Seed Dispersal Research Articles

Genomic signatures of past megafrugivore‐mediated dispersal in Malagasy palms

Abstract Seed dispersal affects gene flow and hence genetic differentiation of plant populations. During the Late Quaternary, most fruit‐eating and seed‐dispersing megafauna went extinct, but whether these animals have left signatures in the population genetics of their food plants, particularly those with large, ‘megafaunal’ fruits (i.e. >4 cm—megafruits), remains unclear. Here, we assessed the population history, genetic differentiation and recent migration among populations of four animal‐dispersed palm (Arecaceae) species with large (Borassus madagascariensis), medium‐sized (Hyphaene coriacea, Bismarckia nobilis) and small (Chrysalidocarpus madagascariensis) fruits on Madagascar. We integrated double‐digest restriction‐site‐associated DNA sequencing (ddRAD) of 167 individuals from 25 populations with (past) distribution ranges for extinct (e.g., giant lemurs and elephant birds) and extant seed‐dispersing animals, landscape and human impact data, and applied linear mixed‐effects models to explore the drivers of genetic variation in Malagasy palms. Palm populations that shared more megafrugivore species in the past had lower genetic differentiation than populations that shared fewer megafrugivore species. This suggests that megafrugivore‐mediated seed dispersal in the past may have led to frequent gene flow among populations. In comparison, extant frugivore diversity only decreased genetic differentiation in the small‐fruited palm. Furthermore, genetic differentiation of all palm species decreased with landscape connectivity (i.e. environmental suitability, forest cover and river density) and human impact (i.e. road density), while migration rates of the small‐fruit palm increased with road density. Synthesis. Our results suggest that the legacy of megafrugivores regularly achieving long dispersal distances is still reflected in the population genetics of palms that were formerly dispersed by such animals. Furthermore, low genetic differentiation was possibly maintained after the megafauna extinctions through alternative dispersal (e.g. human‐ or river‐mediated), long generation times and long lifespans of these megafruit palms. Our study illustrates how species interactions that happened >1000 years ago can leave imprints in their population genetics.

First Evidence of Thalassochory in the Ficus Genus: Seed Dispersal Using the Kuroshio Oceanic Current.

Plants distributed between southern Taiwan and the north of the Philippines are spread among numerous small islands in an area crossed by the powerful Kuroshio current. Oceanic currents can be effective seed-dispersal agents for coastal plant species. Moreover, the Luzon Strait is an area prone to tropical cyclones. The aim of this study is to look at the dispersal capability of an endangered coastal plant species, the Mearns fig (Ficus pedunculosa var. mearnsii), using both experimental and population genetics methods. Southern Taiwan, the Philippines, and the islands between Luzon and Taiwan Island. This study combined two types of analysis, i.e., buoyancy experiments on syconia and double digest restriction-associated DNA sequencing (ddRAD), to analyze the population genetics of the Mearns fig. We first discovered that mature Mearns fig syconia could float in seawater. They have a mean float duration of 10 days to a maximum of 21 days. Germination rates varied significantly between Mearns fig seeds that had undergone different durations of flotation treatment. Population genetic analysis shows a high degree of inbreeding among various Mearns fig populations. Moreover, no isolation by distance was found between the populations and individuals. From our analysis of the genetic structure of the Mearns fig populations, we can clearly highlight the effect of the Kuroshio oceanic current on the seed dispersal of this fig tree. Comprehensive analysis has shown that Mearns fig seeds are still viable before the mature syconium sinks into the seawater, and so they could use the Kuroshio Current to float to the current population locations in Taiwan.

Effects of Seed Size and Frequency on Seed Dispersal and Predation by Small Mammals.

