Find research datasets worth reusing
Search datasets from major research repositories and use ShareScore to quickly assess how well each record supports discovery, access, and reuse.
393
datasets available to search
ShareScore release 0.7.1
Dataset results
393 results for “seed dispersal”
Connectivity from a different perspective: comparing seed dispersal kernels in connected vs. unfragmented landscapes.
Habitat fragmentation can create significant impediments to dispersal. A technique to increase dispersal between otherwise isolated fragments is the use of corridors. Although previous studies have compared dispersal between connected fragments to dispersal between unconnected fragments, it remains unknown how dispersal between fragments connected by a corridor compares to dispersal in unfragmented landscapes. To assess the extent to which corridors can restore dispersal in fragmented landscapes to levels observed in unfragmented landscapes, we employed a stable-isotope marking technique to track seeds within four unfragmented landscapes and eight experimental landscapes with fragments connected by corridors. We studied two wind- and two bird-dispersed plant species, because previous community-based research showed that dispersal mode explains how connectivity effects vary among species. We constructed dispersal kernels for these species in unfragmented landscapes and connected fragments by marking seeds in the center of each landscape with 15N and then recovering marked seeds in seed traps at distances up to 200 m. For the two wind-dispersed plants, seed dispersal kernels were similar in unfragmented landscapes and connected fragments. In contrast, dispersal kernels of bird-dispersed seeds were both affected by fragmentation and differed in the direction of the impact: Morella cerifera experienced more and Rhus copallina experienced less long-distance dispersal in unfragmented than in connected landscapes. These results show that corridors can facilitate dispersal probabilities comparable to those observed in unfragmented landscapes. Although dispersal mode may provide useful broad predictions, we acknowledge that similar species may respond uniquely due to factors such as seasonality and disperser behavior. Our results further indicate that prior work has likely underestimated dispersal distances of wind-dispersed plants and that factors altering long-distance dis
Data from: Inducing seed dispersal by generalist frugivores: A new technique to overcome dispersal limitation in restoration
<p><b>1.</b> Dispersal limitation severely impairs the trajectory of restoration, mainly due to the lack of seed vectors bringing seeds from nearby habitats; a role played by many frugivorous vertebrates that can be absent or reduced in restored or degraded sites.</p> <p><b>2.</b> Here we propose a new technique named Induced Seed Dispersal, that amplifies the role that many generalist frugivores have in seed dispersal. It consists in the offering of seeds embedded in the pulp of commercial fruits or whole native fleshy fruits in feeders to generalist frugivores, which ingest the seeds and defecate them elsewhere. We set feeders in a restored site and monitored the visiting pattern of these frugivores with cameras-traps. We also set seed traps to retrieve seeds dispersed by frugivores and offered around 1500 seeds of <i>Cecropia hololeuca</i> (Urticaceae) per week for one year.</p> <p><b>3</b>. We recorded at least 24 generalist frugivore species of terrestrial mammals, bats, and birds, which ingested/removed the seeds/fruits from the feeders. Seeds of <i>C. hololeuca</i> dispersed by marmosets were retrieved in the seed traps and germinated. We estimated a potential seed rain of more than 600 <i>C. hololeuca </i>seeds ha<sup>-1</sup> mo<sup>-1</sup>.</p> <p><b>4</b>. <i>Synthesis and applications</i>. Our study demonstrates that this new technique can make use of generalist frugivores to assist restoration or regeneration into sites where seed dispersal is compromised by the lack of dispersers or limited seed arrival. Inducing seed dispersal by generalist frugivores is a low-cost and easy-managed technique that can be applied year-round in restoration and forest enrichments at all scales.</p>
Data from: Interactions between seed-dispersing ant species affect plant community composition in field mesocosms
