Kaleidoscope of Colors...
Posted November 19, 2007
I've lived in central and eastern North Carolina more than 80% of my life, and you can't do that without seeing some very nice autumn color displays along the way, but I can only remember a couple of years in the past that (maybe) exceeded the beauty of the leaves that have burst into color around our area over the past couple of weeks. In my day to day travels across town, I've been especially impressed by a few stretches along Holly Springs road and along Avent Ferry where it crosses Lake Johnson just a few miles south of the TV station.
I have to admit that I've found the brilliance of this year's display a little bit of a pleasant surprise, as I was concerned heading into the fall that the dry conditions we've experienced this year might lead to a situation in which a lot of leaves quickly turn brown and drop off the trees without a chance to show their best colors. I'm certainly no arborist or horticulture expert, but from what I've read over the years it isn't unusual for drought conditions to result in relatively drab and short-lived color displays. That said, there have been some aspects of our weather this year that do tend to contribute to colorful leaf displays, and obviously they have more than offset any shortcomings due to the drought.
While there are so many influences that come into play in determining how long the leaves will hang on and how brightly colored they will be that a defitive explanation is probably impossible, we can at least speculate that the warm spring, during which we bagan to dry out in general but did have a couple of significant rainfall events, set trees up to be fairly healthy through the summer, despite the heat and lack of rain that was so prevalent by August. This may be a situation in which the relatively deep root systems of trees paid off with a slower response to drought when compared to lawns and drinking water supplies. In addition, a key to nice fall colors that is mentioned in many discussions of the subject is relatively warm and bright autumn days (which encourages the formation of sugars that can convert to some of the brighter red, purple and orange pigments) with a few crisp, cool (but not too cold) nights along the way. The drought that reached into the fall did leave us with above normal temperatures for September (+3.8 degrees) and October (7.4 degrees above normal) and also provided lots of relatively sunny days with less cloud cover than usual (September had 3 "cloudy" days versus a normal of 12, while for October it was 9 compared to a normal 11), but we have had a number of the needed chilly nights along the way as well. The trees may also have gotten a little boost holding on to their leaves by a couple of substantial rains that came in the middle of September and again toward the end of October.
Whatever the reasons (and I'd welcome any additional explanations that anyone more knowledgeable in the subject might offer - also, any of you who are interested in more background on leaf color processes might like to see an article from the Forest Service at http://na.fs.fed.us/spfo/pubs/misc/leaves/leaves.htm), it's turned out to be an especially picturesque fall. We probably are coming to the end pretty soon, of course, as more leaves will start to brown out and more will fall to the ground. In fact, some of those may get a little help shaking loose on Thanksgiving Day and Black Friday this week, as an approaching cold front brings a sharp temperature transition from highs in the 60s and 70s on Wednesday and Thursday to 40s and 50s on Friday and Saturday. In addition to a chance at some showers and possibly thunderstorms Thursday and Thursday night, that frontal system will likely bring some gusty winds (from the southwest Thursday and the northwest on Friday).