Frequency-dependent predation is common in predator-prey interactions. Size is an important characteristic of seeds and is crucial in the regeneration stage of plant seeds. However, the frequency dependence of animal predation on seed size has not been reported. In this study, we conducted a field experiment and used different sizes of Liaodong oak (Quercus wutaishanica) seeds to test the frequency dependence of intraspecific seed size selection in rodents. We used the number ratio of large to small seeds as the frequency. The results show that the rate of small seeds being eaten in situ was significantly higher than that of large seeds (p < 0.05). The rates of different-sized seeds being eaten after removal decreased with increasing frequencies, and there was no significant difference between frequencies except for 1:9 and 9:1. The rates of large seeds being scatter-hoarded were significantly higher than those of small seeds at different frequencies (p < 0.05). The eating distances after removal of large seeds were significantly longer than those of small seeds at the same frequencies (p < 0.05). Furthermore, the scatter-hoarding distances of large seeds were significantly longer than those of small seeds at three frequencies (1:9, 3:7, and 9:1) (p < 0.05). That is, rodents consumed more small seeds in situ, dispersed and scatter-hoarded more large seeds, and dispersed large seeds over longer distances. Rodents exhibited a negative frequency dependence for small seeds and a positive frequency dependence for large seeds on being eaten in situ. Moreover, rodents exhibited a negative frequency dependence for large seeds and a positive frequency dependence for small seeds on being eaten after removal and scatter-hoarding. These results reveal the frequency dependence of rodent selection on seed size and provide new insights into animal-mediated seed dispersal and the regeneration of plant populations.

Rodents mediate the relationship between seed rain, seed bank, and plant community with increased grazing disturbance.

Seed rain and the soil seed bank represent the dispersal of seeds in space and time, respectively, and can be important sources of recruitment of new individuals during plant community regeneration. However, the temporal dynamics of seed rain and the mechanisms by which the seed rain and soil seed bank may play a role in plant community regeneration with increased grazing disturbance remain unclear. Seed rain, soil seed bank, aboveground vegetation, and rodent density were sampled along a grazing gradient in an alpine marsh on the eastern Tibetan Plateau. We described the temporal dynamics of seed dispersal using Bayesian generalized mixed models, and nonmetric multidimensional scaling and the structural equation model were used to examine the effects of grazing disturbance on the relative role of seed rain and soil seed bank on aboveground plant community regeneration. The temporal dynamics of seed rain changed from a unimodal to a bimodal pattern with increased grazing disturbance. Both species diversity and seed density of the seed rain and seed bank increased significantly with increased grazing disturbance. Increased grazing disturbance indirectly increased the similarity of composition between seed rain, seed bank, and aboveground plant community by directly increasing species diversity and abundance of aboveground plant community. However, increased grazing disturbance also indirectly decreased the similarity of seed rain, soil seed bank, and aboveground plant community by directly increasing rodent density. The similarity between seed rain and aboveground plant community was greater than that of the soil seed bank and aboveground plant community with increased grazing disturbance. Grazing disturbance spreads the risk of seed germination and seedling establishment by changing the temporal dynamics of seed dispersal. Plants (positive) and rodents (negative) mediated the role of seed rain and soil seed bank in plant community regeneration. The role of seed rain in plant community regeneration is higher than the seed bank in disturbed alpine marshes. Our findings increase our understanding of the regeneration process of the plant community, and they provide valuable information for the conservation and restoration of alpine marsh ecosystems.

Apex predators can structure ecosystems through trophic cascades: Linking the frugivorous behaviour and seed dispersal patterns of mesocarnivores

Abstract Current global change scenarios demand knowledge on how anthropogenic impacts affect ecosystem functioning through changes in food web structure. Frugivorous mesocarnivores are a key link in trophic cascades because, while their abundance and behaviour are usually controlled by apex predators, they can provide high‐quality seed‐dispersal services to plant communities. Thus, the recent rewilding of large carnivores worldwide can trigger cascading effects for plants. We investigated the top‐down effects of an apex predator (Iberian lynx Lynx pardinus) on seed‐dispersal services mediated by two mesocarnivore species (red fox Vulpes vulpes and stone marten Martes foina) at the plant community level by comparing areas with and without lynx in a Mediterranean mountain range in Southern Spain. We collected scats of mesocarnivores (n = 1575) to assess frugivory and seed dispersal of 15 plant species over two consecutive fruiting seasons and two habitat types (open and forest). Specifically, we assessed the effect of lynx presence on (i) seed occurrence and fleshy‐fruit biomass per scat, (ii) number of scats containing seeds and (iii) diversity of dispersed seeds. The quantity and diversity of dispersed seeds drastically decreased under predation risk for both mesocarnivore's species. Seed dispersal by stone martens was negatively affected by the presence of lynx, with a marked reduction in the number of scats with seeds (93%) and the diversity of dispersed seeds (46%). Foxes dispersed 68% fewer seeds in open habitats when coexisting with lynx, probably leading to differential contributions to seed‐dispersal effectiveness among habitats. Our study reveals a novel trophic cascade from apex predators to plant communities. The behavioural responses of frugivorous mesocarnivores to predation risk and the reduction in the intensity of their faecal deposition pattern are probably related to their lower abundance when co‐occurring with apex predators. While rewilding apex predators is a successful conservation tool, attention should be paid to cascading effects across food webs, particularly where frugivore megafauna is missing and mesocarnivores provide unique services to plants. Read the free Plain Language Summary for this article on the Journal blog.

