A Bat-Generated Fig Seed Shadow in Rainforest

Biotropica ◽  
1978 ◽  
Vol 10 (2) ◽  
pp. 121 ◽  
Author(s):  
Daniel H. Janzen
Keyword(s):  
Seed Shadow

THE CONSEQUENCES OF DIOECY FOR SEED DISPERSAL: MODELING THE SEED-SHADOW HANDICAP

Evolution ◽  
2007 ◽  
Vol 55 (5) ◽  
pp. 880-888 ◽  
Author(s):  
Jana C. Heilbuth ◽  
Katriina L. Ilves ◽  
Sarah P. Otto
Keyword(s):  
Seed Dispersal ◽  
Seed Shadow

The influence of gibbon primary seed shadows on post-dispersal seed fate in a lowland dipterocarp forest in Central Borneo

2005 ◽  
Vol 21 (3) ◽  
pp. 255-262 ◽  
Author(s):  
Kim R. McConkey
Keyword(s):  
Seed Fate ◽  
Central Kalimantan ◽  
Fruit Abundance ◽  
Seed Shadow ◽  
Dipterocarp Forest ◽  
Lowland Dipterocarp Forest ◽  
Seed Shadows ◽  
Insect Predation ◽  
Dispersal Events

The natural seed shadow created by gibbons (Hylobates mulleri×agilis) in Central Kalimantan, Indonesia, was monitored over 11 mo to discern the role of gibbons and post-dispersal events in the spatial pattern of seed germination. Variability in the content and distribution of 183 scats was used to determine which, if any, scat characteristics influenced seed fate. Nine scat characters were evaluated: (1) seed number; (2) number of seed species per scat; (3) scat weight; (4) seed load; (5) rainfall; (6) scat density; (7) distance to nearest fruiting tree; (8) ripe fig abundance; (9) non-fig fruit abundance. More than 99% of monitored seeds were killed, removed, or had germinated during the monitoring period. Vertebrates killed or removed most seeds (86%) and the probability of them moving seeds was highly dependent on non-fig fruit abundance at the time of deposition; factors (2), (6) and (7) also influenced seed removal/predation by vertebrates, depending on whether seeds were deposited in peak or non-peak times of consumption. Insect predation (2% of seeds) occurred mainly in scats that were deposited in months of high ripe fig abundance, while the actual chance of a seed germinating (11% of seeds) was influenced by non-fig fruit abundance at time of deposition and number of species in the original scat. The gibbon-generated seed shadow was profoundly altered by post-dispersal events and variation in the characteristics of the shadow had little lasting impact on the probability of seeds germinating.

Spatial patterns of primary seed dispersal and adult tree distributions: Genipa americana dispersed by Cebus capucinus

2015 ◽  
Vol 31 (6) ◽  
pp. 491-498 ◽  
Author(s):  
Kim Valenta ◽  
Mariah E. Hopkins ◽  
Melanie Meeking ◽  
Colin A. Chapman ◽  
Linda M. Fedigan
Keyword(s):  
Seed Dispersal ◽  
Spatial Patterns ◽  
Cebus Capucinus ◽  
Spatial Distributions ◽  
Dispersal Patterns ◽  
Seed Shadow ◽  
Adult Trees ◽  
Adult Tree ◽  
Tree Distributions ◽  
Primary Dispersal

Abstract:The spatial distribution of adult trees is typically not expected to reflect the spatial patterns of primary seed dispersal, due to many factors influencing post-dispersal modification of the seed shadow, such as seed predation, secondary seed dispersal and density-dependent survival. Here, we test the hypothesis that spatial distributions of primary seed shadows and adult trees are concordant by analysing the spatial distributions of adult Genipa americana trees and the seed shadow produced by its key primary disperser, the capuchin monkey (Cebus capucinus) in a tropical dry forest in Costa Rica. We mapped the dispersal of G. americana seeds by the capuchins during focal animal follows (mean = 463 min, n = 50) of all adults in one free-ranging group over two early wet seasons (May–July, 2005 and 2006). We mapped the locations of all G. americana trees within a 60-ha plot that lay within the home range of the capuchin group. We conducted multiple spatial point pattern analyses comparing degrees of clustering of capuchin defecations and G. americana trees. We found that adult tree distributions and primary dispersal patterns are similarly aggregated at multiple spatial scales, despite the modification of the primary dispersal patterns and long dispersal distances.

