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Background: Hornbills are known to play an important role in rainforests as agents of seed dispersal. Decades of scientific research has led to a vital body of knowledge on hornbill taxonomy, ecology, distribution, and conservation status. However, the traditional ecological knowledge (TEK) that local people possess on hornbills has largely been underexplored. In 2018, we collaborated with the Iban people of Temburong, Brunei Darussalam, to study their TEK on hornbills., Method: We collaborated with the members of the Iban community from four longhouses and four villages in Temburong, Brunei Darussalam. Our study adopts a qualitative approach; we used detailed semi-directive interviews and brief semi-structured interviews to gather data. The semi-directive interviews documented the TEK related to Hornbills in detail while the brief semi-structured interviews assessed the current status of TEK in the age group of 18-40 years., Results: The results show that the Iban ethnotaxonomy recognises seven folk species of hornbills, with Asian Black Hornbill (Anthracoceros malayanus) and Oriental Pied Hornbill (Anthracoceros albirostris) considered as a single folk species. The Iban TEK on diet and reproductive behaviour of hornbills complement existing scientific records, with the Iban TEK providing additional locale-specific information on the dietary preferences, abundance and conservation threats. However, the average Iban member has lost much of this TEK, and it is the subsistence hunters and agriculturists who have conserved it., Conclusion: There is an urgent need for encouraging transmission of knowledge from the hunters and agriculturists to others through ecotourism and conservation ventures. Our study adds further support to the understanding that the TEK of local communities is an important source of locale-specific knowledge on species of high conservation value such as hornbills.

Species-level dispersal information can give mechanistic insights into how spatial processes impact plant communities. Unfortunately, field-based estimates of the dispersal abilities of multiple members of a community are often lacking for many plant systems. Here, we provide a simple method for measuring dispersal ability for large numbers of grassland plant species based on functional traits. Using this method, we estimated the dispersal ability of 50 co-occurring grassland species using the Wald Analytical Long-distance Dispersal (WALD) model. Grassland plants species are often used for developing community theory, yet species-level estimates of their dispersal abilities are comparatively rare. We use these dispersal measurements to examine the relationship between species dispersal abilities and successional dynamics using data from a 90-yr old field chronosequence. We find that our estimated dispersal measurements matched field-based establishment observations well, and estimated species colonization, competitive, and establishment abilities. We hope that this method for measuring dispersal ability of multiple species within a community, and its demonstrated ability to generate predictions for spatial ecology, will encourage more studies of the explicit role of dispersal in plant community ecology., (© 2018 by the Ecological Society of America.)

The ca. 12,000 islands and islets that encompass the Mediterranean Basin represent a biodiversity hotspot. They have been disconnected from each other and from the continent for hundreds of thousands to millions of years and encompass a high incidence of endemic plant species, with values that can exceed 20% of the local flora. Despite this, relatively few studies have been carried out to unravel ecological and evolutionary aspects of plant reproduction. We synthesise here the available information on the breeding systems, pollination and seed dispersal mode of the Mediterranean island flora. The main objective is to identify general patterns as well as to detect the main gaps in information on reproductive ecology in these particular and vulnerable systems in the face of global change. We also briefly review the information on impacts of invasive species on plant reproduction and dispersal, as these are some of the main threats to island biodiversity in general and Mediterranean island plant diversity in particular. The review has revealed that most available information is very geographically biased towards the western Mediterranean islands, especially the Balearic Islands, although a good fraction of studies have also been carried out on the eastern islands in the Aegean archipelago. Moreover, the majority of data come from species-focused studies, mainly endemic species of restricted range, whereas only a small fraction of studies have been performed at a community level. Relatively little work has involved genetic analyses, mainly focused on assessing the genetic differentiation and variability on narrow endemics. Contrary to our expectations, most island species do not rely on autonomous selfing, which might be related to the relatively high diversity of pollinators. The small, uninhabited, islands might be the last refuges of peculiar interactions that evolved in them in ancient times; they thus should be considered as sanctuaries of extraordinary biodiversity. Finally, we point out the main gaps of information and formulate a set of hypotheses that we believe are worth testing in future studies if we are to advance knowledge on the reproductive biology of Mediterranean island plants., (© 2017 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.)

Change in ecosystem disturbance regimes from human land-use poses a worldwide problem for management of rare species. Two important types of disturbance influencing the persistence of species in Australian ecosystems are habitat fragmentation and fire. In this study, seed dispersal and the germination ecology of Pomaderris vacciniifolia-a critically endangered, rare endemic Australian shrub-were examined to identify likely influences of fire and fragmentation on the decline of populations. The response of seed germination to simulated effects of wildfire and canopy openings was investigated, as was the unaided dispersal capability of seeds from parent plants. A significant increase in germination rate was observed following 100°C heat treatment to seeds, while smoke and light exposure had little influence. Seed imbibition was strongly influenced by heat treatment. The findings indicate a likely positive post-fire germination response, with implications for recruitment success determined by moisture availability following fire. Unaided seed dispersal was limited, which partly explains the apparent decline of populations. Understanding disturbance requirements for threatened species, and subsequent management of landscapes for disturbance, will aid conservation of rare species throughout the world., Competing Interests: The authors have declared that no competing interests exist.

This paper presents a standardized protocol for the non-lethal capture of fishes, sampling of stomach contents and quantification of seed dispersal efficiency by frugivorous fishes. Neotropical pacu Piaractus mesopotamicus individuals were collected with fruit-baited hooks. The diets of 110 fish were sampled using a lavage method, which retrieved >90% of stomach contents of both juveniles and adults and allowed individuals to recover within 5 min of treatment. The proportional volume of six food categories was similar for stomachs and whole digestive tracts retrieved by dissection. Fruit pulp was proportionally lower in the stomach. The abundance and species richness of intact seeds increased with fish size independent of whether only stomachs or whole digestive tracts were analysed. The analysis of stomach contents accounted for 62·5% of the total species richness of seeds dispersed by P. mesopotamicus and 96% of common seeds (seed species retrieved from more than one fish). Germination trials revealed that seed viability was similar for seeds collected from the stomach via lavage and seeds that passed through the entire digestive tract. Therefore, stomach contents provide an unbiased representation of the dietary patterns and seed dispersal of frugivorous fishes., (© 2016 The Fisheries Society of the British Isles.)

