One of the take-home messages from this is that the interaction between pollinators and their landscape differs for different species, and yet this very interaction can have a significant impact on the genetic structure of a plant species' populations. In addition, their results suggest that pollination syndromes do not just capture the morphology and likely pollinators of flowers, but may also impact the population structure and genetic isolation of populations.
There are evolutionary implications as well. Hummingbird pollination has arisen independently in Penstemon at least 10 times, and possibly as many as 20 times, yet a shift back to bee pollination has never been reported. The results from this study may shed light on why that might be. Because populations of a bird-pollinated plant experience greater gene flow among distant populations, there is greater connectivity among these populations. Any changes that might arise due to the local presence of bees would be negated by the gene flow facilitated by birds, which would constrain any adaptations at the local level and prevent plants from shifting back to a more confined bee-pollination syndrome.
Furthermore, the results from Kramer's work can be used directly in restoration efforts. "The Bureau of Land Management is working to increase the species diversity and success of large-scale restoration work on public land in the western United States," Kramer notes. "The BLM supported this work and will be able to put the results of this r
|Contact: Richard Hund|
American Journal of Botany