////Pennsylvania Riparian Forest Buffer Program

Pennsylvania Riparian Forest Buffer Program

What is a Riparian Forest Buffer?

Riparian means “streamside” in Latin (sorry, we’re ecologists after all). A Riparian Forest Buffer is simply an area of native trees and shrubs along a stream. Without forest cover streams are unprotected from polluted runoff and runaway streambank erosion. Bare stream sides are unlikely to host aquatic life which filter pollution out of our water. In other words, clean water and healthy aquatic ecosystems need forested streams. Forests also give us many other benefits of course, from providing habitat for pollinators and wildlife, to sequestering carbon, to providing perennial food sources like native fruits and nuts.

Historically, we haven’t cherished our streamside woods as much as we should have. Many were cleared for development or agriculture. There are currently over 400,000 unforested riparian acres in the Pennsylvania portion of the Chesapeake Bay Watershed alone. Our mission is to reforest as much of these riparian areas as we can by planting trees and shrubs, mostly on private land. This will not only dramatically help clean up our local streams and eventually the Chesapeake Bay itself, but will exponentially improve the properties where trees are planted. Livestock will be healthier, pollinators and other wildlife will return, and landowners will benefit from their new forests, which will only get better with time.

Photo by Ryan Davis.

It is still very common in Pennsylvania for livestock to be pastured around streams, partly because those areas are not suitable for row cropping. Cattle need water too, but they significantly harm aquatic life and water quality by increasing bank erosion and passing waste into streams. Livestock in streams are also at high risk of infections and fatal accidents. Excluding them from the riparian zone and planting trees there instead is a win-win for all.

How Do You Establish a Riparian Buffer?

Establishing a Riparian Forest Buffer is not as simple as planting tree seedlings and watching them grow. The long-term care of the site is what determines whether the site will become a fully mature and healthy forest. Over the past several decades, the procedure for preparing, planting, and maintaining sites has been fine-tuned to yield success.

It is important to prepare the planting site by controlling non-native invasive species which would hamper the young forest’s growth. A few weeks before the proposed planting date, we mark where each tree will be planted with a pin flag. This allows the landowner to visualize the planting and work with us to make adjustments before the trees are in the ground.

We plant young trees and shrubs, typically bare-root or small containerized seedlings. Younger stock is more resilient and more likely to quickly adapt to their new home. We protect these young stems from deer and other herbivores with tree shelters, which stay around the tree for several (typically between 5 and 10) years to ensure that it has a good chance of surviving to maturity.

Photo by Allyson Wells Davis.

Tree shelters are critical. They protect seedlings from deer and other herbivores and assist with post-planting maintenance of sites; imagine trying to check on 2 foot tall trees in a sea of 4 foot tall grass without them! Modern tree shelters are much improved from their older counterparts. They are vented to allow air flow which improves tree health and are flared at the top to reduce trunk abrasions.

After the planting, the real work begins. Sites need regular maintenance. Vegetation control is crucial in order to reduce rodent damage and give enough light to the trees.

The recipe for success:

  • 2-3 mows for each growing season
  • 1-2 applications of herbicide in rings around each tree
  • X the first 3-5 years after planting.

Following these steps will yield a survival rate above 90%, resulting in a nice forest stand within 10-15 years. Not following these steps may yield survival rates below 20%, resulting in a messy tangle of invasive plants with a few nice trees in the mix. The post-planting maintenance is so critical that we pay for it entirely for the first 3 years.

Deer browse on a red maple. This is why we always use tree shelters; it only takes one deer to destroy an entire site. Photo by Ryan Davis.

Too much tall vegetation around tree tubes emboldens rodents to build nests inside, and eventually chow down on our trees. Photo by Ryan Davis

A well-maintained buffer in Lancaster County. Note how low the vegetation is being kept, and the rings of herbicide around each tree that will help deter rodents from entering the shelters. Photo by Ryan Davis.

Within 10 years, a well-maintained buffer site will look like this one, where the shade from the canopy suppresses grasses and functions as a first line of defense against invasive plants. Photo by Ryan Davis.

Our Riparian Forest Buffer Program

Any landowner, from private citizens to municipalities to churches and schools, is eligible for our riparian forest buffer program. We cover 100% of the costs of the trees and supplies required to establish the buffer. This includes invasive plant control, tree tubes and stakes, installation labor, and 3 years of post-planting maintenance.

We require a minimum average buffer width of 35 feet from the top of the streambank. This means that we can dip below 35 feet in tight spots if necessary, as long as the width is made up for in another section of the buffer. We can plant as far as 300 feet from the stream.

This map shows riparian buffers installed in Pennsylvania since Fall of 2017.

Meet the Alliance’s Buffer Experts


Pennsylvania: (Left) Ryan Davis ( and (Right) Brittany Smith ( Phone: 717-517-8698

Interested in learning about riparian forest buffer opportunities and resources in other states? We have Forestry Program staff across the Chesapeake Bay Watershed who are eager to help!


(Left) Maryland: Craig Highfield at or 410-267-5723

(Right) Virginia: Jenny McGarvey at or (804) 977-1657