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393 results for “seed dispersal”
Data from: Seed ingestion and germination in rattlesnakes: overlooked agents of rescue and secondary dispersal
Seed dispersal is a key evolutionary process and a central theme in the population ecology of terrestrial plants. The primary producers of most land-based ecosystems are propagated by and maintained through various mechanisms of seed dispersal that involve both abiotic and biotic modes of transportation. By far the most common biotic seed transport mechanism is zoochory, whereby seeds, or fruits containing them, are dispersed through the activities of animals. Rodents are one group of mammals that commonly prey on seeds (granivores) and play a critical, often destructive, role in primary dispersal and the dynamics of plant communities. In North America, geomyid, heteromyid and some sciurid rodents have specialized cheek pouches for transporting seeds from plant source to larder, where they are often eliminated from the pool of plant propagules by consumption. These seed-laden rodents are commonly consumed by snakes as they forage, but unlike raptors, coyotes, bobcats, and other endothermic predators which eat rodents and are known or implicated to be secondary seed dispersers, the role of snakes in seed dispersal remains unexplored. Here, using museum-preserved specimens, we show that in nature three desert-dwelling rattlesnake species consumed heteromyids with seeds in their cheek pouches. By examining the entire gut we discovered, furthermore, that secondarily ingested seeds can germinate in rattlesnake colons. In terms of secondary dispersal, rattlesnakes are best described as diplochorous. Because seed rescue and secondary dispersal in snakes has yet to be investigated, and because numerous other snake species consume granivorous and frugivorous birds and mammals, our observations offer direction for further empirical studies of this unusual but potentially important channel for seed dispersal.
Data from: Intraspecific variation in seed dispersal of a Neotropical tree and its relationship to fruit and tree traits
The distribution of wind-dispersed seeds around a parent tree depends on diaspore and tree traits, as well as wind conditions and surrounding vegetation. This study of a neotropical canopy tree, Platypodium elegans, explored the extent to which parental variation in diaspore and tree traits explained (1) rate of diaspore descent in still air, (2) distributions of diaspores dispersed from a 40-m tower in the forest, and (3) natural diaspore distributions around the parent tree. The geometric mean rate of descent in still air among 20 parents was highly correlated with geometric mean wing loading1/2 (r = 0.84). However, diaspore traits and rate of descent predicted less variation in dispersal distance from the tower, although descent rate−1 consistently correlated with dispersal distance. Measured seed shadows, particularly their distribution edges, differed significantly among six parents (DBH range 62–181 cm) and were best fit by six separate anisotropic dispersal kernels and surveyed fecundities. Measured rate of descent and tree traits, combined in a mechanistic seed dispersal model, did not significantly explain variation among parents in natural seed dispersal distances, perhaps due to the limited power to detect effects with only six trees. Seedling and sapling distributions were at a greater mean distance from the parents than seed distributions; saplings were heavily concentrated at far distances. Variation among parents in the distribution tails so critical for recruitment could not be explained by measured diaspore or tree traits with this sample size, and may be determined more by wind patterns and the timing of abscission in relation to wind conditions. Studies of wind dispersal need to devote greater field efforts at recording the "rare" dispersal events that contribute to far dispersal distances, following their consequences, and in understanding the mechanisms that generate them.
Data from: Seeds in motion: genetic assignment and hydrodynamic models demonstrate concordant patterns of seagrass dispersal
Movement is fundamental to the ecology and evolutionary dynamics within species. Understanding movement through seed dispersal in the marine environment can be difficult due to the high spatial and temporal variability of ocean currents. We employed a mutually enriching approach of population genetic assignment procedures and dispersal predictions from a hydrodynamic model to overcome this difficulty and quantify the movement of dispersing floating fruit of the temperate seagrass Posidonia australis Hook.f. across coastal waters in southwestern Australia. Dispersing fruit cohorts were collected from the water surface over two consecutive years and seeds were genotyped using microsatellite DNA markers. Likelihood-based genetic assignment tests were used to infer the meadow of origin for seed cohorts and individuals. A three-dimensional hydrodynamic model was coupled with a particle transport model to simulate the movement of fruit at the water surface. Floating fruit cohorts were mainly assigned genetically to the nearest meadow, but significant genetic differentiation between cohort and most-likely meadow of origin suggested a mixed origin. This was confirmed by genetic assignment of individual seeds from the same cohort to multiple meadows. The hydrodynamic model predicted 60% of fruit dispersed within 20 km, but that fruit were physically capable of dispersing beyond the study region. Concordance between these two independent measures of dispersal provide insight into the role of physical transport for long distance dispersal (LDD) of fruit and the consequences for spatial genetic structuring of seagrass meadows.
