Phytoliths: How Plants Can Help Give Insight Into Human History
It is believed that humans came to the prairies more than 12 thousand years ago, initially as hunters following large animals such as the mastadone, an animal from the ice age. Two thousand years later, humans were hunting bison on the prairie and fire was widely used to control, whether to attract or repel, bison movement.
Prairie vegetation has also evolved from 12 thousand years ago, when the area was characterized as mainly open white spruce forest with a grassy understory, to 10 thousand years ago, with climate warming transforming the prairie into an intermixed mosaic of grass and aspen forest. Eight to four thousand years ago, periods of extreme drought generated the expansion of the grasslands to the north and to the west of the province, areas which are now forested.
Although it is difficult to know for certain what vegetation could be found during these historical periods, archaeologists have multiple tools at their disposal to try to distinguish the plant composition. One of these tools, looking at the 'phytoliths' of plants, that is, a "plant stone" or quartz without the crystal structure which is formed within the plant leaves, enables a diagnostic or identification to occur long after the plant existed, allowing a reconstruction to take place.