The late Quaternary megafaunal extinction impacted ecological communities worldwide, and affected key ecological processes such as seed dispersal. The traits of several species of large-seeded plants are thought to have evolved in response to interactions with extinct megafauna, but how these extinctions affected the organization of interactions in seed-dispersal systems is poorly understood. Here, we combined ecological and paleontological data and network analyses to investigate how the structure of a species-rich seed-dispersal network could have changed from the Pleistocene to the present and examine the possible consequences of such changes. Our results indicate that the seed-dispersal network was organized into modules across the different time periods but has been reconfigured in different ways over time. The episode of megafaunal extinction and the arrival of humans changed how seed dispersers were distributed among network modules. However, the recent introduction of livestock into the seed-dispersal system partially restored the original network organization by strengthening the modular configuration. Moreover, after megafaunal extinctions, introduced species and some smaller native mammals became key components for the structure of the seed-dispersal network. We hypothesize that such changes in network structure affected both animal and plant assemblages, potentially contributing to the shaping of modern ecological communities. The ongoing extinction of key large vertebrates will lead to a variety of context-dependent rearranged ecological networks, most certainly affecting ecological and evolutionary processes.

Colonization of vacant habitat is a fundamental ecological process that affects the ability of species to persist and undergo range modifications in continually shifting landscapes. Thus, understanding factors that affect and limit colonization has important ecological and conservation implications. Epiphytic orchids are increasingly threatened by various factors, including anthropogenic habitat disturbance. As cleared areas (e.g. pastures) are recolonized by suitable host trees, the establishment and genetic composition of epiphytic orchid populations are likely a function of their colonization patterns. We used genetic analyses to infer the prevailing colonization pattern of the epiphytic orchid, Brassavola nodosa. Samples from three populations (i.e. individuals within a tree) from each of five pastures in the dry forest of Costa Rica were genotyped with neutral nuclear and chloroplast markers. Spatial autocorrelation and hierarchical genetic structure analyses were used to assess the relatedness of individuals within populations, among populations within pastures and among populations in different pastures. The results showed significant relatedness within populations (mean r=0.166) and significant but lower relatedness among populations within a pasture (mean r=0.058). Our data suggest that colonization of available habitats is by few individuals with subsequent population expansion resulting from in situ reproduction, and that individuals within a tree are not a random sample of the regional seed pool. Furthermore, populations within a pasture were likely colonized by seeds produced by founders of a neighbouring population within that pasture. These results have important ramifications for understanding conservation measures needed for this species and other epiphytic orchids., (© 2013 John Wiley & Sons Ltd.)

Spatial discordance between primary and effective dispersal in plant populations indicates that postdispersal processes erase the seed rain signal in recruitment patterns. Five different models were used to test the spatial concordance of the primary and effective dispersal patterns in a European beech (Fagus sylvatica) population from central Spain. An ecological method was based on classical inverse modelling (SSS), using the number of seed/seedlings as input data. Genetic models were based on direct kernel fitting of mother-to-offspring distances estimated by a parentage analysis or were spatially explicit models based on the genotype frequencies of offspring (competing sources model and Moran-Clark's Model). A fully integrated mixed model was based on inverse modelling, but used the number of genotypes as input data (gene shadow model). The potential sources of error and limitations of each seed dispersal estimation method are discussed. The mean dispersal distances for seeds and saplings estimated with these five methods were higher than those obtained by previous estimations for European beech forests. All the methods show strong discordance between primary and effective dispersal kernel parameters, and for dispersal directionality. While seed rain was released mostly under the canopy, saplings were established far from mother trees. This discordant pattern may be the result of the action of secondary dispersal by animals or density-dependent effects; that is, the Janzen-Connell effect., (© 2013 Blackwell Publishing Ltd.)

Seed dispersal shapes ecological and evolutionary dynamics of plant populations. Here, we extend classical diversity measures to study the impact of disperser behavior on seed dispersal. We begin by extending our previous diversity structure approach, which partitioned seed source diversity within and among dispersal sites, into the more general framework of traditional diversity measures. This statistical approach allows an assessment of the extent to which foraging behavior shapes α and γ diversity, as well as the divergence in seed sources among dispersal sites, which we call δ. We also introduce tests to facilitate comparisons of diversity among dispersal sites and seed vectors and to compare overall diversity among sampled systems. We then apply these tools to investigate the diversity blend of parentage resulting from seed dispersal by two avian seed vectors with very different social and foraging behaviors: (1) acorn woodpeckers, transporting Quercus agrifolia acorns, and (2) long-wattled umbrellabirds, transporting Oenocarpus bataua palm nuts. Using these diversity and divergence measures, we test the hypothesis that different foraging behaviors generate distinctive diversity partitions for the two focal tree species. This approach provides a new tool for assessment of the impact of dispersal agents on the seed source structure of plant populations, which can be extended to include the impact of virtually any propagule vector for a range of systems.

Dromiciops gliroides is an arboreal marsupial found in the temperate forests of South America (36-43 °S). This species is the sole extant representative of the order Microbiotheria, and is a key seed disperser of many native plant species, including the keystone mistletoe Tristerix corymbosus. Here, we synthesized the current knowledge on the ecological aspects of this species, and compared the available information from Argentina and Chile. Population density (23 ± 2 (mean ± SE) individual/ha) and home range (1.6 ± 0.6 ha) appear to be relatively similar across a marked ecological gradient in the mainland, but lower densities (7 ± 2 individual/ha) and smaller home ranges (0.26 ± 0.04 ha) were detected at island sites. We detected regional variation in body condition in Chile, but there were no significant differences across a wider E-W gradient. Movement patterns fit a random walk model; such behavior might have important consequences in shaping plant's spatial patterns. Although our data suggest that D. gliroides is more tolerant to habitat disturbance than previously thought, its incapability to disperse across non-forested areas suggests that the rapid rate of habitat loss and fragmentation that characterizes southern temperate forests likely poses a serious threat to this species. These ecological similarities are surprising given that forests studied receive dramatically different rainfall and correspond to distinct forest types. The evidence synthetized here dispels some of the myths about this species but also stresses the need for more comprehensive ecological studies across its distribution range.

One source of potential harm from the cultivation of transgenic crops is their dispersal, persistence and spread in non-agricultural land. Ecological damage may result from such spread if the abundance of valued species is reduced. The ability of a plant to spread in non-agricultural habitats is called its invasiveness potential. The risks posed by the invasiveness potential of transgenic crops are assessed by comparing in agronomic field trials the phenotypes of the crops with the phenotypes of genetically similar non-transgenic crops known to have low invasiveness potential. If the transgenic and non-transgenic crops are similar in traits believed to control invasiveness potential, it may be concluded that the transgenic crop has low invasiveness potential and poses negligible ecological risk via persistence and spread in non-agricultural habitats. If the phenotype of the transgenic crop is outside the range of the non-transgenic comparators for the traits controlling invasiveness potential, or if the comparative approach is regarded as inadequate for reasons of risk perception or risk communication, experiments that simulate the dispersal of the crop into non-agricultural habitats may be necessary. We describe such an experiment for several commercial insect-resistant transgenic maize events in conditions similar to those found in maize-growing regions of Mexico. As expected from comparative risk assessments, the transgenic maize was found to behave similarly to non-transgenic maize and to be non-invasive. The value of this experiment in assessing and communicating the negligible ecological risk posed by the low invasiveness potential of insect-resistant transgenic maize in Mexico is discussed.