Data from: Seed dispersal anachronisms: rethinking the fruits extinct megafauna ate
BACKGROUND: Some neotropical, fleshy-fruited plants have fruits structurally similar to paleotropical fruits dispersed by megafauna (mammals >103 kg), yet these dispersers were extinct in South America 10–15 Kyr BP. Anachronic dispersal systems are best explained by interactions with extinct animals and show impaired dispersal resulting in altered seed dispersal dynamics. METHODOLOGY/PRINCIPAL FINDINGS: We introduce an operational definition of megafaunal fruits and perform a comparative analysis of 103 Neotropical fruit species fitting this dispersal mode. We define two megafaunal fruit types based on previous analyses of elephant fruits: fruits 4–10 cm in diameter with up to five large seeds, and fruits >10 cm diameter with numerous small seeds. Megafaunal fruits are well represented in unrelated families such as Sapotaceae, Fabaceae, Solanaceae, Apocynaceae, Malvaceae, Caryocaraceae, and Arecaceae and combine an overbuilt design (large fruit mass and size) with either a single or few (<3 seeds) extremely large seeds or many small seeds (usually >100 seeds). Within-family and within-genus contrasts between megafaunal and non-megafaunal groups of species indicate a marked difference in fruit diameter and fruit mass but less so for individual seed mass, with a significant trend for megafaunal fruits to have larger seeds and seediness. CONCLUSIONS/SIGNIFICANCE: Megafaunal fruits allow plants to circumvent the trade-off between seed size and dispersal by relying on frugivores able to disperse enormous seed loads over long-distances. Present-day seed dispersal by scatter-hoarding rodents, introduced livestock, runoff, flooding, gravity, and human-mediated dispersal allowed survival of megafauna-dependent fruit species after extinction of the major seed dispersers. Megafauna extinction had several potential consequences, such as a scale shift reducing the seed dispersal distances, increasingly clumped spatial patterns, reduced geographic ranges and limited genetic variation and increased among-population structuring. These effects could be extended to other plant species dispersed by large vertebrates in present-day, defaunated communities.
Data from: Large frugivores matter: insights from network and seed dispersal effectiveness approaches
1.While large avian frugivores are known to be key dispersers for large‐seeded tree species, their role in community‐wide plant‐disperser networks is still poorly known. Large avian frugivores are also among the most threatened due to anthropogenic impacts. 2.We evaluated the role of large avian frugivores in a plant‐disperser community by a) determining whether the plant‐disperser community was modular, with a distinct community of large frugivores (thereby highlighting their importance), b) determining relative qualitative and quantitative roles played by large‐bodied frugivores vis‐à‐vis other frugivores and c) determining impacts of large‐bodied frugivore loss on the plant‐disperser community. 3.The study was carried at a tropical forest site in north‐east India which is part of the Eastern Himalaya Biodiversity Hotspot. We collected tree watch data (2055 h) from 46 tree species, which represented 85% of tree species that are predominantly bird‐dispersed in the area. 4.We found that the plant‐disperser community was modular, with a distinct module of large‐seeded tree species and large frugivores. Intermediate‐sized frugivores such as barbets and bulbuls were the most connected, while large‐sized frugivores, such as hornbills and imperial‐pigeons were moderately well‐connected. Qualitative and quantitative roles played by different dispersers varied across the gradient of frugivore body size. Hornbills, the largest avian frugivores, consumed a significantly greater number of fruits and swallowed larger proportions of fruits compared to other avian groups. In comparison to similar‐sized frugivores, imperial‐pigeons fed on larger‐sized fruits, highlighting their importance for dispersal of large‐seeded plants. Under simulated extinction scenarios, larger extinction cascades weren't necessarily caused by larger frugivores, however, extinctions of certain large‐bodied frugivores (hornbills, imperial‐pigeons) caused extinction cascades. 5.Integrating information from networks and seed dispersal effectiveness approaches enabled a better understanding of large frugivore role in a plant‐disperser community. While large‐bodied frugivores may not be playing a central role in plant‐disperser communities, they are crucial as seed dispersal service providers for large‐seeded plants. In conjunction with the reported local extinctions of large frugivores like hornbills from the south Asian region, this study's findings highlight the irreplaceable quantitative and qualitative impacts that tropical plant communities are likely to experience in the future.
