, it is important to consider these emergent broad-scale effects of local land-use decisions in biodiversity conservation. [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]

Habitat fragmentation impacts ecosystems worldwide through habitat loss, reduced connectivity, and edge effects. Yet, these landscape factors are often confounded, leaving much to be investigated about their relative effects, especially on species interactions. In a landscape experiment, we investigated the consequences of connectivity and edge effects for seed dispersal by ants. We found that ants dispersed seeds farther in habitat patches connected by corridors, but only in patch centers. We did not see an effect on the total number of seeds moved or the rate ants detected seeds. Furthermore, we did not see any differences in ant community composition across patch types, suggesting that shifts in ant behavior or other factors increased ant seed dispersal in patches connected by corridors. Long‐distance seed dispersal by ants that requires an accumulation of short‐distance dispersal events over generations may be an underappreciated mechanism through which corridors increase plant diversity. [ABSTRACT FROM AUTHOR]

Thousands of plants produce both extrafloral nectaries (EFNs) on their leaves and nutrient‐rich appendages on their diaspores (elaiosomes). Although their individual ecology is well‐known, any possible functional link between these structures has almost always been ignored. Here, we recognized their co‐presence in the shrub, Adenanthos cygnorum (Proteaceae), and studied their function and interaction. We observed that the same ants frequently visit both structures, seeds are attractive to vertebrate granivores but are released into a leafy cup from where they are harvested by ants and taken to their nests, from which seeds, lacking elaiosomes, germinate after fire. We showed that juvenile plants do not produce EFNs and are not visited by ants. We conclude that EFNs are not just an indirect adaptation to minimize herbivory via aggressive ant visitors (the role of a minority) but specifically enhance reproductive success in two ways: First, by inducing ants to visit the plant as a reliable food source throughout the year. Second, by promoting discovery of the seasonally available, elaiosome‐bearing seeds for transport to their nests (the majority of visitors), so avoiding the risk of granivory should seeds instead fall to the ground. Parasitoid wasps play a supporting role in controlling the main insect herbivore whose larvae devour the reproductive apices. Thus, the EFN‐elaiosome relationship has three components that enhance species fitness: foliage protection, seed transport, and granivore escape. A similar system has been described only once before (in an unrelated biome) and, consistent with the objectives of ecology as an integrative science, deserves wider study. [ABSTRACT FROM AUTHOR]

Abstract Habitat fragmentation impacts ecosystems worldwide through habitat loss, reduced connectivity, and edge effects. Yet, these landscape factors are often confounded, leaving much to be investigated about their relative effects, especially on species interactions. In a landscape experiment, we investigated the consequences of connectivity and edge effects for seed dispersal by ants. We found that ants dispersed seeds farther in habitat patches connected by corridors, but only in patch centers. We did not see an effect on the total number of seeds moved or the rate ants detected seeds. Furthermore, we did not see any differences in ant community composition across patch types, suggesting that shifts in ant behavior or other factors increased ant seed dispersal in patches connected by corridors. Long‐distance seed dispersal by ants that requires an accumulation of short‐distance dispersal events over generations may be an underappreciated mechanism through which corridors increase plant diversity.

Ants disperse oak galls of some cynipid wasp species similarly to how they disperse seeds with elaiosomes. We conducted choice assays in field and laboratory settings with ant-dispersed seeds and wasp-induced galls found in ant nests and found that seed-dispersing ants retrieve these galls as they do myrmecochorous seeds. We also conducted manipulative experiments in which we removed the putative ant-attracting appendages ("kapéllos") from galls and found that ants are specifically attracted to kapéllos. Finally, we compared the chemical composition and histology of ant-attracting appendages on seeds and galls and found that they both have similar fatty acid compositions as well as morphology. We also observed seed-dispersing ants retrieving oak galls to their nests and rodents and birds consuming oak galls that were not retrieved by ants. These results suggest convergence in ant-mediated dispersal between myrmecochorous seeds and oak galls. Based on our observations, a protective advantage for galls retrieved to ant nests seems a more likely benefit than dispersal distance, as has also been suggested for myrmecochorous seeds. These results require reconsideration of established ant-plant research assumptions, as ant-mediated seed and gall dispersal appear strongly convergent and galls may be far more abundant in eastern North American deciduous forests than myrmecochorous seeds. [ABSTRACT FROM AUTHOR]

