Formation of Burns Bog

On a geologic scale, Burns Bog is quite a young ecosystem.

Until 10,000 years ago, much of North America was covered in ice. The Cordilleran Ice Sheet covered all of British Columbia. This ice sheet melted much faster than the Laurentide Ice Sheet. This led to floods and the quicker deposition of material. Fine material was deposited in the area where Burns Bog exists today. The glacial till that was left behind, composed of sand, silt, and clay, created an impermeable barrier, meaning no water could seep through. 10,000 years ago, Burns Bog existed as a lake.

Vegetation began to grow around the lake, and over time, this vegetation began to fill the lake. These grasses and woody plants were accumulating faster than they were decomposing, which led to peat formation at the bottom of the lake. Beginning around 6,000 years ago, this peat accumulated to the point where the lake was filled up.

3,000 years ago, sphagnum mosses were introduced into the environment. These ecosystem engineers helped to further shape the environment. Sphagnum moss helps to keep water in the environment, and releases tannins which break down and form tannic acid. While the sphagnum began to make the environment acidic, peat continued to build up. This shifted the flow of mineral rich upland water away from the center of Burns Bog, which meant that rain became the only source of water. To learn more about the plants that make up this ecosystem check out our Plants of the Bog page.

As ecosystems are dynamic, not all of Burns Bog is a true bog. Many microsites are home to different ecosystem types, such as fens, marshes, or swamps. In the historic lagg of Burns Bog, now known as the Delta Nature Reserve, one can also find old growth forests. These forests are home to Western red cedar, Western hemlock, Sitka spruce, and Douglas fir trees.