Diggin' bogs

Wow, that was a cold few days last week, hope your water pipes and septic mounds survived. I was lucky - the only thing I lost was the ability to open my gas cap from inside the car because my cable snapped.

It is often more difficult to enjoy the outdoors when wind chills are so wicked; one place I can count on being fairly comfortable during these times is in the middle of a spruce bog on a pair of snowshoes. I love bogs in all seasons, except when the mosquitoes are in charge. Northern Minnesota is blessed with many bogs. I drive by huge bogs in the Cromwell-Wright area on Highway 210 on my way to visit my parents in McGregor, and every day I drive by a teeny bog near the new roundabout on Highway 33 south of Cloquet.

So, what is a bog, how did they get there, how old are they, and why aren't there bogs in Iowa and southern Minnesota? Let's dig into it: when you actually do dig into a bog you will notice there is no regular soil, no sand, clay, or silt. The material we dig through is peat, which is actually partially decomposed vegetation, mostly sphagnum moss with some reeds and grass-like plants called sedges mixed in.

Typically, this light- to dark brown material called peat consists of 30 percent to 70 percent recognizable plant material; this peat layer is at least 18 inches thick, usually much thicker. With normal soil formation, the vegetation almost completely decays to form topsoil. To form peat, we need the vegetation to lay in a wet environment when it dies; this really slows down the decay because of the lack of oxygen.

I would need to travel back in time about 5,000 to 6,000 years to see our first bogs forming. Back in those days, the last glaciers were gone from Minnesota, the water left behind pooling to form huge shallow lakes that dwarf most of our present-day lakes (see my map). When these giant lakes drained, they left behind huge flat lake bottoms that would become today's bogs. Because the land is flat, the water drains slowly, keeping it wet, and because we have a relatively cooler climate than southern Minnesota and Iowa, the moisture does not evaporate in the summer; hence, we have a cool, wet environment which discourages plant decay and encourages the formation of peat, and that is why there are no peat bogs in southern Minnesota and Iowa.

Next time you are in a peat bog, dig a hole and check it out; you can do it with your bare hands.

FDLTCC science tutor Glen Sorenson was Minnesota Teacher of the Year before he retired from teaching science at Proctor High School after 30-plus years. He is an avid outdoorsman who most recently coached the Lumberjacks Nordic ski team.