Data from: Forest disturbance and seasonal food availability influence a conditional seed dispersal mutualism
The interaction between granivorous scatter-hoarding mammals and plants is a conditional mutualism: scatter-hoarders consume seeds (acting as predators), but the movement of seed by scatter-hoarders may contribute to dispersal (acting as mutualists). Understanding the ecological factors that shape this relationship is highly relevant in anthropogenically disturbed tropical forests where large-bodied frugivores are extirpated. In such forests, large-seeded trees that once depended on these frugivores for dispersal may now only have scatter-hoarders as prospective dispersers. We studied Carapa oreophila (Meliaceae) in an Afromontane forest, to test the hypotheses that the proportion of seeds immediately consumed or hoarded (dispersed) would vary over a disturbance gradient. Temporal replication also afforded exploration of how habitat effects might vary with food availability. Using a Bayesian framework, we demonstrate that seeds were more likely to be hoarded in less disturbed forest, irrespective of temporal variation in food abundance. In contrast, forest disturbance only appeared to increase seed predation in temporal replicates that coincided with sustained food availability. These results highlight the potential variability in the dynamics between plants and scatter-hoarders over fine temporal scales, elucidating possible ecological scenarios where scatter-hoarders might act as mutualists (contributing positively to plant recruitment). Our study also fills important knowledge gaps about the importance of scatter-hoarders as dispersers in tropical forests depleted of large-bodied frugivores, particularly in Africa where scatter-hoarding mutualisms have not been extensively studied.
Importance of intraspecific variation in the pollination and seed dispersal functions of a double mutualist animal species
Although most plants depend on different animals for pollination and seed dispersal, sometimes the same animal species provides both functions, being thus involved in what has been termed a 'double mutualism'. Very little is known on the effectiveness of such species as both pollinators and seed dispersers, and even less on the intraspecific level differences at the contribution of an animal mutualist to plant fitness. In this study, we focused on the interaction between a Mediterranean shrub <i>Cneorum tricoccon</i> L. (Rutaceae) and the Balearic lizard <i>Podarcis lilfordi</i> L. (Lacertidae) in order to assess: (1) the role of this lizard as a legitimate pollinator of the plant (previously thought to be exclusively insect-pollinated), and (2) the intraspecific variation in the use of flowers and fruits by lizard individuals, comparing males, females and juveniles. We further evaluated whether lizards show different fruit size selection depending on sex and age, with potential consequences for seed germination. Lizards visited more flowers and selected more hermaphrodite flowers than insects did, leading to relative increases in both fruit and seed set. Interestingly, female and juvenile lizards were the main flower visitors, whereas males were the main fruit consumers. Males selected the largest fruits (bearing the largest seeds) though this did not increase seed germination, which was only ca. 15%. We concluded that <i>P. lilfordi</i> acts as a legitimate pollinator of <i>C. tricoccon</i> and, thus, confirm that this system constitutes a new case of double mutualism, especially common in island compared to mainland systems. Moreover, our findings show a large variation among conspecific individuals in their role as either pollinators or seed dispersers, with potential implications for plant reproductive success. Our study, therefore, highlights the importance of evaluating plant-animal interactions at the intraspecific level, and calls for more in-depth studies on the consequences of such intraspecific variation.
