scholarly journals Seed dispersal by Ceratogymna hornbills in the Dja Reserve, Cameroon

1998 ◽  
Vol 14 (3) ◽  
pp. 351-371 ◽  
Author(s):  
KENNETH D. WHITNEY ◽  
MARK K. FOGIEL ◽  
AARON M. LAMPERTI ◽  
KIMBERLY M. HOLBROOK ◽  
DONALD J. STAUFFER ◽  
...  
Keyword(s):  
Seed Germination ◽  
Seed Dispersal ◽  
Tropical Forests ◽  
Tree Species ◽  
Forest Regeneration ◽  
Germination Rate ◽  
Gut Passage ◽  
Forest Elephants ◽  
Seed Dispersers ◽  
Passage Times

Seed dispersal is a process critical to the maintenance of tropical forests, yet little is known about the interactions of most dispersers with their communities. In the Dja Reserve, Cameroon, seed dispersal by the hornbills Certaogymna atrata, C. cylindricus and C. fistulator (Aves: Bucerotidae) was evaluated with respect to the taxonomic breadth of plants dispersed, location of seed deposition and effects on seed germination. Collectively, the three hornbill species consumed fruits from 59 tree and liana species, and likely provided dispersal for 56 of them. Hornbill-dispersed tree species composed 22% of the known tree flora of the site. Hornbill visit lengths, visit frequencies, and seed passage times indicated that few seeds were deposited beneath parent trees; in five hornbill/tree species pairings studied, 69–100% of the seeds ingested were deposited away from the parent trees. Germination trials showed that hornbill gut passage is gentle on seeds. Of 24 tree species tested, 23 germinated after passage by hornbills; of 17 planted with controls taken directly from trees, only four species showed evidence of inhibition of germination rate, while seven experienced unchanged germinated rates and six experienced enhanced germination rates. Results suggested that Certaogymna hornbill rank among the most important seed dispersers found in Afrotropical forests, and they deserve increased conservation attention. Ceratogymna hornbills are likely to become increasingly important in forest regeneration as populations of larger mammalian seed dispersers (such as forest elephants and primates) diminish.

scholarly journals Endozoochory and Germination of Selected Ingested Seeds by Malayan Box Turtles (Cuoraamboinensis) from Laguna Province, Philippines

2021 ◽  
pp. 19-27
Author(s):  
Kliff Eldry G. Ibañez ◽  
Larry V. Padilla
Keyword(s):  
Seed Germination ◽  
Seed Dispersal ◽  
Germination Rate ◽  
Dispersal Capacity ◽  
Plant Seed ◽  
Gut Passage ◽  
Significant Difference ◽  
Box Turtles ◽  
Percent Germination ◽  
Pass Through

Aims: Malayan box turtles’ (Cuoraamboinensis) ecological niche are essential in an ecosystem but are often overlooked. This study investigated the germination of selected seeds that passed through the gut of Malayan box turtles to determine its role in promoting seed dispersal and aiding seed germination. Study Design:Experimental approach. Place and Duration of Study:Pamantasan ng Lungsod ng Maynila (University of the City of Manila) and Dasmarinas, Cavite between June 2016 to March 2017. Methodology: The seeds that passed through the turtle’s gut (Gut Passed Seeds) and seeds that did not pass through its gut (Mechanically Extracted Seeds) underwent comparative germination test. The Germination Rate (GR) and Percent Germination (%GR) of each group were determined in the study.Seed shadowing was also conducted to evaluate the turtle’s seed dispersal capacity (endozoochory). Results: Results showed that after gut passage, seed GR and %GR were enhanced on Lycopersiconesculentum, Carica papaya, Psidiumguajava, and Muntingiacalabura. However, Germination Rate and Percent Germination of Passifloraquadrangularis decreased after gut passage. Statistical analyses revealed that there is a significant difference in the GR and %G of M. calabura and %G of L. esculentum, and P. quadrangularis. Thread trailing method showed that C. amboinensis can disperse seeds at a distance of 24.8 to 52.8 meters. Conclusion: This study demonstrates the important role of C. amboinensis in the ecosystem through its contribution to plant seed germination and dispersal.It showed that Malayan box turtles are not only seed dispersal agents but are also important in the germination of seeds that they have ingested and defecated.

scholarly journals Animal movement drives variation in seed dispersal distance in a plant–animal network

2019 ◽  
Vol 286 (1894) ◽  
pp. 20182007 ◽  
Author(s):  
E. Rehm ◽  
E. Fricke ◽  
J. Bender ◽  
J. Savidge ◽  
H. Rogers
Keyword(s):  
Seed Dispersal ◽  
Animal Movement ◽  
Bird Species ◽  
Dispersal Distance ◽  
Dispersal Patterns ◽  
Long Distance ◽  
Gut Passage ◽  
Dispersal Distances ◽  
Seed Dispersal Distance ◽  
Passage Times

Frugivores play differing roles in shaping dispersal patterns yet seed dispersal distance is rarely quantified across entire communities. We model seed dispersal distance using gut passage times and bird movement for the majority (39 interactions) of known bird–tree interactions on the island of Saipan to highlight differences in seed dispersal distances provided by the five avian frugivores. One bird species was found to be a seed predator rather than a disperser. The remaining four avian species dispersed seeds but differences in seed dispersal distance were largely driven by interspecific variation in bird movement rather than intraspecific variation in gut passage times. The median dispersal distance was at least 56 m for all species-specific combinations, indicating all species play a role in reducing high seed mortality under the parent tree. However, one species—the Micronesian Starling—performed 94% of dispersal events greater than 500 m, suggesting this species could be a key driver of long-distance dispersal services (e.g. linking populations, colonizing new areas). Assessing variation in dispersal patterns across this network highlights key sources of variation in seed dispersal distances and suggests which empirical approaches are sufficient for modelling how seed dispersal mutualisms affect populations and communities.

Movements of the bat Sturnira lilium and its role as a seed disperser of Solanaceae in the Brazilian Atlantic forest

2008 ◽  
Vol 24 (2) ◽  
pp. 225-228 ◽  
Author(s):  
Marco Aurelio Ribeiro Mello ◽  
Elisabeth Klara Viktoria Kalko ◽  
Wesley Rodrigues Silva
Keyword(s):  
Seed Dispersal ◽  
Tropical Forests ◽  
Atlantic Forest ◽  
Brazilian Atlantic Forest ◽  
Seed Disperser ◽  
Seed Dispersers

Bats and birds carry out most of the seed dispersal in the Neotropics (Galindo-Gonzáles et al. 2000), and are crucial for the dynamics and regeneration of tropical forests (Whittaker & Jones 1994). However, only a few details are known about the interactions in particular bat–fruit systems. Most frugivorous bats are highly mobile (Bernard & Fenton 2003), and do not harm seeds (Fleming & Sosa 1994), suggesting that they are legitimate and effective seed dispersers (sensu Fleming & Sosa 1994).

scholarly journals Colonization of forest clearings and tree-fall gaps in lowland rain forests of Colombia by hemiepiphytic aroids: experimental and transect studies

2013 ◽  
Vol 29 (2) ◽  
pp. 123-130 ◽  
Author(s):  
Ana María Benavides ◽  
Jan H. D. Wolf ◽  
Joost F. Duivenvoorden
Keyword(s):  
Seed Germination ◽  
Tropical Forests ◽  
Tree Species ◽  
Field Studies ◽  
Forest Edges ◽  
Rain Forests ◽  
Closed Forest ◽  
Germination Success ◽  
Germination Experiment ◽  
Soil Substrates

Abstract:The contribution of vegetative recruitment by non-tree species to the regeneration of tropical forests in man-made clearings or tree-fall gaps tends to be ignored. In a series of field studies near Amacayacu, Colombian Amazonia, we tested if hemiepiphytic aroids quickly colonize such open habitats through seed dispersal, sprouting plant fragments, or lateral invasion of flagellar aroids from the closed forest nearby. A seed germination experiment applying two soil substrates and three shade levels showed that abundant light reduced the germination success of three Philodendron species. A total of 400 cuttings from five Philodendron species were placed in forest clearings and almost 12% of these sprouted within 14 wk. Monitoring more than 2000 aroid plants over 14 mo in different habitats showed that recruitment was low (0.3 plants per 10 m2) compared with initial densities (3.1 plants per 10 m2). Flagellar aroids grew about 2.5 times faster than non-flagellar aroids. In forest edges they reached a mean apical growth of 98 cm in 14 mo. However, non-flagellar aroids were five to six times more abundant than flagellar individuals everywhere. It was concluded that hemiepiphytic aroids colonize open habitats mostly through a post-disturbance survival of plants or plant fragments.

scholarly journals Long Distance Seed Dispersal by Forest Elephants

2021 ◽  
Vol 9 ◽  
Author(s):  
John R. Poulsen ◽  
Christopher Beirne ◽  
Colin Rundel ◽  
Melissa Baldino ◽  
Seokmin Kim ◽  
...  
Keyword(s):  
Seed Dispersal ◽  
National Parks ◽  
Community Dynamics ◽  
Passage Time ◽  
Dispersal Distance ◽  
Long Distance ◽  
Gut Passage ◽  
Average Maximum ◽  
Forest Elephants ◽  
Dispersal Distances

