Trees have been called the “lungs of the planet.” They take in carbon dioxide and release oxygen, keeping the air clean.

They provide habitat for birds, insects, and small animals.

They prevent soil erosion and flooding, and they have been inspiring poets and painters for millennia.

Many diverse types of trees can be found in Florence Shelly Wetlands Preserve, a 400-acre a nature preserve in eastern Susquehanna County, Pennsylvania.

On Sunday, September 10, at 2 PM, retired forester Hank Hartman will lead a walk to identify some of these trees and discuss their special qualities.

Mr. Hartman will identify the dominant trees in the preserve, including maple, ash, a few species of oak, shadbush (named because they flower around the time the shad are running in the rivers), black cherry, and many others. There is even a rare American elm.

Trees planted by humans in the past are also in evidence.

For example, a neat, straight line of sugar maples along the main trail was maintained by farmers almost a hundred years ago alongside a dirt road, so as to be convenient for sugar tapping.

Dense, dark areas of scotch pine and Austrian, or red, pine remain from plantations started by the Conservation Corps during the Depression and never thinned. Mr. Hartman will also discuss current ecological threats to trees, such as the viburnum leaf beetle, which has damaged nearly all the viburnum bushes in the preserve, as you will see from the gray, brittle skeletons lining the trail, and the emerald ash borer.

Hank Hartman, the walk leader, is retired from the U.S. Forestry Department and is an active member of the Pennsylvania State Tree Farm Committee and the Florence Shelly Wetlands Preserve Stewardship Committee, where he also serves as treasurer.

Florence Shelly Wetlands Preserve is located one mile north of Thompson, PA on Route 171.

Parking is available in the lot just opposite Stack Road. The walk will last about two hours and is free to the public.

Although the trails are clearly marked, they are very uneven because of rocks and tree roots, so steady footing is essential!

And since this is a wetlands area, it is a good idea to wear waterproof shoes, especially if we’ve had recent rains.