Data from: Specialized mutualisms may constrain the geographical distribution of flowering plants

It is commonly assumed that the geographical distributions of plants are
governed mainly by abiotic variables. However, interactions with other
organisms, such as pollinators, also have the potential to influence plant
distributions. To investigate this, we developed niche models for 32 plant
taxa that have specialized pollination systems and which are native to a
biodiversity hotspot (South Africa). We found that the distributions of
these taxa are best explained by a combination of biotic (pollinators) and
abiotic factors, rather than by abiotic factors alone. For ~66% of these
plant taxa, pollinator distributions were the factor that provided the
best predictor of their niches. Furthermore, co-occurrence of these plants
and their pollinators, was generally not explained solely by shared
abiotic niches, and thus likely reflects broad-scale positive ecological
interactions. These results are consistent with the proposal that
pollinator distributions may constrain plant distributions and highlight
the general potential for species distributions to be shaped by positive
interactions with other species. This has important consequences for
predicting how distributions of species might change in the face of loss
of their key mutualists.