Friday, November 23, 2012

Missed Opportunities to Work with Nature

     A couple of created storm water features near my home and office have grabbed my attention lately.  Both are related in that they are associated with a nature preserve and in that they are not functioning as they were intended.  Both seem to have suffered from a lack of understanding concerning many of the natural systems involved in the cleaning and release of storm water.
     The first one was actually completed about a month ago and just recently a sign proudly proclaiming that it is a raingarden was added.  The sign has a pretty photo of a real raingarden that looks like the photo from the state storm water web site.  Unfortunately, the project is most definitely not a raingarden.  In fact, the only thing that it has in common with a raingarden is the use of a couple of plants that would survive in one.  The garden is located at the exit end of a pipe that drains water from a series of roof drains off a park building; so it will be the recipient of a good deal of water.  Unlike a raingarden, though, no effort was made to dig out the area and replace the existing soil with a media that would function to hold water and no effort was made to create the grade of a rain garden that would allow water to actually collect and infiltrate into the soil.  This garden is simply an area below a pipe that has been cleared of leaf litter, surrounded by a row of stones and planted with a group of plants (some of which would actually never survive in a raingarden).  The entire garden slopes away from the pipe so virtually no water will ever be slowed down enough to enter the soil and will most likely be more prone to eroding now that it has been disturbed.  What a missed opportunity.
     The second feature is actually a storm water detention device that was built by the Dept. of Transportation (NCDOT) a couple of years ago.  When it was constructed, it was planted with a combination of cattails and willow.  By good fortune and plenty of naturally available seed, a mass of pine seedlings had taken hold along the entire street-side bank.  A sizable number of green frogs had taken up residence and the device was well on its way to becoming a functioning temporary wetland.  It also functioned as an occasional stopping place for a number of waterfowl.  It had in a couple of years gone from an ugly device that held algae filled water and grew mosquitos into a pretty little wetland that actually functioned to clean the storm water and release it slowly into the drain provided.  The cattails, the willows and the pines all worked to clean water in the pond area and to remove it slowly through transpiration.  Because they were working in this way, the mosquito population had gone down noticeably.  In other words, it was actually functioning in the way that a good storm water detention device should function.
     Unfortunately, this week a private contractor came to this detention basin and cleared it out.  Every living thing within the basin was dug out with a backhoe and all of the pine seedlings - which had reached a height of approximately four feet - were cut down to the ground.  The frogs and other wildlife that had been using this pond area are nowhere to be seen.  I predict that this device will once again be filled with smelly, algae filled, mosquito infested water.  Several years of good productive growth was lost.
     What a shame it is when well-intentioned people make terrible decisions because they do not know how water and nature function. 

Friday, November 16, 2012

Where's the Color?

     A friend of mine was walking in the woods the other day and asked me, "Where's the color?"  He had seen lots of very colorful leaves along the road going to the park, but once he was in the park there seemed to be very little color.  He was actually a bit disappointed not to be wowed from the color along the path.
     Imagine his surprise when I pointed up.  The color in a forest is not at eye level, it is above your head in the canopy.  There is plenty of color along the road for the same reason.

     First of all, the bulk of the leaves are in the canopy, which for a mature forest is above your head.  There are plants that grow under the canopy and some of them do change color, but the main body of leaves is above your head.  Along the road, trees will have leaves going all the way to the ground.  This is because the road creates an opening in the forest allowing light to enter.  Trees will grow leaves where there is enough light to support their needs.  So, along the road the canopy in not only above your head it is in a vertical plane paralleling the road.
     The color in the leaves is also a function of the kind of tree and where the leaf is located on the tree.  Some trees will simply always turn yellow.  No matter where the tree is located or what is going on with the weather, they will simply turn yellow.  This is because they turn yellow when the days grow shorter.  With a shorter day, they are not able to manufacture enough chlorophyll and over time they use up the chlorophyll that they have stored in the leaves.  As the chlorophyll amounts drop in the leaves, the other two pigments in the leaves - carotin and xanthophyll - begin to show because they are no longer masked by the green of the chlorophyll.
     Other trees actually manufacture pigments based on the amount of water that they have in their system, the amount of warm sunshine they get during the day, and the amount of nighttime cooling.  The red pigment, anthocyanin, is produced in the leaves of certain trees when they are exposed to warm, bright fall days so that they can produce a good deal of sugar and then cool nights where temperatures drop below 45 degrees, trapping the sugar in the leaves.  These trees will actually not color evenly.  Each part of the tree will change color depending on the amount of sun and cooling that they receive.  Thus leaves at the top of the tree that get more sun will be more colorful than those in the lower parts of the canopy that are shaded by the upper canopy.  Likewise, leaves at the top of the canopy will also be less protected by the surrounding leaves and more subject to temperature drop.  This is also true along the edges of clearings like the area along a road.  Thus the brightest colors will be at the top (or along the roadside).
     Most people will appreciate a fully yellow tree, but they will be much more excited by a bright red one.  Red is simply a more intense color that draws the eye.  If it is exciting red leaves that you are searching for when you are wandering in a forest, then you will need to walk with your head tilted back a good deal of the time.  The brightest color is up in the canopy.