Background and Aims: Seed banks are critical in arid ecosystems and ensure the persistence of species. Despite the importance of seed banks, knowledge about their formation and the extent to which a seed bank can recover after severe perturbation remains scarce. If undisturbed, soil seed banks reflect a long vegetation history; therefore, we would expect that new soil seed banks and those of undisturbed soils require long periods to become similar with respect to both density and composition. In contrast, if soil seed banks are only a short- to mid-term reservoir in which long-term accumulation constitutes only a tiny fraction, they will recover rapidly from the vegetation. To shed light on this question, we evaluated seed bank formation in a semi-arid gypsum community., Methods: Soils from 300 plots were replaced with sterilized soil in an undisturbed semi-arid Mediterranean community. Seasonal changes in seed bank density and composition were monitored for 3 years by comparing paired sterilized and control soil samples at each plot., Key Results: Differences in seed bank density between sterilized and control soil disappeared after 18 months. The composition of sterilized seed banks was correlated with that of the control plots from the first sampling date, and both were highly correlated with vegetation. Nearly 24 % of the seed bank density could be attributed to secondary dispersal. Most seeds died before emergence (66·41-71·33 %), whereas the rest either emerged (14·08-15·48 %) or persisted in the soil (14·59-18·11 %)., Conclusions: Seed banks can recover very rapidly even under the limiting and stressful conditions of semi-arid environments. This recovery is based mainly on the seed rain at small scales together with secondary dispersal from intact seed banks in the vicinity. These results emphasize the relevance of processes occurring on short spatial scales in determining community structure.

Three-dimensional (3D) vegetation structure influences animal movements and, consequently, ecosystem functions. Animals disperse the seeds of 60%-90% of trees in tropical rainforests, which are among the most structurally complex ecosystems on Earth. Here, we investigated how 3D rainforest structure influences the movements of large, frugivorous birds and resulting spatial patterns of seed dispersal. We GPS-tracked white-thighed (Bycanistes albotibialis) and black-casqued hornbills (Ceratogymna atrata) in a study area surveyed by light detection and ranging (LiDAR) in southern Cameroon. We found that both species preferred areas of greater canopy height and white-thighed hornbill preferred areas of greater vertical complexity. In addition, 33% of the hornbills preferred areas close to canopy gaps, while 16.7% and 27.8% avoided large and small gaps, respectively. White-thighed hornbills avoided swamp habitats, while black-casqued increased their preference for swamps during the hottest temperatures. We mapped spatial probabilities of seed dispersal by hornbills, showing that 3D structural attributes shape this ecological process by influencing hornbill behaviour. These results provide evidence of a possible feedback loop between rainforest vegetation structure and seed dispersal by animals. Interactions between seed dispersers and vegetation structure described here are essential for understanding ecosystem functions in tropical rainforests and critical for predicting how rainforests respond to anthropogenic impacts.

Animals disperse seeds in various ways that affect seed deposition sites and seed survival, ultimately shaping plant species distribution, community composition, and ecosystem structure. Some animal species can disperse seeds through multiple pathways (e.g., defecation, regurgitation, epizoochory), each likely producing distinct seed dispersal outcomes. We studied how seed traits (size and toughness) interact with disperser species to influence seed dispersal pathway and how this ultimately shapes the proportion of seeds deposited in various habitat types. We focused on three frugivorous species of duikers (African forest antelopes) in the Dja Faunal Reserve, a tropical rainforest in southern Cameroon. Duikers can both defecate and regurgitate seeds, the latter predominantly occurring during rumination at their bedding sites (or "nests"). We located duiker nests and dungs along 18 linear 1-km-transects to assess: (1) how seed traits affect the likelihood of dispersal via defecation versus regurgitation, (2) if defecated versus regurgitated seeds are deposited at different rates in different forest types (assessed by indigenous Baka), microhabitats, and forest structural attributes (measured by drone lidar), and (3) if these differ between three duiker species that vary in size and diel activity patterns. We found that duikers predominantly defecated small seeds (10 mm length), the latter including 25 different plant species. The three duiker species varied in their nesting habits, with nocturnal bay duikers (Cephalophus dorsalis) nesting in dense understory vegetation at proportions 3-4 times higher than Peter's and yellow-backed duikers (Cephalophus callipygus and Cephalophus silvicultor). As a result, bay duikers deposited larger regurgitated seeds at a higher rate in habitats with denser understory where lianas and palms predominate and near fallen trees. This directed regurgitation seed deposition likely plays an important and unique role in forest succession and structure. This study highlights the importance of ungulate seed dispersal by regurgitation, a vastly understudied process that could impact many ecosystems given the prevalence of ruminating ungulates worldwide.

Abstract Fruit traits mediate animal-plant interactions and have to a large degree evolved to match the sensory capacities and morphology of their respective dispersers. At the same time, fruit traits are affected by local environmental factors, which may affect frugivore-plant trait match. Temperature has been identified as a major factor with a strong effect on the development of fruits, which is of serious concern because of the rising threat of global warming. Nonetheless, this primarily originates from studies on domesticated cultivars in often controlled environments. Little is known on the effect of rising temperatures on fruit traits of wild species and the implications this could have to seed dispersal networks, including downstream consequences to biodiversity and ecosystem functioning. In a case study of five plant species from eastern Madagascar, we addressed this using the elevation-for-temperature approach and examined whether a temperature gradient is systematically associated with variation in fruit traits relevant for animal foraging and fruit selection. We sampled across a gradient representing a temperature gradient of 1.5–2.6 °C, corresponding to IPCC projections. The results showed that in most cases there was no significant effect of temperature on the traits evaluated, although some species showed different effects, particularly fruit chemical profiles. This suggests that in these species warming within this range alone is not likely to drive substantial changes in dispersal networks. While no systemic effects were found, the results also indicate that the effect of temperature on fruit traits differs across species and may lead to mismatches in specific animal-plant interactions.

