Monday, May 17, 2021

Stream buffers (5/17/2021)

In a recent opinion piece in the “Bay Journal” an online weekly “news” paper, Beth McGee from the Chesapeake Bay Foundation writes that of the Bay States it appears that only Maryland is somewhat meeting its requirement of reforesting its stream buffers. Virginia is a distant second (33%) and Pennsylvania seems to have only met 20% of its assigned goal. Stream buffer planting seems to conflict with the agriculture use of the land and nibble away at the acreages of land that can be cultivated or grazed. In other words, it is difficult to promote or enforce.

In a way, it is all understandable. An acre of land used for crops might just be what a farmer needs to make a profit; although if that is what does it, he or she should probably be in a different business. On the other hand, for land developers, an extra acre could result in one or two more residential lots. This would raise the company’s profit margin on the project. Conversely, for a commercial site it would mean more parking and therefore a larger footprint of the industrial or commercial project.

However, little do folks realize what buffer zones do and what they contribute to the environment. So, let’s take it apart. As I mention in my classes, I will try to keep it simple; I am sure there are many more facets to this, but here are some of the important points.

I want to start with the environment. Trees in general are much more efficient in sequestering carbon and thus cleaning the air than agriculture land and pasture. I teach my students in one of my classes that the net primary production or the amount of carbon (CO2) fixed by agriculture and pastureland is between 600 to 650 grams per square meter per year, a forested buffer can produce between 700 when it is young to 1200 grams per square meter per year when it has matured. In other words, a mature buffer can capture almost double the amount of CO2 than a pasture or agriculture field. I don’t have hard numbers for subdivisions and industrial areas, but you can imagine that they capture even less carbon than agriculture fields.

Now let us look at the runoff from all these areas. Forested areas have a higher infiltration rate than agriculture land, pastures, or lawns. Moreover, all the leaf litter will help filter some of the water, and these buffers are generally not fertilized and often not sprayed with herbicides and insecticides. In other words, streams surrounded by wooded buffers receive less polluted runoff. Note that I do not mention the word less or more runoff. These streams will most likely receive less runoff. The water will infiltrate and be taken up by the trees and other plants and used for photosynthesis and transpiration. However, some of this infiltrated water will make its way to the stream in a much slower fashion. It will flow through the soil as opposed of over the soil, being filtered even more. In addition the water will be released more slowly to the streams, thus reducing the chance of flash floods during and just after a rainstorm. Concluding, forested buffers keep the water levels in streams more stable and keep the water in streams cleaner. Finally, trees may actually shade the stream, keeping the water in the stream cooler, which is healthier for all the creatures living in the stream.

A second point, organic farmers know that hedgerows along agriculture fields are very important. Hedgerows provide nesting sites for birds, and birds eat bugs, bugs that harm crops. Wildflowers in these hedgerows attract pollinators and maybe even predator insects, again something that is very useful for your crops. Hedgerows may actually reduce wind damage. In other words, a wooded edge along your field or between the field and the creek may bestow you an advantage.

Developers, you too should encourage stream buffers. People whose home borders the woods and look out on the woods usually pay a premium for their home. These buffers can be used for recreation by putting in walking paths, again increasing property values. When used correctly, buffers can often be used in stormwater calculations and used to offset the need for large stormwater facilities, saving acreage elsewhere. I have seen instances where we were able to change our underground piping for stormwater from large concrete pipes to smaller plastic pipes, saving the client thousands of developing dollars.

You get the idea; wooded stream buffers are really not as bad as they are made out to be. They are environmentally important, and landowners can use them to their advantage.

On a final word, naturally I am biased and over-simplifying here. Regular readers know, I write a lot about trees, stormwater, the environment, etc. In fact, the half-acre lot that our home is on is almost completely wooded, to the extent that I can hardly grow a lawn, or barely have enough sun to grow my bonsai trees. I often rail against and complain about the folks in my neighborhood who cut most or all their trees. The current book I am reading is about trees: Suzanne Simard’s book: “Finding the Mother Tree, Discovering the Wisdom of the Forest.” In other words, I am a tree hugger as I describe in this post and I will keep fighting for them, I honestly know this is one important way to save the earth for future generations.

Our back yard.  We have been laying gravel paths this spring.  Partially so that we don't drag in muddy feet but also in the hope to keep the chiggers and ticks at bay.  As I mentioned before I hate picking up leaves.


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