Those of us who live in the northeastern states and adjacent Canada are a truly privileged bunch, for there are only a few places in the world that see the forests turn color as they do here. At this time of year the forests of our area display a riot of color: from sere brown to lemon yellow, bright orange, brilliant red, maroon and port-wine purple. It’s an ephemeral display, lasting but a few weeks before wind, rain and gravity strip the trees of their leaves.
The display of fall colors brings a parade of leaf-peeping tourists that are always in search of the “peak” of the display. On TV the weather folks announce the southward progression of the peak of fall color; and communities publicize their foliage festivals. Earlier this week as my son and I drove through the valley in which he and his family live we were treated to one of the most brilliant displays of fall color I’ve ever seen. Tongue-in-cheek we decided that the “peak” occurred at 10:38 am on Tuesday, October 1.
We happen to live on the transition between the northern hardwood beech-birch-maple forest and the southern oak-hickory forest. Although named for their dominant species, these forests have scores of associated varieties of trees, shrubs and vines, many of which also display colorful foliage . The commonly used names for the predominant forest types are really simplifications since they contain numerous species of maple, birch, oak and hickory. Because we live in the transition zone, we enjoy a longer foliage season than most people as the different species turn color in a general north-south progression.
First to turn color are the birches, which typically turn pale yellow and lose their leaves early. Next come the leaves of red maple, which unsurprisingly, turn bright red
and those of sugar maple that may vary from yellow through orange to red – often on the same tree and sometimes on the same leaf.
In the oak-hickory forest all the hickories turn bright yellow,
while the oaks vary from yellow to dull red
and some of the associated species are real treats: the orange-gold of sassafras,
and the color spectrum of staghorn sumac
The final fling is the bright yellow of tulip-poplar that grows on the moist fertile soils of the hillside valleys.
For a readable, easily understood explanation of the complicated process leaves undergo to change color visit http://northernwoodlands.org/outside_story/article/the-causes-of-fall-color