Since the inception of Nearby Nature, we have discussed many subjects relating to natural history, geology, plant and animal identification, places to experience nature, and many others. Like huge puzzle pieces so to speak, we have tried to create an awareness of how everything “fits together” and works in harmony creating sights and experiences we enjoy every day. Beginning with the last article we will focus on becoming good stewards of nature. What we can do as mere mortals to combat invasive species, make others more aware of destructive pest and environmental practices, educate ourselves regarding environmental issues and become citizen scientists? By no means are we advocating getting on a soap box in the middle of town square or becoming an eco-terrorist. But what can we do to help the environment in our little corner of the world? That being said, let’s turn our attention to a subject that few people would imagine as being one of the biggest threats to the forests of Ohio and surrounding Great Lakes Region including all of the New England States: Earthworms.
You read correctly earthworms. If you remember the puzzle analogy it is really quite simple. There is no “worm puzzle” piece for the forests in the glaciated regions of North America. Worms don’t fit! During the ice ages, the glaciers acted like big shoes and squished — well, more like scraped — away the topsoil where all the native worms lived. As a result, there are no native worms in most parts of Ohio. Natural colonization by earthworms happens very slowly, with earthworms spreading less than ½ mile per 100 years. So, forests of the Great Lakes Region developed in the complete absence of earthworms. For thousands of years, no earthworms existed in this region until European settlers began arriving around the mid 1800’s. Now as invasive creatures, the earth¬worms have wreaked havoc with hardwood forests, such as those consisting of maple, basswood, red oak, poplar or birch species; similar to the ones in Portage, Geauga, and Trumbull county areas. Worms eat the “duff” or top layer of soil rich in organic matter such as leaves and decaying wood. And boy, are they hungry! Within five years a forest floor can look like a barren wasteland. Seeds from many trees species need the “duff layer” to germinate and when there is none, no seedlings. The lack of duff material also has a drastic and detrimental effect on wild flowers, ferns, birds and some animal species. As a result, some northern hardwood forests that once had a lush understory now have but a single species of native shrub and virtually no tree seedlings, wild flowers, or ferns. To compound the problem, invasive shrubs such as buck thorn, multiflora rose, and honeysuckle begin to take root. Another alarming concern is that earthworms change the forest soils from a fungal to a bacterial-dominated system; as a result the leaf material which normally decays and adds nutrients to the soil fails to do so. The illustration from the Minnesota Department of Natural resources (upper right) gives you a very good visual comparison of the situation.
All of the earthworms you have come to know and love in the Great Lakes region are mostly European or Asian (in the family Lumbricidae). They continue to be transported, intentionally and unintentionally, through a range of human activities such as the dumping of unused fishing bait, transport of compost & mulch, and anything else that moves soil from one area to another. Not all foreign earthworms are destructive. Of the 5,000 species around the globe, only about 16 of the European and Asian varieties do the real damage. One of them is the night crawler (Lumbricus terrestris), a popular fish bait that can measure up to 15 to 20 centimeters (six to eight inches). Another is the Alabama jumper (Amynthas agrestis)—also known as the snake worm or crazy worm—an aggressive Asian worm that lives at high densities and can literally jump off the ground or out of a bait can, according to fishing lore. A voracious eater, it does the most harm to the soil.
Now what can you do to stop this invasion you ask? Well I wouldn’t go out and buy a worm farm! Don’t buy “red wigglers” for your compost pile from the hundreds of seed catalogs that we are getting in the mail this time of year. Begin by going to http://www.greatlakeswormwatch.org/. This is a great web site where you can learn how to identify various types of worms, participate in research studies, and learn to read the signs in the forest. Unfortunately there isn’t much that can be done once an area becomes impacted by worms. The best solution is prevention!
Other Nearby Nature…
Saturday, March 23 (9:00-11:00am)
Eagles can always be seen from this deserted country lane in Trumbull County. Join naturalist Bob Faber on this dry, flat road with an easy-to-see eagle nest, expansive open-sky vistas, and extensive wetlands. On lucky days up to six bald eagles have been seen, sometimes all at once. This site is part of the Grand River-Mosquito Creek State Wildlife Area complex with a total of over 16,000 acres of protected wild land. Other wildlife of this area include sandhill cranes, black bears, bobcats, harriers, river otters, ospreys and a host of other species. Sponsored by Friends of the Hiram College Field Station. Registration is a must as enrollment is limited. Call 330.569.6003 or email firstname.lastname@example.org to register.