Assessing Dandelion Seed Dispersal and Environmental Impact: A Comprehensive Study

The study investigates the dispersal range of dandelion seeds influenced by wind, considering fruit ripening and invasive species’ impact. CFD fluid dynamics simulation using Ansys Fluent software, integrating Navier-Stokes equations and turbulence theory, analyzes seed motion characteristics and dispersion dynamics in an ideal fluid domain. Parameters like air density and viscosity, representing various seasons, were adjusted in diffusion range across different time scales.We obtained the approximate distribution of dandelion seeds across different seasons and climates, finding larger dispersal areas in arid climates due to stronger winds. In comparison, temperate climates exhibit smaller areas due to gentler winds. To assess the impact of an alien plant on the local environment, we constructed judgment criteria using the Analytical Hierarchy Process (AHP). Through pair-wise comparisons, we calculated weightings for criteria encompassing environmental interference, economic influence, and effects on human health. By assigning ratings to each criterion based on logical reasoning and scientific evidence, we quantified the plant’s impact, yielding a score of 5.74 out of 10 for dandelion, indicating an overall positive effect in the community. Sensitivity testing confirmed the robustness of our model.

Effects of Landscape Heterogeneity and Disperser Movement on Seed Dispersal

The primacy of endozoochory for the maintenance and expansion of many woody plant populations is well known, but seed dispersal is not well understood for most species. This is especially true for rare species, where small population size and low fruit production can limit field- or observation-based experiments. Additionally, the effect of environmental heterogeneity on disperser movement is rarely investigated but has been shown to improve estimates of plant population spatial patterns and dynamics. We used simulation experiments to explore the effects of environmental heterogeneity and disperser movement on Lindera subcoriacea seed dispersal, a rare shrub from the southeastern United States with avian-dispersed seeds. Our experiments incorporated environmental heterogeneity and simulated disperser movement for five bird species, based on either landscape permeability or straight path rules. We anticipated that permeability-based movement would result in greater dispersal distances and seed dispersal effectiveness, which characterizes both quantity and quality. Generally, we did not find differences in seed dispersal between permeability and straight path experiments. However, we did find that permeability-based experiments had greater deposition into suitable habitat during flight (23 vs. 1%). These rare but longer distance depositions may be especially important for plants that are influenced by gap or interpopulation dynamics. We also found consistently greater dispersal into high quality habitats regardless of disperser species in permeability experiments, implying that incorporating species-specific assessments of landscape utilization (occupancy) could influence the effectiveness of seed dispersal. Our study suggests that including environmental heterogeneity in seed dispersal models can provide additional insights not provided by avian parameters (e.g., gut capacity, seed retention time, and flight speed) commonly used to inform dispersal models.

