The southern cassowary (Casuarius casuarius johnsonii) remains an important disperser of native plants in fragmented rainforest landscapes

Large-bodied frugivores are essential to the ecological function of rainforest communities. The southern cassowary (Casaurius casuarius johnsonii) is the only large frugivore in the tropical rainforests of Australia. Here, we assessed whether cassowaries remain important to native plant seed dispersal in areas where the rainforest is highly fragmented, and exotic fruits are abundant. To do this, we developed a tri-axial acceleration logger integrated with a motion sensor and VHF radio transmitter. The telemetry device was small enough to be hidden inside a native fruit. The cassowaries ingested it, transported it and defecated it up to 24 h later with the seeds from the fruits they had ingested during the tracking period. The telemetry device was then located by VHF radio and collected with the scat. The distance travelled, activity profile, consumed fruit diversity, and scat energy content were assessed for cassowaries inhabiting regions with different degrees of urbanization. We found that cassowaries inhabiting more urbanized areas consumed the greatest proportion of fruits from exotic plants (~30%) but still incorporated a significant proportion of fruits from native plants in their diet. These individuals existed in higher states of activity and rested less than individuals inhabiting more intact swathes of rainforest, actively moving between urban gardens and the rainforest. The study shows cassowaries have a flexible foraging strategy that has enabled them to persist in rainforest-fragmented landscapes. They remain a significant disperser of seeds from native plants between rainforest patches, and as such, cassowaries remain essential in maintaining native plant diversity within these fragmented patches.     

Diet and Dietary Preferences of the Southern Cassowary (Casuarius casuarius) in North Queensland, Australia

We investigated the diet of the southern cassowary (Casuarius casuarius) by identifying the seeds and fruits in fecal droppings encountered on a set of transects over 2 yr in upland rain forest in the wet tropics of North Queensland. A total of 198 droppings containing 56 plant species were found. We surveyed fleshy fruit availability over the subsequent 68 mo on transects in the same area to ascertain fruiting patterns in the study area. The number of droppings found each month did not correspond to the pattern of available fruit biomass. There was no relationship between the fruit traits of moisture content, flesh to seed mass ratio, color, or crop size to contribution of a species to the diet. During the lean fruiting season (May–July) cassowaries relied more on species that fruited continuously throughout the year as they were significantly over‐represented in droppings, while annual fruiting species were under‐represented. During months of high fruit availability (October–December), continuously fruiting species were still over‐represented in the diet but became less important while annual and biennial species became more important. Significantly more species with large fruit and large seeds appeared in the diet than expected and we confirm that the cassowary contributes to the continued dispersal of these species over long distances and in large quantities.     

Gut passage effect of the introduced red‐whiskered bulbul (Pycnonotus jocosus) on germination of invasive plant species in Mauritius

In Mauritius, many of the worst invasive plant species have fleshy fruits and rely on animals for dispersal. The introduced red‐whiskered bulbul (Pycnonotus jocosus) feeds on many fleshy‐fruited species, and often moves from invaded and degraded habitats into higher quality native forests, thus potentially acting as a mediator of continued plant invasion into these areas. Furthermore, gut passage may influence seed germination. To investigate this, we fed fleshy fruits of two invasive plant species, Ligustrum robustum and Clidemia hirta, to red‐whiskered bulbuls. Gut passage times of seeds were recorded. Gut‐passed seeds were sown and their germination rate and germination success compared with that of hand‐cleaned seeds, as well as that of seeds in whole fruits. Gut passage and hand‐cleaning had significant positive effects on germination of both species. Gut‐passed seeds of both C. hirta and L. robustum germinated faster than hand‐cleaned seeds. However, for L. robustum, this was only true when compared with hand‐cleaned seeds with intact endocarp; when compared with hand‐cleaned seeds without endocarp, there was no difference. For overall germination success, there was a positive effect of gut passage for C. hirta, but not for L. robustum. For both C. hirta and L. robustum, no seeds in intact fruits geminated, suggesting that removal of pulp is essential for germination. Our results suggest that, first, the initial invasion of native forests in Mauritius may not have happened so rapidly without efficient avian seed dispersers like the red‐whiskered bulbul. Second, the bulbul is likely to be a major factor in the continued re‐invasion of C. hirta and L. robustum into weeded and restored conservation management areas.     