<p>1. In generalized mutualisms, species vary in the quality of services they provide to their partners directly via traits that affect partner fitness and indirectly via traits that influence interactions with mutualist species that play similar functional roles. Myrmecochory, or seed dispersal by ants, is a generalized mutualism with ant species varying in the quality of dispersal services they provide to their plant partners. Variation in ant species identity can directly impact seed dispersal patterns and plant community composition; however, we know less about how interactions among seed-dispersing ant species indirectly influence plant partners.</p> <p>2. The invasive ant, <i>Myrmica rubra,</i> is a high-quality seed-disperser in its native range and interacts with myrmecochores (ant-dispersed plants) and the high-quality seed disperser <i>Aphaenogaster </i>sp. in its invaded range. We use this system to examine how interactions between two functionally similar mutualist ant species influence the recruitment and community composition of ant-dispersed plants.</p> <p>3. We performed a field mesocosm experiment and a lab behavioral experiment to compare discovery and dominance behaviors between ant species, and seed dispersal and seedling recruitment of four myrmecochore species among intraspecific interaction treatments of each ant species and an interspecific interaction treatment.</p> <p>4. We found that <i>M. rubra</i> was better at discovering and dispersing seeds, but that <i>Aphaenogaster</i> sp. was dominantly aggressive over <i>M. rubra</i>. Interspecific interactions dampened seed dispersal relative to dispersal by the better disperser. Despite this dampening, we found no effect of interspecific interaction on seedling recruitment. However, community composition of seedlings in the interspecific interaction treatment was more similar to composition in the aggressively dominant ant (<i>Aphaenogaster </i>sp.) treatment than in the better discoverer ant (<i>M. rubra</i>) treatment.</p> <p>5. We show that interspecific interaction between mutualist species in the same functional guild affects the outcome of mutualistic interactions with partner species. Despite the native ant dispersing fewer seeds, its dominance over the subordinate (invasive) ant has the potential to allow for some level of biotic resistance against the effects of M. rubra on plant communities when these species co-exist.</p>
Data from: Tracking temperate fish reveals their relevance for plant seed dispersal
<p>Seed dispersal is a fundamental process for plant communities, especially now that our changing world demands rapid colonization of new habitats. Long-distance dispersal is especially important for plant population persistence and range expansions.</p> <p>The contribution of fishes to plant seed dispersal in aquatic ecosystems (ichthyochory) has long been overlooked. Although we know fish disperse seeds, it is largely unknown where, when and how far – especially in temperate regions. Here we studied the potential of fish to disperse seeds locally and over long distances, specifically hypothesizing that i) dispersal by fish depends on the season, ii) individual fish contribute differently to seed dispersal, and iii) water regulating structures (barriers) inhibit seed dispersal.</p> <p>We tested our hypotheses by acoustically tracking 71 common carp (Cyprinus carpio) with 21 hydrophones in a 38km-long study system for >2 years in the Netherlands. We calculated potential seed dispersal throughout this system by combining nearly 1.5 million location registrations with experimentally assessed retention times of seeds after ingestion (i.e. time between ingestion and egestion).</p> <p>Seed dispersal on local scales was quantitatively most important during summer and autumn, with high dispersal potential in a range of four kilometres from the location of seed ingestion. Long-distance dispersal up to 16 km was possible at low probabilities in spring. In winter, most seeds were egested within two km. Maximum and median dispersal distances varied widely among individuals, emphasizing variation in effectiveness among individual fish for seed dispersal. Less than two percent of all fish movements reached beyond sluices and weirs, indicating that anthropogenic barriers in freshwater systems strongly reduced the potential of common carp to disperse seeds to these areas.</p> <p>This study shows that common carp can locally disperse plant seeds with high probabilities, and over distances up to 16 km with low probabilities throughout temperate ecosystems. This can contribute to restoration and maintenance of plant community diversity. However, this ecosystem function of fish to plants requires intact fish populations – because not all individual fish contribute equally to dispersal – and unrestricted connectivity throughout aquatic ecosystems.</p>
Data from: Long-term monitoring of seed dispersal by Asian elephants in a Sundaland rainforest