Effect of dormancy on the emergence of Tabernaemontana heterophylla seedlings in different substrates

The composition and dynamics of plant communities are determined by the survival, dispersal and persistence of seeds in the soil, some of the fundamental aspects for understanding plant biology, among which seed dormancy is of particular importance. The aim of this work was to find out whether seed dormancy is affected by certain substrates in order to improve the production of Tabernaemontana heterophylla seedlings. Treatments were carried out with different substrates (T1. Sand, T2. Vegetable clay, T3. Vegetable clay + sand (1:1 ratio), T4. Vermiculite, T5. Cattle manure, T6. Sawdust and T7. Organic compost) in 7 x 4 factorial schemes, the results of which were subjected to an analysis of variance and a comparison of means with the Tukey test at a probability of 5%. The seeds with visible germination structure (hypocotyl) showed an apical meristem in a dormant stage. The number of normal seedlings did not exceed 25% of the germinated seeds in all treatments, with a high proportion of non-viable seeds observed. In the absence of technical information on overcome dormancy, it is important to use strategies that stimulate germination and subsequent seedling growth. The slow germination combined with the presence of dormancy in the hypocotyledon were factors that negatively affected the propagation of the species studied.

Seeding detection and distribution evaluation using the developed automatic maize seeding machine

Seeding is a time-consuming and labour-intensive process in the detection of maize seeds germination rate. Automatic seeding can reduce labour requirements and improve efficiency. The quality of automatic seeding plays an important role in collecting accurate germination rates. In this research, a newly developed automatic maize seeding machine (AMSM) was used to detect the maize seeds and evaluate distribution by advanced computer vision and analysis methodologies. Three methods were utilized to detect maize seeds after they were loaded into the holes of the seed plate of AMSM: colour segmentation + connected component analysis, support vector machine (SVM) + sliding window, and YOLOV5. The results showed that compared with colour + connected component analysis and sliding window + SVM, YOLOV5 exhibited higher accuracy and improved computational efficiency. When the input image pixel size was 960 × 960, the precision of YOLOV5 + merge-NMS was 97.3 %, the recall was 0.918, the F1-score was 0.945, and the processing time of a single image was 0.38 ms, which is the optimal performance. YOLOV5 + merge-NMS demonstrated robust detection maize seeds in images with different illumination equalization processing. Based on maize seeds detection results, seeding distribution evaluation was realized with an average accuracy of 91.14 %. In addition, the normal seeding of the AMSM was 82.3 %. Utilization of YOLOV5 + merge-NMS enables rapid and precise detection of maize seeding while establishing a basis for accurately calculating seed distribution. The AMSM can meet the requirements of automatic maize seeds detection and distribution evaluation and the developed methodologies have the potential for automatic germination detection.

Behaviour, body mass and sex: How intraspecific variation influences seed dispersal by a scatter‐hoarding rodent

Abstract Intraspecific variation plays a pivotal role in shaping ecological dynamics. As the dispersal of seeds of most woody plants is mediated by animals, individual variation within the animal dispersers holds considerable implications for plant population and ecology. We explored how individual traits (such as sex, body mass and exploration levels) of yellow‐necked mice (Apodemus flavicollis) impact the dispersal of common oak (Quercus robur) acorns. Over 3 years, we collected data on seed fate and the specific mice responsible for their dispersal. The relationship between individual traits and seed dispersal was not static, but influenced by yearly environmental conditions. Heavier individuals tended to carry seeds farther, yet contrary to our expectations, sex had no effect on the distance of seed dispersal. Moreover, the exploration rate showed an inconsistent association with seed consumption and dispersal distance, while it positively impacted the distance of dispersal from the nearest tree. Synthesis. Our findings suggest a more nuanced role of individual traits in seed dispersal than often assumed, with noticeable annual variation significantly influencing these impacts. Consequently, it appears there is no single, universally beneficial individual type to ensure maximal benefits to plants. Rather, the traits conferring advantages in seed dispersal are dynamic, subject to change over time in response to environmental context. Read the free Plain Language Summary for this article on the Journal blog.