Myrmecochory is a widespread mutualism between angiosperm plants and ants, where seed dispersal is facilitated by a nutrient-rich appendage known as the elaiosome. Some species of phasmids (Phasmatodea) have convergently evolved an appendage, the egg capitulum, that is analogous to the elaiosome. Research into ant-mediated dispersal of phasmid eggs is limited. It is unknown whether there are species-specific interactions between ants and phasmid eggs, nor if this variation in ant species behaviour towards eggs parallels behaviour towards seeds. We observed the behaviour of five Australian ant species towards Extatosoma tiaratum eggs and Acacia longifolia seeds. We found that ant species show significant variation in the likelihood of dispersing phasmid eggs and plant seeds. Iridomyrmex purpureus removed the largest quantities of eggs and seeds. Rhytidoponera metallica also removed large amounts of seeds but less eggs. Three species did not remove any eggs but removed small amounts of seeds. We found a species-specific component to dispersal of phasmid eggs and seeds by ants, indicating that this mutualism may depend on partner identity and abundance. Although seeds and eggs have convergently evolved to exploit ant behaviours, they elicit different behaviours in certain ant species, highlighting the complex nature of this interaction. Some phasmids have evolved a strategy that utilises ants to disperse eggs. We investigated whether there are species-specific interactions between ants and eggs and if variation in ant behaviour towards eggs parallels that towards seeds. We found that some species show different behavioural responses to eggs and seeds, suggesting a species-specific component to dispersal. Photograph by Hannah Smart. [ABSTRACT FROM AUTHOR]

Seed dormancy varies greatly between species, clades, communities, and regions. We propose that fireprone ecosystems create ideal conditions for the selection of seed dormancy as fire provides a mechanism for dormancy release and postfire conditions are optimal for germination. Thus, fire‐released seed dormancy should vary in type and abundance under different fire regimes. To test these predictions, we compiled data from a wide range of fire‐related germination experiments for species in different ecosystems across the globe. We identified four dormancy syndromes: heat‐released (physical) dormancy, smoke‐released (physiological) dormancy, non‐fire‐released dormancy, and non‐dormancy. In fireprone ecosystems, fire, in the form of heat and/or chemical by‐products (collectively termed 'smoke'), are the predominant stimuli for dormancy release and subsequent germination, with climate (cold or warm stratification) and light sometimes playing important secondary roles. Fire (heat or smoke)‐released dormancy is best expressed where woody vegetation is dense and fires are intense, i.e. in crown‐fire ecosystems. In such environments, seed dormancy allows shade‐intolerant species to take advantage of vegetation gaps created by fire and synchronize germination with optimal recruitment conditions. In grassy fireprone ecosystems (e.g. savannas), where fires are less intense but more frequent, seed dormancy is less common and dormancy release is often not directly related to fire (non‐fire‐released dormancy). Rates of germination, whether controls or postfire, are twice as fast in savannas than in mediterranean ecosystems. Fire‐released dormancy is rare to absent in arid ecosystems and rainforests. The seeds of many species with fire‐released dormancy also possess elaiosomes that promote ant dispersal. Burial by ants increases insulation of seeds from fires and places them in a suitable location for fire‐released dormancy. The distribution of these dormancy syndromes across seed plants is not random – certain dormancy types are associated with particular lineages (phylogenetic conservatism). Heat‐released dormancy can be traced back to fireprone floras in the 'fiery' mid‐Cretaceous, followed by smoke‐released dormancy, with loss of fire‐related dormancy among recent events associated with the advent of open savannas and non‐fireprone habitats. Anthropogenic influences are now modifying dormancy‐release mechanisms, usually decreasing the role of fire as exaptive effects. We conclude that contrasting fire regimes are a key driver of the evolution and maintenance of diverse seed dormancy types in many of the world's natural ecosystems. [ABSTRACT FROM AUTHOR]