Mutualistic interactions are key to biodiversity generation and maintenance, being pollination and seed dispersal interactions essential for plant reproduction. However, anthropogenic habitat disturbance can alter these interactions. We studied the regional and local effects of habitat disturbance on two generalist mutualist animals of southern Chile temperate rainforests: the hummingbird Sephanoides sephaniodes and the marsupial Dromiciops gliroides, which perform key roles as pollinator and seed disperser, respectively. We sampled 12 sites corresponding to four disturbance conditions (mature native forest, secondary forest, native forest under selective logging, and exotic forest plantations) in which we estimated the number of S. sephaniodes and D. gliroides records (as a proxy of relative abundance) using camera traps. We measured seven habitat structure variables at each site, known to influence their occurrence. Specifically, we examined S. sephaniodes and D. gliroides abundance variation at (i) a regional scale (among disturbance conditions) and (ii) at a local scale (among sampling sites). Dromiciops gliroides abundance decreased as disturbance increased, but S. sephaniodes abundance was highly variable. At the local scale, S. sephaniodes and D. gliroides abundances were largely variable among sites, influenced by habitat structural features, such as bamboo and shrub cover and woody debris. Our results show that although habitat disturbance may influence mutualist abundances, they can tolerate disturbance if minimum structure and resource requirements are met, but respond idiosyncratically to local conditions. Examining local-scale variability may provide valuable information on ecological processes, which often goes unnoticed when local sites are considered as replicates in landscape-level studies.

Abstract Phenolic compounds (phenolics) are secondary metabolites ubiquitous across plants. The earliest phenolics are linked to plants' successful transition from an aquatic to a terrestrial environment, serving as protection against damaging ultraviolet (UV) radiation, and as antioxidants to reduce oxidative stress in an atmosphere with an increasingly high O2:CO2 ratio. In modern plants, phenolics are best known for the defense against fungal and bacterial pathogens and as antifeedants that deter herbivory. Phenolics also play a role in seed dormancy, delaying germination, and lengthening viability in the seed bank. Many plants' seeds are endozoochorous – dispersed by animals, like birds, who eat and later excrete the seeds. Plants send visual signals to attract birds with UV‐sensitive (UVS) vision for pollination and seed dispersal. As fruits ripen, antioxidant activity and phenolic content decrease. The waxy cuticle of fruits increases in UV reflection as phenolic rings, which absorb UV light, degrade. The UV contrast that birds detect may act as an honest signal, indicating nutritional changes in the fruit. However, there is little evidence to support the evolution of UV coloration during ripening being driven by frugivore selection. Antioxidant properties of fruit phenolics may be dually adaptive in plants and avian frugivores.

The research relevance of the complex, multi-stage process of natural regeneration of forest communities, as well as interactions and transformations, is determined by the rapidly growing challenges posed by climate change, deforestation and biodiversity loss. The study aims to assess the state and to identify the ecological and coenotic specificity of natural seed regeneration of the leading forest-forming species of the Left-Bank Polissya of Ukraine. The study was carried out using a set of methods, primarily geobotanical, population and mathematical and statistical. The process of natural recovery was studied in communities that are typical for the region and belong to 42 syntaxa in the rank of associations and 24 syntaxa in the rank of association groups. The study revealed the specifics of such forest-forming species as Pinus sylvestris L., Quercus robur L., Acer platanoides L., Betula pendula Roth., Populus tremula L., and Tilia cordata Mill. The study established that the representation of the undergrowth of the main forest-forming species in the forest plant communities of the Left-Bank Polissya of Ukraine varies quite significantly. The study described the determinants of the species composition of restoration, including the peculiarities of seed (fruit) dispersion and the adaptive potential of plants. The study determined that the condition of the understory and its population density are determined by the level of soil moisture (the highest values of understory density in most species were recorded in forests with soils moistened at the level of fresh and wet hygro-tops), and this process may intensify against the background of climate change. The results of the study can be used to develop effective strategies for forest management, biodiversity conservation and sustainable forest management in the Left Bank Polissia region, which will help improve the environmental situation and create favourable conditions for the restoration of forest ecosystems

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Abstract Conspecific adults impose strong negative density‐dependent effects on seed survival nearby parent trees, however, the underlying mechanisms are diversified and remain unclear. In this study, we presented consistent evidence that parent‐scented forest floor masked seed odor, reduced cache recovery rate by scatter‐hoarding animals, and then increased seed dispersal far away from mother trees. Our results showed that seed odors of Korean pine Pinus koraiensis match well with the volatile profile of their forest floor. Moreover, scatter‐hoarding animals selectively transported P. koraiensis seeds toward the areas where seed odor was more contrasting against the background substrate, possibly due to the fact that accumulation of conspecific volatile compounds in caches hindered seed detection by scatter‐hoarding animals. Our study provides insight into the role of leaf litter in directing seed dispersal process, representing a novel mechanism by which P. koraiensis increases selection for seed dispersal far away from the parent tree.

Reductions in natural habitats urge that we better understand species' interconnection and how biological communities respond to environmental changes. However, ecological studies of species' interactions are limited by their geographic and taxonomic focus which can distort our understanding of interaction dynamics. We focus on bird–plant interactions that refer to situations of potential fruit consumption and seed dispersal. We develop an approach for predicting species' interactions that accounts for errors in the recorded interaction networks, addresses the geographic and taxonomic biases of existing studies, is based on latent factors to increase flexibility and borrow information across species, incorporates covariates in a flexible manner to inform the latent factors, and uses a meta-analysis dataset from 85 individual studies. We focus on interactions among 232 birds and 511 plants in the Atlantic Forest, and identify 5% of pairs of species with an unrecorded interaction, but posterior probability that the interaction is possible over 80%. Finally, we develop a permutation-based variable importance procedure for latent factor network models and identify that a bird's body mass and a plant's fruit diameter are important in driving the presence of species interactions, with a multiplicative relationship that exhibits both a thresholding and a matching behavior. for this article are available online. [ABSTRACT FROM AUTHOR]

Natural regeneration in forest management, which relies on artificial planting, is considered a desirable alternative to reforestation. However, there are large uncertainties regarding the natural regeneration processes, such as seed production, seed dispersal, and seedling establishment. Among these processes, seed dispersal by wind must be modeled accurately to minimize the risks of natural regeneration. This study aimed to (1) review the main mechanisms of seed dispersal models, their characteristics, and their applications and (2) suggest prospects for seed dispersal models to increase the predictability of natural regeneration. With improving computing and observation systems, the modeling technique for seed dispersal by wind has continued to progress steadily from a simple empirical model to the Eulerian-Lagrangian model. Mechanistic modeling approaches with a dispersal kernel have been widely used and have attempted to be directly incorporated into spatial models. Despite the rapid development of various wind-dispersal models, only a few studies have considered their application in natural regeneration. We identified the potential attributes of seed dispersal modeling that cause high uncertainties and poor simulation results in natural regeneration scenarios: topography, pre-processing of wind data, and various inherent complexities in seed dispersal processes. We suggest that seed dispersal models can be further improved by incorporating (1) seed abscission mechanisms by wind, (2) spatiotemporally complex wind environments, (3) collisions with the canopy or ground during seed flight, and (4) secondary dispersal, long-distance dispersal, and seed predation. Interdisciplinary research linking climatology, biophysics, and forestry would help improve the prediction of seed dispersal and its impact on natural regeneration.