Improving precision and robustness in level control of coupled tank systems: A tree seed optimization and [formula omitted]-analysis approach

Background:Efficient control of liquid levels in interconnected tank systems is a fundamental challenge in various industries, including chemical processes, wastewater treatment, and manufacturing. The traditional approach to achieving precise control has relied on Proportional–Integral–Derivative (PID) controllers, whose performance largely depends on tuned parameters. However, tuning PID controllers for complex and nonlinear systems like coupled tanks remains a challenging task. In recent years, nature-inspired optimization algorithms have gained prominence in control system design. The tree seed optimization (TSO), inspired by the dispersion of tree seeds in search of optimal growth conditions, has shown promise in solving complex optimization problems. This study seeks to explore the application of TSO in tuning PID controllers for coupled tank systems. Methodology:This research employs the TSO to optimize PID controller parameters for enhanced liquid-level control in coupled tank systems. The optimization process involves integrating performance metrics and closed-loop gain constraints to achieve optimal control of coupled tank systems. The imposed constraints aim to ensure robustness and system stability in the face of uncertainties and disturbances. Besides, μ analysis quantifies the robustness of the system by assessing its ability to tolerate uncertainties. Findings:Simulation studies conducted in this research verify the efficacy of the proposed TSO-based approach for tuning PID controllers in coupled tank systems. Compared with various methods, the TSO consistently yields better control performance, reduces settling time, and minimizes overshoot. The robustness of the optimized controllers is also evaluated, showing the ability to handle varying operating conditions effectively.

Structure and vulnerability of the ichthyochory network in wetland forests of Central Amazonia

AbstractThe interaction between fish and plants is vital for the dynamics of ecosystems since it influences plant distribution and regeneration patterns. In the floodable areas of the Amazon, these interactions are mainly structured by the flood pulse, which enables seed dispersal via water (hydrochory) and fish (ichthyochory), and which contributes to the formation of complex mutualistic networks. Our study evaluated the structure (modularity, nestedness, specialisation, and robustness) of the network of dispersal of seeds by frugivorous fish in a floodplain forest in Central Amazonia. We expect the binary network to have a nested pattern, while the weighted network is expected to have a non‐nested structure; that generalist frugivorous species should constitute the core of the network, while specialist frugivorous species will be peripheral; that the size of fish and seeds is related to specialisation, and that the robustness of the network weakens as generalist frugivorous fish are removed. We found 5012 intact seeds from 49 plant species in the digestive tracts of 11 species of frugivorous fish. A nested and modular pattern was found for the binary and weighted networks, albeit with a low degree of nestedness. Our network proved relatively robust when the frugivores were removed, whereby all the fish and plant species became peripheral. No relationship was found between the size of the fish and the seeds and the degree of specialisation. Considering the anthropogenic impacts that can cause modifications in seed dispersal networks, knowing the structure of mutualistic networks is fundamental in order to be able infer the vulnerability of the interactions as a result of changes in the ecosystem.

Optimal Selection of Seed-Trees Using the Multi-Objective NSGA-II Algorithm and a Seed Dispersal Model

Optimal seed-tree selection during natural regeneration of shade-intolerant species requires ensuring an ample and uniform seed supply from residual trees with the smallest possible seed-tree density. Here, we propose a novel approach for seed-tree selection using the genetic algorithm. Data are derived from a 3-hectare even-aged stand of Pinus canariensis C.Sm. ex DC, comprising 364 mature trees and 103 seed-traps. Seeds were collected in 2007 and 2008. After constructing a seed-dispersal model for each seed-crop year, we employ the multi-objective non-dominated sorting genetic algorithm to identify the smallest seed-tree set that maximizes post-treatment seed supply and its spatial homogeneity. Optimal solutions range from a maximum of 68.4% to a minimum of 38.1% reduction in stand density, resulting in a 59.5% to 28% reduction in post-felling seed supply. The coefficient of variation of among-site seed-flux varies from 28% to 59.5%. Proposing a treatment involving the removal of 240 trees (65.9% stand-density reduction) and leaving 40 seed-trees per hectare, our findings provide insights into balancing the conflicting objectives of sufficient post-treatment seed supply at a minimum seed-tree density. This approach marks a departure from traditional practices, as the decision about which trees to cut is historically left to the discretion of field managers.