The Red Cedar (Juniperus virginiana L.) Seed Shadow along a Fenceline

1985 ◽  
Vol 113 (1) ◽  
pp. 200 ◽  
Author(s):  
Anthonie M. A. Holthuijzen ◽  
Terry L. Sharik
Keyword(s):  
Juniperus Virginiana ◽  
Seed Shadow ◽  
Red Cedar

The Size of a Local Peak in a Seed Shadow

Biotropica ◽  
1978 ◽  
Vol 10 (1) ◽  
pp. 78 ◽  
Author(s):  
Daniel H. Janzen
Keyword(s):  
Seed Shadow

Estimate of the seed shadow created by the Asiatic black bear Ursus thibetanus and its characteristics as a seed disperser in Japanese cool-temperate forest

Oikos ◽  
2011 ◽  
Vol 120 (2) ◽  
pp. 280-290 ◽  
Author(s):  
Shinsuke Koike ◽  
Takashi Masaki ◽  
Yui Nemoto ◽  
Chinatsu Kozakai ◽  
Koji Yamazaki ◽  
...  
Keyword(s):  
Temperate Forest ◽  
Black Bear ◽  
Asiatic Black Bear ◽  
Seed Shadow ◽  
Ursus Thibetanus ◽  
Seed Disperser ◽  
Cool Temperate ◽  
Cool Temperate Forest

scholarly journals Seed shadow of Swietenia macrophylla remnant trees in a Mexican rainforest: mplications for forest management

2014 ◽  
Vol 92 (4) ◽  
pp. 599 ◽  
Author(s):  
Raúl E. Alcalá ◽  
Roxalma L. Alonso ◽  
Gabriel Gutiérrez-Granados
Keyword(s):  
Forest Management ◽  
Swietenia Macrophylla ◽  
Seed Shadow ◽  
Para Determinar

<p>Entender los procesos relacionados con la regeneración y coexistencia de árboles es un tema de gran relevancia en paisajes tropicales perturbados por actividades humanas. En este estudio, se evaluó la sombra de semillas en ocho árboles remanentes de <em>Swietenia macrophylla</em> para determinar las posibles consecuencias de la tala selectiva sobre los primeros estadíos de la regeneración natural de la especie. Se esperaba encontrar una dispersión limitada y una marcada pérdida de semillas debido a las interacciones bióticas. Para probar esto, la sombra de semillas por árbol fue evaluada en cuatro transectos radiales (30 × 1 m) que redundaron en 960 cuadros de 1 m<sup>2</sup> usados para el muestreo. También se consideró el efecto de la dirección del viento y las características de los árboles, así como el diámetro a la altura del pecho y el área de proyección de la copa, como posibles factores que infl uyen en la sombra de semillas. Además, se registró el número de semillas depredadas y las infectadas por hongos. En total se encontraron 540 semillas de <em>S. macrophylla</em> en los 960 cuadros usados para evaluar la sombra de semillas. Cerca de 86% de estos cuadros mostraron 0 o 1 semilla, mientras que 80% de las semillas se encontraron dentro de los primeros 20 m con respecto a los árboles madre. La regresión entre el número de semillas perdidas por interacciones bióticas y la distancia al árbol madre se ajustó a un modelo cuadrático que explicó el 52.4% de la varianza total. Estos resultados sugieren que los árboles pequeños y remanentes de <em>S. macrophylla</em> muestran una baja capacidad de dispersión causada por una sombra de semillas limitada y una elevada tasa de pérdida de semillas por interacciones bióticas. Los resultados indican que la remoción de los árboles más grandes para su venta podría estar impactando negativamente sobre los primeros estadíos de la regeneración natural de esta especie de alto valor, y que consecuentemente, la extracción selectiva podría amenazar la permanencia local de la caoba en bosques manejados de la zona Maya.</p>

Two-stage dispersal of Guarea glabra and G. kunthiana (Meliaceae) in Monteverde, Costa Rica

1999 ◽  
Vol 15 (4) ◽  
pp. 481-496 ◽  
Author(s):  
Daniel G. Wenny
Keyword(s):  
Costa Rica ◽  
Seed Dispersal ◽  
Seed Predation ◽  
Soil Surface ◽  
Vegetation Density ◽  
Seed Shadow ◽  
Secondary Dispersal ◽  
Germination Success ◽  
Tayassu Tajacu ◽  
Para Determinar

