Letter to the Editor: ‘Why Stream Project Post-Construction Plantings Are Not Ecological Restoration’
ALEXANDRIA, VA – Earlier today, The Zebra Press received a second letter about the Taylor Run Stream Restoration project. The full text of the letter appears below:
Wearing my educator’s hat, and regarding post-construction stream project plantings, installing “2,300 new trees and thousands of new shrubs” along post-construction Taylor Run in the City of Alexandria, Virginia (the numbers of which are irrelevant), of various species that collectively bear no fidelity to a known natural community let alone the habitat it is replacing, does not constitute a functional natural forest community. Moreover, plantings of “late successional” species outside their appropriate natural habitats typically result in a high mortality of the plantings. (College of William and Mary environmental science professor Doug DeBerry and others have well documented this general failure of post-construction plantings in the scientific literature.)
Trying to substitute a naturally balanced forest community with an overstuffed mass planting also fails to recognize that the habitat as a whole is worth far more than any of the individual components. Clearing mature stream valley forests and replacing them with artificial plantings – both in species makeup and numbers of plants – is an obvious adverse environmental impact that negates any net increase in function or added ecosystem services (improvement) required by the terms and conditions of the Nationwide Permit 27 (NWP).
For these reasons, and others, the “2,300 new trees and thousands of new shrubs” cited for the Taylor Run project will amount to little more than a glitzy “plant dump” and is not an ecological restoration best practice. The stark reality is that anyone over the age of 35 will not see a mature canopy tree along the Taylor Run project footprint again in their lifetime, and certainly nothing like the old-age giants growing there today (estimated to be 180-220 years of age). (Skeptics can visit the failed natural channel design project along Donaldson Run at Zachary Taylor Park in Arlington County to see for themselves. Plenty of other examples too.)
It is also unlikely that the stream valley’s existing natural features will return – naturally or otherwise – because the living foundation of the habitat, the result of millennia of evolution and complex interactions of organisms and geologic conditions, cannot be replicated – and certainly not by a “forest-in-a-can” method. One cannot plant a forest community, such as the globally and state rare Acidic Seepage Swamp, one can only plant individual trees and other vegetation. Only nature and very long periods of time can produce diverse, ecologically functioning natural communities.
– Rod Simmons,environmental scientist and ecological restoration specialist
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