The study of soil science fascinates me. Last year, during an introductory physical geography lecture, it was brought to my attention how diverse and intricate soil networks are, and how the geomorphic processes we observe across Canada correspond to the soil types referenced in our lectures. I have always had a relationship with soil and the minerals found within. From playing in the mud as a child and making friends with the worms housed by the depths of our garden, weeding and spreading compost in our flower beds as a teen, to sculpting clay and producing ceramics in early twenties, I’ve always found peace in understanding the components of what lies below. One of my earliest memories is from a beach here on southern Vancouver Island called Arbutus Cove, where a concave bay with vegetated coastal bluffs hugs a beautiful sandy beach facing the North Cascade Mountains of Washington State. I loved this beach because of the edge it gave me in my sand-castle building endeavours: all the best amateur sculptors would visit the slopes of the bluffs and grab a handful of moist, mucky clay to bring back to their sand castle for some extra architectural support. I now know these clays to be those of the Dashwood Drift, an ice-marginal glacio-marine deposit from the early Pleistocene (>65,000- 37,000 YBP).
Welcome to my blog. I began writing this blog in the summer of 2020 when I was gearing up to start my second year of undergraduate studies at the University of Victoria. After a couple years of bombing around the many mountains of the Garibaldi range near Whistler BC I was undoubtably ready to deepen my understanding of the processes shaping the landforms I had grown so fond of. My inspiration to write came from all the coastal environments of southern Vancouver Island could offer, the therapeutic voices of the oceans guiding my thought processes as I solidified the direction in which I decided to take my studies. Now entering the last semester of my 3rd year at UVic in the Coastal Studies concentration of my program, I’ve become a total nerd for all things geomorphology: the study of landscape evolution. I study the forces acting on hillslopes, the climate’s role in eroding bedrock and the formations that result, how tectonics shape our coastlines and mountain ranges and in turn how these landscapes themselves influence the climate. I study fluvial systems and how hydrology is so fundamentally carved out by the glacial history of regional topography and I froth at sedimentary deposits and the stones they create. I like rocks, but I love to understand how they form and the forces they’ve been subjected to.
And then we have soil. Soil is like this happy medium between the biotic and abiotic world, while rooted in the fungal kingdom, collectively providing the ingredients for life to flourish on our planet. It’s the living shell of deeper geology and a sort of interactive conduit between the external atmosphere, hydrosphere and biosphere, completely dependent on time.
Let’s talk about soil types. Do you know your soils? If you were to take a look at a soil-order map of Canada, illustrating the diverse soil types across our country, you’d notice how beautiful British Colombia looks: so obviously mountainous and divided. There are ten major soil types across Canada. By far the most abundant in terms of mass, as illustrated on most maps of our beautiful country, is the massive layer of permafrost that covers our Northern territories, also known by Pedologists (soil scientists) as Cryosolic soil (Government of Canada, 2004). Cryosolic soil is defined by having a horizon, or ‘profile’ if you will, where the soil temperature remains below freezing point throughout all months of the year. If you graduated from a highschool in BC, you probably know more about this than you think! Permafrost is the term coined for Cryosolic soil types, a vast terrain that interacts with frost action, constantly mixing frozen water molecules into the shallow depths of the permafrost layer. In these soils, this layer must occur within the top two meters of the surface to be classified as cryosolic. If this mixing of frost and soil (also referred to as cryoturbation) does not occur, the permafrost layer must be seen within the top meter depth (University of Saskatchewan, 2019). This is really not that deep, if you think about it! Calling our country “the Great White North”, though not entirely covered in snow, is a really accurate description of this dominant, frozen soil type.
Two of the other major soil types include Brunisolic soils and Podzolic soils, both soil types we see here in BC. It fascinates me to think of how much of our provinces’ land mass is mountainous, rocky terrain, and in turn coded grey to indicate no-soil type. It also fascinates me how the Southern tip of Vancouver Island is a completely different soil type in itself. Both Victoria and a narrow strip of coastline stretching up the East coast of the island consists of Brunisolic soil, while the rest of the island is completely Podzolic. Brunisolic soil is one of the three forest-soil types, (alongside Podzolic and Luvisolic), and can be thought of as a classification for young forest soils. Brunisolic soil is simply a stage in soil evolution: a several-thousand year sequence that begins with unweathered parent material known as Regosolic soils (regolith). The Brunisolic stage, though it may last many thousands of years, contains soil well on its way to becoming Podzolic or Luvisolic: mature forested soil (University of Saskatchewan, 2020). Essentially, the Southern tip of Vancouver Island is less developed, on an evolutionary timeline, than the rest of the Island’s Podzolic soils. It’s my understanding that the mechanisms that cause this transformation into mature forest soil have to do with fungal-plant interactions going on within the terrain, fixing nitrogen and other essential nutrients and developing vast networks of fertile soil beds for mature forest growth.
In Cowichan Bay, my family and I have been lucky enough to build our home amidst a bed of rich Cowichan Valley soil: a dense, nutrient rich soils with a significant clay component. The almighty sediment-carrying Cowichan River can be attributed to having provided the area with nutrient rich valleys, brought to the land via successive floods over thousands of years (CVRD, 2010). The Cowichan clay-loam that provides the area with its dense, explosive vegetation, stunning estuaries and old growth forests can be credited to the ice age our valley saw only 15,000 years ago during the Fraser glaciation of the Late Pleistocene. In this recent ice age, a large ice cap depleted over Vancouver Island, depressing the island over 150 meters down into the earth. Left behind were large deposits of glacial till: a mix of sand, soil, clay and gravel, transported to lowlands by what we now recognize as the Cowichan River, forming pockets of fertile land such as the Chemanius and Cowichan estuaries. The weight of the ice formed the iconic shapes of Salt Spring Island’s Mount Tuam and Mount Maxwell, as well as Maple Bay and Mount Tzouhalem. The moving and melting ice also cut major features into the landscape we call home today, including the U-shaped Cowichan Valley, and the deep depression of Lake Cowichan and the Cowichan River. May we acknowledge that the ancestors of Cowichan Tribes arrived on this land not long after the end of our most recent ice age, roughly 8,000 to 10,000 years ago. The word Cowichan, or “Khowutsun” translates to “the land warmed by the sun” (1st View, 2019).
If we were choosing favourite non-renewable resources, soil is it for me. Tell me how we’re going to grow food to feed 9 billion people by 2050 while we overexploit this finite resource through every agricultural sector in the world. I worry about the non-recoverable loss, degration and irreversible damage we’ve already caused, but I believe the first step in preserving our beautiful soils is education. It shouldn’t even be a question anymore if the value of soils need to be recognized and protected or if the element of time can be substituted by artificial means. Without prioritizing soil health over economic means, we’re rolling the dice with a finite resource and the critical role it plays in our survival.
– J