Seed limitation of woody plants in Neotropical savannas

The failure of seeds to arrive at all suitable sites (seed limitation) greatly affects plant distribution and abundance. In contrast to tropical forests, the degree of seed limitation in Neotropical savannas is unclear because empirical studies at the community level are scarce. We estimated seed li...

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Detalles Bibliográficos
Autores: Salazar, Ana, Goldstein, Guillermo Hernan, Franco, Augusto C., Miralles Wilhelm, Fernando
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2012
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/68261
Acceso en línea:http://hdl.handle.net/11336/68261
Access Level:acceso abierto
Palabra clave:Cerrado
Seed Dispersal
Seed Removal
Seed Viability
https://purl.org/becyt/ford/1.6
https://purl.org/becyt/ford/1
Descripción
Sumario:The failure of seeds to arrive at all suitable sites (seed limitation) greatly affects plant distribution and abundance. In contrast to tropical forests, the degree of seed limitation in Neotropical savannas is unclear because empirical studies at the community level are scarce. We estimated seed limitation of 23 woody species from annual seed rain measurements along a tree density gradient in the savannas of Central Brazil. These savannas differ in tree density and canopy cover, from closed to open savannas, and are located along shallow topographic gradients. We also studied post-dispersal seed predation and removal of 17 representative woody species, and seed viability loss over time of 12 common woody species under dry-storage conditions. Annual seed rain was lower in open (410 seeds/m 2) than in closed savannas (773 seeds/m 2). Average seed limitation across woody species was higher than 80% along the tree density gradient. More than 60% of seeds of the studied woody species were predated or removed within 30-45 days in all savannah types. Seeds of most common woody species (66%) lost their viability in less than 12 months of dry storage. This study shows that Neotropical savannah woody plants are strongly seed-limited because of low and poor distribution of seeds among sites, post-dispersal seed removal, and short seed longevity. The high seed limitation of tree species in Neotropical savannas, particularly in open savannas, also may contribute to maintain their relatively low tree densities and help to explain the spatial variation of tree abundance along topographic gradients.