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Wildlife Watching at Joseph E. Ibberson Conservation Area

The Forest

The common tree species of Joseph E. Ibberson Conservation Area are:

  • Red, black, scarlet, and chestnut oak
  • White, Virginia, and table mountain pine
  • Tulip popular
  • Eastern hemlock
  • Black gum
  • Basswood
  • Black walnut
  • Black locust
  • Wild black cherry
  • Black birch
  • Red maple
  • Sassafras
  • American beech
  • Hickories

This diversity of trees produces nuts, seeds, berries, and browse for wildlife like white-tailed deer, squirrels, ruffed grouse, wild turkey, black bear, and many species of birds.

These tree species are just the latest species to grow here. The original forest, before settlers arrived, was probably large white pine and eastern hemlocks. This dark, quiet forest quickly fell to the logger’s ax.

The forest that regrew was probably similar to the forest of today, with the addition of the American chestnut. The impressive chestnut dominated some of the forests of Pennsylvania until a blight killed most of the trees. Occasional American chestnuts still survive long enough to produce nuts, but the blight eventually kills them.

Drastic changes like forest fires have probably altered this forest several times. Another change is happening right now. Thousands of white pine seedlings are growing under the taller deciduous trees.

For years, the mature pines along Pine Trail and other locations deposited seeds throughout the forest, but the seeds never germinated. Two successive years of defoliation of the deciduous trees by gypsy moths allowed sunlight to strike the forest floor, which caused the white pine seeds to germinate.

It will be interesting to see if the white pines will replace the deciduous trees, making this forest resemble the original dark, quiet forest.


The conservation area is in the Ridge and Valley Province of the Appalachian Mountains, which is characterized by long parallel mountain ridges and wide, flat valleys. These mountains were raised up by the collisions of the continents of North America and Africa.

These mountain building events, called orogenies, folded and bent the rock layers and lifted them up. The Appalachian Mountains were once very tall, but 220 million years of erosion have worn away the tops of the mountains, leaving behind wide, flat valleys and short, steep mountains of hard rock.

Most of the bedrock of Peters Mountain is composed of hard sandstone tilted at a steep angle. Much of Powells Valley is underlain by a combination of soft rocks like shales, siltstones, and sandstones. Due to the rich valley soils, this area is often called the “bread basket of Dauphin County.”