Effects of tidal creeks on Spartina Alterniflora expansion: A perspective from multi-scale remote sensing

Rapid expansion of Spartina Alterniflora (S. alterniflora) has led to severe ecological consequences in coastal wetlands in China. Better understanding of the mechanism of S. alterniflora expansion is of great importance for its control and management. Although previous research has reported that the expansion of S. alterniflora is closely related to tidal creeks via field investigations, few studies have quantitatively investigated their relationships using remote sensing at different scales. In this study, we utilized time series satellite remote sensing imagery with different spatial resolutions to investigate the effects of tidal creeks on S. alterniflora expansion at both landscape scale and patch scale. We took the Yellow River Delta (YRD), China as our study area, where S. alterniflora has spread across the intertidal wetlands during the past decade. At landscape scale, we first derived the yearly maps of S. alterniflora and tidal creeks during 2009–2020 based on Landsat-series satellite imagery, then analyzed the spatio-temporal relationship between S. alterniflora and tidal creeks. By using grid analysis method, we evaluated the change of S. alterniflora area and tidal creek length and compared their change time. The results showed that 30.46 % of the grids experienced no change in tidal creeks while expansion of S. alterniflora, and 54.02 % of the grids experienced S. alterniflora area increase after the lengthening of tidal creeks. The results indicated that relationship between tidal creeks and S. alterniflora in YRD was dominated by “tidal creeks promoting S. alterniflora expansion”. We then simulated the S. alterniflora expansion at patch scale using an improved spatially explicit individual-based model based on S. alterniflora maps derived from Landsat imagery (30 m) and GF-1 high spatial resolution imagery (2 m), respectively. The results showed that consideration of long-distance dispersal of seeds along the direction of tidal creeks considerably enhanced the simulation accuracy, regardless of the spatial resolution of the S. alterniflora maps. High-resolution S. alterniflora maps yielded higher simulation accuracies. Our study suggests that the long-distance dispersal of seeds led by tidal creeks is an important manner for S. alterniflora expansion. Satellite remote sensing imagery have great potential to discover the mechanism of S. alterniflora expansion, facilitating control of S. alterniflora at the early invasion stage.

Dispersal and persistence of cup plant seeds (Silphium perfoliatum): do they contribute to potential invasiveness?

Background and aims – The cup plant (Silphium perfoliatum) is being grown in Germany as a promising new bioenergy crop with an increasing area under cultivation in the last years. Its alien status, its high productivity, and high reproductive potential could carry the risk of this species becoming invasive. The present study investigates the dispersal and persistence of cup plant seeds, to contribute to the assessment of its invasive potential. Material and methods – For this purpose, four experimental studies were conducted in Germany, Central Europe: wind dispersal distance was measured in a field experiment for wind speeds up to 7 m.s-1. The seeds were offered to rodents in different habitats near to a cup plant field. We observed seed persistence and germination over 4 weeks storing in water and over 4 years storing in different soil depths. Key results – Cup plant seeds are dispersed by wind only over a few meters. In the forest, rodents removed 100% of the offered seeds, in open habitats none. Independent of the duration of storage in water, germination rate of the cup plant seeds was constantly high. Most of the seeds already germinated in water in the first two weeks. Stored on the soil surface and at 10 cm soil depth, the seeds germinated already in the first two years. Stored at 30 cm depth, one third of the seeds retained their germination ability over four years. Conclusion – Wind serves as short-distance dispersal vector for cup plant seeds. Rodents remove the seeds, but it is unknown whether they disperse them or just eat them. Water could disperse the seeds, which retain their germination ability, over long distances. The cup plant could therefore spread and possibly become invasive in Central Europe, and therefore measures are suggested to prevent its dispersal and spontaneous settlement.

Frugivory by carnivores: Black‐backed jackals are key dispersers of seeds of the scented !nara melon in the Namib Desert

AbstractCarnivorous mammals have been reported to feed on fleshy fruits and disperse seeds, but these interactions are seldom observed and are poorly understood in hyper‐arid regions. Scent may play a key role in these interactions, given that most carnivores have sensitive olfactory systems and dichromatic vision. The !nara (Acanthosicyos horridus: Cucurbitaceae) in the Namib Desert produces large (10–20 cm diameter) melons that remain green while undergoing increased volatile emissions with a changing chemical profile as they ripen. Using extensive camera trapping, we found that the fruits are consumed mainly by black‐backed jackals (Canis mesomelas) and rarely also by other carnivores such as cape fox (Vulpes chama) and brown hyaena (Hyaena brunnea). We found that scent cues play a crucial role as jackals mainly sought fruits at night and easily located ripe fruits that were experimentally buried beneath the sand to remove visual cues. Seeds retrieved from jackal scat showed improved germination relative to un‐ingested seeds. This study highlights the importance of fruit scent in mediating seed dispersal mutualisms involving carnivores.