Seed dispersal of Guarea glabra and G. kunthiana (Meliaceae) in Monteverde, Costa Rica was studied to determine how seed predation and secondary dispersal affect the distribution of seeds available for recruitment. The arillate seeds are consumed mainly by birds that regurgitate or defecate the seeds intact. After dispersal, 45.6% of G. glabra and 26.6% of G. kunthiana seeds were buried 1–3 cm in the soil, presumably by scatterhoarding rodents such as agoutis (Dasyprocta punctata). G. glabra seeds that were not cached were eaten mostly by beetles, and 33.7% of the seeds remained cached after 12 wk. The cached G. glabra seeds did not germinate, however, perhaps as a result of experimental procedures used to mark the seeds. In greenhouse experiments, G. glabra seeds buried to mimic scatterhoarding had higher germination success than seeds on the soil surface. G. kunthiana seeds not cached were eaten by peccaries (Tayassu tajacu) and other seed predators (60%) or were inviable (10%). Only nine (7.5%) viable G. kunthiana seeds remained in caches after 12 wk. Secondary dispersal resulted in a rearrangement of the seed shadow. G. glabra seeds were moved to sites with less leaf litter and lower vegetation density, while G. kunthiana seeds were moved farther from conspecific trees and closer to fallen logs during secondary dispersal. Considering the high rates of seed predation in the field for both species, the germination advantages for G. glabra in the greenhouse, and the shifts in microhabitat during scatterhoarding, it is likely that secondary dispersal by scatterhoarding rodents is an important stage in Guarea recruitment.RESUMEN. Dispersión de semillas de Guarea glabra y G. kunthiana (Meliaceae) en Monteverde, Costa Rica fureon examinadas para determinar como la predación de semillas y dispersión secundaria afectan la distribución de semillas disponibles para recrutamiento. Las semillas ariladas son consumidas principalmente por aves que regurgitan o defecan la semilla intacta. Luego de dispersión, 30–45% de las semillas fueron enterradas 1–3 cm en el suelo, posiblemente por roedores que disperan y acumulan como al agouti (Dasyprocta puncaata). Semillas de G. kunthiana que no fueron escondidas fueron comidas por pécaris (Tayassu tajacu) y otros predadores de semillas (60%) o no fueron viables (10%). Solo neuve (7.5%) semillas viables de G. kunthiana permanecieron en los escondites luego de 12 semanas. En contraste, semillas de G. glabra que no fueron escondidas fueron comidas mayormente por escarabajos que por pécaris, y 33.7% de las semillas permanecieron escondidas luego de 12 semanas. Las semillas esconditas de G. glabra enterradas para imitar dispersión y acumulión tuvieron una germinación mayor que semillas en la superficie del suelo. Dispersión secundaria resulto en un rearreglo de la sombra de semillas. Las dos especies experimentaron un leve aumento neto en la distancia promedio de conspecificos en frutos luego de dispersión y acumulación. Semillas de G. kunthiana fueron movidas cerca de troncos caidos durante dispersión secundaria, mientras semillas de G. glabra fueron movidas a lugares con menos lecho de hojas y baja densidad de vegetación. Considerando la alta proporción de predación de semillas en el campo para ambas especies, la ventaja de germinación de G. glabra en el invernáculo, y el cambio en micrambiente durante dispersión y acumulación, es posible que dispersión secundaria por roedores que dispersan y acumulan es importante in etapas de recrutamiento en Guarea.

The effect of seed dispersal limitations on the spatial distribution of a gap species, seaside goldenrod (Solidago sempervirens)

1993 ◽  
Vol 71 (7) ◽  
pp. 978-984 ◽  
Author(s):  
Philip C. Lee
Keyword(s):  
Seed Dispersal ◽  
Seed Storage ◽  
Coastal Dunes ◽  
Seed Rain ◽  
Significant Drop ◽  
Seed Shadow ◽  
Ammophila Breviligulata ◽  
Seed Sources ◽  
Transition Areas ◽  
Solidago Sempervirens

This study examined the seed ecology of seaside goldenrod, Solidago sempervirens L., a gap species, on coastal dunes dominated by American beachgrass, Ammophila breviligulata. A test was done to determine whether lower densities of S. sempervirens on undisturbed primary dune grasslands were due to limited seed dispersal or barriers to seedling establishment. Seed rain was greater within blowouts and transition areas than in immature and mature grasslands. Blowouts and transition areas produced prominent seed shadows and served as primary seed sources. Both seed shadow measurements and inflorescence removal experiments suggested that the majority of seeds fell to the ground within 10 m outside blowouts. Experiments involving the hand broadcasting of seeds increased densities of seedlings in undisturbed areas. Plots with hand-drilled seeds showed no differences in percent emergence between transition and undisturbed areas; however, both were significantly greater than blowouts. Persistent seed storage in the soil was probably negligible. Seed bank densities at 5 m depth did not accurately reflect temporal or spatial patterns of seed rain. Often very low densities or no seeds were found in collected samples within an area. Furthermore, emergence percentages of field-buried seeds showed a significant drop-off after a single year. Thus, this study concluded that lower densities of plants in undisturbed areas were, in part, due to lack of seed dispersal from blowouts. Key words: seed dispersal, gap species, patchy disturbances, dune ecology, grassland ecology.

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