For almost 40 years, field scientists strapped on cross-country skis, shouldered backpacks with supplies and set out over three miles of snow and rocks to a field station by a meadow high in the Rocky Mountains as soon as the snow began melting. Every other day, they counted each flower they found, identified the plant it belonged to and kept meticulous records of their observations.
Their observations provide the longest-running scientific study of its kind and tell a story of biological change that teaches scientists new lessons about phenology the timing of biological events and how they shift under the influence of climate change.
Unlike previous phenological studies that relied mostly on documenting the first appearance of flowers, the new analysis is the first to not only look at when flowers first appear, but also at peak flowering, that is, the time of year when most flowers are blooming, and the last day of flowering in a season. The study was led by Paul CaraDonna, a third-year doctoral student in the Department of Ecology and Evolutionary Biology at the University of Arizona, and Amy Iler, a postdoctoral researcher from the University of Maryland. The results are published this week in the journal Proceedings of the National Academy of Sciences.
The paper paints a much more complex picture than previous phenological studies on which ecologists have relied to gather clues about how climate change affects the timing of biological events like flower buds popping, animals emerging from hibernation, leaves turning in the fall or flocks of birds taking off for their seasonal migration.
"We already knew that the timing of biological events, such as emergence of the first flowers in a season, has been shifting toward earlier dates, but we show it's more complicated than that," said Iler, who is affiliated with the Rocky Mountain Biological Laboratory where the research was carried out.
Analyzing the l
|Contact: Daniel Stolte|
University of Arizona