Ingestion by an endemic frugivore enhances seed germination of endemic plant species but decreases seedling survival of exotics

Aim To test whether ingestion by endemic frugivores differentially affects the seed germination time, germination percentage and seedling survival of endemic, native and exotic fleshy fruited plant species, and to identify the principal processes and attributes driving such effects. Location Round Island, Mauritius. Methods We conducted a germination and seedling survival experiment for 3 months to test whether ingestion (gut passage and deposition in faeces) by the endemic Telfair’s skink (Leiolopisma telfairii) had a differential effect on the germination time, germination percentage and seedling survival of two endemic, four native and two exotic fleshy fruited plant species. To assess the importance of factors involved in the ingestion process, we used a factorial design with gut passage (gut‐passed vs. not gut‐passed), depulping (whole fruit vs. manually depulped seed) and the presence of faecal material (faeces vs. without faeces). In addition, the roles of species‐specific traits, seed size and deposition density (average number of seeds per faeces) were examined. Results Exotic species had a higher germination percentage than indigenous (native and endemic) species when not ingested. Following skink ingestion, there was no longer a difference, as ingestion enhanced germination percentage most in endemic species. The exotic species still germinated faster overall than the indigenous species, despite ingestion accelerating the germination time of endemics. However, ingestion strongly reduced seedling survival of the exotic species, while having no negative effect on the survival of indigenous seedlings. Overall, ingested indigenous seeds were more likely to germinate and the seedlings more likely to survive than ingested exotic seeds and seedlings. Seed size, deposition density and the removal of fruit pulp by either manual depulping or gut passage were important predictors of germination time, germination percentage and seedling survival. Main conclusions These endemic frugivores can enhance the competitiveness of endemic compared with exotic fleshy fruited plants at the critical germination and seedling establishment stage. Consequently, conservation and restoration of mutualistic endemic plant–animal interactions may be vital to mitigating the degradation of habitats invaded by exotic plants, which is of particular relevance for island ecosystems in which large numbers of endemics are threatened by exotic invaders.     

The effect of frugivory on postdispersal seed removal and germination in the pantropical forest tree Antiaris toxicaria Leschenault

The quality of seed treatment by frugivores has an effect on seed removal after dispersal, seed germination and tree recruitment. We provide information on postdispersal seed removal, germination and subsequent recruitment in tropical forest tree species Antiaris toxicaria in Ghana. We tested whether postdispersal seed removal and germination rates were differentially affected by the following seed treatments: seeds that were spat out by monkeys with all fruit pulp removed and spitting seeds with fruit pulp partially removed as observed in some birds and bats. We used seeds of intact ripened fruits as control. Frugivore seed treatment and distance from bole affected seed removal patterns, whereas intact seeds were significantly removed from all seed stations. The germination success was greater for seeds that were spat out by monkeys and poor for seeds with fruit pulp partially removed and intact fruits. More recruits were recorded at the edge of the adult A. toxicaria canopy radius. There was weak relationship (r² = 0.042) between the number of recruits and distance away from the adult tree. Results suggest that the subsequent recruitment in tropical forest tree species may be enhanced by some frugivore fruit‐handling behaviour where fruit pulp is removed from the seeds without destroying the seeds.     

