The damage that occurred from Hurricane Helene in western North Carolina was disastrous. It is acknowledged as a geologically significant event. The flooding from rivers and tributaries affected topography and even permanently changed the course of stream channels. It is tragic for those who lost homes and saw their former yards cleared of vegetation, leaving nothing but bare soil, much of it eroded sediment from the flooding waterways. Only expensive restoration and construction can begin to attempt a return to some kind of new “normal,” and this will likely take many years given the geographical range of destruction in our mountain river and stream valleys.
Many people who lived slightly or even much higher than the flooded lands also suffered major levels of damage involving treefalls on their homes, vehicles, and yards. At some point, homeowners will be able to focus on the last of these as they begin to address landscape needs. There are a number of changes that will occur as a result of Helene’s fury that will need addressing. Some of these can be beneficial, while some definitely problematic. This article focuses on these homeowners.
Treefalls
So, you lost one or more big trees in your yard. What should you do. Replant large maturing deciduous trees to replace those magnificent oaks, hickories, tulip poplars, etc.? Or not? Before making decisions, it’s important to know what you can expect to see if you do nothing.
First, it’s important to ask some questions. Did the tree(s) fall because their roots were restricted in some way, such as too close to a building foundation or covered by too large an area of concrete driveway, patio, or road? Were they growing on a slope with shallow soil and/or over a layer of rock?
Secondly, when a large tree falls in a forest, or in a yard, it will create an opening that may be up to ¼ to ½
acre in size. This opening, which has been shaded for many decades, will suddenly receive more hours of intense sunlight, which will cause warmer soils. These soils will also receive more precipitation during the first half hour or so of a thundershower when rainfall is most intense, since there will be no foliage to catch the initial rain and slow its introduction into the dry soil. This is the time the ground is most susceptible to erosion. Frontal systems may bring more rainfall than thunder storms, but its precipitation usually occurs over a few days, and at a slower pace that allows for soil uptake and less runoff.
Disturbance and Invasion
Another unwanted change that will likely occur -- and one that was not a concern prior to the 1980’s -- is that the newly sunlit and disturbed soil will become invaded by non-native invasive species of herbs, shrubs, vines, and/or trees. Non-native invasive plants (NNIP) have the ability to invade disturbed soils quickly, before many native plants can become established. Do you have knowledge of any such plants that were already present before Helene came through? These would be likely to resprout from roots that remain in the soil even if their above-ground stems were swept away by wind or water. If these get a start and go unnoticed or uncontrolled, your yard may become a jungle nightmare within a very short time.
Additionally, other previously absent NNIP may suddenly now appear. Depending upon the species, seeds of invasive plants are brought in by wind, water runoff, birds, and mammals, including perhaps, the soles of your own shoes or auto tires.
Erosion
What is the grade status of your site? Is it basically level or do you have moderate or steep slopes? Did any areas suffer from erosion? Were trees on any sloped areas uprooted? If so, there will certainly be erosion here, which will continue and likely worsen through time. Do you have a small stream that suffered only slightly from loss of streamside vegetation or bank erosion? These small losses will grow worse through time and should therefore be addressed before they do.
Restoration Options
Tree Replacement - If you are leery of replacing trees following structural or vehicle damage from a fallen tree, fine. But consider doing so anyway, by planting smarter. If the storm-fallen tree was originally planted too close to a building and your site offers places to plant farther away, why not replant? One major benefit that large maturing trees can provide is to offer shade from hot summer sun, while allowing winter sunlight to provide a level of warmth in winter after leaf fall. In this way, trees can lower cooling and heating bills. Ecologically, large-growing trees offer food and cover for native insects, from pollinators to predators of insect pests. Oaks, for example, support over 500 species of native insects whereas the non-native ginkgo tree attracts only five.
Additionally, any trees that are replanted will take decades to ever reach a size or weakened condition that would become a threat to home or auto. And, by having a certified arborist do some selective pruning at an early time in a tree’s life, it can be trained so that large limbs will not become a threat to your roof line when it reaches an older age. Many thousands of pounds can be trimmed from a tree canopy that will greatly reduce risk of uprooting without causing harm that topping does, but will still will leave the tree’s natural shape intact. If replacement with a large growing tree species is not feasible, consider planting one or more smaller native trees. There are a number of good possibilities that provide attractive blooms and fruits for birds, and even for yourself.
Non-Native Invasive Plants – Now is the time to begin carefully monitoring the plant species that begin to colonize areas where the soil has been disturbed and/or that have suddenly become exposed to sunlight. Maybe most or all plants that sprout, whether from seeds or buried roots, will be native species that previously grew there or moved in from adjacent property. If so, consider yourself
lucky, and replant with others compatible with them in this particular ecosystem.
But there is a high likelihood that a few will be non-native and invasive, so they should be controlled as soon as they begin to appear. In their early stage, such plants can be easily pulled or dug up. Do not simply prune or mow them, since that will only encourage roots to spread and cause numerous new sprouts to grow. They must be removed, so don’t hesitate to so!
Erosion and Sedimentation – If you have areas that are fairly level or not too steep, yet the storm’s heavy runoff washed away some soil or carved out small ditches in the process, there are a couple of possibilities for restoration and future management. Observe where the erosion begins. This is usually at the upper part of a grade and this is where to begin controlling the flow. This can often be done simply by filling in the lost soil, raking the area, and installing plants to establish a root zone that stabilizes the soil and provides leaf cover to help slow down the initial precipitation. If any erosion is later seen beginning further
downslope the same action could be repeated.
Another option would be to re-sculpt the grade to accommodate future runoff events so that it better handles such drainage. Given climate model predictions that more precipitation is in store, taking such a proactive stance will lessen the severity of such events. You now know the path that runoff will want to follow, so consider turning the new ditch into a gentle swale with sides that slowly grade into the higher surrounding property. This will spread the dynamic stream current energy over a much larger area, reducing its speed and erosive action. Planting this area with native plants that typically grow along stream corridors will help further prevent erosion during future storms. In other words, “If you can't lick ‘em, then join ‘em,” by planting what nature would grow in these more dynamic zones.
For more information on ecological property management; non-native invasive plants; NNIP removal; and replacement with native insect and wildlife attractive plants, contact Bob at http://www.restoraflora.com/
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