There may be a connection between orchid scent, altitude, and visits from pollinators, according to a new study that was conducted in the Swiss Alps.
Karin Gross, lead author of the study and a researcher at University of Zurich’s Institute of Systematic Botany in Switzerland, said that the new study is the first to find that various patterns of selection influence the regional differences in floral scent.
Tom Mirenda, an orchid collection specialist for the Smithsonian Gardens, said that the study shows how natural selection works, and how speciation and evolution occurs.
Orchids are flowering plants from the family Orchidaceae. Like many other flowers, orchids have a symbiotic relationship with their pollinators. (note: symbiosis is close and often long-term interaction between two different biological species) The flowers provide food to the pollinators, and in return, the animals facilitate the plants’ reproduction by transporting pollen from one plant to the other.
In the study – published Wednesday (Feb. 17) in the journal PLOS One – the researchers analysed the relationship between pollinators and orchids in the Swiss Alps. They looked at the flower colour, size, and scent, and they also examined the specific features of the pollinators.
According to Dr. Gross, floral scent is important in understanding the evolutionary changes among flowering plants. The floral scent is a crucial signal that mediates the interactions between pollinator and plant, Gross explained.
In lowland areas, a scent’s potency influenced the pollinators when choosing a preferred flower. However, that made no difference at higher altitudes, the researchers found.
Dr. Mirenda said that high in the mountains it was probably too cold for lowland pollinators to survive. Because the orchid seeds were carried from the lower valley to a new location, they changed their fragrance to attract other pollinators that would help the flowers survive – this correlates with the theory of speciation, or the evolutionary process by which biological populations that have become isolated evolve to turn into distinct species.
Researchers said that lowland pollinators may someday move to higher elevations due to warming temperatures caused by climate change. According to Gross, the new study may help make future predictions in relation to global warming.