Data from: Context-dependent seed dispersal by a scatter-hoarding corvid
1. Corvids (crows, jays, magpies and nutcrackers) are important dispersers of large-seeded plants. Studies on captive or supplemented birds suggest that they flexibly adjust their scatter-hoarding behaviour to the context of social dynamics and relative seed availability. Because many corvid-dispersed trees show high annual variation in seed production, context-dependent foraging can have strong effects on natural corvid scatter-hoarding behaviour. 2. We investigated how seed availability and social dynamics affected scatter-hoarding in the island scrub jays (Aphelocoma insularis). We quantified rates of scatter-hoarding behaviour and territorial defence of 26 colour-marked birds over a three-year period with variable acorn crops. 3. We tested whether caching parameters were correlated with variation in annual seed production of oaks as predicted by the predator dispersal hypothesis, which states that caching rates and distances should vary with seed abundance in ways that benefit tree fitness. We also tested whether antagonistic interactions with conspecifics would affect scatter-hoarding adversely, as found in experimental studies. 4. Caching behaviour varied with acorn availability. Caching distances correlated positively with annual acorn crop size, increasing by as much as 40% between years. Caching rates declined over time in years with small acorn crops, but increased when crops were large. Acorn foraging and caching rates were also negatively correlated with rates of territorial aggression. Overall foraging rates, however, were not associated with aggression, suggesting that reduced dispersal rates were not simply due to time constraints. 5. Our field results support laboratory findings that caching rates and distances by scatter-hoarding corvids are context-dependent. Furthermore, our results are consistent with predictions of the predator dispersal hypothesis and suggest that large seed crops and social interactions among scatter-hoarders affect dispersal benefits for oaks and other masting tree species.
Data from: Integrating plant species contribution to mycorrhizal and seed dispersal mutualistic networks
Mutualistic interactions like those established between plants and mycorrhizal fungi or seed dispersers are key drivers of plant population dynamics and ecosystem functioning, however, these interactions have rarely been explored together. We assembled a tripartite fungi-plant-disperser network in the Gorongosa National Park - Mozambique, to test 1) if the diversity and importance of plant mutualists above- and belowground are correlated, and 2) whether biotically and abiotically dispersed plants are associated with similar or distinct arbuscular mycorrhizal fungi (AMF) communities. We quantified seed dispersal by animals during one year and characterized the community of 26 common plant species. Sixteen plant species were dispersed by 15 animals and colonized by 48 AMF virtual taxa (VT), while the remaining ten plant species were not dispersed by animals and associated with 34 AMF VT. We found no evidence for a correlation between the number of plant partners above- and belowground or on plant specialization on both types of partners. We also found no evidence for differentiation of AMF communities between biotically and abiotically dispersed plants. Altogether, these results suggest that the establishment of plant interactions with seed dispersers and mycorrhizal fungi are largely independent and that both biotically and abiotically dispersed plants seem to associate with similar communities of AM fungi.
Data from: Are gastropods, rather than ants, important dispersers of seeds of myrmecochorous forest herbs?
Seed dispersal by ants (myrmecochory) is widespread and seed adaptations to myrmecochory are common, especially in the form of fatty appendices (elaiosomes). In a recent study, slugs were identified as seed dispersers of myrmecochores in a Central European beech forest. Here we used 105 beech forest sites to test whether myrmecochore presence and abundance is related to ant or to gastropod abundance and whether experimentally exposed seeds are removed by gastropods. Myrmecochorous plant cover was positively related to gastropod abundance, but negatively to ant abundance. Gastropods were responsible for most seed removal and elaiosome damage, while insects (and rodents) played minor roles. These gastropod effects on seeds were independent of region or forest management. We suggest that terrestrial gastropods can generally act as seed dispersers of myrmecochorous plants or even substitute myrmecochory, especially where ants are absent or uncommon.
