Forest Industry Safety & Training Alliance, Inc.

August 2013


Last month, we discussed how detrimental exotic invasive plants are to our native ecosystems and a threat to our economy.  Let’s continue down that path by learning about another exotic invasive species; one that many of us, especially myself, never considered to be a problem until a few years ago.  Earthworms!

That’s right, our farm friendly, favorite fishing food (for the fish, not us) is wreaking havoc in our northern forests.  Why is that, you ask?  We know that since the Ice Age, worms have not been part of the natural ecosystem in the upper Midwest.  The leaf litter and other organic material had become accustomed to decomposing slowly by the native bacteria and fungi.  This results in what we know as the duff layer.  Duff is important to the northern forests because it provides our native understory species and seedlings exactly what they prefer.

While worms are great for aerating and quickly decomposing agricultural soils, their zeal for munching organic matter results in heavy “castings” (fancy word for poop), which resemble clay soils and become easy compacted.  Far from the fluffy duff layer northern forests are known for.  When conditions aren’t right for native understory species and seedlings, guess what plants feel right at home; that’s right, exotic invasive species, like garlic mustard and buckthorn are waiting to take over areas such as these and do everything it can to dominate and shade out the desirable plants our economy and local wildlife depend on.

Research has shown that worms also tend to prefer maple forests.  The main reason for this is that maples tend to drop their leaves early in the fall, when the worms are still active closer to the surface.  Also, maple leaves are thin and light, making them more palatable than say, a heavy, stout oak leaf that worms will not feed on.  Do you have a favorite hunting spot in a northern hardwood forest?  Do you tap your maples for sap production?  Do you have a stand of northern hardwoods that has, or will be providing you with timber income?  All of these sites are facing serious risk of degradation because worms are speeding up changes in soils faster than our native plants can adapt.  This simply sets the stage for overwhelming establishment of exotic invasive species.  If you read the FISTA corner article last month, you now know how worms and non-native invasive plants are joining forces to attack our livelihood head on!

So how are worms spreading so fast?  I mean, they really don’t cover a lot of ground in a day, or lifespan for that matter.  To put it bluntly, the answer is “us”.  We, humans are responsible for the drastic spread of invasive, European worms.  Ever had a few red worms or nightcrawlers left in a carton after a fishing trip?  What did you do with them; toss them into the yard or by the boat dock?  Many are also brought in on soil attached to landscaping plants.  Worms can even be ordered online or through gardening catalogs to assist with composting.  I’m sure there are other ways worms can hitch a ride on a plane, train or automobile, but these are the most common.

Now that worms and other non-native invasive species are here, our best approach is to go the extra mile to slow their spread to uninfected areas.  This includes disposing of our bait properly; don’t throw it in the water or on the ground.  Keeping our equipment clean and free of mud that can harbor worms, their eggs and other seed from invasive species helps too.  As the boots on the ground, we are often burdened with the initial responsibilities of keeping invasive species at bay.  Of course, it is also our responsibility as the original stewards of the land to ensure the forests of today are available for the generations of tomorrow.

Ben Parsons, FISTA Training Coordinator, is originally from West “By God”, Virginia as they say in that part of the Appalachian Mountains. His family’s deeply rooted philosophy of living off the land was monumental in deciding to earn a degree in Forest Management from West Virginia University.  Throughout his career, Ben has had the opportunity to tackle a wide variety of assignments.  He measured Forest Inventory and Analysis research plots in Virginia and Georgia, been involved with urban and utility forestry operations throughout the Appalachian region, procured lowland hardwood timber in the swamps of South Georgia, managed logging contracts and harvest operations in Arkansas and specialized in water quality and harvest planning as well as fighting forest fires in Virginia. As FISTA Training Coordinator, helping to meet your safety and educational needs is the number one priority here at FISTA.  For more information, contact Ben at 800-551-2656 or