Factors affecting establishment success of the endangered Caribbean cactus Harrisia portoricensis (Cactaceae)

 

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Detalles Bibliográficos
Autores: Rojas-Sandoval, Julissa, Meléndez-Ackerman, Elvia
Formato: artículo original
Estado:Versión publicada
Fecha de Publicación:2012
Descripción:Early plant stages may be the most vulnerable within the life cycle of plants especially in arid ecosystems. Interference from exotic species may exacerbate this condition. We evaluated germination, seedling survival and growth in the endangered Caribbean cactus Harrisia portoricensis, as a function of sunlight exposure (i.e., growing under open and shaded areas), different shade providers (i.e., growing under two native shrubs and one exotic grass species), two levels of predation (i.e., exclusion and non-exclusion) and variable microenvironmental conditions (i.e., temperature, PAR, humidity). Field experiments demonstrated that suitable conditions for germination and establishment of H. portoricensis seedling are optimal in shaded areas beneath the canopy of established species, but experiments also demonstrated that the identity of the shade provider can have a significant influence on the outcome of these processes. Harrisia portoricensis seedlings had higher probabilities of survival and grew better (i.e., larger diameters) when they were transplanted beneath the canopy of native shrubs, than beneath the exotic grass species, where temperature and solar radiation values were on average much higher than those obtained under the canopies of native shrubs. We also detected that exclusion from potential predators did not increase seedling survival. Our combined results for H. portoricensis suggested that the modification of microenvironmental conditions by the exotic grass may lower the probability of recruitment and establishment of this endangered cactus species.
País:Portal de Revistas UCR
Institución:Universidad de Costa Rica
Repositorio:Portal de Revistas UCR
Lenguaje:Inglés
OAI Identifier:oai:portal.ucr.ac.cr:article/4022
Acceso en línea:https://revistas.ucr.ac.cr/index.php/rbt/article/view/4022
Access Level:acceso abierto
Palabra clave:columnar cactus
harrisia portoricensis
megathrysus maximus
mona island
nurse plants
seed germination
seedling survival
cactus columnares
isla de mona
plantas nodriza
germinación de semillas
supervivencia de plántulas