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Plants can reduce the fitness costs of granivory by satiating seed predators. The most common satiation mechanism is the production
of large crops, which ensures that a proportion of the seeds survive predation. Nevertheless, satiation of small granivores
at the seed level may also exist. Larger seeds would satiate more efficiently, enhancing the probability of seed survival
after having been attacked. However, a larger seed size could compromise the efficiency of satiation by means of large crops
if there were a negative relationship between seed size and the number of seeds produced by an individual plant. We analyze
both types of satiation in the interaction between the holm oak Quercus ilex and the chestnut weevil Curculio elephas. Both crop size and acorn size differed strongly in a sample of 32 trees. Larger crop sizes satiated weevils, and higher
proportions of the seeds were not attacked as crop size increased. Larger seeds also satiated weevil larvae, as a larger acorn
size increased the likelihood of embryo survival. Seedling size was strongly related to acorn size and was reduced by weevil
attack, but seedlings coming from large weeviled acorns were still larger. The number and the size of the acorns produced
by individual trees were negatively related. Larger proportions of the crop were infested in oaks producing less numerous
crops of larger acorns. However, contrary to expectations, these trees did not satiate more effectively at the seed level
either. Effective satiation by larger acorns was precluded by larger multi-infestation rates associated to smaller seed crops,
in such a way that the proportion of attacked seeds that survived did not vary among trees with different acorn sizes. These
results highlight the need of considering satiation by means of large crops and large seeds in studies of predispersal seed
predation. Long-term monitoring on individual oaks will help to assess whether there is a trade-off between the number and
the size of the acorns and, if it existed, how it could condition the fitness consequences of both types of satiation. 相似文献
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