Data from: Toucans (Ramphastos ambiguus) facilitate resilience against seed dispersal limitation to a large-seeded tree (Virola surinamensis) in a human-modified landscape
Large-seeded plants may suffer seed dispersal limitation in human-modified landscapes if seed dispersers are absent or unable to disperse their seeds. We investigated dispersal limitation for the large-seeded tree Virola surinamensis in a human-modified landscape in southern Costa Rica. During two fruiting seasons, we monitored crop size, seed removal rates, the number of fruiting conspecifics within 100 m, and feeding visitation rates by frugivores at trees located in high and low forest disturbance conditions. Seed removal rates and the total number of seeds removed were high regardless of the disturbance level, but these parameters increased with tree crop size and decreased with the number of fruiting V. surinamensis trees within a 100 m radius. Trees at low disturbance levels were more likely to be visited by seed dispersers. Black mandibled toucans (Ramphastos ambiguus) and spider monkeys (Ateles geoffroyi) were the most important seed dispersers, based on visitation patterns and seed removal rates. Spider monkey feeding visits were more frequent at high disturbance levels, but the monkeys preferentially visited isolated trees with large yields and surrounded by a low number of fruiting Virola trees within 100 m. Toucan visitation patterns were not constrained by any of the predictors and they visited trees equally across the landscape. We suggest that isolated and highly fecund Virola trees are an important food resource for spider monkeys in human-modified landscapes and that toucans can provide resilience against seed dispersal limitations for large-seeded plants in human-modified landscapes in the absence of hunting.
Data from: Early genetic consequences of defaunation in a large-seeded vertebrate-dispersed palm (Syagrus romanzoffiana)
Plant populations are seriously threatened by anthropogenic habitat disturbance. In particular, defaunation may disrupt plant-disperser mutualisms, thus reducing levels of seed-mediated gene flow and genetic variation in animal-dispersed plants. This may ultimately limit their adaptive potential and ability to cope with environmental change. Tropical forest remnants are typically deprived of medium to large vertebrates upon which many large-seeded plants rely for accomplishing effective seed dispersal. Our main goal was to examine the potential early genetic consequences of the loss of large vertebrates for large-seeded vertebrate-dispersed plants. We compared the genetic variation in early-stage individuals of the large-seeded palm Syagrus romanzoffiana between continuous protected forest and nearby partially defaunated fragments in the Atlantic Forest of South America. Using nine microsatellites, we found lower allelic richness and stronger fine-scale spatial genetic structure in the disturbed area. In addition, the percentage of dispersed recruits around conspecific adults was lower, although not significantly, in the disturbed area (median values: 0.0 vs 14.4%). On the other hand, no evidence of increased inbreeding or reduced pollen-mediated gene flow (selfing rate and diversity of pollen donors) was found in the disturbed area. Our findings are strongly suggestive of some early genetic consequences resulting from the limitation in contemporary gene flow via seeds, but not pollen, in defaunated areas. Plant-disperser mutualisms involving medium–large frugivores, which are seriously threatened in tropical systems, should therefore be protected to warrant the maintenance of seed-mediated gene flow and genetic diversity in large-seeded plants.
Data from: Fishing-down within populations harms seed dispersal mutualism
Large fish are often the most effective seed dispersers, but they are also the preferred target for fisheries. We recently started to comprehend the detrimental impacts of the extirpation of large frugivorous fish species on natural forest regeneration, but we lack a general understanding of how intraspecific size-selective harvest affects fish–fruit mutualism. Our literature review demonstrated that large individuals within populations positively affect diverse aspects of seed dispersal, from consuming a higher diversity of seeds to enhancing germination. Furthermore, we filled a research gap by studying how individual size variations within two small frugivorous fish species (<16 cm) affect seed dispersal in flooded savannas. Even within small-bodied species, large individuals swallow a higher number of intact seeds, but not necessarily a higher proportion. Overall, our results demonstrate the disproportional role of large-bodied individuals as key seed dispersers in flooded habitats. Consequently, fishing-down within both large- and small-bodied species can negatively affect seed dispersal and natural regeneration in overfished wetlands.
How far do Asian hornbills disperse seeds?
