The effects of successional habitat variation and time of flowering on seed production in Rumex acetosella
1991
Escarre, J. | Thompson, J.D.
(1) The effects of time since abandonment and date of flowering on the number and biomass of seeds of Rumex acetosella were studied at monthly intervals over a single growing season in a successional series of abandoned fields at two sites near Paris, France. (2) Overall, a decrease in filled-seed production per plant was observed with increasing successional age, but only for the early summer period. A similar trend was observed for reproductive effort, i.e. filled-seed production per unit of vegetative biomass. (3) There were significant differences between the populations in the mean weight of filled seeds, but only for two of the five monthly surveys. The successionally intermediate and advanced populations at one of the sites showed the greatest seed biomass. (4) There were no significant negative correlations between the number and biomass of seeds when all the populations were pooled, but seed mass was negatively correlated with seed number at four sites in June. (5) Although the results provide no evidence for a trade-off between the various components of seed production in R. acetosella, they do indicate that genetically based differences in sexual resource allocation occur among plants growing along a successional habitat gradient.
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