Animals deliver an important ecosystem service by dispersing plant seeds. Seed dispersers have different effects on the germination success of seeds. This study aimed at examining the effect of seed processing by the patas monkey (Erythrocebus patas) and two flying foxes (Micropteropus pusillus and Epomophorus gambianus) on the germination success of African ebony (Diospyros mespiliformis). Flying foxes and patas monkeys were kept in cages and fed ad libitum with African ebony fruits. Seeds processed were collected, measured, and germinated. Seeds processed by monkeys and flying foxes were compared to control seeds which were removed by hand from fruits. Our results showed that the patas monkey and flying foxes preferably processed smaller seeds. Flying foxes improved the germination success from 6.67 to 72.5%. They also reduced the mean germination time up to 5 days. The patas monkey also improved the germination success from 6.67 to 52.5% and reduced the mean germination time up to 4 days. The effect of flying foxes and the patas monkey on the seed germination and its implication for the African ebony plantation dynamic should be explained to communities for their conservation.

Population connectivity through seed and pollen dispersal determines the genetic diversity, adaptive potential, and demography of plant metapopulations. In wind-pollinated trees, population connectivity is typically maintained by long-distance pollen flow, counteracting the genetic differentiation generated by drift and restricted seed dispersal. Although strong population fragmentation is theoretically expected to disrupt connectivity in forest trees, empirical evidence remains scarce and inconclusive. We investigated contemporary connectivity within a network of small remnant populations of a declining conifer (Taxus baccata L.), which have been hypothesized to be largely isolated from each other. We tested this hypothesis using molecular data for adult trees and naturally recruited seedlings from all known remnants across a fragmented landscape spanning a length of 20 ​km, and a specifically designed statistical approach to quantify contemporary pollen and seed migration rates between populations. We additionally assessed dispersal potential using a spatially explicit parentage analysis to estimate seed and pollen dispersal kernels within one of the remnants. Estimated pairwise migration rates between populations were barely detectable for seeds, while they were larger (up to 1.1%) and significant for pollen. Both seed and pollen migration rates decreased with geographic distance between populations, more steeply in the case of pollen migration. According to parentage-based dispersal kernels, 51.8% of seeds and 11.4% of pollen travel less than 25 ​m, whereas 0.2% of seeds and 36.1% of pollen travel more than 250 ​m from a source tree. In addition, 1.2% of pollen can travel more than 2.5 ​km. We showed that strong present-day population fragmentation, with separation distances over a few kilometers between small fragments, can substantially limit the connectivity of a wind-pollinated declining tree, leading to low pollen-mediated contemporary gene flow and null or virtually null demographic connectivity via seed dispersal.

Abstract Amidst climate change, enhancing plant dispersal pathways is crucial for adapting ecosystems and preserving biodiversity. In our human‐dominated landscapes, urban and rural green spaces, especially gardens, are promising conduits for plant dispersal. Non‐native plants are known to benefit from these spaces, yet the potential benefits for at‐risk native plants remain unclear. Here, I synthesized data on dispersal traits, comparing endangered native plants with non‐endangered and non‐native species in Germany. To make my analysis pertinent to understanding the potential role of gardens in aiding the dispersal of at‐risk native plants, I further contrasted the dispersal ecology of garden‐friendly endangered plants with non‐native plants known to escape gardens. I analysed several traits including seed weight, terminal velocity, dispersal distance, germination rate, dispersal mode, seed structures and seedbank type. Overall, dispersal traits between native and non‐native plants showed minor, but in some cases statistically significant differences. Endangered plants were more often wind‐dispersed and more frequently had seed appendages conducive to a wider range of dispersal vectors. Conversely, non‐native plants leaned more towards non‐assisted local dispersal, heavier seeds and more persistent seed banks. Other traits were largely consistent across groups. This research shows that endangered native plants possess a dispersal ecology similar to non‐native species, which frequently spread from green spaces like gardens. Thus, integrating endangered flora into our green spaces could help to promote an essential aspect of species survival: dispersal.

Wind disperses the pollen and seeds of many plants, but little is known about whether and how it shapes large-scale landscape genetic patterns. We address this question by a synthesis and reanalysis of genetic data from more than 1,900 populations of 97 tree and shrub species around the world, using a newly developed framework for modeling long-term landscape connectivity by wind currents. We show that wind shapes three independent aspects of landscape genetics in plants with wind pollination or seed dispersal: populations linked by stronger winds are more genetically similar, populations linked by directionally imbalanced winds exhibit asymmetric gene flow ratios, and downwind populations have higher genetic diversity. For each of these distinct hypotheses, partial correlations between the respective wind and genetic metrics (controlling for distance and climate) are positive for a significant majority of wind-dispersed or wind-pollinated genetic data sets and increase significantly across functional groups expected to be increasingly influenced by wind. Together, these results indicate that the geography of both wind strength and wind direction play important roles in shaping large-scale genetic patterns across the world's forests. These findings have implications for various aspects of basic plant ecology and evolution, as well as the response of biodiversity to future global change.

Abstract Seed dispersal is one of the most important ecosystem functions globally. It shapes plant populations, enhances forest succession, and has multiple, indirect benefits for humans, yet it is one of the most threatened processes in plant regeneration, worldwide. Seed dispersal distances are determined by the diets, seed retention times and movements of frugivorous animals. Hence, understanding how we can most effectively describe frugivore movement and behaviour with rapidly developing animal tracking technology is key to quantifying seed dispersal. To assess the current use of animal tracking in frugivory studies and to provide a baseline for future studies, we provide a comprehensive review and synthesis on the existing primary literature of global tracking studies that monitor movement of frugivorous animals. Specifically, we identify studies that estimate dispersal distances and how they vary with body mass and environmental traits. We show that over the last two decades there has been a large increase in frugivore tracking studies that determine seed dispersal distances. However, some taxa (e.g. reptiles) and geographic locations (e.g. Africa and Central Asia) are poorly studied. Furthermore, we found that certain morphological and environmental traits can be used to predict seed dispersal distances. We demonstrate that flight ability and increased body mass both significantly increase estimated seed dispersal mean and maximum distances. Our results also suggest that protected areas have a positive effect on mean seed dispersal distances when compared to unprotected areas. We anticipate that this review will act as a reference for future frugivore tracking studies, specifically to target current taxonomic and geographic data gaps, and to further explore how seed dispersal relates to key frugivore and fruit traits.

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.

