New Waves in Landscape Remediation

 Scott LaFleur

     Landscape remediation is a fast-growing sector of the land management industry that is nurtured by the innovative spirit of its practitioners.  Though many projects in remediation are large-scale and overseen by municipal entities, the benefits of new insights and techniques are becoming available to the average homeowner.   

     Erosion of soil and nitrogen-loading of ponds and lakes from runoff are two major landscape issues being addressed by the Midwestern, foundation-based JF New ecological services company.  Three innovative products employed in these efforts are biologs, live stakes, and floating islands.  Biologs and live stakes are used as part of a riparian anchoring system.  These devices will accommodate various slope ratings, channel speeds and biodegradation requirements.  The ecological beauty of these products is their ability to become part of the solution.  Biologs are made of coconut fiber, filled with soil, and planted with native species that are appropriate to the site and of local origin. The biologs are then held in place with live stakes. These live stakes, usually Cornus, Salix or Sambucus, are harvested when dormant and stored under climatic control.  When installed to support biologs these live stakes will begin to sprout. The stakes send out roots, aiding in erosion control, and vegetative growth to support the diversity of life that occurs near the water’s edge.  These systems need never be removed, and within five years they are an unnoticeable part of the landscape.  Stabilized, vegetated riparian zones help to impede future contamination of ponds, lakes, and streams.

     Vegetated floating islands, created by Floating Islands International in Shepherd, Montana, are unique native wetland gardens, used to help restore and maintain an ecological balance in ponds and lakes.  Floating islands are an excellent water stewardship tool.  Using a recycled polymer matrix and bonded with extra buoyant marine Styrofoam set on a lightweight aluminum frame, floating islands are a state-of-the-art design.  This technology creates a super-wetland that allows water to circulate and plant roots to grow through the island.  This enhanced wetland improves water quality by removing nitrates, phosphates, ammonia, and heavy metals.  Floating islands create critical riparian habitat used by all types of creatures from microbes to birds. They control erosion by reducing wave action and they beautify the aquatic environment. 

     Floating islands work by enhancing a naturally-occurring symbiotic relationship.  This relationship involves native plant communities and naturally-occurring microbes to remove excess nutrients and pollutants from the pond environment.  The roots of the plants are in direct contact with the water and are constantly extracting nutrients.  Nutrients in the pond are not always in a form that is readily available for plant uptake; this is where the microbes come in.  The microbes work to break down the nutrients, making them available to the plants.  Non-plant microbes, such as fungi and bacteria, grow quickly and process nutrients faster than algae.  This in turn starves the algae, reducing algal blooms and the resulting damage to fish and other aquatic populations. 

     Floating islands are more effective than naturally-occurring wetlands because of increased surface area.  The matrix of fibers used in construction of the island in conjunction with root hairs provides high specific surface area for colonization of nitrate- and phosphate-reducing microbes.  This allows bio-filtration and nutrient removal to occur quickly.  Aerobic microbial purification occurs by direct oxidation of biodegradable matter and by endogenous respiration where organic material is oxidized.  During this process the water is oxygenated, allowing fish, frogs and other aquatics to breathe and to thrive.

     This new breath of life given to the aquatic environment allows the “circulatory system” of a pond to function correctly.  In turn, the symbiotic relationship of the pond and all its inhabitants reestablishes itself.  The floating islands provide food for many creatures and while creating a physical refuge for fish hiding from herons or other predators. Frogs will deposit their eggs on the roots.  Turtles will climb aboard to bask in the sun.  Birds will stop to rest and ducks will nest.  Salamanders will patrol the waterline and the buzz of activity will crescendo with the myriad of bees, damsel flies, and nectar-feeding insects.  Floating islands provide us all at once with a way of actively participating in the conservation of native flora, cleaning our polluted waterways, and artfully enhancing the beauty of our surroundings.

     The beauty of these products is that they are simple enough to be used by anyone and on projects large or small.   Not only are erosion and water pollution controlled, but habitat is created in the process.  While floating islands, biologs and live stakes on their own are not a complete solution to our polluted water ways, they are an accessible and versatile part of the solution. 

     Scott LaFleur is Director of Horticulture at New England Wild Flower Society and its Botanic Garden, Garden in the Woods, in Framingham, MA.