In this study, the anatomical structure of seed-coat of Pombalia bigibbosa (A. St.-Hil.) Paula-Souza and P. calceolaria (L.) PaulaSouza from Argentina was studied for the first time in the Violaceae. The anatomy of seed-coat revealed the presence of three layers in testa derived from outer integument in both species however the presence of layers in tegmen was different between the analyzed species, P. bigibbosa presented two layers meanwhile P. calceolaria exhibited three layers derived from the inner integument in the mature seed-coat. The presence of a conspicuous elaiosome with oily drops was observed in both species, this structure had been observed in the genus Viola and it would be related with the attraction and dispersion mediated by ants in these species of the genus Pombalia in nature. In this sense, the myrmecochory in these violets species explains the multiple evolutionary origins in the angiosperm plants and is proposed like an example of convergent evolution. [ABSTRACT FROM AUTHOR]

Generalized mutualisms, such as seed dispersal by ants (myrmecochory), involve guilds of mutualistic partners that exchange services. Partners within guilds vary in traits that affect the quality of mutualistic services. Research aimed at uncovering within-guild variation in partner quality primarily considers the identity of partner species. However, mutualism-related traits vary within species, especially for populations in states of incomplete speciation where the distinction between intra- and interspecific variation is not well defined. Ants in the genus Aphaenogaster are mutualists and the major disperser of seeds of understory plants adapted to dispersal by ants (myrmecochores) in eastern North American forests. A. rudis and A. picea are polyphyletic with overlapping morphological features. We ask if functional variation partitions discretely between named species or along a continuum in this species complex. We collected replicate colonies of three populations, each of the named species. We performed 2D morphometrics on the thorax to quantify complex morphological variation among colonies. We performed lab behavioral trials, measuring behaviors that influence seed dispersal quality such as foraging, seed dispersal rate and preference, and intra- and interspecific aggression. Morphometrics revealed differences between species but also continuous variation in diagnostic features. We found behavioral differences between species, with A. rudis being a better disperser and having higher intraspecific aggression and A. picea being a more active forager and dominant over A. rudis. Behavior also varied along a continuum between species corresponding with colony morphometrics, with intermediate phenotypes having intermediate behavior. This work shows that it is important to consider partner identity in species complexes of mutualistic partners at multiple levels of biological organization. [ABSTRACT FROM AUTHOR]

Abstract Seed dispersal by ants is an important means of migration for plants. Many myrmecochorous plants have specialized appendages in their seeds called elaiosome, which provides nutritional rewards for ants, and enable effective seed dispersal. However, some nonmyrmecochorous seeds without elaiosomes are also dispersed by ant species, suggesting the additional mechanisms other than elaiosomes for seed dispersal by ants. The seeds of the achlorophyllous and myco‐heterotrophic herbaceous plant Monotropastrum humile are very small without elaiosomes; we investigated whether odor of the seeds could mediate seed dispersal by ants. We performed a bioassay using seeds of M. humile and the ant Nylanderia flavipes to demonstrate ant‐mediated seed dispersal. We also analyzed the volatile odors emitted from M. humile seeds and conducted bioassays using dummy seeds coated with seed volatiles. Although elaiosomes were absent from the M. humile seeds, the ants carried the seeds to their nests. They also carried the dummy seeds coated with the seed volatile mixture to the nest and left some dummy seeds inside the nest and discarded the rest of the dummy seeds outside the nest with a bias toward specific locations, which might be conducive to germination. We concluded that, in M. humile seeds, volatile odor mixtures were sufficient to induce seed‐carrying behavior by the ants even without elaiosomes.

