The effects of serotiny and rainfall-cued dispersal on fitness: bet-hedging in the threatened cactus Mammillaria pectinifera
Por:
Peters E.M., Martorell C., Ezcurra E.
Publicada:
1 abr 2011
Categoría:
Ecology, Evolution, Behavior and Systematics
Resumen:
Serotiny-the retention of seeds in the mother plant for over a year-in unpredictable environments may increase the probability that at least some seeds are dispersed during favorable periods. Propagules may be expelled when environmental cues announcing favorable conditions occur, or be gradually released into the environment. This could be a bet-hedging strategy increasing the long-term fitness by reducing interannual variability in reproduction. However, the impact of seed retention on the population dynamics of serotinous species and its contribution to fitness has been barely explored under field conditions. We assessed these issues in the threatened Mammillaria pectinifera, a small globose cactus that gets established only in exceptionally rainy years. This species expels some seeds actively during unusually rainy periods, while dispersing others passively over several years. Dynamics of the seeds in the mother plant over two very contrasting years in terms of precipitation was in
Filiaciones:
Peters E.M.:
Direccion General de Investigacion de Ordenamiento Ecologico y Conservacion de los Ecosistemas, Instituto Nacional de Ecología-SEMARNAT, Mexico, D.F., Mexico
Martorell C.:
Univ Nacl Autonoma Mexico, Fac Ciencias, Dept Ecol & Recursos Nat, Mexico City 04510, DF, Mexico
Ezcurra E.:
Department of Botany and Plant Sciences, University of California-Riverside, Riverside, CA, United States
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