Cattail Bog, Sony NEX Shots, Minneapolis, Minnesota, February 2012, photo © 2013 by Liz Anne Schultz. All rights reserved.
When you live in a land of lakes, you tend to develop an intimate relationship with wetland geography. Liz passes Theodore Wirth Park on her journey to and from work and sometimes stops to take photographs of one of its hidden gems—the Quaking Bog. The park’s Quaking Bog is a five-acre acid bog where nearly 200 mature tamaracks shade the understory sphagnum moss. Bogs (also known as mires, quagmires, muskegs, and fens) are remnants of the last glacial age. They each develop differently, depending on climate and typography, and often occur when the water at the ground surface is acidic and low in nutrients.
Bogs are often classified based on their location in the landscape and source of water. There are valley bogs, raised bogs, blanket bogs, quaking bogs, and cataract bogs. Quaking bogs develop over a lake or pond, with bog mats (thick layers of vegetation) about three feet thick on top. Quaking bogs bounce when people or animals walk on them, giving them their name. My most vivid memory of walking a bog was a side trip we took on a canoe trip in the Boundary Waters. Here are the impressions of two writers from one of my favorite books on topography, Home Ground: Language for an American Landscape:
The low-lying area saturated with water creates a hollow of decomposed vegetation in wet, spongy ground. This strange land is called a bog, a word that’s been used since about 1450 to refer to such places. The ground sinks underfoot—-collapses, sucks under. It is a netherworld dimly lit, and a rank smell hangs in the air. Yet a bog is far from dead. It supports plant life; as an ecological system, it can be described as a plant community. Cattails, rushes, sedges, and bulrushes are plants that initially creep into a lake and begin to transition that body of water into a bog. The term most often applies to wetlands that have little inflow of water through streams and are fed, instead, mainly by precipitation. What happens is that the plant material growing in the lake dies off and eventually becomes peat. When the dead and dying vegetation rises to the water level of the lake, this accumulation of peat forms a dome, which prohibits any new plants from growing. Without the inflow and outflow of water, a black skin forms, an oily and idle mire locked in a world of its own contrivance. A foot stepping in goes beneath the surface, fast like a thief. Bogs can be found throughout the United States—Web’s Mill Bog, New Jersey, for instance, and Hanging Bog near Cedar Rapids, Iowa. The term bog is also often used in literature to represent the cessation of growth, or a human’s stuck place. In The Red Badge of Courage, Stephen Crane uses a bog to express the conditions of the Civil War. “He is obliged to walk upon bog tufts and watch his feet to keep from the oily mire….The youth went again into the deep thickets. The brushed branches made a noise that drowned the sounds of the cannon. He walked on, going from obscurity into promises of a greater obscurity.”
-Elizabeth Cox from her home ground, Chattanooga, Tennessee
The quaking bog is one of the most novel features of forests of the northern United States, especially those in New England and Wisconsin. It’s an area of sphagnum moss, rushes, sedges, and decaying vegetation, the whole mass of which is floating on a pool of water. The surface appears solid and stable, until trusted with the weight of a step. What seems to be firm ground then shivers, sinks, and rises, like a natural trampoline or waterbed. If the first shimmy of this rich root mass underfoot is not heeded, one might easily break through the entangled mat into water and loose mud below, as if one had stepped into quicksand. The quaking bog suggests in perceptible human time the larger ripple, rise and fall, and shifting of the Earth’s surface in geologic time.
-Robert Morgan from his home ground, the Southern Appalachians of western North Carolina, though he has lived in the Finger Lakes region of upstate New York for thirty-five years, and in many ways that seems like home also
National Geographic Education – Encyclopedic Entry – Bog
Video – What Is A Quaking Bog?
-posted on red Ravine, Thursday, March 6th, 2013