Secondary diaspore removal on the ground is an important ecosystem process. In this process, solitary foraging ants with larger body sizes are more efficient because they may remove more diaspores, faster and carry them at greater distances. Therefore, we sought to test the effects of the sizes of the morphological traits of ants, removal strategy, and nest distance on secondary diaspore removal, testing hypotheses related to the efficiency of this process. We evaluated the removal of artificial diaspores by ants in 15 areas of Cerrado sensu stricto (tropical savanna), collecting data on diaspore removal strategy (solitary or group), nest distance, diaspore discovery time, diaspore removal time, and the number of diaspores removed. Larger ants tended to remove diaspores alone and remove diaspores faster than smaller ones. Ants that removed diaspores alone removed more diaspores than ants that removed diaspores in groups. However, we did not find a linear relationship between ant size and diaspore removal. This is likely due to a limitation on, or a preference by larger ants for removing larger diaspores, while the smaller diaspores may have hindered manipulation or been less attractive to larger ants. Thus, the removal strategy was the best predictor of efficient diaspore removal performance, where the solitary foraging ants discover and remove diaspores quickly and remove more diaspores, mainly from the closest nests to the sampling point. However, the benefits (or not) of removing more diaspores still need to be evaluated.

We compared the species composition of seedlings germinated on ten recently abandoned Formica polyctena nests with the plant species on active nests and the plant species composition of the forest floor around the nests. Compared to no plants at all, when the nests were inhabited, seedlings of 12 different vascular plant species germinated on the nests after their abandonment. Four of them were myrmecochorous, of which two occurred only on the nests. After abandonment, ant activity ceases, the water content of the nests increases, and decomposition of the organic nest material is accelerated, resulting in faster nutrient mineralization. Consequently, more nutrients are available for plants. Our results suggest that abandoned nests can serve as "regeneration niches", ensuring genetic diversity, especially in plant populations which rely mainly on vegetative propagation. However, more research on a larger scale is needed to assess the role of wood ants and their abandoned nests in forest vegetation development. [ABSTRACT FROM AUTHOR]

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Simple Summary: Myrmecochory is seed dispersal of numerous plant species mediated by ants. We investigate ant–plant interactions under field conditions across two study sites in Central Europe. Three obligatory myrmecocohrous plants are chosen for the experiments: snowdrop Galanthus nivalis, hollow root Corydalis cava and European wild ginger Asarum europaeum. We experimentally alter diaspore morphology and record seed removal rates across five treatments: elaiosomes without seeds, diaspore without elaiosome, 1/2 elaiosome + diaspore, 1/2 diaspore + elaiosome and control. Elaiosomes of European wild ginger constitute about 30% of diaspore weight, elaiosomes of snowdrop constitute 13% and elaiosomes of hollow root constitute only 7.5%. Diaspore/elaiosome removal rates are highest in European wild ginger (34%), followed by hollow root (26%) and snowdrop (10%). Only two ants interact with diaspores, the acorn ant Temnothorax crassispinus and the red ant Myrmica ruginodis. Ants respond to elaiosome/seed ratio by removing elaiosomes without diaspores most frequently, followed by 1/2 diaspore + elaiosome, control, diaspores without elaiosomes and 1/2 elaiosome with diaspore. Plants do not effectively manipulate ant behavior and no dispersal benefits from interactions with ants are observed. 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. [ABSTRACT FROM AUTHOR]

Curcuma stahlianthoides, a new species of Curcuma subg. Hitcheniopsis (Zingiberaceae: Zingi beroideae) from northeastern Thailand is described and illustrated here. The flower morphology of C. stahlianthoides resembles several other species formerly classified in the genus Stahlianthus, but the inflorescences are composed of up to 11 plain green fertile bracts, conforming to the typical inflorescence structure in the genus Curcuma. This combination of characters is similar to C. leonidii from Vietnam, to which it is compared for the diagnostic purposes. Previous molecular results indicate that Stahlianthus should be merged with Curcuma subg. Hitcheniopsis and C. stahlianthoides is the second species providing morphological justification to do so. A detailed description based on living flowering material, colour plates including the flower dissection, and notes on distribution, habitat and phenology are also provided. The status of Vulnerable is proposed for this species based on the IUCN guidelines and criteria. Observations on ant-aided seed dispersal of this species are reported and discussed within present knowledge of myrmecochory in gingers. [ABSTRACT FROM AUTHOR]