Tipping Points in Seed Dispersal Mutualism Driven by Environmental Stochasticity

Tipping Points in Seed Dispersal Mutualism Driven by Environmental Stochasticity

Seed dispersal by frugivores without seed swallowing: Evaluating the contributions of stomatochoric seed dispersers

Abstract 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. 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. Stomatochoric dispersers can displace large quantities of seeds, including large seeds and those of large fruits, and over short to long distances (&gt;1 km). Compared with 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. 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. 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. Read the free Plain Language Summary for this article on the Journal blog.

Effects of Habitat and Fruit Scent on the Interactions between Short-tailed Fruit Bats and Piper Plants.

Piper is a mega-diverse genus of pioneer plants that contributes to the maintenance and regeneration of tropical forests. In the Neotropics, Carollia bats use olfaction to forage for Piper fruit and are a main disperser of Piper seeds via consumption and subsequent defecation during flight. In return, Piper fruits provide essential nutrients for Carollia year-round. There is evidence that the types and diversity of Piper frugivores are influenced by the primary habitat type of different Piper species (forest and gap), with forest Piper depending more on bats for seed dispersal; however, this pattern has not been tested broadly. We aimed to characterize and compare the interactions between Carollia and Piper across forested and gap habitats, and further investigate whether differences in fruit traits relevant to bat foraging (i.e., scent) could underlie differences in Carollia-Piper interactions. We collected nightly acoustic ultrasonic recordings and 24 h camera trap data in La Selva, Costa Rica across 12 species of Piper (six forest, six gap) and integrated this information with data on Carollia diet and Piper fruit scent. Merging biomonitoring modalities allowed us to characterize ecological interactions in a hierarchical manner: from general activity and presence of bats, to visitations and inspections of plants, to acquisition and consumption of fruits. We found significant differences in Carollia-Piper interactions between forested and gap habitats; however, the type of biomonitoring modality (camera trap, acoustics, diet) influenced our ability to detect these differences. Forest Piper were exclusively visited by bats, whereas gap Piper had a more diverse suite of frugivores; the annual diet of Carollia, however, is dominated by gap Piper since these plants produce fruit year-round. We found evidence that fruit scent composition significantly differs between forest and gap Piper, which highlights the possibility that bats could be using chemical cues to differentially forage for gap vs. forest Piper. By integrating studies of Piper fruit scent, plant visitation patterns, and Carollia diet composition, we paint a clearer picture of the ecological interactions between Piper and Carollia, and plant-animal mutualisms more generally.

The role of feeding roosts in seed dispersal service bats provide in urban areas

AbstractIn urban ecosystems, bats play an essential role in seed dispersal, which is facilitated by their use of feeding roosts. However, there are several knowledge gaps in this ecosystem service that bats provide in urban areas. We aimed to describe the fruits consumed by bats in an urban area, the selection and use of feeding roosts, and the patterns of seed dispersal by fruit bats in a Brazilian city. We collected and identified the seeds deposited under feeding roosts and tested for differences in the size of the seed of fruits consumed by bats and the seeds of fruits available in the study area. We also captured and identified bats feeding near roosts using mist nets and assessed the vegetation structure and urban variables that might influence the bats' tree choice for roosts. We found that Artibeus lituratus, Artibeus planirostris, and Platyrrhinus lineatus potentially used feeding roosts and preferred the tallest trees, which were located further away from artificial light. The average distance of seed dispersal was 105.5 meters, and the average size of the dispersed seeds did not differ from the seeds of the fruits available in the area, suggesting that bats are not limited to dispersing only tiny seeds. However, the prevalence of exotic seeds raises concerns that bats may spread exotic species, especially in surrounding protected areas. These results highlight the importance of frugivorous bats as significant seed dispersers in urban areas and emphasize the need for further research to understand their role in shaping urban ecosystems.Abstract in Portuguese is available with online material.