Featured image: Clare Kaczmarek, Ohiopyle State Park
In Pennsylvania, the Department of Conservation and Natural Resources, along with many watershed groups, non-profit conservation organizations, and other state and local entities are working hard and partnering together to plant more riparian forest buffers. But what is a riparian forest buffer, and why are we working so hard to get more of them on the landscape in PA?
Breaking down the term “riparian forest buffer” into the three words that comprise the phrase makes it very simple to understand.
The term Riparian, according to Merriam-Webster, means relating to, living, or located on the bank of a natural watercourse, such as a river. Riparian comes from the Latin riparius, which is the same root word that gives us the term River.
Forest, of course, is a much more familiar word to us all. But to be consistent, it is defined as a dense growth of trees and underbrush covering a large tract.
Putting riparian and forest together, we get trees densely planted over a large tract next to a watercourse. We’re starting to see the picture come into focus.
And finally, we have the term Buffer. While this word has several meanings, we utilize it here in the sense of something that serves as a protective barrier.
To pull it all together, we have trees densely planted over a large tract next to a watercourse that serves as a protective barrier. And that’s it! That’s a riparian forest buffer.
Of course, as with many things, the answer to the question “what is a riparian forest buffer?” can often bring about more questions. People often wonder why a stream needs to be buffered or protected. What are we protecting it from? The easy answer is “pollution”, but specifically, in Pennsylvania, we are concerned with protecting our streams and rivers from excess nitrogen, phosphorus, and sediment pollution.
Nitrogen and phosphorus are chemical elements used as fertilizers. These elements are necessary for plant growth and survival. Sediment comes from the erosion of soil- it is dirt displaced.
Nitrogen, phosphorus, and sediment all exist naturally within streams and rivers. However, in excess, they become pollutants, wreaking havoc on the natural balance of these systems.
When streams and rivers have an excess of nitrogen, phosphorus, and sediment, the water becomes dangerous for human consumption, and unsafe for recreational uses as well. It is expensive to treat contaminated drinking water in order to make it safe again.
Excess nitrogen, phosphorus, and sediment are generated through human uses of our lands in developed areas (towns and cities), and on farms, which are all parts of a watershed.
A watershed is an area of land that drains to a specific point. Mountaintops and ridges typically form boundary lines between watersheds. As the water falls on one side of a mountain, that water will all run downhill in one direction. The stormwater that falls on the other side of the mountain will flow in a different direction. Each side of the mountain is part of a different watershed.
At higher elevations, small creeks and streams begin to form as stormwater runs over the land, finds a common low point, and begins flowing together. These small creeks and streams are often referred to as “headwaters”, because they are the “head”, or the top, of a watershed.
Small, headwater creeks and streams continue to flow towards each other, joining together at even lower points on the landscape, forming larger streams. Larger streams flow together, creating bigger rivers. And so and so forth until a river reaches a bay, a gulf, an ocean, or other similar outlets.
The area from the tip of the mountain where the rainwater first fell, to the point where all of the resulting streams and rivers are joined together at the outlet, is referred to as one “watershed”.
However, our watersheds are not only made up of the network of streams and rivers that branch across our landscapes. Rain and stormwater also must flow over land to get into our waterways. On the land in between streams and rivers are our cities and towns, our homes and roads, and our farm fields and businesses.
These areas of land that drain to our waterways literally shed the stormwater that falls onto the land, downhill, into specific streams and rivers. When we think of it this way, it is clear that the land is an inseparable part of the watershed. The land itself is what is shedding the water into the streams and rivers. Together, these connected areas of land and water make up individual watersheds.
Each river or stream has its own area of land that makes up its watershed. Smaller streams flow into larger rivers, connecting and creating larger watersheds. The larger watersheds are made up of many small watersheds, all linked together.
When our land is shedding water into streams and rivers, the water that is being shed readily picks up excess nitrogen, phosphorous, sediment, and other pollutants from farm fields, cities, and towns. The stormwater carries that pollution into our waterways, where it becomes concentrated, and begins to cause problems.
All Pennsylvanians need places to live, conduct business, and grow our food. We should utilize best practices to reduce the amount of pollution we create while going about our lives. However, we cannot reasonably expect to entirely eliminate the human-caused excess of nitrogen, phosphorus, and sediment that is ultimately picked up by stormwater runoff. But we can do our best to protect our streams and rivers from that pollution. Planting riparian forest buffers is a great way to do just that!
Riparian forest buffers intercept water flowing over the land, slowing it down, and soaking up some of the stormwater before it reaches a stream or river. Tree roots help to trap the sediment in the stormwater, keeping it on the land where it belongs. Trees and shrubs take up and make use of the nitrogen and phosphorus in the stormwater, using those nutrients to grow, and preventing the excess of these elements from reaching the streams and rivers, where they can become problematic pollutants.
Beyond helping humans by reducing water pollution and flooding impacts, riparian forest buffers also keep streams and rivers healthy for their own sake. Streams and rivers are not just networks of natural channels for water, directing it all to the ocean. Rather, our streams and rivers are ecosystems, teeming with life.
In Penn’s Woods, unsurprisingly, our stream ecosystems evolved surrounded by forests. In fact, the basis for the aquatic food web in our streams and rivers is highly dependent on fallen tree leaves. In a natural system, where a stream is surrounded by a forest, tree leaves fall into the stream in the autumn. The tree leaves, and the algae that grow on the leaves in the water, feed stream bugs. These stream bugs in turn feed fish, amphibians, and reptiles.
Many terrestrial critters then depend upon fish and other stream creatures for food, while also depending on the stream for a source of drinking water. The streams support the forest ecosystem, while forests also support the stream.
Forests are critical to wildlife, and healthy watersheds, healthy streams, and healthy forests are undeniably interconnected. Planting and maintaining riparian forest buffers creates forested habitats in the most critical places. Riparian forest buffers serve as natural migration corridors for birds, mammals, reptiles, and amphibians.
For generations, we simply weren’t aware of the importance of keeping our streamsides buffered with forests. Many riparian forests were cleared for farming, development, and other human uses of the land. Now that we have come to know how critical riparian forest buffers are to our own health, and to the health of the wildlife and our environment in general, it is important that we protect existing riparian forest buffers, and plant new riparian forest buffers around streams whenever and wherever possible.
A riparian forest buffer needs to be at least 35 feet wide to help stop pollution. A 50-foot-wide buffer does an even better job of improving water quality and protecting the stream. Wider, 100+ foot buffers next to streams provide the greatest benefits.
We’re working to shift the paradigm in Pennsylvania so that future generations expect to see forests around streams, and immediately recognize the important role trees play in clean water. We hope to create a more forested future for everyone.
Do you want to know more about how riparian forest buffers impact our economy and are essential in the creation of the beverages we love? Watch Forests, Clean Water, and Craft Beverages on PPFF’s Youtube page!
Teddi Stark is the Watershed Forestry Program Manager with the DCNR Bureau of Forestry and the Western Pennsylvania Conservancy. Teddi has an MS in Park and Resource Management, and 13+ years of experience working on watershed restoration efforts in Pennsylvania. Teddi lives in Harrisburg with her husband and two dogs, with whom she enjoys hiking and traveling.