By dispersing seeds long distances, large, fruit-eating animals influence plant population spread and community dynamics. After fruit consumption, animal gut passage time and movement determine seed dispersal patterns and distances. These, in turn, are influenced by extrinsic, environmental variables and intrinsic, individual-level variables. We simulated seed dispersal by forest elephants (Loxodonta cyclotis) by integrating gut passage data from wild elephants with movement data from 96 individuals. On average, elephants dispersed seeds 5.3 km, with 89% of seeds dispersed farther than 1 km. The longest simulated seed dispersal distance was 101 km, with an average maximum dispersal distance of 40.1 km. Seed dispersal distances varied among national parks, perhaps due to unmeasured environmental differences such as habitat heterogeneity and configuration, but not with human disturbance or habitat openness. On average, male elephants dispersed seeds farther than females. Elephant behavioral traits strongly influenced dispersal distances, with bold, exploratory elephants dispersing seeds 1.1 km farther than shy, idler elephants. Protection of forest elephants, particularly males and highly mobile, exploratory individuals, is critical to maintaining long distance seed dispersal services that shape plant communities and tropical forest habitat.

Role of dispersal in the invasion of an exotic tree in an East African submontane forest

2004 ◽  
Vol 20 (4) ◽  
pp. 449-457 ◽  
Author(s):  
Norbert J. Cordeiro ◽  
David A. G. Patrick ◽  
Billy Munisi ◽  
Vipul Gupta
Keyword(s):  
Tree Species ◽  
Germination Rate ◽  
East African ◽  
Dispersal Agent ◽  
Exotic Tree ◽  
Germination Success ◽  
Seed Dispersers ◽  
Blue Monkey ◽  
Dispersal Effectiveness

Early successional tree species typically attract numerous generalist frugivores, many of which serve as seed dispersers. This study evaluated whether several such dispersers facilitated the invasion of an exotic, early successional tree species, Maesopsis eminii (Rhamnaceae), in submontane forests of the East Usambara Mountains, Tanzania. The primary seed dispersers and their dispersal effectiveness were determined through focal watches at eight trees. Only 3 of 13 frugivores that consumed Maesopsis fruits functioned as seed dispersers (silvery-cheeked hornbill Ceratogymna brevis, Fischer's turaco Tauraco fischeri and blue monkey Cercopithecus mitis). On average, hornbills dispersed >26 times more seeds than monkeys, and >3 times as many seeds as turacos per visit and were thus considered the most important disperser. Seed germination was not affected by gut passage through hornbills. Germination in four microhabitats was experimentally evaluated to determine whether microhabitat influences germination success. Large gaps and forest edges had significantly higher germination rates compared with understorey locations; the germination rate in small gaps was not significantly different from that in the understorey. Expansive Maesopsis invasion in the East Usambaras was likely enhanced in both rapidity and scale by the presence of an extremely effective dispersal agent, the silvery-cheeked hornbill.

scholarly journals Hydropriming changes temperature thresholds for seed germination of tree species from the Caatinga, a Brazilian tropical dry forest

2021 ◽  
Vol 43 ◽  
Author(s):  
Joana Paula Bispo Nascimento ◽  
Bárbara França Dantas ◽  
Marcos Vinicius Meiado
Keyword(s):  
Seed Germination ◽  
Tree Species ◽  
Germination Rate ◽  
Tropical Dry Forest ◽  
Dry Forest ◽  
Regression Curves ◽  
Temperature Thresholds ◽  
Different Temperatures ◽  
Pre Treatment ◽  
Lower Limits

Abstract: This study evaluates the effects of hydration and dehydration cycles (HD cycles) on seed germination of four Caatinga tree species (Anadenanthera colubrina var. cebil, Enterolobium contortisiliquum, Pityrocarpa moniliformis and Pterogyne nitens) subjected to different temperatures and determine the thermal upper and lower limits of germination. For this, seeds were subjected to 0, 1, 2 and 3 HD cycles and set to germinate at temperatures of 5, 10, 15, 25, 35, 40 and 45 °C. Germinability and t50 were calculated and the differences of these parameters were compared by two-way ANOVA. In addition, germination rate (GR = 1/t50), as well as ceiling (Tc), optimum (To) and base (Tb) temperatures were calculated to estimate the limits below or above which the seeds fail to germinate. We observed that the more HD cycles, the better the seed responds, especially at extreme temperatures. Seeds of all studied species showed To between 25 and 35 °C, Tb < 10 °C, and Tc > 40 °C. The slope of regression curves for germination rate showed that submitting seeds to HD cycles expands its thermal tolerance range, revealing that this seed pre-treatment can be efficient for species as it increases their tolerance to thermal stress.

Thermal requirements of seed germination of ten tree species occurring in the western Brazilian Amazon

2019 ◽  
Vol 29 (2) ◽  
pp. 115-123 ◽  
Author(s):  
L. Felipe Daibes ◽  
Semirian C. Amoêdo ◽  
Jeane do Nascimento Moraes ◽  
Natália Fenelon ◽  
Débora Rosa da Silva ◽  
...  
Keyword(s):  
Seed Germination ◽  
Tree Species ◽  
Germination Rate ◽  
Brazilian Amazon ◽  
Thermal Time ◽  
Base Temperature ◽  
Germination Capacity ◽  
Thermal Dependence ◽  
Germination Time ◽  
Thermal Requirements

AbstractRegeneration from seed affects species assembly in plant communities, and temperature is the most important environmental factor controlling the germination process. Thermal dependence of seed germination is thus associated with species occurrence in an ecosystem. Hence, we aimed to investigate the role of temperature on seed germination of ten tree species from the western Brazilian Amazon. Seeds were collected in the state of Rondônia, Brazil, and set to germinate under constant temperatures ranging from 10 to 40°C in germination chambers. We calculated germination capacity (G%), germination rate (GR50, reciprocal of germination time), and thermal parameters, such as cardinal temperatures and thermal time requirements. Most species had a large range of temperatures showing G% ≥80%, with optimal temperature varying from 20 to 40°C. Base temperature ranged from 6 to 12°C and ceiling temperatures were mainly >40°C. Astronium lecointei and Parkia nitida showed high germination capacity under temperatures of 35–40°C, while germination of Theobroma cacao dropped from 100% to zero under temperatures between 37 and 40°C. The climax species Cedrela fissilis had the slowest germination time (10 days) and highest thermal time requirement, while seeds of Enterolobium schomburgkii (a late-successional species) germinated within the first day of the experiment. Rapid recruitment of Amazon species could be favoured with treefall disturbance, which increases temperatures in the understory, but sharp limits might be found in the supra-optimal range of temperatures. Such patterns might indicate different regeneration strategies in the tropical rainforest, providing important information regarding seed germination among Amazon species.

scholarly journals Frugivory and seed dispersal in a hyperdiverse plant clade and its role as a keystone resource for the Neotropical fauna

2020 ◽  
Author(s):  
João Vitor S Messeder ◽  
Fernando A O Silveira ◽  
Tatiana G Cornelissen ◽  
Lisieux F Fuzessy ◽  
Tadeu J Guerra
Keyword(s):  
Seed Germination ◽  
Seed Dispersal ◽  
Meta Analysis ◽  
Resource Scarcity ◽  
Long Distance ◽  
Gut Passage ◽  
Dispersal Mechanism ◽  
Neotropical Fauna ◽  
Coexisting Species ◽  
Seed Handling

Abstract Background and Aims Much of our understanding of the ecology and evolution of seed dispersal in the Neotropics is founded on studies involving the animal-dispersed, hyperdiverse plant clade Miconia (Melastomataceae). Nonetheless, no formal attempt has been made to establish its relevance as a model system or indeed provide evidence of the role of frugivores as Miconia seed dispersers. Methods We built three Miconia databases (fruit phenology/diaspore traits, fruit–frugivore interactions and effects on seed germination after gut passage) to determine how Miconia fruiting phenology and fruit traits for &gt;350 species interact with and shape patterns of frugivore selection. In addition, we conducted a meta-analysis evaluating the effects of animal gut passage/seed handling on Miconia germination. Key Results Miconia produce numerous small berries that enclose numerous tiny seeds within water- and sugar-rich pulps. In addition, coexisting species provide sequential, year long availability of fruits within communities, with many species producing fruits in periods of resource scarcity. From 2396 pairwise interactions, we identified 646 animal frugivore species in five classes, 22 orders and 60 families, including birds, mammals, reptiles, fish and ants that consume Miconia fruits. Endozoochory is the main dispersal mechanism, but gut passage effects on germination were specific to animal clades; birds, monkeys and ants reduced seed germination percentages, while opossums increased it. Conclusions The sequential fruiting phenologies and wide taxonomic and functional diversity of animal vectors associated with Miconia fruits underscore the likely keystone role that this plant clade plays in the Neotropics. By producing fruits morphologically and chemically accessible to a variety of animals, Miconia species ensure short- and long-distance seed dispersal and constitute reliable resources that sustain entire frugivore assemblages.

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