<p>Biotic seed dispersal of plants is a complex phenomenon that is influenced by multiple seed disperser species with implications for plant fitness and range expansions. While inter-species variation has been well-studied, the importance of incorporating intraspecific variation in seed dispersal is increasingly being acknowledged. We compared seed dispersal patterns of breeding and non-breeding great hornbills <i>Buceros bicornis</i> and a breeding wreathed hornbill <i>Rhyticeros undulatus</i> by combining data on fruiting tree visitations, gut passage time and movement data from tagged hornbills. Seed dispersal probability at nest trees (by breeding males) was low (< 12%) suggesting that males scatter-disperse seeds, unlike breeding females that deposit seeds below nest trees. Median seed dispersal distance of great hornbills was 294 m and 254 m in the breeding and non-breeding season respectively, and, the distribution tail was shorter for breeding birds (2.5 km) than non-breeding birds (13 km). The median and maximum seed dispersal distance by the wreathed hornbill was 1.35 km and 11 km respectively. This study highlights intraspecific variation in seed dispersal patterns across sexes and breeding and non-breeding male hornbills and potential variation between two hornbill species. This is the first study that estimates long-distance seed dispersal by Asian hornbills. </p>
Data from: Chemical tradeoffs in seed dispersal: Defensive metabolites in fruits deter consumption by mutualist bats
Although fleshy fruits function primarily to attract seed dispersers, many animal-dispersed fruits contain potentially toxic secondary metabolites. These metabolites can provide defense against seed predators and pathogens, but their effects on dispersers are still poorly understood. In some cases plants may experience a tradeoff, where the metabolites that provide fruit defense also reduce seed disperser preferences. In other cases the bioactivity of fruit secondary metabolites may be directed primarily at pests with no negative effects on seed-dispersing vertebrates. We tested the effects of amides, a group of nitrogen-based defensive compounds common in the plant genus Piper (Piperaceae), in interactions with the primary seed dispersers of Piper in the neotropics – fruit-feeding bats in the genus Carollia (Phyllostomidae). In a series of flight cage experiments, pure amides and amide-rich fruit extracts reduced the preferences of bats for Piper fruit, affecting both the bats' initial choices to remove Piper infructescences and the proportion of fruit consumed from individual infructescences once they were removed. However, the effects of amides varied considerably among three species of Carollia and among the specific individual amides and extracts tested. Overall, our results support the hypothesis that plants experience a tradeoff between seed dispersal and fruit defense, but the strength of this tradeoff and the overall fitness consequences may depend strongly on ecological context.
Data from: Seed dispersers help plants to escape global warming
Plants are shifting their ranges towards higher elevations in response to global warming, yet such shifts are occurring at a rate slower than is needed to keep pace with a rapidly changing climate. There is, however, an almost complete lack of knowledge on seed dispersal across altitude, a key process to understand what constrains climate-driven range shifts. Here, we report the first direct empirical evidence on altitudinal seed dispersal mediated by two common frugivorous mammals: the red fox Vulpes vulpes and the pine marten Martes martes. We conducted a three-year (bait-marking) experiment in a mountainous region of Spain. We offered experimental fruits containing colour-coded seed mimics at feeding stations that simulated source trees. The colour codes allowed us to identify the exact origin of seed mimics found later in mammal scats. Nearly half (47%) of the dispersal events occurred towards higher elevations, despite only ca 25% of the study area being above the average altitude of the feeding stations (1344 m). Seeds dispersed uphill gained an average of 106 m (median = 111 m) and a maximum of 288 m, greatly exceeding the estimated requirements to escape warming (35.4 m per decade). Yet, foxes mediated much more uphill seed dispersal than martens (57% and 26% of dispersal events, respectively), which can be explained by between-disperser differences in home range size and habitat specificity. Dispersers with larger home ranges move farther and potentially disperse more seeds to higher altitudes, while habitat generalism is necessary to transport seeds above vegetation belts delimiting contrasting habitat types. We discuss how both traits (home range size and habitat specificity) can be used to infer altitudinal seed dispersal across disperser species and mountainous landscapes.