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Abstract The evolution of dispersal at range margins received much attention recently, especially in the context of dynamic range shifts, such as those following climate change. However, much less attention has been devoted to study variation in and selection on dispersal at nonexpanding range margins, where populations are often small and isolated, and empirical test is dearly missing. To fill this gap, we tested whether dispersal of an ant‐dispersed perennial plant (Sternbergia clusiana) is quantitatively and/or qualitatively reduced toward a nonexpanding range margin. We evaluated plant investment in dispersal structures (elaiosome), seed removal rates, and the relative abundance, activity, and behavior of low‐ and high‐quality seed‐dispersing ants in six sites ranging from mesic Mediterranean site to arid site (>600 to

Abstract Morphological and chemical attributes of diaspores in myrmecochorous plants have been shown to affect seed dispersal by ants, but the relative importance of these attributes in determining seed attractiveness and dispersal success is poorly understood. We explored whether differences in diaspore morphology, elaiosome fatty acids, or elaiosome phytochemical profiles explain the differential attractiveness of five species in the genus Trillium to eastern North American forest ants. Species were ranked from least to most attractive based on empirically‐derived seed dispersal probabilities in our study system, and we compared diaspore traits to test our hypotheses that more attractive species will have larger diaspores, greater concentrations of elaiosome fatty acids, and distinct elaiosome phytochemistry compared to the less attractive species. Diaspore length, width, mass, and elaiosome length were significantly greater in the more attractive species. Using gas chromatography–mass spectrometry, we found significantly higher concentrations of oleic, linoleic, hexadecenoic, stearic, palmitoleic, and total fatty acids in elaiosomes of the more attractive species. Multivariate assessments revealed that elaiosome phytochemical profiles, identified through liquid chromatography–mass spectrometry, were more homogeneous for the more attractive species. Random forest classification models (RFCM) identified several elaiosome phytochemicals that differed significantly among species. Random forest regression models revealed that some of the compounds identified by RFCM, including methylhistidine (α‐amino acid) and d‐glucarate (carbohydrate), were positively related to seed dispersal probabilities, while others, including salicylate (salicylic acid) and citrulline (L‐α‐amino acid), were negatively related. These results supported our hypotheses that the more attractive species of Trillium—which are geographically widespread compared to their less attractive, endemic congeners—are characterized by larger diaspores, greater concentrations of fatty acids, and distinct elaiosome phytochemistry. Further advances in our understanding of seed dispersal effectiveness in myrmecochorous systems will benefit from a portrayal of dispersal unit chemical and physical traits, and their combined responses to selection pressures.

Summary: Quantifying ecological interactions can inform restoration practitioners of the recovery of ecosystem function in restored areas. Plant–animal interactions that move seeds are critical for plant recruitment, animal food sources and ecosystem function, but seed movement immediately after sowing can affect calculations of seedling emergence in restored areas. We set up seed cafeterias in undisturbed, native vegetation and restored areas to quantify and compare the removal of seeds of eight native plant species of banded ironstone ranges to determine the recovery of this ecological interaction and the potential effect on monitoring protocols. Overall, the average amounts of seeds removed from cafeterias over two days were between 17 and 23%, but this varied considerably between replicates. Seeds with or without a food body (i.e. elaiosome) were both removed from cafeterias by invertebrates. Seeds removed by invertebrates (most likely ants) after surface sowing for restoration are expected to negatively affect calculations of seedling emergence because the known quantity of sown seeds has been reduced, deflating emergence calculations. Restoration protocols should consider the potential negative effect of seed movement on seedling emergence. Encouragingly, these restoration areas have maintained ecological interactions that move seeds in the landscape at comparable levels to undisturbed vegetation. [ABSTRACT FROM AUTHOR]

