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Adirondack Explorer

July, 2017

Bogs and Fens
Author: Ronald B. Davis

Review by: Ed Kanze

Bogs and fens are wetlands. At least they are if you can call a wet place with nothing but peat, or sphagnum moss, underfoot “land.” Such features, not quite land and not quite water, dot the Adirondack landscape. Whenever and wherever we hike, we march around and over them, sometimes on boardwalks, planks, or corduroy.

Botanists, birdwatchers, and naturalists in general tend to go ape over patches of peat. If you’ve ever wondered what’s the big deal or wanted to distinguish a bog from a fen and comprehend the physical factors that make such places different from each other and from all the rest of the landscape, Ronald B. Davis’s Bogs And Fens: A Guide to the Peatland Plants of the Northeastern United States and Adjacent Canada may be just the book for you.

Pitcher plants trap and devour insects.
Photo by Carl Heilman II

First, let’s join Davis in getting tricky definitions out of the way. A bog, he writes, is “a peatland with a major part of its area (along with its rooting zone) out of reach of water that has been in contact with mineral soil since it fell as rain or snow.” Davis, a retired University of Maine biologist with a lifetime of bog and fen research under his belt, struggles to give a clear definition of what a bog actually is. Well he should. This is squishy ground. I suppose the key takeaway point is that the water that hydrates the plants in a bog, or at least the lion’s share of them, comes from the sky. It does not on its way into the bog percolate through soil, where it might pick up nutrients. Bog water is impoverished of nutrients. It arrives distilled, straight from the clouds.

A fen, writes Davis, is “a wetland whose vegetation sits atop peat, [and in which] some of the water that bathes plant roots has recently been in contact with mineral soil, rock, or mineral deposits since falling as rain or snow.”

“Wait!” you say. The last bog you visited—say, the Bloomingdale Bog near Saranac Lake or the “bog” at the Paul Smith’s College Visitor Interpretive Center—had a stream flowing through it, a stream that surely carried runoff that passed through mineral soil. This bog cannot be a bog. It must be a fen. According to Davis and his colleagues in the exciting world of bog biology, you are correct.

Bogs and Fens
By Ronald B. Davis
University of New
England Press, 2016
Paperback, 304 pages, $24.95

Well, maybe you are. Big peaty places such as the Nature Conservancy’s Spring Pond Bog have been determined to be neither bog nor fen but a mosaic of both.

Confused? I’m with you. The subject is a conceptual quagmire because, as you may notice and as Davis points out in this book, “many peatlands that are popularly called ‘bogs,’ and many that appear with ‘bog’ in their name, may actually be fens.” And there’s also the issue of different kinds of fens. Some are mildly alkaline and called rich fens. They support different plant communities than do intermediate fens, which straddle the pH fence, and poor fens, which are acidic and might as well be bogs as far as most of us are concerned.

What’s the casual hiker and plant lover to do? Forget the definitions. Or at least don’t ruffle your composure trying to hang on to their slippery nuances. Just get out there. Enjoy the wonders of peatlands—bogs, fens, whatever—wherever you find them.

For those who would get to know them, Davis’s Bogs and Fens has a wealth to offer. Here are the stars of the constellation of beautiful and sometimes quirky plants that thrive in peatlands. Meet the round-leaved and spatulate-leaved sundews, miniature Venus flytraps that catch and digest insects and spiders for a living. Learn also about that grandest of our leafy meat-eaters, the purple pitcher plant. Pitcher plants have evolved extraordinary leaves modified to catch raindrops. Pools of water collect inside the bases of their leaves, and by various means, the plants hoodwink insects into landing on them, falling in, and drowning. Then the pitchers, swirling with enzymes, digest them. By this clever stratagem (you’d see it as diabolical if you were a beetle or fly), the plants derive vital nitrogen and phosphorus in a nutrient-poor place where those elements are hard to come by.

If Little Shop of Horrors flora is not your cup of tea, then bogs, fens, and Davis’s book offer alternatives that may entrance you. A generous portion of the Adirondack region’s most glamorous flowers bloom in these places. Davis introduces them one by one with informative text and photos. My favorite is the grass pink, also known as the calopogon orchid. It can stand more than a foot in height and bears handsomely shaped flowers ranging in color from pink to magenta. Also on hand are the rose pogonia, or snake-mouth orchid, often in bloom at the same time as the grass pink but notably smaller and more delicate, and the white-fringed bog orchid, which makes up for its lack of bright color with an abundance of blooms on a single plant.

Spring Pond Bog north of Tupper Lake is a mixture of fens and bogs.
Photo by Carl Heilman II

Woody plants of bogs and fens that add beauty and atmosphere include such stalwarts as Labrador tea, easily recognized by the curled margins and fuzzy undersides of its leaves, bog laurel, sheep laurel, bog rosemary, sweetgale, leatherleaf, American larch (most Adirondackers call this deciduous conifer “tamarack”), and black spruce.

Not all bog and fen plants command the attention. Some, unless you know what to look for, are easy to miss. In this category I think of the cranberries, whose tiny leaves make the creeping plants difficult to spot except when they’re laden with tart red fruit, and various grasses, sedges, and rushes. Exceptions in this category are the several species of sedge often called “cottongrass,” which Davis and scientists in general refer to as cottonsedges.

One of my favorite plants in Davis’s book is one I’ve never seen in the Adirondacks and that is likely absent from our region’s cold, balsam-scented core: poison sumac. It’s easy for me to be pleased by this handsome but notorious plant. I’ve never managed to catch the rash it inflicts on most who touch it. I’m always glad to find poison sumac, especially in late summer or early fall, because its branches are laden then with clusters of white, fatty fruits. These, along with the berries of the closely related and even more notorious poison ivy, are prized by migrating songbirds. One of the most ecstatic experiences I’ve ever had as a birdwatcher was to find myself in the middle of a poison-sumac swamp, the branches of the plants quivering under the weight of hungry warblers, vireos, and thrushes. While making sure not to brush against the plants, I thanked them for supplying favorite birds aviation fuel they’d need to reach wintering grounds in Central America, South America, and the Caribbean.

Given that mosses are plants, and that Davis’s book calls itself “a guide to peatland plants,” I found it disappointing that the volume contains precious little about mosses. But no book can do it all, and any book that tries to stumbles. For mosses, readers are advised to turn to Ralph Pope’s beautiful and thorough Mosses, Liverworts, and Hornworts: A Field Guide to Common Bryophytes of the Northeast (Comstock, 2016). For all the rest, Davis’s thorough, colorful, meticulous treatment of the plants of bogs and fens will remain the best of its class for years to come.

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