The tutor continues coverage of soils found in Canada.
In a few earlier posts (you can find them in my Canadian geography section) I covered forest soil types in Canada.
Grassland soils are not so familiar to me. I’ve spent a few weeks in grassland areas; perhaps a regret of mine is that I don’t know them better.
Not all Canadian grassland is located in the prairies; however, the prairies embody grassland.
A key feature of grassland soil is that, left alone, it continually accumulates organic material. Generally, the reason is that decomposition of plant matter is hindered – by months of cold weather, lack of water, or both.
Canadians are commonly aware of the winter months of prairie deep freeze. The prairies are quite dry as well, compared to other populated regions. Behold Regina’s precipitation, compared to cities outside the prairies:
On the Canadian prairies, a simplified explanation of the soil development might be as follows: during the spring and summer, the grass grows quickly, manifesting tremendous production of fresh organic matter above the soil (the grass you see) and below the soil (its roots). Rather suddenly, in the fall, a killing frost hits. The dead plant material lies on the ground. In the deepening cold, it can only decompose very slowly, if at all.
With the roots, the process is less noticeable, but there is continuous decay and renewal. Below ground, the decay faces similar challenges as above.
In the spring, when the soil temperature reaches above 5°C, the cycle restarts. While the grass thrives once more, the rainfall is insufficient for complete decomposition of last year’s dead plant matter. What does decompose, releases nutrients that feed this year’s grass. The leftovers just add to the active soil layer. Therefore, the soil’s organic content increases year after year.
In the context of carbon footprint awareness, the Canadian prairies serve as a carbon reservoir; by the process described above, they effectively remove carbon from the atmosphere.
Soil description is a complex but rewarding study. I hope to write more posts about it soon:)
Stanford, Quentin H., ed. Canadian Oxford School Atlas, 6th Ed. Toronto: Oxford University Press.
Jack of Oracle Tutoring by Jack and Diane, Campbell River, BC.