In warm temperate forests where light availability is generally low, roadsides often provide a refuge for myrmecochores. Therefore, whether or not ants disperse seeds along the roadsides should critically affect the regeneration of myrmecochores. Nonetheless, the dispersal behaviors of ants along roadsides have rarely been investigated in warm temperate forests. This study examined the road preference of two seed dispersing ants in warm temperate Japan, Formica japonica and Pheidole nodus. We located ant nests using baits placed at the vicinity of myrmecochorous sedges and examined the road preferences of ants and their consequences for seed dispersal by comparing the observed road proximity of ant nests with the simulated value assuming a random dispersal direction. Nests of both ant species were significantly closer to the road than in those simulated assuming random dispersal, which confirmed their road preferences. The road preference of F. japonica reduced the risk of seed loss into the forest interior to one‐ninth of the random dispersal. This trend was not observed in P. nodus due to its short dispersal distance relative to roadside width. Although light availability was higher around nests of P. nodus due to their closer proximity to the road than nests of F. japonica, adult sedges were located farther from the road than the nests of P. nodus. This implies that nests of P. nodus are unsuitable microhabitats for sedges. These results suggest that ants can disperse seeds along forest roadsides in warm temperate forests, but the efficiency vary among ant species. [ABSTRACT FROM AUTHOR]

Aim: Invertebrate‐mediated dispersal has previously been proposed to promote angiosperm diversification and distribution. However, little is known about the specific impact of invertebrate‐mediated dispersal on the biogeography and current distribution of plants. We aim to infer the influence of vespicochorous (hornet) and myrmecochorous (ant) dispersal on the historical biogeography of herbaceous monocot species. Location: Southeast Asia, East Asia, Australia, North America. Taxon: Family Stemonaceae. Method: We sampled ca. 75% of the species diversity in Stemonaceae (28 out of 37 species), covering the entire distribution range of the family, to reconstruct the biogeographic history of this family. Using phylogenetic logistic regression analyses, we then tested the relationship between dispersal modes and geographic distributions. Results: Stemonaceae originated on the Asian mainland during the late Cretaceous and then dispersed to North America, the western Malay Archipelago and eastern Malay Archipelago and Australia between the late Cretaceous and Pliocene. Geographical ranges of ant‐ versus hornet‐dispersed Stemonaceae species are significantly different, with vespicochorous species having broader distribution ranges than myrmecochorous species. Main conclusions: Invertebrate‐mediated dispersal in Stemonaceae may promote narrow endemism and play an important role in shaping the current distribution of species. Most lineages dispersed by ants failed to cross biogeographic barriers and exhibit limited range expansion overland. Vespicochorous lineages were able to cross oceanic barriers and occupy larger continental areas and/or occur on oceanic islands. [ABSTRACT FROM AUTHOR]

Ant-mediated secondary dispersal (myrmecochory) of phasmid eggs using a fleshy nutrient-rich appendage called capitulum remains poorly studied, albeit the egg capitula are present in a large number of phasmid species worldwide. We here report our unexpected collection of 42 multi-species phasmid eggs deposited together with seeds in the four nests of the myrmicine ant species, Acanthomyrmex glabfemoralis Zhou & Zheng, 1997, in southern China and northern Vietnam. The collected phasmid eggs were composed of five egg morphospecies that most likely belong to some related genera in the two lonchodid subfamilies, Necrosciinae and Lonchodinae. None of the collected phasmid eggs had an intact capitular structure, indicating a strong likelihood of their consumption by the ants. To our knowledge, these records are the first published field evidence of myrmecochory in the Oriental phasmid species and these two subfamilies, supporting the broad occurrence of the myrmecochory in phasmids. Notes on the seeds deposited in these nests are also provided herewith. [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.

