On the way to Golden, we cut across Alberta, taking the scenic route to the mountains along the David Thompson highway, rather than the boring QE2 to the Trans-Canada. The David Thompson (Highway 11) passes through the foothills, along side Abraham Lake and the Kootney Plains before joining Icefields Parkway (in Banff National Park) at Saskatchewan Crossing.
Just west of the Kootney Plains, we encountered this sight...
Along the north side of the road, the forest had been recently burned. Some trees were spared, but most of the trunks were charred and the trees were dead - maybe the recent pine beetle outbreak made them susceptible.
In any case, I was very excited to see the ecological principle of succession in action!
Fireweed is a staple of the Alberta landscape; it grows pretty much anywhere. It is often considered an agressive weed because it grows so well and spreads so quickly, but it plays an important role in nature. Fireweed is one of the first plants to grow in areas that have recently been damaged by fires.
Fire is a natural disaster that will often remove all species from the community. Many plants and animals are unable to recolonize an area after a fire because the resources they need to survive are no longer avaliable (food, shelter, etc). When new plants and animals colonize an area like this, it is called secondary succession. (Primary succession is when there was nothing there before - a whole new area is avaliable, such as a lava flow or newly exposed rock after a landslide.)
Fireweed spreads via seeds that look very simliar to dandelion fluffs; each comes attached to it's own little fluffy parachute. This means they are able to reach all parts of an environment very quickly, and will remain there until conditions are favorable for sprouting - such as a freshly burnt forest. This plant is also not very picky in the type of soil it grows in, meaning it can take advantage of newly open areas very quickly. (The first organisms to colonize after such an event are called pioneer species.)
Pioneer species are important because they change the conditions of the environment they colonize. Certain trees cannot grow in the open - small shrubs and bushes are needed to protect the seedlings until they are larger. Certain animals prefer grassy fields to tall trees to seek protection in. Seeing fields of magenta fireweed growing in this burned out forest is a striking reminder of how fires are a healthy part of nature, and are necessary for keeping the natural beauty of the Rocky Mountain forests alive.
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