The Grain-for-Green Program in China is one of the largest payments for ecosystem services programs, and it is regarded as effective for protecting the ecological environment and mitigating disasters. However, research into the effects of revegetation on seed dispersal as an ecosystem service remains limited. Thus, we compared the effects of different types of vegetation restoration (i.e., natural forest (NF), Grain-for-Green forest (GG), and abandoned cropland (AC)) in the Taihang Mountains on the rodent abundance, seed dispersal, and seedling recruitment in Quercus variabilis forest and the pathways involved. The results showed that NF and GG clearly had similar effects on the rodent composition and abundance, but the seed removal rate, seed dispersal distance, and scatter-hoarded proportion were higher under GG than AC, thereby indicating that GG may provide a similar seed dispersal service compared to NF. By contrast, the scatter-hoarding acorn proportions and dispersal distance were significantly lower under AC than NF. Therefore, GG stands could supply an equivalent seed dispersal service to NF, as well as increasing the rodent composition and abundance, and improving the seed dispersal services and capacity for plant movement, thereby contributing to accelerated vegetation restoration at the landscape scale, with significant implications for conserving biodiversity.

Abstract Seed dispersal is a critical phase in plant reproduction and forest regeneration. In many systems, the vast majority of woody species rely on seed dispersal by fruit‐eating animals. Animals differ in their size, movement patterns, seed handling, gut physiology, and many other factors that affect the number of seeds they disperse, the quality of treatment each individual seed receives, and consequently their relative contribution to plant fitness. The seed dispersal effectiveness framework (SDE) was developed to allow systematic and standardized quantification of these processes, offering a potential for understanding the large‐scale dynamics of animal–plant interactions and the ecological and evolutionary consequences of animal behavior for plant reproductive success. Yet, despite its wide acceptance, the SDE framework has primarily been employed descriptively, almost always in the context of local systems. As such, the drivers of variation in SDE across systems and the relationship between its components remain unknown. We systematically searched studies that quantified endozoochorous SDE for multiple animal species dispersing one or more plant species in a given system and offered an integrative examination of the factors driving variation in SDE. Specifically, we addressed three main questions: (a) Is there a tradeoff between high dispersal quality and quantity? (b) Does animal body mass affect SDE or its main components? and (c) What drives more variation in SDE, seed dispersal quality, or quantity? We found that: (a) the relationship between quality and quantity is mediated by body size; (b) this is the result of differential relationships between body mass and the two components, while total SDE is unaffected by body mass; (c)neither quality nor quantity explain more variance in SDE globally. Our results also highlight the need for more standardized data to assess large‐scale patterns in SDE.

Both dispersal- and niche-based factors can impose major barriers on tree establishment. Our understanding of how these factors interact to determine recruitment rates is based primarily on findings from mature tropical forests, despite the fact that a majority of tropical forests are now secondary. Consequently, factors influencing seed limitation and the seed-to-seedling transition (STS) in disturbed landscapes, and how those factors shift during succession, are not well understood. We used a 3.5-yr record of seed rain and seedling establishment to investigate factors influencing tree recruitment after a decade of recovery in a tropical wet forest restoration experiment in southern Costa Rica. We asked (1) how do a range of restoration treatments (natural regeneration, applied nucleation, plantation), canopy cover, and life-history traits influence the STS and (2) how do seed and establishment limitation (lack of seed arrival or lack of seedling recruitment, respectively) influence vegetation recovery within restoration treatments as compared to remnant forest? We did not observe any differences in STS rates across restoration treatments. However, STS rates were lowest in adjacent later successional remnant forests, where seed source availability did not highly limit seed arrival, underscoring that niche-based processes may increasingly limit recruitment as succession unfolds. Additionally, larger-seeded species had consistently higher STS rates across treatments and remnant forests, though establishment limitation for these species was lowest in the remnant forests. Species were generally seed limited and almost all were establishment limited; these patterns were consistent across treatments. However, our results suggest that differences in recruitment rates could be driven by differential dispersal to treatments with higher canopy cover. We found evidence that barriers to recruitment shift during succession, with the influence of seed limitation, mediated by species-level seed deposition rates, giving way to niche-based processes. However, establishment limitation was lowest in the remnant forests for large-seeded and late successional species, highlighting the importance of habitat specialization and life-history traits in dictating recruitment dynamics. Overall, results demonstrate that active restoration approaches such as tree planting catalyze forest recovery, not only by decreasing components of seed limitation, but also by developing canopy cover that increases establishment rates of larger-seeded species.

Determining the spatial patterning of tree species can provide inferences on underlying ecological processes. Gonystylus brunnescens is a South-east Asian subcanopy forest tree. To determine the spatial patterns of this species, we recorded the distribution of all individuals in a 0.4 ha sampling plot in eastern Borneo. We found that the pattern deviated from random and was well-described by the Matérn cluster model; clusters had a radius of approximately 4.2 m and contained an average of six seedlings each. This supports the hypothesis of animal-dispersed seeds and, due to a clear lack of association of juveniles with adults, may be due to scatter-hoarding of seeds by small mammal seed dispersers.

Abstract Background Fleshy fruits evolved to be attractive to seed dispersers through various signals such as color and scent. Signals can evolve through different trajectories and have various degrees of reliability. The strongest substrate on which reliable signals can evolve is when there is an inherent link between signal and reward, rendering cheating costly or impossible. It was recently proposed that aliphatic esters in fruit scent may be predictive of sugar content due to their synthesis from products of sugar fermentation. We test this hypothesis on a case study of wild fig species (Ficus tiliifolia) from Madagascar, which relies on seed dispersal by lemurs. Results We found a strong positive correlation between signal (esters) and reward (sugar). We also found that non-esters, including direct fermentation products, in fruit scent do not indicate sugar levels, which implies that this relationship is not simply a product of fruit maturation wherein more mature fruits emit more scent and contain more sugar. Conclusions While based on a single taxon, these results strongly support the hypothesis that a biochemical link between ester synthesis and sugar may render the ester fraction of fruit scent an honest signal for fruit quality, with consequences for animal sensory and feeding ecology, and the evolution of plants in the context of seed dispersal.

