Contagious seed dispersal beneath heterospecific fruiting trees and its consequences.

Journal Article · Mon May 03 04:00:00 EDT 2004 · Oikos

DOI:https://doi.org/10.1111/j.0030-1299.2004.13388.x· OSTI ID:835559

Kwit, Charles ^[1]

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1. USDA Forest Service, Savannah River

Kwit, Charles, D.J. Levey and Cathryn H. Greenberg. 2004. Contagious seed dispersal beneath heterospecific fruiting trees and its consequences. Oikos. 107:303-308 A n hypothesized advantage of seed dispersal is avoidance of high per capita mortality (i.e. density-dependent mortality) associated with dense populations of seeds and seedlings beneath parent trees. This hypothesis, inherent in nearly all seed dispersal studies, assumes that density effects are species-specific. Yet because many tree species exhibit overlapping fruiting phenologies and share dispersers, seeds may be deposited preferentially under synchronously fruiting heterospecific trees, another location where they may be particularly vulnerable to mortality, in this case by generalist seed predators. We demonstrate that frugivores disperse higher densities of Cornus florida seeds under fruiting (female) I lex opaca trees than under non-fruiting (male) I lex trees in temperate hardwood forest settings in South Carolina, U SA . To determine if density of Cornus and/or I lex seeds influences survivorship of dispersed Cornus seeds, we followed the fates of experimentally dispersed Cornus seeds in neighborhoods of differing, manipulated background densities of Cornus and I lex seeds. We found that the probability of predation on dispersed Cornus seeds was a function of both Cornus and I lex background seed densities. H igher densities of I lex seeds negatively affected Cornus seed survivorship, and this was particularly evident as background densities of dispersed Cornus seeds increased. These results illustrate the importance of viewing seed dispersal and predation in a community context, as the pattern and intensity of density-dependent mortality may not be solely a function of conspecific densities.

• Research Organization: USDA Forest Service, Savannah River, New Ellenton, SC
• Sponsoring Organization: USDOE Office of Environmental Management (EM)
• DOE Contract Number: AI09-00SR22188
• OSTI ID: 835559
• Report Number(s): na; 04-17-P
• Journal Information: Oikos, Journal Name: Oikos Journal Issue: 2 Vol. 107; ISSN 303-308
• Country of Publication: United States
• Language: English

Related Subjects

60 APPLIED LIFE SCIENCES
AVOIDANCE
Contagious seed dispersal
FORESTS
HYPOTHESIS
MORTALITY
PROBABILITY
SEEDLINGS
SEEDS
SOUTH CAROLINA
TREES