Fall has finally arrived after three months of temperatures in the 90s! The long hot spell and the lack of summer rain have caused autumn’s annual color show to be postponed. The foliage on many oak trees has bypassed color altogether, gone straight to brown and started to fall. Take heart! Some trees are now starting to change colors including maples, dogwoods, sourwoods, sumacs and hickories.
Cooler temperatures and shorter days signal trees to put on a vibrant show before trees go dormant. We are starting to see color at the higher elevations in the North Georgia Mountains. If you are a “leaf peeper” like me, you’ll want to keep track of Leaf Watch 2010, sponsored by Georgia State Parks and the Georgia Forestry Commission. In the weeks ahead, you can follow leaf color progression across north Georgia and get recommendations for where to find the best color. You can access the site at Leaf Watch 2010 through October and November.
This year you can also see leaves change in real time by viewing the webcam set up at Black Rock Mountain State Park in the Blue Ridge Mountains. Just click here for color changes in the park: Black Mountain State Park Webcam. You can also follow leaf color progression at Brasstown Bald, our highest mountain, by going to Brasstown Bald Webcams.
Ever wonder what causes leaves to change colors? A chemical reaction within the leaf cells is initiated by the shorter days and cooler nights of autumn. The green leaf pigment (chlorophyll) which produces food for trees during the spring and summer begins to break down in the fall as deciduous trees go dormant and the green color begins to fade. Leaves are taken over by other pigments from yellow/orange (carotenoids) to red (anthocyanin) and color combinations in between. The amount of pigment is based on the tree species, and other environmental factors.
Weather can affect the intensity of the color each autumn. Warm, sunny days with cool temperatures above freezing at night encourage the vibrant red pigment and the best overall color. If we have an early frost, the red will be less intense. Rain and clouds can also affect the brilliance of fall colors. In 2009 we had the right conditions for a marvelous display of color. The long period of hot weather well into September that we endured this year is postponing and may limit the intensity and duration of our leaf color display.
Don’t forget to check out the fall color right here at home. Line Creek Nature Preserve in Peachtree City and Sams Lake Bird Sanctuary in Fayetteville will offer opportunities to view the beautiful colors of autumn in the weeks ahead.