A molecular framework for the embryo growth in germinating seeds of Solanum lycocarpum A. St.‐Hil., a nurse plant species

We are clarifying how the functional embryo growth occurs in germinating seeds of Solanum lycocarpum A. St.‐Hil., a nurse plant with a central role in forest dynamics in the Cerrado (a biodiversity hotspot). For that, we used classical seed germination measurements (germinability, mean germination time, mean germination rate, coefficient of variation of the germination time, synchronisation index and germination time range) and gene expression of mRNA codifying key proteins/enzymes for the success in the seed–seedling transition (Cyclin, Actin, Small Heat Shock Protein, Glutathione S‐transferase, Malate Dehydrogenase, Alcohol Dehydrogenase). Our findings demonstrate: (a) Although germination kinetics in S. lycocarpum seeds is slower than that in tomato seeds, the fold change of genes codifying key enzymes for the embryo development is similar in germinating seeds of both species. (b) The genes used here are useful, from a technical point of view, for classifying commercial seed samples of the species in relation to physiological quality. More notably, cyclin and malate dehydrogenase genes have a greater expression, both in germination sensu stricto and in immediate post‐germination. (c) A molecular framework for the embryo growth in germinating seeds of S. lycocarpum can be a functional explication for the species to be a nurse plant. Thus, the overlapping of classical and contemporary measurements is especially interesting to those species playing a central role in the environment, such as nurse plants, and may represent a new conservationist paradigm.     

Linking frugivore activity to early recruitment of a bird dispersed tree,Eugenia umbelliflora (Myrtaceae) in the Atlantic rainforest

Seed dispersal by animals is a complex process involving several distinct stages: fruit removal by frugivores, seed delivery in different microhabitats, seed germination, seedling establishment, and adult recruitment. Nevertheless, studies conducted until now have provided scarce information concerning the sequence of stages in a plant's life cycle in its entirety. The main objective of this study was to evaluate the immediate consequences of frugivore activity for Eugenia umbelliflora (Myrtaceae) early recruitment by measuring the relative importance of each fruit‐eating bird species on the establishment of new seedlings in scrub and low restinga vegetation in the Atlantic rainforest, Brazil. We conducted focal tree observations on E. umbelliflora trees recording birds' feeding behaviour and post‐feeding movements. We also recorded the fate of dispersed seeds in scrub and low restinga vegetation. We recorded 17 bird species interacting with fruits in 55 h of observation. Only 30% of the handled fruits were successfully removed. From 108 post flight movements of exit from the fruiting trees, 30.6% were to scrub and 69.4% to low restinga forest. Proportion of seed germination was higher in low restinga than in the scrub vegetation. Incorporating the probabilities of seeds' removal, deposition, and germination in both sites, we found that the relative importance of each frugivorous bird as seed dispersers varies largely among species. Turdus amaurochalinus and Turdus rufiventris were the best dispersers, together representing almost 12% probability of seed germination following removal. Our results show the importance of assessing the overall consequence of seed dispersal within the framework of disperser effectiveness, providing a more comprehensive and realistic evaluation of the relative importance of different seed dispersers on plant population dynamics.     

Germination of Prosopis juliflora (Sw) DC seeds after scarification treatments

Invasive plant species are the second most important threat to global biodiversity loss after land‐use change. Invasive species can modify native community composition, deplete species diversity and affect ecosystem processes. The Caatinga is one of the most human‐affected Brazilian ecosystems owing to non‐sustainable use of its natural resources. Prosopis juliflora is an important invasive plant species in the Caatinga ecosystem. Seed germination is a critical stage in plant life cycles and is a major factor in the establishment and success of invasive plant species. Among the factors that affect seed germination and dormancy, coat‐imposed seems to be the most important for P. juliflora. In Prosopis species, the ingestion of fruits by wild and domestic animals may promote and accelerate germination, enhancing the dispersal of seeds and fruits of these species. We investigated the germination capacity of P. juliflora seeds after artificial mechanical and chemical scarification and analyzed the changes in seedling vigor caused by the scarification treatments. Germination rate, germination time (TMG) and germination synchrony (E) differed significantly with the length of the scarification treatments in H₂SO₄ for both seeds with endocarps and seeds without endocarps (non‐endocarp seeds). Sulfuric acid affected plant survival more strongly than germination rate, particularly in non‐endocarp seeds.     

Seed dispersal by Galápagos tortoises

Aim Large‐bodied vertebrates often have a dramatic role in ecosystem function through herbivory, trampling, seed dispersal and nutrient cycling. The iconic Galápagos tortoises (Chelonoidis nigra) are the largest extant terrestrial ectotherms, yet their ecology is poorly known. Large body size should confer a generalist diet, benign digestive processes and long‐distance ranging ability, rendering giant tortoises adept seed dispersers. We sought to determine the extent of seed dispersal by Galápagos tortoises and their impact on seed germination for selected species, and to assess potential impacts of tortoise dispersal on the vegetation dynamics of the Galápagos. Location Galápagos, Ecuador. Methods To determine the number of seeds dispersed we identified and counted intact seeds from 120 fresh dung piles in both agricultural and national park land. To estimate the distance over which tortoises move seeds we used estimated digesta retention times from captive tortoises as a proxy for retention times of wild tortoises and tortoise movement data obtained from GPS telemetry. We conducted germination trials for five plant species to determine whether tortoise processing influenced germination success. Results In our dung sample, we found intact seeds from > 45 plant species, of which 11 were from introduced species. Tortoises defecated, on average, 464 (SE 95) seeds and 2.8 (SE 0.2) species per dung pile. Seed numbers were dominated by introduced species, particularly in agricultural land. Tortoises frequently moved seeds over long distances; during mean digesta retention times (12 days) tortoises moved an average of 394 m (SE 34) and a maximum of 4355 m over the longest recorded retention time (28 days). We did not find evidence that tortoise ingestion or the presence of dung influenced seed germination success. Main conclusions Galápagos tortoises are prodigious seed dispersers, regularly moving large quantities of seeds over long distances. This may confer important advantages to tortoise‐dispersed species, including transport of seeds away from the parent plants into sites favourable for germination. More extensive research is needed to quantify germination success, recruitment to adulthood and demography of plants under natural conditions, with and without tortoise dispersal, to determine the seed dispersal effectiveness of Galápagos tortoises.     

Can rodents enhance germination rates in rainforest seeds?

The decline of large coevolved frugivorous species within fragmented habitats can have an effect on ecological processes, for example, seed dispersal and germination. It is therefore necessary for more resilient species to ensure essential processes are maintained within the system. This study investigates the influence of two rodent species, Melomys cervinipes (Fawn‐footed Melomys) and Rattus fuscipes (Bush Rat), on the germination process of rainforest fruits. Both species are endemic to north Queensland rainforest and commonly found in fragmented habitats in high densities. We found in 85% of fruit species tested, rodent feeding increased seed germination rate by a factor of 3.5. Our results suggest that rodents can play a significant role in enhancing germination rates of fruits in the tropical rainforest of far north Queensland.     

Role of Brycinus lateralis (Teleostei: Alestidae) in dispersal and germination of Nymphaea nouchali (Angiospermae: Nymphaeaceae) seeds on a seasonal floodplain of the Okavango Delta,Botswana

Seed passage through the gut of vertebrates can be important for seed dispersal, but might influence seed viability. The ability of seeds to germinate after ingestion by seed-eating fish is important for the population dynamics of some plant species, and significant in the evolution of plant–fish interactions. Certain fish in the Okavango Delta, Botswana, are fruit- and seed-eaters and could act as seed dispersers. We sampled 14 fish species in 2013, finding Nymphaea nouchali var. caerulea seeds in the digestive tracts of eight, most commonly in the striped robber Brycinus lateralis. Seeds extracted from the gut of this species had an overall mean germination success of 11.7%. This fish species might well be a legitimate seed disperser, having a positive effect on seed dispersal from parent plants in the Okavango Delta. The current study represents one of the first investigations of the likelihood of seed dispersal by fish on the African continent.     

