The Impact of Landscape Disturbance on Spatial Genetic Structure in the Guanacaste Tree, Enterolobium cyclocarpum (Fabaceae)

Date

2010

Authors

Gonzales, Eva
Hamrick, James L.
Smouse, Peter E
Trapnell, Dorset W.
Peakall, Rodney

Journal Title

Journal ISSN

Volume Title

Publisher

Oxford University Press

Abstract

We examined spatial genetic structure (SGS) in Enterolobium cyclocarpum (the Guanacaste tree), a dominant tree of Central American dry forests in 4 sites in Guanacaste Province, Costa Rica. In disturbed dry forest sites (e.g., pastures), E. cyclocarpum is primarily dispersed by cattle and horses, whose movements are restricted by pasture boundaries. The study sites varied in tree densities and disturbance. Allozyme analyses of adult trees demonstrated significant levels of SGS in 3 of 4 sites. SGS was primarily due to clusters of young adults located along seasonal streams, rocky areas, and in abandoned pastures. SGS was highest in the first distance class in the least disturbed population, which also had the lowest density of large adults. Low, but significant SGS characterized the site with the highest number of large adults located in individual pastures. The semiurban site, had no clusters of young adults and, probably as a result, failed to exhibit SGS. Our results demonstrate that disturbance can strongly influence SGS patterns and are consistent with a landscape model in which the location of potential recruitment sites, restricted seed disperser movements, and the number and location of maternal individuals dictate the level and pattern of SGS.

Description

Keywords

Keywords: alloenzyme; adult tree; article; forest; gene cluster; genetic variability; landscape; legume; nonhuman; pasture; population density; priority journal; seasonal variation; spatial autocorrelation analysis; Costa Rica; Demography; Ecosystem; Environment; F Enterolobium cyclocarpum; Landscape disturbance; Landscape genetics; Seed dispersal; Spatial genetic structure; Tropical dry forest

Citation

Source

Journal of Heredity

Type

Journal article

Book Title

Entity type

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Restricted until

2037-12-31