Climate Change Lesson 9 : Plant and Animal Phenology
Phenology is the branch of ecology that explores the seasonal timing of life cycle events, such as the migration of birds, the blooming of flowers and woody plants, animal reproduction, and the emergence of insects and other organisms. It crosses multiple scientific disciplines by relating biological processes to seasonal conditions. Because many biological events are triggered by or timed to climatic conditions, observations of plants and animals can be an indicator of climate changes through ecosystem impacts and disruptions caused by climate changes. Just as there are regional differences in temperatures and other weather patterns, there are regional differences in biological events. Factors such as altitude, topography, and the buffering of temperature changes by large bodies of water such as the Great Lakes contribute to theseregional differences.
Phenology researchers record the timing of various biological events from year to year in a specific geographical location. If people use comparable techniques to record such observations over many years, the data can paint a picture of climatic trends in that place over those years. Aldo Leopold, a notable Wisconsin ecologist and environmental writer, recorded many years of phenology data. His observations supported his ideas about a land ethic, which he defined as harmony between humans and ecosystems. His forceful articulation of this belief made him one of the most effective early proponents of conservation in the United States. Phenological observations have been done in many other places; the Leopold observations are a well-known example of a long record, but the general principle has been observed in hundreds of places around the world.
Case Study: The production of cherries is a major industry in northern Michigan. Cherry orchards line the eastern shore of Lake Michigan from Benton Harbor to the Traverse City area. Michigan’s cherry production is about 250 million pounds, and represents about 75 percent of the tart cherries and 20 percent of the sweet cherries grown annually inthe United States.
The sandy soil and temperate weather conditions along the eastern shore of Lake Michigan are excellent for growing fruit. That’s because Lake Michigan was formed during the last Ice Age, some 12,000 years ago by retreating glaciers that dug deep trenches in sandy areas that were once a sea bed. Much of that sandy soil remains along the eastern shoreline. The winds blowing from Lake Michigan help to moderate the area’s weather by cooling the orchards in the summer and warming them during the winter.
Today, Michigan has about 3.8 million tart cherry trees and about 0.5 million sweet cherry trees. The changing climate will definitely affect this industry.