Sept. 22 was the first official day of fall, and the shrubbery in Pennsylvania isn't hesitating to display its autumn hues.

But the leaves changing colors early is a bad sign for the health of the trees, said Marc Abrams, professor of forest ecology and physiology. The trees in the area are showing the effects of the drought that plagued the state this past summer.

In central Pennsylvania, fall colors should peak between Oct. 11 and Oct. 26, but Abrams estimated that trees are about two or three weeks ahead of schedule.

During the normally wet spring and early summer months, trees produce the food they need in the form of chlorophyll. The breakdown of the chlorophyll makes the leaves change color in the fall, Abrams said.

The early summer months were wet, so the amount of chlorophyll in the leaves should be normal, Abrams said. However, the trees have started the breakdown process earlier than normal because the last few months were so dry. This is why some leaves are already starting to brown.

"Early coloration is classic sign of drought," Abrams said.

The drought not only affects when the leaves change but also how much color the leaves will show.

"When we have a dry year, it tends to reduce the intensity of the coloration," said Sam Bricker, assistant district forester in Rothrock State Forest.

Two species of trees that Abrams noticed showing especially early signs of fall are black birch and red maple, which usually don't change until October, he said.

Abrams said he is concerned that the peak for trees this fall will be earlier than usual.

"Any tree that's changing now won't have a good color in the middle of October," he added.

Bricker said that in very dry areas of the forest, some trees have died, but other stresses also affect the health of trees each year. Disease and insects combined with drought are harmful as well, he said.

"In certain places, we had almost total defoliation due to gypsy moths," Bricker said.

Mark McLaughlin, program director of Shaver's Creek Environmental Center, also said drought may not be the only thing harming the trees.

"I think some of the trees that are less healthy to begin with are browning out faster," he said.

While trees will be affected this fall by the drought, Abrams is not worried about any permanent effect on the trees. He said some trees die due to drought, but those trees will be replaced in the fall.

Bricker said he did not think the general health of the forest will be severely affected either.