Newsletter, December 2022 (No. 25)
Bogs, Fens, and Mires
by Steve Young
There are a lot of wetland features scattered around our area which, since the time of the first European settlers, people have called bogs. These are places you usually stayed away from, except perhaps to pick cranberries. They are unstable underfoot; if you jump up and down, you can even feel waves forming in the underlying saturated material, and trees and bushes will sway as if a strong wind were blowing. You could lose a horse, or an ox, in these places, and there are often deep pools of dark water that seemed to be bottomless.
Modern hydrologists and plant ecologists have narrowed down the definition of a bog, and what we have traditionally called bogs are now mostly considered to be fens. What’s the difference? In a ‘true’ bog, the moisture saturating the surface layer is derived entirely from rain water—it’s said to be ombrotrophic, from the same word root as umbrella. This usually means that the surface is raised at least slightly above the surrounding terrain, so no water can flow into it, or onto it, from an outside source. In a fen, water can flow in, by streams or other sources. This is important, since the streams can carry various dissolved plant nutrients, so that a fen can, in theory, support a much richer vegetation. If a peaty wetland has a brook running through it, you know it’s a fen.
In the real world, of course, the distinction is much less clear. A true raised bog can form only in an area of cool, wet climate, more typical of maritime Canada, easternmost Maine, or the northern British Isles. We’re at about the edge of the area in which these conditions occur, but many of our wetlands look, to a botanist, pretty much like traditional bogs. More likely, if they’re very extensive, they may be fens which contain boggy areas. The easy way out of any semantic problem is to simply call all well-developed peatlands ‘mires.’ This honors any lost—mired—draft animals and follows an old tradition in many northern European languages. A Norwegian with the surname Myrdahl would have had ancestors living in a boggy valley.
The main feature of both bogs and fens is that the ‘soil’ is almost pure organic matter, formed by the decay of peat-forming plants. The most important of these are the many species of Sphagnum. This is a moss, and, therefore, has no true roots. The top grows continuously, while the lower portions die off and become peat. This is how a true bog’s surface becomes raised; as long as rainfall is high and evaporation low, the Sphagnum can grow to rise above the surrounding terrain, while peat accumulates below. This is what is mined extensively in Canada and sold as peatmoss. Left in place, it is one of the most important carbon sinks in the world, which is worth thinking about if you use peatmoss in your garden.
Sphagnum holds many times it’s weight in water, in empty, thin-walled cells that impede evaporation. The moss also alters the chemistry of the water—bog water is so acidic that a relatively few plants that are highly adapted to bog conditions can grow there. And many of them normally grow only there. Especially important are members of the heath family (Ericaceae,) which includes cranberries, blueberries, heather, Labrador tea, and leatherleaf. The tough stems of these plants provide the fibrous framework that holds peat together, so that it can be harvested in chunks—‘peats’--as is traditionally done in treeless western Scotland.
If you fly over—or send a drone over—an extensive peatland area, you’ll be struck by how varied in color and texture the surface is. This variation reflects all sorts of subtle differences in microelevation, soil and water chemistry, and it makes peatlands a goldmine for botanists. One patch may be dominated by a particular Sphagnum species, be full of spectacular—and rare—orchids, while another, only a few feet away, may show up as a deep blue-green from the foliage of bog rosemary—Andromeda.
Northern peatlands go back in time only to the end of the last Ice Age, about 14,000 years ago in our area. The retreating glaciers left water-filled hollows and kettle ponds, and these slowly filled in, or perhaps only covered the surface, with peatland vegetation. Some of these hidden ponds are very deep—I’ve measured one to be at least 70 feet. Those dark, bottomless waters could be hiding almost anything, perhaps a mastodon preserved in the tannic acid-rich waters for 10,000 years or so!
A Love Affair With Rivers
by Laurie Gullion
I grew up on the banks of the Merrimack and Nashua rivers when they flowed in different colors—depending on what color dyes the paper and textile mills were using that day. It was well before the Clean Water Act of 1972 could combat the pollution, and we never considered recreating on or in the rivers. Luckily I had an exposure to different places, different watersheds, and water so clean we could drink it.
My grandparents’ summer camp on a sandy New Hampshire lake offered swimming where we could see the bottom—long before summer homes lined the shoreline. My father’s hunting and fishing camp in the northern Maine allowed us to canoe on gin-clear ponds and to fish tumbling streams that were a quick walk through the woods.
I turned my love for rivers and lakes into a career where I have introduced hundreds of students and clients to the wonders of traveling on water, particularly in northern regions here in the Northeast and abroad. And I feel fortunate that I have had such access to beautiful places. Now in my “backyard”, a great day is time spent somewhere on the watersheds that surround my home in Craftsbury.
I come from parents who were involved with environmental issues in a variety of capacities—in their jobs, as founding members of a land trust, as board members of watershed councils. I remember the day my father lamented the lack of younger people on various committees, as he wondered who would continue the land protection efforts when his generation was gone. He made me think deeply (which I believe was his intention). Raising the ecological awareness of my students wasn’t enough? There was more for me to do.
My husband Bruce and I bought our Craftsbury land in 2007—the same year that the Northern Rivers Land Trust began its work in earnest. Lovely Cass Brook flows noisily through our forested property to the Black River, beginning its long journey toward the St. Lawrence River. I love the idea of it. And I love this sparkling stream with its trout, ostrich ferns lining the shore, the occasional beaver making its presence known. Once an escape, the land is now our home.