The importance of many mutualistic interactions is poorly understood because information on their frequency and distribution at wide spatial scales is lacking. One such interaction is that between ants and plants bearing diaspores equipped with elaiosomes, which function as a reward for ants in exchange for dispersion. Our aim was to estimate the number of taxa having elaiosome-bearing diaspores in the Ibero-Balearic territory and its relationship to several factors. We estimated that at least 572 species and subspecies, almost one-third endemic, are present, which corresponds to ca. 5.1% of European angiosperms and 9% of Iberian ones. Because this number of elaiosome-bearing taxa is much higher than those given so far for the Northern Hemisphere, the Ibero-Balearic territory should be considered an important center of myrmecochory, with myrmecochorous species richness significantly positively correlated with ruggedness, latitude, and longitude. In contrast to other myrmecochorous territories (Australia and Cape Province), where numerous trees and shrubs develop on acid substrates, most myrmecochores in the Ibero-Balearic area are perennial herbs occupying basic substrates. Such perennial herbs are more frequent in the Eurosiberian floristic region, whereas annuals abound in the Mediterranean region. The enumerated taxa mainly inhabit forests, scrubs, and anthropized sites. Among them, 56.5% carry the elaiosome on seeds (especially strophiole and caruncle types). In 36.7%, the elaiosome is borne on indehiscent fruits, such as achenes in Asteraceae, where they are found either at the base of the style or the basal hilum, and at the base of nutlets (Boraginaceae and Lamiaceae). [ABSTRACT FROM AUTHOR]

Ants can shape vegetation as seed dispersers and ecosystem engineers. When anthills are long-lasting, they are known to change soil and vegetation characteristics. However, it is unclear whether plant species traits and species composition vary between ant guilds and between parts of individual anthills. We compared different aspects of soil and vegetation (composition, seedling abundance, and functional traits) between anthills and the surrounding mesophilous pasture in Czechia. This pasture hosts eight ant species, which belong to both seed dispersers and non-dispersers. Where feasible, we divided anthills into centres and margins for the analyses. Anthills (area 90.5–4051.7 cm2; 5–19 plant species) displayed different and more heterogeneous (less similar within anthill plot type) vegetation composition when compared to the surrounding area, with more seedlings and several species restricted to anthills. Further, anthills were more functionally diverse and exhibited several differences in traits, both at the community and intraspecific level. Anthill centres had higher surface temperatures in hot sunny days, higher levels of phosphorus and pH than margins, while margins had higher moisture and carbon content than surrounding vegetation. Further, anthill vegetation differed between ant guilds with more myrmecochorous species found at nests of seed dispersers. Overall heterogeneity in this mesophilous pasture was enhanced by the presence of anthills. Further, the anthills themselves are heterogeneous due to variable sizes, persistence, and differences between their centres and margins on long-lasting anthills. Anthills can thus enhance plant diversity by maintaining disturbed microsites and enhancing the growth of seedlings and less competitive plants. [ABSTRACT FROM AUTHOR]

