Stories tagged forest regrowth

May
18
2007

Burning out: The forest fires of today lead to the forests of tomorrow. The heat and pressure of the fire explodes cones filled with seeds that start the growth of a new forest days after the fire has stopped. (Photo from the US Department of the Interior)
Burning out: The forest fires of today lead to the forests of tomorrow. The heat and pressure of the fire explodes cones filled with seeds that start the growth of a new forest days after the fire has stopped. (Photo from the US Department of the Interior)
The recent forest fires in the northern Minnesota have scorched a huge chunk of the Superior National Forest. But they’re also the beginning of the next generation of huge trees to grow in the wild.

Even as the fires were crackling through the branches of pines, birch and spruce, the start of new tree growth was already popping. The heat from the burning trees pops open the cones on those trees, releasing seeds that have been waiting to get loose for years. Millions of those seeds were dumped on the forest floor and within less than a month, a fraction of those seeds to germinate, pop through the soil and start growing into little seedlings. Give them another 30 or 40 years, and hikers going through the area where this year’s fires have wiped out most trees, those seedlings will have grown tall enough that hikers won’t even know the area had been devastated by fires in 2007.

In fact, fire is a natural part of the forest’s regeneration system. Most forest trees need to be exposed to fire every 50 to 100 years to invigorate new growth. As we found out in Yellowstone National Park nearly 20 years ago, suppressing forest fires too long can actually be detrimental to forests. Extreme efforts to prevent forest fires there led to a huge consumption of trees when fire finally broke out.

University of Minnesota-Duluth biology professor John Pastor was quoted this week in the Star Tribune saying: “When people canoe through the Boundary Waters Canoe Area (BWCA) and see all these beautiful forests, every one of those forests started with a fire.”

As a rule of thumb, timber experts say that any particular chunk of ground in the forest should be touched by intense fire every 50 to 100 years.

But the power of the fire is just the first step in forest regrowth. Weather patterns in the affected area over the nest year will play a big role in how the new forests develop. A summer of drought could kill the newly released seeds and short-circuit any new growth. That could give new species of trees a chance to grow in the area. Normal rains mixed with the nutrients left on the ground from the fire could be a great booster shot to getting the seeds off to a flying start.

Other natural benefits can be seen from fires. For instance, the once-rare black-backed woodpecker is now a regular site in the BWCA with the abundance of dead trees from recent smaller fires and the 1999 wind blow down of trees. New shrubs and ground vegetation is appealing to different kinds of wildlife to snack on.