Boston Globe: The annual rituals of nature -- the date when the marsh marigold first unfurls its yellow petals or when the common alder pushes out its leaves -- are among the most sensitive indicators of climate change.
And Concord, known more for its rebellious history and its illustrious writers, also contains a valuable cache of data, spanning more than 150 years, about the habits of plants and animals in town. Henry David Thoreau was one of the first chroniclers, filling an estimated 2,000 pages of his...