Phenology, Flowers, & Climate Change
Western Spring Beauty, Colorado (credit: Southwest Colorado Wildflowers)
Anyone with a garden where the seasons are distinct has observed when the first blooms appear in the Spring. This environmentally controlled events were carefully noted 150 years ago by Henry David Thoreau who recorded flowering times in Concord, Massachusetts. His notes on 'first blooming' and other life-cycle events is now an important of ecological science, phenology.
Plants are very sensitive to their environments so they represent good biological indicators of climate change due to increasing temperatures or declining snow cover. A study published by Global Change Biology shows just how sensitive they actually can be over a very short time period. The research was led by Dartmouth graduate Zachariah Gezon who studied the Western Spring Beauty, a mountain wildflower.
The plant is one of the earliest to emerge from under the snow after it thaws in the Rockies. Using a clever experimental design, Gezon showed how the bulbous plant would react to shifting dates of snow disappearance. The researchers cleared snow from designated test plots when there was still more than three feet remaining on surrounding areas outside their plots. In the cleared areas, an early flowering response was triggered in the dormant bulbs similar to what would be expected if climate change had induced temperatures to melt the snow. The time of flowering within the test plots occurred earlier than which happened to uncleared areas. Over the three year study, Spring Beauty bloomed 10 days earlier in the cleared spaces than similar plants in areas remaining snow covered. Besides its sensitivity to an earlier simulated 'melting' in a future warmer mountain environment, the flowering occurred before insect pollinators hatched so no seeds were produced.
The ecological concept behind phenology is explained in a video. A national organization, the National Phenology Network exists so "citizen scientists" can contribute their own observations to help further this important science on the cutting edge of climate change.
WHB