![]() ![]() Our results indicated resistance to change in tree fecundity in Mediterranean-type forest subjected to an average 15% decrease in the amount of soil moisture, suggesting that these ecosystems may adapt to a progressive increase in arid conditions. unedo was associated with a stronger decrease in growth in the rainfall-reduction plots compared to the control plots, suggesting that these species were able to maintain their fecundity by shifting their allocation of resources away from growth. unedo but not the more drought-tolerant P. Drought, however, affected the allocation of resources in Q. Rainfall reduction did not decrease tree fecundity. We evaluated the impact of experimentally induced 18 years of drought on reproduction of three contrasting forest trees: Quercus ilex, Phillyrea latifolia, and Arbutus unedo. However, little is known about the effects of anthropogenic environmental changes on reproductive ecology of trees. Recruitment is a primary determinant of the long-term dynamics of plant populations in changing environments. Future research should be aimed at addressing whether this process could be a factor assisting in the coexistence of Q. Therefore, our results demonstrate that similar patterns of seeding fluctuation over time in coexisting species mediated by an environmental cue (summer drought) may contribute to the reduction of the impact of seed predation at a within-species level. Moreover, at a longer time scale (over seven years), we observed a significant reduction in the mean proportion of acorns depredated for each oak and the variability in both species' acorn production combined. Satiation and starvation of predators was recorded for the two oaks, and this effect was increased by the year-to-year variability in the size of the acorn crop of the two species combined. Mean yearly acorn pre-dispersal predation by invertebrates was considerably higher in Q. humilis, and 60% in the two species together. The increase in CVp from initial to mature acorn crop (after summer) accounted for 33% in Q. Nevertheless, interannual differences in summer water stress modified the likelihood of abortion during acorn ripening and enforced within- and, particularly, between-species synchrony and population variability in acorn production. The two species exhibited a very different pattern across years in their initial acorn crop size (sum of aborted, depredated, and sound acorns). humilis was highly variable among years, with high population variability (CVp) values. humilis) and the consequences on within-species and between-species acorn predation, by monitoring 15 mixed forests (450 trees) over seven years. We tested for the existence of an environmental factor enforcing synchrony in acorn production in two sympatric Mediterranean oaks (Quercus ilex and Q. To achieve these benefits, coexisting species subjected to the same predator would benefit from a similar pattern of seeding fluctuation over time that could lead to a reduction in predation at the within-species level. ![]() Temporally variable production of seed crops by perennial plants (masting) has been hypothesized to be a valuable mechanism in the reduction of seed predation by satiating and starving seed consumers. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |