Fish Creek Provincial Park is in the city of Calgary, Alberta (where I live) but it definitely doesn’t feel urban.
We went for a dog walk there today. Two dogs, three humans, so I got to take pictures and the others did the dogging.
The park takes up a large, flat valley through which the tiny Fish Creek flows until it meets the bigger Bow River. Like so many of the landforms around here, this valley is the result of the glaciers. As they melted, there was a lot of water and it had to go somewhere. This is one of the remaining meltwater channels left over from the last Ice Age.
Because we are only about 100 miles from the alpine glaciers on top of some of the Rocky Mountain peaks, Fish Creek and the Bow River still do carry glacial meltwater, but much less of it. Still, every now and then there is a flood. In June 2005 most of the paths and bridges in Fish Creek park were wiped out by a massive flood that re-formed much of the valley bottom.
What struck me today was how diverse the plant life in Fish Creek is. Even though we are talking about one small area, that area happens to feature a good mix of micro-environments, and on top of that, different parts have different uses, different management regimes, and different histories. It all shows in the plant life.
In this part of the world, we have a lot of trees but only a few native species. Among the deciduous trees, two kinds of poplars prevail: Balsam Poplar (Populus balsamifera) and Trembling Aspen (Populus tremuloides). The Balsam Poplar, whose bark is shown in the picture, is the one you’ll find in valley bottoms. They grow quickly and get quite tall. The bark of the mature tree is thick and ridged, and provides some protection against the wind, heat and fires.
It seems to me that the Balsam Poplars reach their full height of about 25 metres (about 75 feet) or close to it more often than the Trembling Aspens get to theirs (30 metres). Of course, that’s just my unscientific perception.
In Fish Creek Park, we didn’t walk in a true forest but in a grassland with some trees and a lot of shrubs. Walking in a poplar forest is a wonderfully fragrant experience, especially in the spring. When the buds are opening and the resin is fresh, the trees have an unmistakable earthy perfume.
If you look closely at the next picture (which you can enlarge by clicking on it), you should see some cattails growing in the middle of the scene. We think of these as swamp plants, though here there isn’t a big swamp, just some ground that stayed very moist all year. This picture has grasses, shrubs, forbs, trees, a real mixture. If you think about it, each of these started with the same resources: soil, climate, the amount of sunshine, the amount of rain and so on. Yet look at the variety of life that resulted.
Whenever I watch one of those underwater life documentaries, I’m amazed by the variety of shapes and sizes of fish and other sea creatures. But really, when you think about it, we have the same diversity around us every day. It’s Nature’s best weapon, biodiversity.
The pale green berries in this picture belong to the Saskatoon berry (Amelanchier alnifolia), and when they ripen, they will be dark purple and very tasty, if a little dry. Remember, water is scarce here so plants aren’t going to be making a lot of juicy berries. The Saskatoon berries will be eaten by all kinds of creatures and as those birds and bears wander around doing what they do in the woods, the seeds will be dispersed along with some built-in fertilizer. Some of them won’t be eaten, but will fall where they are and either germinate or be washed to some other place to try and establish themselves.
In contrast to the Saskatoon, the Wolf Willow (Elaeagnus commutata) has a hard, dry fruit that humans don’t find appetizing. Inside there’s a single seed.
The silvery leaves and fruit of the Wolf Willow are a sign of a plant growing in a dry, sunny place. The silver colour reflects the sun, helping the plant to conserve moisture.
Unlike those two shrubs, the Canada Thistle (Circium arvense) is a herbaceous plant, not a woody one. It’s a non-native, brought to North America in the 1600s by the British and French, initially to the eastern US.
From this picture of the fluffy seeds of the thistle, you might imagine that it spreads mainly by seed. After all, each plant produces many seeds, each with its own little parachute. They can ride the wind for miles, easily.
What makes the Canada Thistle more of an agricultural pest, though, is its tough root system. The top of the plant may take a beating, but the underground part spreads widely. Bad for farmers, good for thistles.
Well, I didn’t mean this adventure to turn into a biology lesson, but I do find the grasslands interesting. Here’s something a little more dramatic to end with.
Calgary is part of the Canadian prairies, those great plains where buffalo (bison) used to roam in great herds until we hunted them to death. The Plains people were dependent on buffalo for food, shelter, tools, medicine, everything. One way they hunted the animals was to skilfully rush a herd over a cliff. The kinds of cliffs available in Alberta are typically like the one in the picture: the edges of river valleys. This particular spot may not have been a buffalo jump, I don’t know. I do know that there are some jump sites in Fish Creek Park, and in the interpretive centre, there is a display about buffalo.
That reminds me that some day I want to go to a World Heritage site not terribly far away: Head-Smashed-In Buffalo Jump. Another adventure.