Tree That Grew Along with Mount Holyoke Now Helps Students Learn about Climate

A tree that was planted in 1837, MHC's first year, and cut down last month is now helping geology students study climate change. The seven women in geology professor Al Werner's Global Climate Change seminar have been studying the climate record through geologic time this semester, and have worked their way up to relatively recent times. When the majestic elm that stood outside Mary Woolley Hall succumbed to rot this spring and was taken down, Werner asked to have a four-inch-thick cross section of the trunk saved. The campus carpentry shop staff finished and sealed the slab so it can be used in classes.

<<< Margaret Baker '99 uses digital calipers to measure the thickness of each ring in a 160-year-old tree. Her geology seminar is using the crosssection to study climate change.

Students determined the tree's age--160 years--by counting the rings indicating each year's growth. Ring thickness is related to how good the growing conditions are each year, so students are measuring the width of each ring using digital calipers. Then they compare the size of each ring with data collected in Amherst on local climate conditions. For the rest of the semester, they'll compare the two sets of data to see how sensitive this tree was to climate changes.

They're also expanding their analysis by graphing the climate data to see variations and patterns over time. According to geologist Steve Roof, statistics show that the average temperature has risen slightly over the last 160 years. He believes this is due to what we now call global warming. "We see a consistent temperature rise over time, and changes of a degree of two are very significant," Roof says. Both Roof and Werner are quick to point out, however, that the observed warming may be due to natural climatic variability and not necessarily due to human-induced global warming. "Only time will tell if human activity is causing the earth's climate to change," Werner said.

In addition to the tree section's scientific uses, Werner also sees it as a metaphor for the College where it lived for 160 years. "Like the College, the tree grew from a small sapling to become large and majestic, suffering through hardship, recovering, and experiencing strong growth," he says.