Data from: Population-level plant pollination mode is influenced by Quaternary climate and pollinators

Patterns in ecology are the products of current factors interacting with
history. Nevertheless, few studies have attempted to disentangle
the contribution of historical and current factors, such
as climate change and pollinator identity and behaviour, on plant
reproduction. Here, we attempted to separate the relative
importance of current and historical processes on geographical patterns
of the mating system of the tree species Curatella americana
(Dilleniaceae). Specifically, we asked: 1) How do Quaternary and
current climate affect plant mating system? 2) How does
current pollinator abundance and diversity relate to plant mating
system? 3) How does mating system relate to fruit/seed quantity
and quality in Curatella americana? We recorded
pollinators (richness, frequency and body size) and performed
pollination tests in ten populations of C. americana spread over
3,000 km in the Brazilian savannah. The frequency of self-pollination
in the absence of pollinators was strongly influenced by
historical climatic instability and not by present-day
pollinators. In contrast, seed set from hand-cross and natural pollination
were affected by pollinators (especially large bees) and
temperature, indicating the importance of current factors on
out-cross pollination. Two populations at the Southern edge of the
species’ distribution showed high level of hand-cross-pollination
and high flower visitation by large bees, but also a high level
of autogamy resulting from recent colonization. Our results indicate
that historical instability in climate has favoured 
autogamy, most likely as a reproductive insurance strategy
facilitating colonization and population maintenance over time, while
pollinators are currently modulating the level of
cross-pollination.