<p><span><span><span><span><span><span><span><span><span><span><span>Asian elephants (<i>Elephas maximus</i>) have inhabited almost all forests in tropical Asia until recently, yet little is known about their role in ecological processes, particularly in the Sundaic forests of Southeast Asia. These forests are peculiar in their phenology, with supra-annual and highly irregular episodes of mast fruiting. Here we present a long-term (six-year) monitoring of the seeds dispersed by elephants in dipterocarp forests of northern Peninsular Malaysia. We conducted monthly dung surveys at two mineral licks (11.3 km apart) frequently visited by elephants. Additionally, we recorded haphazard observations of seeds and seedlings in elephant dung at other locations. We recorded a minimum of 48 morphospecies from at least 25 plant families dispersed by elephants. Elephant seed dispersal was very heterogenous in space, with only 30.3 % of the morphospecies dispersed at both sites (Jaccard dissimilarity index = 0.48). Temporally, elephants dispersed seeds in sporadic pulses of abundance and diversity, without any apparent seasonality (seeds appeared in 19.1 % of 1,284 dung piles and 57.1 % of the 63 months in which we found dung) and with long periods without any seed being dispersed. Nearly half (48 %) of the plants dispersed by elephants belong to a megafaunal dispersal syndrome. Our long-term approach allowed us to unravel an important aspect of Asian elephants' role and effectiveness in the seed dispersal cycle. Sundaland's forests are undergoing a rapid loss of their previously common megaherbivores (rhinos and elephants), with profound and long-term consequences for ecosystem functioning.</span></span></span></span></span></span></span></span></span></span></span></p>
Genetic variation in an ephemeral mudflat species: the role of the soil seed bank and dispersal in river and secondary anthropogenic habitats
<p>Many ephemeral mudflat species, which rely on a soil seed bank to build up the next generation, are endangered in their natural habitat due to the widespread regulation of rivers. The aim of the present study was to elucidate the role of the soil seed bank and dispersal for the maintenance of genetic diversity in populations of near-natural river habitats and anthropogenic habitats created by traditional fish farming practices using <i>Cyperus fuscus</i> as a model. Using microsatellite markers, we found no difference in genetic diversity levels between soil seed bank and above-ground population and only moderate differentiation between the two fractions. One possible interpretation is the difference in short-term selection during germination under specific conditions (glasshouse versus field) resulting in an ecological filtering of genotypes out of the reservoir in the soil. River populations harboured significantly more genetic diversity than populations from the anthropogenic pond types. We suggest that altered levels and patterns of dispersal together with stronger selection pressures and historical bottlenecks in anthropogenic habitats are responsible for the observed reduction in genetic diversity. Dispersal is also supposed to largely prohibit genetic structure across Europe, although there is a gradient in private allelic richness from southern Europe and Anatolia (high values) to northern, especially north-western, Europe (low values), which probably relates to postglacial expansion out of southern and/or eastern refugia.</p>
Data from: Resilience of seed production to a severe El Niño‐induced drought across functional groups and dispersal types
More frequent and severe El Niño Southern Oscillations (ENSO) are causing episodic periods of decreased rainfall. Although the effects of these ENSO-induced droughts on tree growth and mortality have been well studied, the impacts on other demographic rates such as reproduction are less well known. We use a four-year seed rain dataset encompassing the most severe ENSO-induced drought in more than 30 years to assess the resilience (i.e. resistance and recovery) of the seed composition and abundance of three forest types in a tropical dry forest. We found that forest types showed distinct differences in the timing, duration and intensity of drought during the ENSO event, which likely mediated seed composition shifts and resilience. Drought-deciduous species were particularly sensitive to the drought with overall poor resilience of seed production, whereby seed abundance of this functional group failed to recover to pre-drought levels even two years after the drought. Liana and wind-dispersed species were able to maintain seed production both during and after drought suggesting that ENSO events promote early successional species or species with a colonization strategy. Combined, these results suggest that ENSO-induced drought mediates the establishment of functional groups and dispersal types suited for early successional conditions with more open canopies and reduced competition among plants. The effects of the ENSO-induced drought on seed composition and abundance were still evident two years after the event suggesting the recovery of seed production requires multiple years that may lead to shifts in forest composition and structure in the long-term, with potential consequences for higher trophic levels like frugivores.
Data from: Seed-dispersal networks in tropical forest fragments: area effects, remnant species, and interaction diversity
<p>Seed dispersal interactions involve key ecological processes in tropical forests that help to maintain ecosystem functioning. Yet this functionality may be threatened by increasing habitat loss, defaunation and fragmentation. However, generalist species, and their interactions, can benefit from the habitat change caused by human disturbance while more specialized interactions mostly disappear. Therefore changes in the structure of the local, within fragment, networks can be expected. Here we investigated how the structure of seed-dispersal networks changes along a gradient of increasing habitat fragmentation. We analysed 16 bird seed-dispersal assemblages from forest fragments of a biodiversity-rich ecosystem. We found significant species-, interaction- and network-area relationships, yet the later was determined by the number of species remaining in each community. The number of frugivorous bird and plant species, their interactions, and the number of links per species decreases as area is lost in the fragmented landscape. In contrast, network nestedness has a negative relationship with fragment area, suggesting an increasing generalization of the network structure in the gradient of fragmentation. Network specialization was not significantly affected by area, indicating that some network properties may be invariant to disturbance. Still, the local extinction of partner species, paralleled by a loss of interactions and specialist-specialist bird-plant seed dispersal associations suggests the functional homogenization of the system as area is lost. Our study provides empirical evidence for network-area relationships driven by the presence/absence of remnant species and the interactions they perform.</p>
A large-scale assessment of plant dispersal mode and seed traits across human-modified Amazonian forests
1. Quantifying the impact of habitat disturbance on ecosystem function is critical for understanding and predicting the future of tropical forests. Many studies have examined post-disturbance changes in animal traits related to mutualistic interactions with plants, but the effect of disturbance on plant traits in diverse forests has received much less attention. 2. Focusing on two study regions in the eastern Brazilian Amazon, we used a trait-based approach to examine how seed dispersal functionality within tropical plant communities changes across a landscape-scale gradient of human modification, including both regenerating secondary forests and primary forests disturbed by burning and selective logging. 3. Surveys of 230 forest plots recorded 26,533 live stems from 846 tree species. Using herbarium material and literature, we compiled trait information for each tree species, focusing on dispersal mode and seed size. 4. Disturbance reduced tree diversity and increased the proportion of lower wood-density and smaller-seeded tree species in study plots. Unexpectedly, disturbance also increased the proportion of stems with seeds that are ingested by animals and reduced those dispersed by other mechanisms (e.g. wind). Older secondary forests had functionally similar plant communities to the most heavily disturbed primary forests. 5. <i>Synthesis</i>. Anthropogenic disturbance has major effects on the seed traits of tree communities, with implications for mutualistic interactions with animals. The higher importance of animal-mediated seed dispersal in disturbed and recovering forests highlights the importance of avoiding defaunation or promoting faunal recovery. The changes in mean seed width suggest larger vertebrates hold especially important functional roles in these human-modified forests. Monitoring fruit and seed traits can provide a valuable indicator of ecosystem condition, emphasising the importance of developing a comprehensive plant traits database for the Amazon and other biomes.
