Résumé
1. The phenology of organisms corresponds to the temporal match between
the components of their life cycle and the seasonal distribution of
resources and hazards. Flowering has been extensively studied to describe
the reproductive phenology of plants, but in comparison, other key events
for reproductive success such as the seed maturation period and the time
of seed dispersal have been considerably less investigated. 2. This study
describes the temporal sequence of onset of flowering and seed dispersal,
and the time necessary to mature seeds in 138 species growing in the
strongly seasonal climate of Mediterranean southern France. Data for the
three traits were compiled from several original surveys to characterize
the reproductive phenology of 47 annual, 67 perennial herbaceous and 24
low stature woody species. The timing of these three phases was assessed
in relation to local climatic conditions, and the degree to which they
were coordinated was tested. 3. All three phenological traits spanned a
wide range of values from early spring to late summer. Annuals flowered
slightly earlier than perennials but the largest difference between these
groups was found for the seed maturation period, which was much shorter in
annuals. This resulted in earlier dispersal dates in these species, which
occurred before periods of high water deficit. Significant positive
correlations were found between onset of flowering, onset of seed
dispersal, and seed maturation period. This suggests a consistent pattern
of coordination between the different phases of reproductive phenology
across species. 4. Our results show that while the time slot for flowering
appears restricted to periods with adequate temperature and water
availability for most species, the seed maturation period and dispersal
phase can occur during periods of substantial water deficit, at least for
perennials. They also suggest that the different species can be arrayed
along a fast-slow continuum based on reproductive events, from early
flowering species with short seed maturation and early dispersal to late
flowering species with long seed maturation and late dispersal. Whether
this relates to the postulated fast-slow continuum identified for the
functioning of vegetative organs is a promising avenue for future
research.