Seed Rain

Seed rain and seedling establishment under isolated trees and artificial perches by dispersal seed birds, on a Cerrado region, Mato Grosso do Sul, Brazil. The objective on this research was to evaluate the importance of isolated trees and artificial perches on an area with pasture located at Embrapa Gado de Corte in Campo Grande, State of Mato Grosso do Sul, Brazil, as landing sources to seed dispersal birds. It was evaluate rates of seeds fall under isolated trees and artificial perches. Seed collector traps were installed under trees and perches to seed rain capture, as well plots were done to verify the seedling establishment, from January until December/2006. It was not observed statistical difference between seed rain for trees and perches, as well did not have direct relation between seed rain and the months with more and less rain, due the differences flowering periods for the Cerrado's plant species. Isolated trees and artificial perches attracted different bird species ...

Declines in cottonwood,(Populus spp.) recruitment,along alluvial reaches of large rivers in arid regions of the western United States have been attributed to modified flow regimes, lack of suitable substrate, insufficient seed rain, and increased interspecific competition. We evaluated,whether,and how,these factors were operating during 1993‐1996 to influence demographics,of Fremont,cottonwood,(P. deltoides Marshall subsp. wislizenii (Watson) Eckenwalder) along reaches of the Green

Abstract: Bats are abundant and effective seed dispersers inside the forest, but what happens when a forest is fragmented and transformed into pasture? The landscape at Los Tuxtlas, Mexico, originally rainforest, is greatly fragmented and covered with pastures. We analyzed the seed rains produced by frugivorous bats and birds under isolated trees in pastures in the fragmented landscape and the contribution of this process to vegetational recovery. We surveyed bats and obtained fecal samples under isolated trees in pastures. We also collected seed rain below the canopy of 10 isolated Ficus trees, separating nocturnally dispersed seeds from diurnally dispersed seeds. We caught 652 bats of 20 species; 83% of captures were frugivores. The most abundant species were Sturnira lilium (48%), Artibeus jamaicensis (18%), Carollia perspicillata (12%), and Dermanura tolteca (11%). Fecal samples contained seeds of 19 species in several families: Piperaceae (50%), Moraceae (25%), Solanaceae (12%), Cecropiaceae (10%), and others (3%). Sturnira lilium was the most important disperser bat in pastures. Seed rain was dominated by zoochorous species (89%). We found seed diversity between day and night seed captures to be comparable, but we found a significant interaction of disperser type (  bird or bat) with season. Seven plant species accounted for 79% of the seed rain: Piper auritum (23%), Ficus (  hemiepiphytic-strangler tree) spp. (17%), Cecropia obtusifolia (10%), P. amalago (10%), Ficus (  free-standing tree) spp. (8%), P. yzabalanum (6%), and Solanum rudepanum (5%). Bats and birds are important seed dispersers in pastures because they disperse seeds of pioneer and primary species (trees, shrubs, herbs, and epiphytes), connect forest fragments, and maintain plant diversity. Consequently, they might contribute to the recovery of woody vegetation in disturbed areas in tropical humid forests.Resumen: Los murciélagos son abundantes y efectivos dispersores de semillas en la selva húmeda alta. Pero, ¿qué sucede cuando la selva es fragmentada y convertida en pastizales? El paisaje en Los Tuxtlas, México, cuya vegetación original era la de bosque lluvioso, está fuertemente fragmentado y dominado por pastizales. Analizamos la lluvia de semillas producida por murciélagos y aves frugívoras bajo árboles aislados en pastizales del paisaje fragmentado, y la contribución de este proceso a la recuperación de la vegetación. Capturamos murciélagos y obtuvimos muestras fecales bajo árboles aislados en pastizales. Colectamos la lluvia de semillas bajo 10 Ficus aislados, separando las semillas “nocturnas” de las “diurnas.” Capturamos 652 murciélagos de 20 especies, el 83% de ellos fueron frugívoros. Las especies dominantes fueron: Sturnira lilium (48%), Artibeus jamaicensis (18%), Carollia perspicillata (12%), y Dermanura tolteca (11%). Las muestras fecales contenían semillas de 19 especies de varias familias: Piperaceae (50%), Moraceae (25%), Solanacea (12%), Cecropiaceae (10%), y otras (3%). Sturnira lilium resultó ser el murciélago dispersor más importante del pastizal. En la lluvia de semillas el 89% de las especies fueron zoócoras. No se encontró diferencia en la diversidad de semillas depositadas en la noche o en el día; sin embargo, hubo una interacción significativa del tipo de dispersor (ave o murciélago) con la época del año. Siete especies dominaron el 79% del total de la lluvia: Piper auritum (23%), Ficus ( hemiepífito-matapalo; 17%), Cecropia obtusifolia (10%), P. amalago (10%), Ficus (terrestre; 8%), P. yzabalanum (6%) y Solanum rudepanum (5%). Los murciélagos y las aves son importantes dispersores en pastizales ya que dispersan semillas de especies pioneras y primarias (árboles, arbustos, hierbas y epífitas); conectan remanentes de selva y mantienen la diversidad vegetal. Consecuentemente pueden promover la recuperación de la vegetación leñosa en áreas perturbadas de regiones tropicales húmedas.Resumen: Los murciélagos son abundantes y efectivos dispersores de semillas en la selva húmeda alta. Pero, ¿qué sucede cuando la selva es fragmentada y convertida en pastizales? El paisaje en Los Tuxtlas, México, cuya vegetación original era la de bosque lluvioso, está fuertemente fragmentado y dominado por pastizales. Analizamos la lluvia de semillas producida por murciélagos y aves frugívoras bajo árboles aislados en pastizales del paisaje fragmentado, y la contribución de este proceso a la recuperación de la vegetación. Capturamos murciélagos y obtuvimos muestras fecales bajo árboles aislados en pastizales. Colectamos la lluvia de semillas bajo 10 Ficus aislados, separando las semillas “nocturnas” de las “diurnas.” Capturamos 652 murciélagos de 20 especies, el 83% de ellos fueron frugívoros. Las especies dominantes fueron: Sturnira lilium (48%), Artibeus jamaicensis (18%), Carollia perspicillata (12%), y Dermanura tolteca (11%). Las muestras fecales contenían semillas de 19 especies de varias familias: Piperaceae (50%), Moraceae (25%), Solanacea (12%), Cecropiaceae (10%), y otras (3%). Sturnira lilium resultó ser el murciélago dispersor más importante del pastizal. En la lluvia de semillas el 89% de las especies fueron zoócoras. No se encontró diferencia en la diversidad de semillas depositadas en la noche o en el día; sin embargo, hubo una interacción significativa del tipo de dispersor (ave o murciélago) con la época del año. Siete especies dominaron el 79% del total de la lluvia: Piper auritum (23%), Ficus ( hemiepífito-matapalo; 17%), Cecropia obtusifolia (10%), P. amalago (10%), Ficus (terrestre; 8%), P. yzabalanum (6%) y Solanum rudepanum (5%). Los murciélagos y las aves son importantes dispersores en pastizales ya que dispersan semillas de especies pioneras y primarias (árboles, arbustos, hierbas y epífitas); conectan remanentes de selva y mantienen la diversidad vegetal. Consecuentemente pueden promover la recuperación de la vegetación leñosa en áreas perturbadas de regiones tropicales húmedas.

