Fall colors are at their height, but the climax this year falls short of the glorious display of last year. Sure, some of the maples have turned a brilliant red, as have some of the sumac bushes and red oaks. And an occasional sugar maple or, even better, an entire aspen has turned bright, golden yellow. But more often, a maple will have turned only partly red along some branches, the rest remaining green. Some branches are already

bare, with the rest of the tree partly red and partly green. Some leaves, especially

on oaks and beeches, have gone directly from green to brown.

Drought is the main culprit this year,

says William Livingston, chairman of the Department of Forest Ecosystems at the University of Maine. He lives in Old Town and has watched the dry weather and warm days until recently cut back the normal brilliance of the fall colors. The already bare branches are the result of what specialists call “early leaf drop.”

Another damper this year, says Professor Livingston, has been a long succession of warm nights. They cause what’s known as “translocation of sugar.” The bright reds of fall require sugar in the leaves. Warm nights cause the sugar to flow out of the leaves and back into the stems. This translocation can halt the change from green to red and spoil some of fall’s usual splendor.

Still, if you watch for them, you can still spot some bright reds and oranges and yellows against the bright blue of the sky, crisscrossed these days by vapor trails as Air National Guard pilots hasten to put in flying time before they are called up. So the outdoor scenes this year provide some of the usual beauty, along with a reminder that the war against terrorism has begun.