Data from: Do benefits of seed dispersal and caching by scatterhoarders outweigh the costs of predation? An example with oaks and yellow-necked mice
<p>Numerous interactions between plants and animals vary in their outcome between antagonism and mutualism. Interactions between plants and scatterhoarding animals provide a prime example of this phenomenon. Scatterhoarders consume large quantities of seeds (potentially reducing plant establishment), yet also disperse seeds and bury them in shallow caches (potentially improving recruitment). Despite intense work on mechanisms that cause these interactions to shift along an antagonism-mutualism continuum, it remains difficult to quantify their final outcomes.</p> <p>We demonstrate how readily available field data can be used to reach this goal, with interactions between rodents and two oaks species (sessile oak Quercus petraea, and red oak Q. rubra) as an empirical example. Our approach consists of quantifying the net outcome of the interaction through collecting data on different vital rates (e.g. probability that cached seeds survive to germination, probability of seedling recruitment with and without rodents; near and far from conspecific trees; with and without seed pilferage) and assembling them in a simple mathematical model.</p> <p>We found that during the period of the study, interactions between scatterhoarding rodents and both focal oaks were antagonistic. Even though caching increased the likelihood of seedling establishment, this effect was not strong enough to compensate for the costs of seed predation. Furthermore, there was no evidence that the short-distance transportation that is usually provided by small mammals benefited early oak recruitment.</p> <p>Synthesis. Our empirical results demonstrated that certain common assumptions -- that caching by rodents invariably benefits plant recruitment; that improved seedling establishment after seed burial is sufficient to make plant-scatterhoarder interactions mutualistic; that transportation away from maternal plants is highly beneficial -- do not always hold and should be tested rather than taken for granted.</p>
Fine‐scale habitat heterogeneity and vole runways influence seed dispersal in Plagiobothrys nothofulvus
<p class="Normal1"><b>PREMISE:</b><i> </i>Seed dispersal allows plants to colonize new sites and contributes to gene flow among populations. Despite its fundamental importance to ecological and evolutionary processes, our understanding of seed dispersal is limited due to the difficulty of directly observing dispersal events. This is particularly true for the majority of plant species that are considered to have gravity as their primary dispersal mechanism. The potential for long-distance movement of gravity-dispersed seeds by secondary dispersal vectors is rarely evaluated. </p> <p class="Normal1"><b>METHODS: </b>We employ whole-genome assays of maternally inherited cpDNA in <i>Plagiobothrys nothofulvus</i> to resolve patterns of genetic variation due to effective (realized) seed dispersal within a 16 hectare prairie that is characterized by a mosaic of habitat types. We evaluate the effects of microgeographic landscape features extracted from micro-UAV aerial surveys on patterns of seed dispersal using landscape genetics methods.</p> <p class="Normal1"><b>RESULTS: </b>We found evidence of high resistance to seed-mediated gene flow (effective dispersal) within patches of <i>P. nothofulvus</i>, and strong genetic structure over distances of less than 20 meters. Geographic distance was a poor predictor of dispersal distance, while landscape features had stronger influences on patterns of dispersal<a name="_Hlk22028649"> (distance and direction of seed movement)</a>. Patterns of dispersal were best predicted by the combined distribution of flower patches, habitat type, and the network of vole runways, with the latter explaining the largest proportion of variation in the model.</p> <p class="Normal1"><b>CONCLUSIONS: </b>Our results suggest that primary dispersal occurs mostly within microhabitats and infrequent secondary dispersal may occur over longer distances due to the activity of small mammals and other vertebrates.</p>
Data from: Lowland tapirs facilitate seed dispersal in degraded Amazonian forests
The forests of southeastern Amazonia are highly threatened by disturbances such as fragmentation, understory fires and extreme climatic events. Large-bodied frugivores such as the lowland tapir (Tapirus terrestris) have the potential to offset this process, supporting natural forest regeneration by dispersing a variety of seeds over long distances to disturbed forests. However, we know little about their effectiveness as seed dispersers in degraded forest landscapes. Here, we investigate the seed dispersal function of lowland tapirs in Amazonian forests subject to a range of human (fire, fragmentation) and natural (extreme droughts, windstorms) disturbances, using a combination of field observations, camera traps, and Light Detection and Ranging (LiDAR) data. Tapirs travel and defecate more often in degraded forests, dispersing much more seeds in these areas [9,822 seeds per ha/yr (CI95% = 9,106; 11,838)] than in undisturbed forests [2,950 seeds per ha/yr (CI95% = 2,961; 3,771)]. By effectively dispersing seeds across disturbed forests, tapirs may contribute to natural forest regeneration – the cheapest and usually the most feasible way to achieve large-scale restoration of tropical forests. Through the dispersal of large-seeded species that eventually become large trees, such frugivores also contribute indirectly to maintaining forest carbon stocks. These functions may be critical in helping tropical countries to achieve their goals to maintain and restore biodiversity and its ecosystem services. Ultimately, preserving these animals along with their habitats may help in the process of natural recovery of degraded forests throughout the tropics.