The inclusion of environmental variation in studies of recruitment is a prerequisite for realistic predictions of the responses of vegetation to a changing environment. We investigated how seedling recruitment is affected by seed availability and microsite quality along a steep environmental gradient in dry tundra. A survey of natural seed rain and seedling density in vegetation was combined with observations of the establishment of 14 species after sowing into intact or disturbed vegetation. Although seed rain density was closely correlated with natural seedling establishment, the experimental seed addition showed that the microsite environment was even more important. For all species, seedling emergence peaked at the productive end of the gradient, irrespective of the adult niches realized. Disturbance promoted recruitment at all positions along the environmental gradient, not just at high productivity. Early seedling emergence constituted the main temporal bottleneck in recruitme...

Currently biological invasions are considered one of the world's most serious conservation problems. Ligustrum lucidum is the most abundant exotic tree in secondary forest patches of montane forests of NW Argentina. We studied the determinants of success of the early stages of its life cycle in distinct habitat types, with the hope of identifying vulnerabilities that could be exploited to control the invasion. Seed arrival, germination, seedling recruitment and survival, and sapling growth were studied in edges, gaps and forest interior. Seed arrival was also assessed under perches and in open fields. Germination was studied in forest and grassland patches. L. lucidum seedling survival and sapling growth were compared with the most abundant native species survival and growth. Seed arrival was strongly seasonal with a peak in mid-August. Seed rain did not differ significantly among habitat types, however there was a tendency for edges to receive more seeds when only dispersed see...

Abstract: Bats are abundant and effective seed dispersers inside the forest, but what happens when a forest is fragmented and transformed into pasture? The landscape at Los Tuxtlas, Mexico, originally rainforest, is greatly fragmented and covered with pastures. We ...

The extend to which seed dispersal influences seedling recruitment is of major importance for forest dynamics. In non-equilibrium situations, seed dispersal might be of even further importance as it is a major determinant of the rate and composition of secondary succession. We modelled primary seed dispersal in a planted pine–spruce stand intensively recolonized by Abies alba and Fagus sylvatica, an

In disturbed sites, some groups of seeds might be excluded from the seed rain due to their dispersal modes or seed size, and some groups might be successful as a result of disturbance effects. In the present study, we examined the seed rain in natural treefall gaps and in an area of regenerating forest following an accidental burning, which occurred 4 years before this study. Both of these disturbed areas were compared with nearby forest understorey. The number of seeds, number of species, and proportion of wind-dispersed seeds were compared between these disturbed and undisturbed areas. The treefall gaps have received lower numbers of seeds and species than the nearby understorey, but the number of wind-dispersed seeds did not differ between these areas. The lowest seed number observed in treefall gaps can be attributed to a lower number of animal-dispersed seeds, suggesting that animals may be avoiding treefall gap areas. A higher number of seeds and a lower number of species were observed in the burned area when compared to the adjacent understorey. The high number of small-sized seeds and of wind-dispersed seeds in the burned area was almost surely a consequence of the local production of the pioneer plants established after the burning. In this study, substantial differences were observed in the characteristics of the seed rain at disturbed sites, when compared with undisturbed understorey. However, these two distinct types of disturbance showed quite differing patterns, as treefall gaps received lower number of seeds while the burned area received a higher number of seeds, with a greater proportion of wind-dispersed seeds. The exception was for species richness, which was quite low at both these disturbed sites.