Abstract Carnivorous mammals disperse seeds through endozoochory and diploendozoochory. The former consists of ingestion of the fruit, passage through the digestive tract, and expulsion of the seeds, a process that allows scarification and dispersal of the seeds over long or short distances. The latter is typical of predators that expel seeds that were contained in the prey and the effects of which may differ from those of endozoochory with respect to the retention time of the seeds in the tracts, as well as their scarification and viability. The objective of this study was to conduct an experimental evaluation comparing the capacity of each mammal species in terms of the dispersal of Juniperus deppeana seeds and, at the same time, to compare this capacity through the two dispersal systems: endozoochory and diploendozoochory. We measured dispersal capacity using indices of recovery, viability, changes in testas, and retention time of seeds in the digestive tract. Juniperus deppeana fruits were collected in the Sierra Fría Protected Natural Area in Aguascalientes, Mexico, and were administered in the diet of captive mammals: gray fox (Urocyon cinereoargenteus), coati (Nasua narica) and domestic rabbits (Oryctolagus cuniculus). These three mammals represented the endozoochoric dispersers. For the diploendozoochoric treatment, seeds excreted by rabbits were incorporated into the diets of captive mammals: bobcat (Lynx rufus) and cougar (Puma concolor), in a local zoo. Seeds present in the scats were then collected, and recovery rates and retention times were estimated. Viability was estimated by X‐ray optical densitometry and testa thicknesses were measured and surfaces checked using scanning electron microscopy. The results showed a recovery of seeds greater than 70% in all the animals. The retention time was

The distribution and abundance of plants across the world depends in part on their ability to move, which is commonly characterized by a dispersal kernel. For seeds, the total dispersal kernel (TDK) describes the combined influence of all primary, secondary and higher-order dispersal vectors on the overall dispersal kernel for a plant individual, population, species or community. Understanding the role of each vector within the TDK, and their combined influence on the TDK, is critically important for being able to predict plant responses to a changing biotic or abiotic environment. In addition, fully characterizing the TDK by including all vectors may affect predictions of population spread. Here, we review existing research on the TDK and discuss advances in empirical, conceptual modelling and statistical approaches that will facilitate broader application. The concept is simple, but few examples of well-characterized TDKs exist. We find that significant empirical challenges exist, as many studies do not account for all dispersal vectors (e.g. gravity, higher-order dispersal vectors), inadequately measure or estimate long-distance dispersal resulting from multiple vectors and/or neglect spatial heterogeneity and context dependence. Existing mathematical and conceptual modelling approaches and statistical methods allow fitting individual dispersal kernels and combining them to form a TDK; these will perform best if robust prior information is available. We recommend a modelling cycle to parameterize TDKs, where empirical data inform models, which in turn inform additional data collection. Finally, we recommend that the TDK concept be extended to account for not only where seeds land, but also how that location affects the likelihood of establishing and producing a reproductive adult, i.e. the total effective dispersal kernel.

As the single opportunity for plants to move, seed dispersal has an important impact on plant fitness, species distributions and patterns of biodiversity. However, models that predict dynamics such as risk of extinction, range shifts and biodiversity loss tend to rely on the mean value of parameters and rarely incorporate realistic dispersal mechanisms. By focusing on the mean population value, variation among individuals or variability caused by complex spatial and temporal dynamics is ignored. This calls for increased efforts to understand individual variation in dispersal and integrate it more explicitly into population and community models involving dispersal. However, the sources, magnitude and outcomes of intraspecific variation in dispersal are poorly characterized, limiting our understanding of the role of dispersal in mediating the dynamics of communities and their response to global change. In this manuscript, we synthesize recent research that examines the sources of individual variation in dispersal and emphasize its implications for plant fitness, populations and communities. We argue that this intraspecific variation in seed dispersal does not simply add noise to systems, but, in fact, alters dispersal processes and patterns with consequences for demography, communities, evolution and response to anthropogenic changes. We conclude with recommendations for moving this field of research forward.

Abstract Under habitat fragmentation, plant species' survival hinges on the ability of individuals to disperse from one habitat patch to another. While there is evidence that severe habitat fragmentation leads to evolution of reduced dispersal ability and that such decreased mobility is generally detrimental for species' survival, it is unknown whether species adapt via a gradual loss in dispersal ability or via a sudden shift from frequent to infrequent dispersal between patches (i.e., a critical transition). Using both a spatially explicit deterministic and individual‐based stochastic model of hydrochorous seed dispersal, we show that a small increase in inter‐patch distance can generate an abrupt shift in plant seed dispersal strategy from long to short distances. Most importantly, we found that a substantial increase in connectivity between habitat fragments is required to reverse this loss of long‐distance dispersal, due to an evolutionary hysteresis effect. Our theory prompts for re‐consideration of the eco‐evolutionary consequences of habitat fragmentation as restoring habitat connectivity may require restoration of much higher connectivity levels than currently assumed.

Seed dispersal is a key process in the conservation of coastal wetland vegetation. In this study, we selected a typical plant of the Yellow River Delta, namely, Suaeda salsa, to explore its dispersal process and environmental impact factors. The seed flow of S. salsa gradually increased along the direction from the sea to the inland, and the seed flow in the supratidal zone was significantly greater than that in the intertidal and subtidal zones. Seed germination in the subtidal zone was the smallest, whereas the intertidal zone was the largest. Different tidal zones also had significant effects on seed germination. In addition, by analyzing the relationship among tidal inundation frequency, inundation depth, distance from the tidal channel, elevation, soil water and salinity, and seed flow and germination, the influence of tides was more significant than microtopography as well as soil water and salinity. In coastal wetlands, tides were the key factor affecting seed dispersal. In particular, seed flow and germination decreased with the increase of tidal inundation frequency and depth, but they were inhibited by the strengthening of tides within a certain range. Overall, different tidal zones should be selected for the recovery of different stages of seed dispersal and germination, while also taking tidal characteristics into account.

The Tropical Dry Forest is one of the most threatened ecosystems due to the loss of vegetation cover caused by anthropogenic activities. Understanding how plant-animal interactions occur in this type of ecosystem is particularly important because these interactions promote the maintenance and functioning of the ecosystems. Therefore, the objective of this study was to identify interactions between fruit bats and plants through mutualistic interaction networks in ten tropical dry forest fragments in Valle del Cauca, Colombia. For this purpose, we characterized the bat community, as well as the seeds found in their feces; with the data obtained, the structural properties of the network (nestedness, modularity and robustness) were evaluated. Our results show 36 species and 1142 individuals of bats, where we identified 19 669 seeds grouped in 85 interactions between 18 bat species and 19 plant species. Moreover, the resulting interaction network presented a nestedness, modular structure, robust to the loss of specialist species but susceptible to the loss of generalist species. These results demonstrate the importance of bats for the analysis of plantanimal interactions and highlight them as a key group to be considered in conservation and restoration plans in highly disturbed ecosystems such as the Tropical Dry Forest of Valle del Cauca. [ABSTRACT FROM AUTHOR]