Individual body mass and sex of a frugivorous bird affect the quality of seed dispersal
<p><span>Frugivorous animals play crucial roles dispersing seeds</span><span> away from parental plants and influencing plant recruitment. Most studies focus on comparisons of seed dispersal services provided by distinct species of animals, but neglect how within-species variation may affect dispersal. Individual traits, such as body mass and sex, are related to metabolic rates, gut load capacity, and transit times that potentially influence dispersal quantity and quality. Here, we aim to answer if individual traits (body mass and sex) of Pale-breasted Thrushes (<em>Turdus leucomelas</em>) affect seed dispersal quality by testing the following hypotheses (a) individual traits influence seed retention time and germination, (b) seed retention time affects seed germination and (c) seed passage through the gut enhances germination. We found that females retained seeds in the gut for longer periods than males. Gut-passed and manually depulped seeds had similar germination success. However, heavier birds, irrespective of sex, had longer seed retention times and promoted higher germination. Our results indicate that intraspecific differences in the morphological traits of frugivores are a source of variation in dispersal outputs and may help to explain complex patterns of seed dispersal. We highlight the importance of considering the quality of seed dispersal at an individual level, as well as at a species level, and reinforce that some individuals may contribute more to seed germination, and potentially recruitment, than others. Finally, a decrease in body masses of tropical birds in response to global warming may cascade to a decrease in seed dispersal quality. </span></p>
Data from: Seed dispersal mode and habitat connectivity underpin variation in carbon stocking between Brazilian biomes
<p>In tropical forests, about 60 to 80% of woody plant species depend on animal-plant interactions for dispersal. The dependence on animal species for dispersal makes this interaction very fragile in the face of anthropogenic changes in land use. Disrupting seed dispersal processes, principally zoochoric dispersal, could significantly alter the long-term carbon storage potential of tropical forests. An important question is how landscape structure changes tree carbon stocks in different types of tropical vegetation and how variation is mediated by the dispersal mode of animal (zoochoric) or abiotic (non-zoochoric) seeds. We focused on tree plots at 126 sites in Brazil spanning four types of forest and savanna vegetation, and calculated carbon stored in zoochoric, non-zoochoric, and large frugivore-dispersed species. Our results showed that carbon stocks in zoochoric species and non-zoochoric species differ significantly among vegetation types, with rainforests having higher stocks in zoochoric species and semideciduous seasonally dry tropical forests having higher values in non-zoochoric species. A greater area of native vegetation promotes higher proportions of carbon stocks dispersed by large frugivore species, whereas a higher mean shape index reduces this proportion. Synthesis: This study highlights that seed-dispersal type underpins the variation in carbon stocks between vegetation types and that the maintenance of habitat of large dispersers and connectivity are key for retaining carbon stocks in zoochoric species, particularly in rainforest and cerrado sensu stricto.</p>
The ability to disperse large seeds, rather than body mass alone, defines the importance of animals in a hyper-diverse seed dispersal network
<p>1. Large-bodied animals play irreplaceable roles in seed dispersal, partly due to their capacity to disperse large seeds. Understanding this role at a community level has been limited by the paucity of network studies that include large vertebrates, and the almost complete absence of studies including synzoochoric dispersers. Synzoochoric dispersers can disperse seeds disproportionately large for their body size, potentially overlapping the roles of large-bodied animals. A comprehensive network, inclusive of large vertebrates and synzoochorous dispersers, is imperative to understand seed dispersal at a community level.</p> <p>2. Here, we analysed the seed dispersal network of a hyper-diverse Sundaic forest in Malaysia using local ecological knowledge and including multiple forms of endozoochorous and synzoochorous dispersal. We evaluated the extent to which three disperser traits: body mass, seed-handling ability (size of the largest seed dispersed), and diet explained the importance of animals in the network. We evaluated dispersers' relative importance using four network metrics — degree of specialisation (nested rank), species strength, within-module connectivity (z-value), and between-modules connectivity (c-value).