A comparative study of seed morphology in relation to desiccation tolerance and other physiological responses in 71 Eastern Australian rainforest species

Seed characteristics were measured in 71 Eastern Australian rainforest species representing 30 families. Sensitivity to desiccation to low moisture contents (< 10%) occurred in 42% of species. We estimate, based on findings from 100 species from this present study and previously published reports, that 49% of Eastern Australian rainforest species have non‐orthodox seeds. Germination level and time to 50% germination were not significantly different between desiccation sensitive (DS) and desiccation tolerant (DT) seeds. The estimation of seed desiccation sensitivity based on predictors is an important tool underpinning ex situ conservation efforts. Seed characteristics differed significantly between DS and DT seeds; that is, DS seeds had: (i) larger fruits (19 949 mg vs 8322 mg); (ii) larger seeds (1663 mg vs 202 mg); (iii) higher seed moisture contents (49.7% vs 35.5% fresh weight); (iv) lower oil content (7.3% vs 24.8% yield); and (v) less investment in seed coats (0.19 vs 0.48 seed coat ratio). Only 25% of DS seeded species had oily seeds compared with 87% of DT seeded species. Most green embryos were DS. Seed coat ratio was the best predictor of seed DS (80% correctly predicted). Seed moisture content at maturity was also related to germination time. Mean seed size was correlated (?0.657, P = 0.01) with mean seed oil content in 46 species. Further research on seed storage physiology of possible oily and/or DS seeded species is crucial to ensure future long‐term security of this biodiversity, particularly for species currently threatened in situ and/or of socioeconomic importance in Eastern Australian rainforests.     

Seed weight and germination behavior of the submerged plant Potamogeton pectinatus in the arid zone of northwest China

Variation in seed weight is common within and among plant species, but few studies have attempted to document the pattern of seed weight and germination attributes for aquatic macrophytes at a large scale. This study examined within‐species variation in seed weight and germination attributes and the effects of environmental factors on seed traits of the submerged plant Potamogeton pectinatus in the arid zone of northwest China. Our results showed that the average seed weight was 0.24 g per 100 seeds with a coefficient of variation (CV) of 28.4% among the eight P. pectinatus populations. The total germination fraction of seeds of P. pectinatus was relatively poor, less than 35% in seven P. pectinatus populations, and the lowest germination percentage found was only 2%. There were significant differences in seed weight, time to onset of germination, and total germination fraction among the eight different populations. Hierarchical partitioning analysis showed a strongly positive correlation between seed weight and water temperature and pH. Seed weight and the maternal environmental factors significantly affected both time to initiation of germination and total germination fraction. Our results suggest that (1) seed weight variation in P. pectinatus primarily is the result of temperature variation during fruit development; (2) relatively poor germination fraction suggests that seeds are relatively unimportant in the short‐term survival of populations and that it may be another adaptive trait allowing plants to take place in the right place and at the right time, especially in harsh environment; and (3) variation in seed germination traits should be determined by local environmental and intrinsic factors that interact in a complex fashion.     

Seed dynamics of resprouting shrubs in grassy woodlands: Seed rain,predators and seed loss constrain recruitment potential

Abstract Measuring the fate of seeds between seed production and seedling establishment is critical in understanding mechanisms of recruitment limitation of plants. We examined seed fates to better understand the recruitment dynamics of four resprouting shrubs from two families (Fabaceae and Epacridaceae) in temperate grassy woodlands. We tested whether: (i) pre‐dispersal seed predation affected seed rain; (ii) post‐dispersal seed predation limited seed bank accumulation; (iii) the size of the seed bank was related to seed size; and (iv) viable seeds accumulated in the soil after seed rain. There was a distinct difference in seed production per plant between plant families with the legumes producing significantly more seeds per individual than the epacrids. Seed viability ranged from 43% to 81% and all viable had seed or fruit coat dormancy broken by heat or scarification. Pre‐dispersal predation by Lepidopteran larvae removed a large proportion of seed from the legume seed rain but not the epacrids. Four species of ants (Notoncus ectatomoides, Pheidole sp., Rhytidoponera tasmaniensis and Iridomyrmex purpureus) were major post‐dispersal seed removers. Overall, a greater percentage of Hardenbergia (38%) and Pultenaea (59%) seeds were removed than the fleshy fruits of Lissanthe (14%) or Melichrus (0%). Seed bank sizes were small (<15 seeds m^?2) relative to the seed rain and no significant accumulation of seed in the soil was detected. Lack of accumulation was attributed to seed predation as seed decay was considered unlikely and no seed germination was observed in our study sites. Our study suggests that seed predation is a key factor contributing to seed‐limited recruitment in grassy woodland shrubs by reducing the number of seeds stored in the soil.     

