INVESTIGADORES
ORDANO Mariano Andres
artículos
Título:
Generous-like flowers: nectar production in two epyphitic bromeliads and a meta-analysis of removal effects
Autor/es:
MARIANO ORDANO; JUAN FRANCISCO ORNELAS
Revista:
OECOLOGIA
Editorial:
Springer
Referencias:
Lugar: Berlin/Heidelberg, Deutchland; Año: 2004 vol. 140 p. 495 - 505
ISSN:
0029-8549
Resumen:
Animal-pollinated
angiosperm plants that respond positively to nectar removal by replenishment
invest energy that can entail a reproductive cost. We investigated whether or not
nectar removal stimulates replenishment in two hummingbird-pollinated bromeliad
species. Nectar replenishment rates were also assessed by removing nectar from
manually pollinated flowers because pollination events might be used as signals
to save energy by preventing allocation to postpollination nectar production.
Then we synthesized the current understanding of nectar removal effects by
reviewing existing published studies with a meta-analysis. The magnitude and
significance of estimated nectar removal effects and factors associated with
variation in size and direction of nectar removal effects were elucidated with
the meta-analysis. We found that both Tillandsia species strongly respond to
repeated nectar removal by producing more than three times of additional
nectar. Nectar secretion patterns were not altered by pollination (stigmatic
pollen deposition) and we found no evidence of nectar reabsorption. Although
the effect size varied widely across systems and/or environmental conditions,
the meta-analysis showed that nectar removal had overall a positive effect on
nectar replenishment (mainly among species inhabiting wet tropical habitats
such as Tillandsia), and a negative effect on the secretion of additional
sugar, suggesting that those plants are resource limited and conservative in the
secretion of additional sugar