</p> <p>3. We found that seed-handling ability had the biggest effect on a disperser's importance, with strong effects on three network metrics (species strength, ecological specialization, z-value) and moderate effects on connectivity between modules. Body mass was important in defining interactions within modules, and dietary differences defined the ecological specialisation of species in seed dispersal.</p> <p>4. Important dispersers in our network were large-seed dispersers (e.g., rats, gibbons), large-bodied animals, in particular the Asian elephant, and animals with frugivorous diets such as hornbills.</p> <p>5. Synthesis. Our work uncovers the significance of seed-handling ability in identifying pivotal seed dispersal roles in tropical rainforests. Key dispersers include large-bodied herbivores and medium-sized frugivores that could disperse large seeds by endozoochory, and smaller rodents that dispersed similar-sized seeds by synzoochory. Many of the species that emerged as particularly important for the seed dispersal network are currently threatened (e.g., the Asian elephant, gibbons, and hornbills). Their protection or reintroduction should be a top conservation priority. </p>
The individual-based network structure of palm-seed dispersers is explained by a rainforest gradient
<p>How species interactions change in space and time is a major question in ecology. In tropical forests, plant individuals share mutualistic partners (pollinators or seed dispersers), yet we have little understanding of the factors affecting these individual interaction patterns. We used a seed dispersal individual-based network describing interactions between individuals of a palm species with bird species to investigate how intrinsic and extrinsic characteristics of individual plants influence the network structure. In our work we evaluated if average canopy height, number of fruits, distance to forest gap, and habitat type influence the role of palm individuals in the network. From 102 palms, 62 individuals had their seeds dispersed at least once: 17 individual palms in the restinga, 15 in the lowland and 30 in the pre-montane habitat. Twelve bird species were recorded dispersing <em>Euterpe edulis</em> seeds in our study area.</p>
Data from: The effects of human-altered habitat spatial pattern on frugivory and seed dispersal: a global meta-analysis
<p>Seed dispersal by frugivorous animals is important for plant mobility, regeneration, and persistence. Human-caused landscape change is thought to disrupt seed dispersal, but evidence is scarce. We performed a comprehensive meta-analysis on the effects of habitat spatial pattern on frugivory and seed dispersal. We found 233 effects from 71 studies. At a patch or local scale, altered habitat spatial pattern was measured as declining patch size, increasing patch isolation, or habitat edge (vs. interior). At a landscape scale it was measured as declining amount of habitat, increasing mean patch isolation, increasing number of patches, or increasing habitat edge in the landscape.</p> <p>We found overall negative effects of altered habitat spatial pattern on: (i) the quantity of frugivory or seed dispersal, (ii) the number of species involved in a plant-frugivore interaction, and (iii) seed dispersal distance. Moderator variable analysis was only possible for the first of these. It revealed negative responses of the quantity of frugivory or seed dispersal to habitat loss at both the local scale (declining patch size), and the landscape scale (declining habitat amount), but little evidence for a response to habitat edge at either scale. In addition, altered habitat spatial pattern reduced the quantity of frugivory or seed dispersal more strongly in temperate than tropical areas. Finally, the few-recorded effects of landscape-scale fragmentation per se (increasing patch density or edge density) on the quantity of frugivory or seed dispersal were mixed and weak. Our meta-analysis reinforces the notion that habitat loss is a major threat to frugivory and seed dispersal by animals, and reveals an insufficiency of studies of the effects of habitat fragmentation per se. Thus, based on the current literature, we conclude that maintaining and increasing habitat amount is vital for maintaining seed dispersal by frugivorous animals.</p>
