Association of State Wetland Managers - Protecting the Nation's Wetlands.

The Compleat Wetlander: Creating a Toad Friendly Wetland – Or Any Wetland at all is a Challenge

This week I begin a year-long program to become a ‘Maine Master Naturalist’ http://www.mainemasternaturalist.org/MMNP/Home.html Our first reading assignment is “Reading the Forest Landscape: A Natural History of New England” by Tom Wessels.  The book is—

A full and wholly original portrait of New England’s forests, tracing their evolution from pre-colonial days to the present through a study of the patterns we see today. Read this book, its many fans have said, and no walk in the woods will ever be the same.

Frankly, I am feeling a strong sense of déjà vu after participating in a workshop taught by Tom Biebighauser on wetlands restoration and creation where we spent a lot of time understanding how altered the landscape really is.

Over the past 300 years over 100 million acres of wetlands have been lost in the lower 48 states mostly through drainage for agriculture.  In the past 30 years a small but significant portion of those acres have been restored. Other existing wetlands have been enhanced and otherwise altered for different purposes.  In addition a small number of new wetlands have been created.  The science of wetland restoration and creation is relatively young but is rapidly growing and evolving through application, research and experience.  The science of wetland drainage, in contrast, is much older and much better established.  What is often not wellunderstood is that wetland restoration is now applied to a landscape that has been drained and drained and drained.  A field where a wetland restoration project is located may include drainage installed in the 1900s over drainage installed in the 1800s over drainage installed in the 1700s.  It’s hard to believe until you walk the land with someone who can interpret the history of the landscape.

Also important is that clearing the land and converting it to agriculture led to the erosion of millions of tons of soil downslope to be deposited in rivers and their floodplains.  Dams and other structures were constructed to alter the flow of water.  These structures also end up storing millions of tons of sediment, which sometimes buried the dams.  Thus, while streams and rivers might look stable, often they are not.  Streams go through succession just like forests do.  When streams are straightened and altered, they are put back to an earlier stage in succession.  This becomes quickly apparent when there is a flood.  Water and sediment carve new channels. Head cuts work their way upstream.  Bridges, buildings, roads and other infrastructure are damaged. Straightening streams, cutting down forests, and filling and draining wetlands has thrown the system out of whackand it’s trying to get back to the way it was.  Absent human intervention it may take 5  years, 500, 5,000 or more.  This is another aspect that makes wetland and stream restoration challenging.  We can change one part of the landscape and restore a wetland that disappeared or stabilize a stretch of stream, but it’s a tiny action against a vast backdrop of 300 years of aggressive alteration.  The landscape that exists throughout much of the United States today is dramatically different from the landscape where wetlands existed 100, 200, or 300 years ago.

Given all this change, how can wetland restoration and creation be successful?  I found some answers at the afore-mentioned wetland creation workshop for professionals hosted by Mass Audubon May 22-24.  The workshop focused on creating spadefoot toad habitat on Cape Cod but Tom Biebighauser, Ian Ives, Bryan Windmiller and Eric Derleth all shared their ideas and expertise on wetlands and stream restoration.  Over the three-day workshop two wetlands were created for spadefoot toad, but the concepts covered ranged much farther covering: 1) reading the landscape to uncover the history of past drainage, 2) ensuring adequate hydrology and 3) designing a successful project.

Much more information can be found in two books by Tom Biebighauser:

Wetland Restoration and Construction: a Technical Guide” and “Wetland Drainage, Restoration and Repair.”  In addition Tom teaches workshops around the country.  Whether they are wetland creation or restoration depends on the project.  For more information about Tom’s books and a schedule of future workshops visit: www.wetlandandstreamrestoration.org

Additional pictures documenting the workshop including a visit to natural spadefoot toad habitat, views of last year’s wetland creation projects and the construction of a created wetland for spadefoot toad can be found on the Association of State Wetland Managers’ facebook group page at: http://www.facebook.com/media/set/?set=oa.10150828629181792&type=1

In sum, my personal Maine Master Naturalist reading list just became a whole lot more important and a whole lot longer!

This entry was posted in ASWM staff, dredge and fill, ecosystem, Maine, natural history, restoration, wetland books, wetlands and tagged , , , , , , . Bookmark the permalink.

Leave a Reply

Your email address will not be published. Required fields are marked *

Web Analytics