Diversity--The Spice of Life

As we travel through this area, it may look appear upon first glance that there is a marked lack of variety in the various trees in the valley. Primarily composed of lodgepole pine, white spruce, trembling aspen and balsam poplar, it seems to hide the fact that diversity is very important in nature.

We hear of farmers fighting off insect infestations as if beset upon by some medieval plague. In actual fact the infestation has been caused by man and not by nature. By filling a vast area with a single type of plant, farmers have declared war against natures constant fight to produce diversity. This is a battle very difficult to win as there are many ways that these monocultures can be attacked. As soon as a huge pocket of food is produced, animals and disease specifically adapted to this food will move in. Grasshoppers and wheat rust are only a few of the ways in which nature will fight off these endless fields of wheat.

Farmers spend much of their time trying to keep out other plants that would quickly colonize their fields and the rest trying to curb the insects and disease that attack the results. This is not a unique situation. In forests like the ones found in the Bow valley, diversity is also maintained by natural forces like disease, insects and fire. For instance, when a fire moves through an area, it removes pine and spruce and allows a large variety of new species to move into the area. As the years go by, slowly the pines, poplars and spruce take over. If another fire doesn't occur, the spruce will eventually begin to dominate by shading out all of its competitors. In many parts of Canada, these spruce forests are the norm--once again forming a huge monoculture. This time insects moved in to help reduce the number of spruce. The spruce budworm has destroyed huge areas of spruce and thus opened the area for colonization by other species.

In Alberta where there are huge lodgepole pine forests, the mountain pine beetle has performed the same service. In the area of Waterton Lakes National Park, huge areas have been killed by this beetle. At present it hasn't established a firm footing in this area but time may change that as it spreads northward.

Diversity in species is assisted through genetic diversity. Plants rarely reproduce themselves, but require another plant to fertilize them. This causes a constantly varying genetic makeup which increases the plants ability to adapt to changing conditions. It may allow them to build up an immunity to diseases or to survive drastic climatic changes. It is through genetic diversity that evolution takes place and evolution requires adaptation. A very slight genetic advantage may allow one individual to survive when others of its species cannot. As a result, it will be more likely to reproduce and pass on this characteristic. This 'natural selection' is based largely on the concept of genetic diversity.