The role of Rhytidoponera metallica (Hymenoptera,Formicidae) in facilitating post‐fire seed germination of three ant‐dispersed legume species

The fire avoidance hypothesis proposes that a benefit of seed dispersal by ants (myrmecochory) is to protect seeds from being killed during fire and to facilitate post‐fire germination of seeds that require heat shock to break their physical dormancy. The aim of this study was to quantify the effect of fire and seed burial by a predominant seed‐dispersing ant, Rhytidoponera metallica (subfamily: Ectatomminae) on germination levels of three ant‐dispersed legume species (Pultenaea daphnoides, Acacia myrtifolia and Acacia pycnantha). Experimental burial of seeds within aluminium cans at a site prior to being burnt and at an adjacent unburnt site showed that fire increased germination levels, particularly for seeds buried at 1‐ and 2‐cm deep and that overall, germination levels differed among the three plant species. To quantify seed burial depths and post‐fire germination levels facilitated by R. metallica ants, seeds were fed to colonies prior to fire at the burnt and unburnt sites. Of the seeds buried within nests that were recovered, between 45% and 75% occurred within the upper 6 cm of the soil profile, although unexpectedly, greater percentages of seeds were recovered from the upper 0–2 cm of nests in the unburnt site compared with nests in the burnt site. Germination levels of buried seeds associated with R. metallica nests ranged from 21.2% to 29.5% in the burnt site compared with 3.1–14.8% in the unburnt site. While increased seed germination levels were associated with R. metallica nests following fire, most seeds were buried at depths below those where optimal temperatures for breaking seed dormancy occurred during the fire. We suggest that R. metallica ants may provide fire avoidance benefits to myrmecochorous seeds by burying them at a range of depths within a potential germination zone defined by intra‐ and inter‐fire variation in levels of soil heating.     

Effects of gut passage,feces, and seed handling on latency and rate of germination in seeds consumed by capuchins (Cebus capucinus)

One of the key measures of the effectiveness of primary seed dispersal by animals is the quality of seed dispersal (Schupp: Plant Ecol 107/108 [1993] 15–29). We present data on quality of seed dispersal by two groups of white‐faced capuchins (Cebus capucinus) in Costa Rica to test the hypothesis that capuchin seed handling results in effective primary dispersal for some fruit species they consume. We examined seed handling for 27 plant species, and germination rates of 18 species consumed by capuchins. For five of the most commonly swallowed seed species, we determined germination rates and average time to germination (latency) for seeds ingested and defecated by capuchins and compared these to seeds removed directly from fruit and planted. For the same five species, we compared germination rates and latency for passed seeds planted in capuchin feces to those cleaned of feces and planted in soil. For three of five species, differences in proportion of germinated seeds were significantly higher for gut passed seeds than for controls. For four of five species, germination latency was significantly faster for gut passed seeds than for controls. Feces had either no effect on seed germination rate or precluded germination. Data presented here support the hypothesis that white‐faced capuchins are effective primary dispersers. Am J Phys Anthropol 2009. © 2009 Wiley‐Liss, Inc.     