Most plant diversity in eastern deciduous forests occurs in the understory herbaceous layer. Ant-dispersed plants (myrmecochores) reside within that layer, and they often are reported to be a substantial part of understory plant abundance and diversity that is particularly threatened by global change because of their relatively short dispersal distances. Indeed, they are often, but not always, reported to be lacking or absent from young forests where they may fail to re-colonize after extirpation due to their dispersal limitations. Our objective was to characterize the woodland myrmecochorous plant communities across the northern- and southernmost reaches of eastern deciduous forests using vegetation from 2687 plots in 44 U.S. National Parks. We asked whether (a) myrmecochorous plants are a substantial portion of understory herbaceous communities in eastern North American deciduous forests, and (b) if they are particularly dispersal limited relative to other understory herbaceous dispersal guilds. If myrmecochores are notable in abundance and extent in understory herbaceous communities, we expected that they would comprise ~ 30% of the species and ~ 55–60% of the abundance, as reported in the literature. If myrmecochores, as a guild, are more dispersal limited than other dispersal modes (anemochory, autochory, zoochory), we also expected that myrmecochore species richness would be more limited by park age and area than other dispersal guilds because they would take longer to re-colonize. In contrast with the published literature on myrmecochores, our data suggest that myrmecochorous plants are much less common as reported in eastern deciduous understory herbaceous communities (~ 9% of herbaceous species; ~ 12% of herbaceous abundance), but twice as common as the global percentage of myrmecochorous plants (~ 4.5%). We also found that they are not particularly impacted by forest size and fragmentation. Ants appear to disperse myrmecochorous seeds at 1/20th the distance of wind-dispersed plants, but the dispersal distances for myrmecochores are about the same as other animal-dispersed plants and slightly less than gravity-dispersed plants in these same forests. Moreover, our data also suggest that myrmecochores, particularly large-seeded myrmecochores, may not occur in enough abundance to contribute meaningful biomass toward ant diets. Of course, species abundance does not equal species importance, and many keystone species impact ecosystems more than their abundance might suggest. Ant-mediated seed dispersal is a model system for understanding ecological and evolutionary dynamics, and certainly contributes toward understanding the threats of fragmentation and climate change in eastern deciduous forest systems, but they may not be as abundance or threatened as previously reported. [ABSTRACT FROM AUTHOR]

Seed dispersal by ants is an important interaction in North American eastern deciduous forests, where 30–40% of understory plants are myrmecochores, with seeds that possess lipid‐rich appendages (elaiosomes) that attract seed‐dispersing ants. Contemporary forests are fragmented and have regenerated from being previously cleared (secondary forests). In secondary forests, and especially along edges, myrmecochores are a depauperate component of forests. Here, we assess if seed dispersal of myrmecochores by ants, particularly the keystone disperser, Aphaenogaster sp., is intact in forest interiors compared to edges. In three North American northeastern deciduous forests, we compared myrmecochore cover and richness, seed dispersal by ants, and the abundance and richness of ants and other forest floor invertebrates between interiors and edges. We also conducted a seed removal experiment, excluding either ants, rodents (seed predators), or ants and rodents, to test their effects on seed dispersal between interiors and edges. We found differences in the composition of understory plants between interiors and edges, with edges lacking myrmecochores. We also found that seed dispersal by ants was lower in two of the three edges and corresponded to Aphaenogaster sp. abundance. Antagonistic interactions with an invasive slug that is an elaiosome robber, Arion subfuscus, was more apparent than damage by rodents in the experiment, negatively affected dispersal by ants more at edges than in interiors. Here we show that changes in mutualistic and antagonistic interactions affect seed dispersal at forest edges and that not all forest edges are the same, with some more intact than others. Understanding how seed dispersal is impacted in contemporary forests is important towards the goal of conserving and restoring depauperate forest understory communities. [ABSTRACT FROM AUTHOR]

Copyright of Biotropica is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Diaspore removal by ants is a crucial stage for successful myrmecochory and can be directly or indirectly affected by natural or anthropic changes to environments. Among the consequences of such changes is variation in habitat attributes, such as changes in conditions and resources and, consequently, decreased diaspore removal or even the loss of this ecological function. The aim of this study was to assess whether canopy and litter cover affect diaspore removal by ants in the Cerrado. We considered canopy and litter cover as proxies of humidity and temperature and evaluated whether changes in these environmental conditions could affect diaspore removal by ants. We hypothesized that the greater the canopy and litter cover (higher humidity and lower temperature), the greater the number of diaspores removed by ants. We tested this hypothesis by establishing three classes of cover for each proxy: low, intermediate, and high. We placed artificial diaspores under each cover class and quantified the number of diaspores removed. We found that variation in canopy and litter cover did not affect the number of diaspores removed by ants in areas of cerrado sensu stricto. Variation in habitat attributes in natural environments were less important for diaspore removal than in modified areas. Our results indicate that understanding the processes and habitat atributes involved in diaspore removal by ants is important for conserving the Cerrado.