We've reach the fourth weekend in October and the autumn foliage is now at its peak here at Wahkeena and the Hocking Hills.
Many vibrate colors can be seen, especially in the maples. I do not know if there is a more pleasing sight then seeing the colorful canopy against a clear blue sky.
There are also more muted color like the shot about. This slop is dominated by oaks, which change from green to yellows and than browns fairly quickly.
On cold nights the chloroplasts (cells that produce the green pigment chlorophyll) are killed. Chlorophyll is actually made up of two greens and two yellows. When the supply of green is used up the yellow pigment become visible. You can see this in the leaves of the hickory tree above.
The Sugar Maple above has used up almost all of the remaining chlorophyll in its leaves. And below the American Beech has done the same. The beech leaves however will quickly turn to brown because of the presence of tannin which is also found in the leaves of oak trees.
Below is a common understory shrub, Maple-leaved Viburnum (Viburnum acerifolium) .
The Red, blue and purple colors in trees and shrubs are due to a substance called anthocyanin. Anthocyanins form when sugar is abundant in the cells of the leaves.
The beavers have claimed another casualty. This time an elm tree on the main dam of Lake Odonata. This tree is a short distance of the large beaver lodge so they will not have to take the branches far before caching them at the bottom of the pond.
The warm sunny days of the past week have been much appreciated by the Autumn Meadowhawks (Sympetrum vicinum). This dragonfly is one of the last to emerge from the aquatic nymph stage.
The pair above is seen in the "mating wheel" The bright red male clasps the head of the duller female. She then curls her abdomen forward to the base of the male's abdomen to retrieve his semen and thus fertilizes her eggs. Some have suggested that this position may have been the inspiration for the valentine heart!