Data from: Seed dispersal by ungulates as an ecological filter: a trait-based meta-analysis
Plant communities are often dispersal-limited and zoochory can be an efficient mechanism for plants to colonize new patches of potentially suitable habitat. We predicted that seed dispersal by ungulates acts as an ecological filter – which differentially affects individuals according to their characteristics and shapes species assemblages – and that the filter varies according to the dispersal mechanism (endozoochory, fur-epizoochory and hoof-epizoochory). We conducted two-step individual participant data meta-analyses of 52 studies on plant dispersal by ungulates in fragmented landscapes, comparing eight plant traits and two habitat indicators between dispersed and non-dispersed plants. We found that ungulates dispersed at least 44% of the available plant species. Moreover, some plant traits and habitat indicators increased the likelihood for plant of being dispersed. Persistent or nitrophilous plant species from open habitats or bearing dry or elongated diaspores were more likely to be dispersed by ungulates, whatever the dispersal mechanism. In addition, endozoochory was more likely for diaspores bearing elongated appendages whereas epizoochory was more likely for diaspores released relatively high in vegetation. Hoof-epizoochory was more likely for light diaspores without hooked appendages. Fur-epizoochory was more likely for diaspores with appendages, particularly elongated or hooked ones. We thus observed a gradient of filtering effect among the three dispersal mechanisms. Endozoochory had an effect of rather weak intensity (impacting six plant characteristics with variations between ungulate-dispersed and non-dispersed plant species mostly below 25%), whereas hoof-epizoochory had a stronger effect (eight characteristics included five ones with above 75% variation), and fur-epizoochory an even stronger one (nine characteristics included six ones with above 75% variation). Our results demonstrate that seed dispersal by ungulates is an ecological filter whose intensity varies according to the dispersal mechanism considered. Ungulates can thus play a key role in plant community dynamics and have implications for plant spatial distribution patterns at multiple scales.
Data from: seed dispersal by frugivores without seed swallowing: evaluating the contributions of stomatochoric seed dispersers
<p>The process of seed dispersal that underpins ecosystem maintenance is performed by diverse arrays of fruit-eating animals. However, seed dispersal studies are primarily focused on a subset of these animal communities that disperse seeds by endozoochory. Stomatochory (seed dispersal in which seeds are carried externally and are not swallowed) is rarely considered to be effective, despite an increasing number of taxa-focused studies that indicate otherwise.</p> <p>We collated the available information on stomatochory to provide a quantitative overview of the dispersal mechanism, including plant-types and fruit-traits dispersed, dispersal distances and germination potential for all available taxa. We compared seed sizes dispersed, dispersal distances, and germination potential with corresponding data on endozoochory for bats and primates. We also identified the main taxa dispersing seeds by stomatochory and assessed what factors influenced the distances that they carried seeds to.</p> <p>Stomatochoric dispersers can displace large quantities of seeds, including large seeds and those of large fruits, and over short to long distances (> 1 km). Compared to similar-sized endozoochoric dispersers, they can disperse larger seeds, but over shorter distances, on average. Similar to endozoochory, seed handling by stomatochory also improves the germination potential of dispersed seeds. Dispersal distances achieved by stomatochory were influenced by body mass, daily path length, seed width, fruit type and seed handling techniques.</p> <p>Five main taxonomic groups of stomatochoric dispersers were identified: bats, parrots, squirrels, corvids and Old World monkeys (cercopithecines). Parrots perform dispersal services for the largest fruits and over the longest distances. However, given the lack of research on stomatochory, it is likely other taxa are also important stomatochoric dispersers but have not been identified yet.</p> <p>More research attention must be directed towards seed dispersal services that are not provided by endozoochory. Many stomatochoric dispersers are common animals within communities and could be playing dominant seed dispersal roles, even without swallowing seeds. Community-wide studies should incorporate all seed dispersal interactions, rather than focusing solely on endozoochory. This will ensure a more robust understanding of community-wide patterns.</p>
Persistence of seed dispersal in agroecosystems: effects of landscape modification and intensive soil management practices in avian frugivores, frugivory and seed deposition in olive croplands
