Charting climate change and local loss of flora from Thoreau's journals

March 25, 2014 9:53 AM

From 1851 to 1858, Henry David Thoreau noted a number of natural occurrences in detail, including the first flowering dates for over 500 species of wildflowers in Concord. Additionally, Alfred Hosmer, a botanist in the same area, had recorded the flowering dates of over 600 species of wild plants in 1878 and from 1888 to 1902. With that data, Richard Primack, a biology professor at Boston University, and fellow researcher Abraham Miller-Rushing spent years aligning old plant names with current names to study the change flowering patterns from the recorded past to present. Their phenological study concluded that plants in Concord, on average, are now flowering 10 days earlier than they were in Thoreau's time (full article for the journal BioScience).

Primack and Miller-Rushing also looked at the photographs of Thoreau's locations, captured by Herbert Wendell Gleason between 1900 and 1921. This data indicates not only earlier flowering dates, but also local extinction of flora.

To expand the scope of their study, Primack and Miller-Rushing looked for historic records of bird-arrival dates (noted by Thoreau, William Brewster [Archive.org] and Ludlow Griscom) and appearance of insects in the spring. There is no clear pattern of arrival dates changing over time, and getting sufficient data on insect appearance is more difficult than obtaining other accurate and detailed historic records.

posted by filthy light thief (3 comments total)

Thoreau and phenology, previously.
posted by filthy light thief at 9:54 AM on March 25, 2014

I have been reading everything I can on phenology and folk wisdom largely to figure out the best times to sow seeds, given unpredictable weather patterns. This is an awesome post.
posted by annathea at 6:22 PM on March 25, 2014

Excellent post. Thanks, filthy light thief.
posted by homunculus at 12:20 AM on March 27, 2014