Top-down control by large herbivores is a well-known driver of plant diversity structure and productivity. Yet, for forest ecosystems the sign and magnitude of herbivore control across resource gradients is not well understood. We conducted a series of replicated large herbivore exclusion experiments in defaunated and non-defaunated Atlantic forests of Brazil to evaluate the effects of large herbivores on tropical plant communities. We hypothesized that the top-down impact of large herbivores on seedling recruitment, species richness, diversity and productivity would change across a natural gradient in the density of a key plant resource, the palm Euterpe edulis, which is thought to act as a foundation species. We found both positive (agonistic) and negative (antagonistic) spatially-structured effects of large herbivores on plant communities driven by an interaction between large herbivores and palm density on non-defaunated sites, but not on defaunated sites. Indeed, through its interaction with large herbivores, palm trees were able to regulate the spatial structure of seedling communities. In the non-defaunated forest, the negative impact of large herbivores on plant recruitment and species richness decreased substantially as palms became more abundant and canopy cover decreased. Furthermore, large herbivores caused a 185% increase but a 194% decrease in aboveground seedling productivity in areas of high and low palm density, respectively. In contrast, in the defaunated forest we did not find any consistent large herbivore impacts on plant recruitment or species richness across the gradient of palm density, and herbivore activity consistently had negative effects on seedling productivity. Analyses using camera trap data indicate that white-lipped peccaries (Tayassu peccari) played a key role in modulating recruitment and seedling productivity, while tapirs (Tapirus terrestris) contributed significantly to an increase in plant diversity, hence playing a functionally complementary role. Our results demonstrate that a key interaction between large forest-dwelling tropical herbivores and their palm resource results in landscape-scale modulation of plant communities through positive and negative spatially-structured feedbacks, and support the view that palms might act as foundation species in tropical forests. Anthropogenic pressures posed by defaunation and illegal palm harvesting in the Neotropics might lead to the functional loss of this interaction and the collapse of the spatial structure along palm density gradients, with cascading effects on the dynamics and productivity of tropical forests.

Abstract The Mesopotamian spiny‐tailed lizard, Saara loricata, is one of the largest lizard species in the Middle East. Here, we report on the diet of the lizard and their potential role in seed dispersal in Southwestern Iran. We analyzed lizard fecal pellet groups (n = 124) for their food item composition and seed content. We calculated the relative frequency of occurrence (FO%), relative volume (V%), and importance value (IV%) for each food item. Moreover, the number of seeds of each plant food item was counted. Our findings reveal the first solid evidence of omnivorous behavior in the lizard. In total, 16 plant food items and 14 animal food items were identified. Herbaceous plants (IV = 110.2%) and invertebrates (4.8%) were the most important food groups. The plant food items with the highest FO% were Poaceae (56.4%), Centaurea sp. (43.5%), and Medicago polymorpha (27.4%); and the V% for these items were 53.6%, 30.9%, and 13.1%, respectively. Most of the seeds that were consumed by lizards were from Poaceae (547 seeds; 47.81%) and Fabaceae (285 seeds; 24.91%). We also found that each individual lizard could play an equal role in the seed dispersal of all plant families identified. Previous studies show that plant species density and richness are important features for the burrow site selection of Mesopotamian spiny‐tailed lizard. This study highlights the potential role of lizards in influencing the vegetation communities around their burrows through seed dispersal.

Bird-mediated seed dispersal enhances invasions of many alien plant species. Typically, this mutualism is composed of a generalist assemblage of frugivorous birds in which morphological trait matching between bird and plant species is often thought to be poor due to low reciprocal adaptation. Despite this longheld notion, trait matching between local birds and alien plants has not been investigated. Here, we assessed trait matching by comparing functional traits in multidimensional space for local birds (bill, wing and tarsus size) and two alien invasive plants (fruit and seed size, fruit and seed shape) in an urban area. To do this, we measured bird functional traits in museum specimens and plant functional traits in individuals located in the study area. We found significant trait matching between birds and alien invasive plants (i.e., frugivorous birds interacted with morphologically corresponding invasive plant species). In addition, we detected a positive correlation between morphological and functional specialization of bird species so that extreme morphologies played specialized functional roles. Contrary to the idea that alien plant mutualisms are mediated by generalized seed dispersers without a close match between bird and alien plant traits, our results indicate that species with different morphologies forage on distinct plant species. These findings highlight the importance of studying the functional role of local birds in mutualistic interactions with alien invasive plants, and how these functional roles may promote invasion processes.

For tens of thousands of years, passenger pigeons (Ectopistes migratorius) were a dominant member of eastern North American forest communities, with megaflocks comprising up to several billion individuals. The extinction of passenger pigeons in the early twentieth century undoubtedly influenced associated species and ecosystems as interactions stemming from the pigeons disappeared suddenly. Here, we strive to better understand what was probably one of the most significant of these interactions-that between passenger pigeons and seed bearing trees. Using the band-tailed pigeon (Patagioenas fasciata) and the rock dove (Columba livia) as physical and ecological proxies, we evaluated passenger pigeon dietary range and potential to disperse seeds. Our findings suggest that the passenger pigeon's dietary range, observed historically to be taxonomically broad, was constrained to certain seed sizes due to bill gape size. In addition, we conclude that the digestive process invariably destroyed consumed seeds but the potential for a nutrition/dispersal mutualism might still have existed via regurgitation and post-mortem release of crop contents. Our results highlight the range of ecological interactions that can be lost with species' extinction and the inherent challenge of understanding the consequences of those interactions.

Abstract Although many plants are dispersed by wind and seeds can travel long distances across unsuitable matrix areas, a large proportion relies on co‐evolved zoochorous seed dispersal to connect populations in isolated habitat islands. Particularly in agricultural landscapes, where remaining habitat patches are often very small and highly isolated, mobile linkers as zoochorous seed dispersers are critical for the population dynamics of numerous plant species. However, knowledge about the quali‐ or quantification of such mobile link processes, especially in agricultural landscapes, is still limited. In a controlled feeding experiment, we recorded the seed intake and germination success after complete digestion by the European brown hare (Lepus europaeus) and explored its mobile link potential as an endozoochoric seed disperser. Utilizing a suite of common, rare, and potentially invasive plant species, we disentangled the effects of seed morphological traits on germination success while controlling for phylogenetic relatedness. Further, we measured the landscape connectivity via hares in two contrasting agricultural landscapes (simple: few natural and semi‐natural structures, large fields; complex: high amount of natural and semi‐natural structures, small fields) using GPS‐based movement data. With 34,710 seeds of 44 plant species fed, one of 200 seeds (0.51%) with seedlings of 33 species germinated from feces. Germination after complete digestion was positively related to denser seeds with comparatively small surface area and a relatively slender and elongated shape, suggesting that, for hares, the most critical seed characteristics for successful endozoochorous seed dispersal minimize exposure of the seed to the stomach and the associated digestive system. Furthermore, we could show that a hare's retention time is long enough to interconnect different habitats, especially grasslands and fields. Thus, besides other seed dispersal mechanisms, this most likely allows hares to act as effective mobile linkers contributing to ecosystem stability in times of agricultural intensification, not only in complex but also in simple landscapes.