Fall Foliage - 2007

The photographs below show foliage color at the end of September in 2005, 2006, and 2007 at the edge of the pasture adjacent to the headquarters of the Harvard Forest. The following presentation shows the progression of foliage from 2005 thru 2007. 

2005	2006	2007

Based on observations of leaf color and leaf drop on the same trees over the past 18 years by John O'Keefe, 2005 was a rather late fall and 2006 was an early fall, about a week ahead of 2005. It is still to soon to say where 2007 will wind up, but the very dry weather in August and early September led to some drought stress and color/drop of leaves, most noticeable on the birches and maples.

The bright sunny days this September have led to good anthocyanin (red pigment) production. Unlike the yellow carotenoid pigments, which are present through the growing season and then unmasked as chlorophyll breaks down in the fall, these red anthocyanins are produced by sunlight during leaf senescence. Learn more about leaf color.