The impact of consumption of fruit by vertebrate and invertebrate frugivores on the germination success of an Australian rainforest seed

Abstract The consumption of fruits by vertebrates and invertebrates can be both advantageous or detrimental to the survival of the seeds they contain. This study investigated the effect of fruit size and consumption of fruit pulp by rodents and beetles on the germination of the seeds of Acmena graveolens, a tropical rainforest canopy tree found in northern Australia. As fruit size increased, germination success and the amount of pulp remaining on the fruits was greater. When beetles were absent, germination success was highest when most of the pulp was removed by rodents, suggesting that they removed an inhibitor of germination. When beetles were present, germination success did not differ significantly across pulp categories, so beetles apparently enhanced germination in seeds with little pulp initially removed, possibly by further removal of fruit pulp. In this study, both rodents and beetles enhanced germination success of A. graveolens seeds by consumption of fruit pulp. Acting as facilitators of germination is a relatively unusual role for both these frugivores that are generally considered to act as seed predators or (in the case of rodents) dispersers.     

The role of frugivorous birds in fruit removal and seed germination of the invasive alien Cotoneaster franchetii in central Argentina

Many invasive plant species have fleshy fruits that are eaten by native frugivorous birds which disperse their seeds and may facilitate their germination, playing an important role in plant invasion success. The fleshy‐fruited shrub Cotoneaster franchetii (Rosaceae) is an important invasive alien in the mountainous regions of central Argentina. To determine the role of avian frugivorous in fruit removal of this species, we conducted a frugivore exclusion experiment including bagged and unbagged branches in 75 plants of C. franchetii. At the end of the dispersal period, we compared the percentage of missing fruits (removed by birds + naturally dropped) in unbagged branches with the percentage of naturally dropped fruits in bagged branches. To assess whether any mechanism acting on seeds during their passage through bird guts (de‐inhibition by pulp removal and/or seed scarification) affects seed germination of this species, we compared percentage and speed of germination among seeds obtained from faeces of the native frugivorous Turdus chiguanco, from manually de‐pulped fruits, and from intact fruits. The percentage of missing fruits per shrub in unbagged branches was significantly higher than the percentage of naturally dropped fruits in bagged branches, suggesting that frugivorous birds play an important role in fruit removal of C. franchetii in the study area. Seeds from bird faeces and from manually de‐pulped fruits germinated in higher percentage and faster than seeds from intact fruits. Germination percentage and speed of seeds from manually de‐pulped fruits were significantly higher than those of gut‐passed seeds. These results indicate that T. chiguanco increases and accelerates seed germination of C. franchetii through pulp removal, but not through seed scarification. Overall, our findings indicate that native frugivorous birds facilitate the dispersal and germination success of C. franchetii, likely playing an important role in its invasion throughout the mountainous region of central Argentina.     

Seed Dynamics of Early and Late Successional Tree Species in Tropical Abandoned Pastures: Seed Burial as a Way of Evading Predation

We explored different treatments to enhance the probability of sowed seeds of two early successional (ES, Cecropia obtusifolia and Ochroma pyramidale) and two late successional (LS, Brosimum costaricanum and Dialium guianense) species to escape predation and germinate in abandoned cattle‐raising pasture fields in Southeastern Mexico. ES species were sown in groups of 50 seeds under three treatments: invertebrate exclusion, burial, and exposition to seedeaters. LS species were sown in groups of 10 seeds under three treatments: vertebrate exclusion, burial, and exposition to seedeaters. We registered seed predation and germination 2, 4, 8, 16, 32, and 64 days after the initial sowing. Overall, ES showed higher predation rates (mean ± SE = 0.45 ± 0.07 seed seed^?1 day^?1; n = 3) than LS species (0.09 ± 0.02 seed seed^?1 day^?1). Cecropia obtusifolia was completely predated in all treatments after 8 days. Burial and exclusion treatments reduced final predation in circa 6% for O. pyramidale, relative to that of exposed seeds (85% after 8 days); most germination occurred in buried seeds (3.7%). In B. costaricanum, burial enabled germination by 10%; exposed and excluded seeds were removed 100%. Dialium guianense showed 12% germination in buried seeds and circa 20% of the seeds were not removed after 64 days. Direct sowing would be a recommended rainforest restoration practice for species with relatively large seeds if deposited in groups and buried. Studies which address variation across numerous sites are necessary in order to generate more consistent seed predation patterns and rainforest restoration principles in tropical pastures.