Saturday, November 10, 2012

Pink Light in a Forest

     I love to spend time wandering in the woods and have left a good deal of my own property wooded as a result.  In fact, I have created a woodland garden.  This began with the basic mature hardwood forest that remained after the construction of my house and after the felling of a number of trees due to a hurricane that passed through the area soon after I moved in.  Although the garden might appear to be simply an area that was left to grow wild, on second glance even the casual visitor might begin to notice strategically located groupings of native woodland perennials and shrubs living under the canopy.  The curving set of steps leading down the hillside to the creek might also be a dead giveaway that this is not simply forgotten wild land.
     In the fall, the prime attraction is without a doubt the tree canopy.  By the end of summer even the hardiest of woodland flowers have disappeared and the color and attention is primarily in the plants that produce berries.  Most of these berries are gone when the leaves begin to turn color.  They have been greedily eaten by the hosts of birds that swoop through.  The eye and attention is most definitely upward, and the color is most prevalent on the edges of openings where the leaves are more inclined to be effected by frost and to be more visible.
     Closer to the ground the forest will still be shady in the fall although the amount of light does increase as the season progresses.  One delight that I like to see this time of the year in the forest is the bright pink of the Mapleleaf Viburnum (Viburnum acerifolium).  This plant turns an amazing pink that looks as if someone has turned on light behind every leaf.  It is not a big plant.  In fact, they only reach about five feet at maturity, which adds to the delight and impression of light because the leaves are at eye level and the entire plant can be readily.  Instead of viewing the leaves from underneath, as is the case with tree canopies, you are actually able to view these leaves from the top of the leaf and at close range.  Added to this, is the fact that the plants will often still have clusters of deep blue (almost black) berries.
     This is a great plant to use in your woodland garden for more than just its fall wonder, although the color is incredible.  The plant is native to the North Carolina woods and begins the year with clusters of white flowers in the late spring.  These lead to clusters of berries that attract a number of birds and mammals for food.  It also provides good cover in its tangle of branches for many of these animals.  Finally, it is a relatively easy plant to grow.  Plant your Mapleleaf Viburnum in well-drained but moist soils in areas that get partial shade and they will thrive.  I like to put them in clusters of three to five for effect, but even singly they are a most delightful plant.

Friday, November 2, 2012

Do you know what is in your storm water?

     With a sizable area of the country sitting in storm water left behind by hurricane Sandy and a winter storm, I would like to again focus on storm water.  This week I would like to ask you:  Do you know what is in your storm water?  I would be willing to bet that a number of people who never thought about storm water before this week could now answer that question - at least to some extent.
     Storm water is water that has hit the ground through rainfall.  In a natural, not man altered environment, the bulk of this water will infiltrate into the ground, work its way through the soil and into the water table and may eventually emerge back on the surface having been cleaned by the soil as water in creeks, streams, ponds and ultimately the oceans.
     Man has interfered with this system through his building of structures and paving of roads, parking and walks.  As a result, we have more storm water to deal with when we have rain.  This storm water washes downhill instead of soaking into the soil.  When it does, it picks up a good deal of contaminates - both natural and man caused.
     Rain falls through the air near the earth and as it does, it collects gasses that can be dissolved in the water.  The primary gas that is picked up in the fall to earth is nitrogen.  This is an element that is greatly needed by plants.  In nature this is the primary way that nitrogen is disseminated into the soil.  When impervious areas are created, rain does not soak into the soil and is instead concentrated and allowed to run off into streams.  Nitrogen in concentrations cause algae in water areas like slow-moving streams and ponds to grow rapidly.  As it dies, it decomposes and the process of decomposition robs the water of dissolved oxygen.  This leads to the death of fish and other organisms that depend on that dissolved oxygen.
     A similar kind of die-off can occur when soil is allowed to flow off a site as erosion.  The soil left unprotected dissolves in water running downhill.  It clouds the water killing aquatic plants.  When the plants die off and decompose, they too use up the dissolved oxygen leaving none for the aquatic organisms that depend on it.
     Storm water also tends to pick up anything that will float in it and anything that will dissolve in it as it heads downhill.  That translates to picking up garbage that might be laying in the path of the water.  This also means that it picks up all kinds of waste that can be dissolved into the water.  Water flowing off farms and yards will pick up excess insecticides, herbicides, fungicides and fertilizers.  Water flowing off parking lots and streets will pick up fluids like motor oil that might leak out of cars.  It will also pick up whatever people might toss out onto the soil like paints, solvents and other chemicals.
     Water washing downhill will also pick up whatever pathogens might be left on the soil surface.  In a natural system, waste from the animals living in the area will be broken down and treated where it is deposited.  With the addition of pets and livestock to that natural system, excess pathogens are deposited.  Cats and dogs, along with livestock like cattle, pigs and poultry can provide huge increases in the bacteria and other pathogens that end up in the surface water if people are not careful to pick up and treat the waste from their animals.  After all, those animals would not naturally be concentrated in one area.
     It is important to remember what will end up in the storm water.  Everyone has to deal with that water at some point in the system.  We all need to work to keep that water clean and safe.