<p>Farming impacts on animal-mediated seed dispersal through mechanisms operating at least at two spatial scales: first, at the landscape scale, through habitat loss and land conversion to agriculture/livestock grazing, and second, by local intensification (farm scale) of the agricultural practices. Nonetheless, these two scales of farming impact on the seed dispersal function have been rarely integrated. In particular, studies evaluating the effect of agriculture in the seed dispersal function of frugivorous birds in Mediterranean ecosystems are lacking. We evaluate the role of the landscape transformation, from fruit-rich woodland habitats to olive grove landscapes, together with the local intensive practices of soil management on the persistence of the seed dispersal function for Mediterranean fleshy-fruited plants in olive landscapes of south Spain.</p> <p>We used bird censuses, mist-nets and seed traps to characterize avian frugivore assemblages, frugivory, and seed deposition in seminatural woodland habitat (SNWH) patches and olive fields of 40 olives farms of 20 localities distributed across the whole range of olive cultivation in Andalusia (southern Spain).</p> <p>We found that despite of a still remarkable dispersal function in olive grove landscapes, avian frugivore abundance and diversity, frugivory, and seed arrival decreased in olive fields compared to SNWH patches. Likewise, SNWH cover loss and/or olive growing expansion decreased avian frugivory and seed arrival. Interestingly, habitat effects in the olive farms often depended on the landscape context. In particular, less diverse fruit-eating bird assemblages pooled in SNWH patches as olive grove cover increased or SNWH decreased in the landscape, while remained relatively invariant in the olive fields. Finally, compared to conventional intensive agriculture, low-intensity management increased frugivory and seed deposition.</p> <p>We conclude that olive fields are less permeable to frugivores than expected by its agroforest-like nature, and that presence of SNWH patches is crucial for the maintenance of frugivory and seed dispersal in agricultural landscapes. Results evidence that woodland habitat loss by olive expansion and the intensive practices seriously threaten the dispersal service in olive-dominated landscapes. Maintenance, restoration and promotion of woodland patches should be prioritized for the conservation of the seed dispersal service and for enhancing the functional connectivity in human-shaped olive landscapes.</p>
Distribution of 8 species of large-seeded pines and their primary animal seed-dispersers in China: match or mismatch?
<p class="1"><span><b>Aim: </b>The geographic distribution of plants influenced by seed dispersal, but this influence on plants that use animals as seed dispersers is often overlooked. Here, we took large-seeded pines and primary seed dispersers as examples to explore the effects of existing or potential seed dispersal on the distribution of plants based on the geographical distribution of the two trophic species, it required understanding of (a) the distribution range and distribution characteristics of each species, and (b) the overlapping of distribution areas of animals and plants to explore whether they match.</span></p> <p class="1"><span><b>Location: </b>China</span></p> <p class="1"><span><b>Methods:</b> To find the target species, we identified eight large-seeded pine species in China in terms of seed size and wing traits as well as four primary seed disperser species in terms of body size, seed-diet, food hoarding behavior and frequencies in existing studies. Then, we obtained species distribution information from books and literature and used ArcGIS for mapping. Finally, we analyzed the distribution relationship by overlapping the distribution areas and patterns comprehensively. </span></p> <p class="1"><span><b>Results: </b>We identified eight species of large-seeded pines (<i>Pinus fenzeliana</i>,<i> P. gerardiana</i>,<i> P. dabeshanensis</i>,<i> P. koraiensis</i>,<i> P. pumila, P. bungeana, P. armandii</i>, and<i> P. sibirica</i>) and four species of primary seed dispersers (<i>Nucifraga caryocatactes</i>,<i> Sciurus vulgaris</i>,<i> Tamias sibiricus</i>, and<i> Sciurotamias davidianus</i>). These eight species of large-seeded pines interlaced from the Northeast to the Southwest of China along the mountains with an average altitude of 1000-2000 m, while each species of primary seed disperser had a wide distribution range that overlapped completely or partially with that of four or more species of the large-seeded pines. Not only that, our findings provided potential seed dispersers for pines that lack sufficient research on seed dispersal.</span></p> <p class="1"><span><b>Main conclusions:</b> The distribution pattern of large-seeded pines and the primary seed dispersers was matched, we believed that reciprocal relationship promotes this distribution pattern. Our study highlights the importance of incorporating the ecological consequences of geographical distribution into reciprocal interactions between species and biodiversity conservation.</span></p>
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These curated guides explain access requirements, typical timelines, costs, and reuse considerations for widely used research datasets.
Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.