Lost mutualisms: seed dispersal by Sumatran rhinos, the world's most threatened megafauna
<p>Diverse assemblages of seed-dispersing megafauna once existed in Asian rainforests, but are now almost solely represented by elephants. Asia's rhinos persist in remnant, ecologically-extinct populations and the most threatened of these is the Sumatran rhino, Dicerorhinus sumatrensis. To understand the seed dispersal role of Sumatran rhinos, we consolidated information on fruit consumption, seed dispersal and fruit traits from a two-month field study (Sumatra), local ecological knowledge (Peninsular Malaysia), and published and unpublished accounts. We evaluated differences between the taxa and traits of fruits dispersed by rhinos and elephants, and identified other dispersers of megafaunal-syndrome fruits that were rhino-dispersed. At least 79 plant species were dispersed by rhinos: overstorey plants (trees and climbers; 78% of species) had large, usually "mammal-coloured", fruits and seeds, and were mainly drupes and berries; 61% of these were megafaunal-syndrome fruits (>4 cm wide). Understorey plants (herbs, shrubs, small trees) had small, often capsular, fruits and seeds that are potentially dispersed following the "foliage-is-the-fruit" hypothesis. Rhinos were the only known disperser for 35% of the megafaunal-fruit genera. The highest dispersal overlap shown was with elephants: fruits dispersed by rhinos tended to be capsular and were smaller than fruits dispersed by both elephants and rhinos. Given these findings and the different foraging and ranging behaviour of Sumatran rhinos and elephants, we suggest these megafauna had important differences in their seed dispersal roles. Asian rainforests have, therefore, lost an important seed dispersal mutualist. Conservation efforts should aim to protect and restore the ecological function of these unique creatures.</p>
Changes in the structure of seed dispersal networks when including interaction outcomes from both plant and animal perspectives
<p>Interaction frequency is the most common currency in quantitative ecological networks, although interaction quality can also affect benefits provided by mutualisms. Here, we evaluate if interaction quality can modify network topology, species' role and whether such changes affect community vulnerability to species loss. We use a well-examined study system (bird-lizard and fleshy-fruited plants in the 'thermophilous' woodland of the Canary Islands) to compare network and species-level metrics from a network based on fruit consumption rates (Interaction Frequency, IF), against networks reflecting functional outcomes: a Seed Dispersal Effectiveness network (SDE) quantifying recruitment, and a Fruit Resource Provisioning network (FRP), accounting for the nutrient supply of fruits. Nestedness decreased in the FRP and the SDE networks, due to the lack of association between fruit consumption rates and (1) nutrient content, and (2) recruitment at the seed deposition sites, respectively. The FRP network showed lower niche overlap due to resource use complementarity among frugivores. Interaction evenness was lower in the SDE network, in response to a higher dominance of lizards in the recruitment of heliophilous species. Such changes, however, did not result in enhanced vulnerability against extinctions. At the plant species level, strength changed in the FRP network in frequently consumed or highly nutritious species. The number of effective partners decreased for species whose seeds were deposited in unsuitable places for recruitment. In frugivores, strength was consistent across networks (SDE vs IF), showing that consumption rates outweighed differences in dispersal quality. In the case of lizards, the increased importance of nutrient-rich species resulted in a higher number of effective partners.</p> <p>Our work shows that although frequency strongly impacts interaction effects, accounting for quality improves our inferences about interaction assembly and species role. Thus, future studies including interaction outcomes from both partners' perspectives will provide valuable insights about the net effects of mutualistic interactions.</p>
Habitat loss shapes the structure and species roles in mutualistic seed dispersal networks
<p>This dataset has the variables used in the paper "Habitat loss shapes the structure and species roles in tropical seed dispersal networks" as well as the script to perform the analysis.</p>
ScienceDex guides
Understand access before you commit
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.