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The Wagner Bog Trail has been preserved by the provincial government since 1971 and was officially designated a protected Natural Area in 1975 because of its outstanding ecological features. It remains a beautiful natural sanctuary close enough for easy access by those who live in Edmonton. We started early, around 7:00 AM, and benefited by being almost completely alone.
The trail itself isn't too long, but it passes through a number of distinctly different environments, from parkland to marl ponds, and everything in between. Accessible from the Yellowhead, the main east/west highway, the trail heads south and soon hits the parkland section.
Zone1. The parkland environment is in state of continual change – in a good year, aspen and other small trees are grow into the pastures and meadows, then in dryer years they get pushed back. To help cover the maintenance costs and to keep the encroaching trees at bay, local farmers are allowed to mow the pastures a couple of times a year. The grass quickly grows back, and provides a home for wildlife like the pocket gopher, and butterflies like the clouded sulphur and brown wood nymph.
Zone 2. The trail then hits the edge of the forest, a completely different world. Here, balsam poplar and aspen (also of the poplar family) grow. Both species rapidly colonize open ground by means of suckers. Genetically, that means that every clump of trees is identical – each is a clone of the parent.
Zone 3. Very quickly, the forest the trail passes through changes and turns into a swamp. Lots of willows, and this is also prime territory for gooseberries and currant bushes when in season. We came across some marsh marigolds.
Other common flowers in that environment include wild mint, and water hemlock, notorious for its poisonous roots and leaves. If you're into eating wild plants, be cautious – the plant resembles the edible cow parsnip.
With lots of pools of stagnant water, this is also a perfect environment for mosquitoes. There are about 30 species that breed at Wagner; only some require a blood meal in order to lay eggs, and of those, only the females bite.
The moisture also encourages the growth of lichens on the trees and on any rocks. Each one is a combination of two very different organisms, a fungus and an alga. The algae are imbedded in the upper layer, above the filaments of the fungus, of a plant body (thallus) that is unlike either one alone. The fungus absorbs sugars made during photosynthesis by the alga, and the alga get the protection of the tough thallus, and some of the water absorbed by the fungal filaments. This symbiotic relationship allows lichens to pioneer in hostile environments such as rocks, trees and bare, dry ground. Most of the ones you see at Wagner are foliose (leaf-like); the ones you see encrusting mountain rocks are known as crustose.
Judging from the evidence, there are lots of porcupine the area; in winter, the willow branches provide accessible food for them and for jackrabbits. You will also see both black-capped and boreal chickadees, and we heard any number of different bird calls as well. Hard to see them all in the dense forest, but they were there! Deer tracks, of course, and fox.
Zone 4. As the willow swamp dries up, the forest becomes a mixed one, with white spruce, tamarack (larch) and Alaska birch. As a deciduous conifer, the tamarack is interesting. Its needles turn golden in the fall, in contrast to the surrounding spruce, then fall off in the winter. There is sufficient light for an understory of tall shrubs, mainly young willows and red osier dogwood. This is good territory for jackrabbits, red squirrels and for ruffed grouse. We heard some drumming, but they stayed out of sight.
Zone 5. In the next distinctive area along the trail, the white spruce is replaced by black spruce, tamarack and Labrador tea. The forest is relatively dense and uniform, and is characteristic of the muskeg (treed bogs) that cover much of northern Alberta. In this type of plant community the soil is usually wet, acidic and low in nutrients.
Decomposition is slow, and the light levels are low under the canopy, so few plants grow on the forest floor. That makes it easier to distinguish the snowshoe hare runs that thread through the area.
As we neared the marl ponds, we began to see sphagnum hummocks, a common feature of wetlands. The ones at Wagner are formed of the kind of peat moss that is familiar as a garden compost. Since sphagnum requires acidic conditions, its growth is restricted here because the water is mostly alkaline and is rich in minerals. If you're looking for a nice soft spot to take a nap, the hummocks make for a soft and comfortable pillow, but you might get a bit damp. Later in the year the hummocks will be home to the sundew plant, a carnivorous plant whose low nitrogen diet is supplemented by the bugs it catches.
Zone 6. The marl ponds are the highlight of the show! The forest gives way quickly to an open type of wetland known as a fen. Ridges and islands of denser vegetation, dry enough to support shrubs and small trees, alternate with ponds and marshes. The bottom of the ponds is a mixture of marl (lime) and the peaty remains of aquatic plants. The water is rich in minerals, seeping up from limestone beds deep underground, and there is enough calcium carbonate in it that one plant, the stonewort, turns white and becomes hard to the touch!
The fen is home to many different kinds of moisture-loving plants. Bulrushes are a major component, as are coltsfoot, bog rosemary, saline shooting star and seaside arrow grass. Later on, we can expect to see elephant's head, rush aster, lobelia, gentian and many others. Brown mosses (others are green) edge the pond – called 'fen pasta' by some, it is only found where the water is rich in minerals.
The animal life of the fen ponds is prolific. It includes snails, leeches, water beetles, dragonfly nymphs, and several other insects. The rare aquatic Dolomedes striatus spider is big enough that it hunts small fish as well as aquatic invertebrates. In the spring and early summer, the ponds always contain tadpoles, both black toad tadpoles and greenish-brown wood frog tadpoles. The toads will be western or boreal. All the amphibians have different calls, and a summer evening can get quite noisy!
Decomposition in a marl pond is quite slow. If dead plant material accumulates faster than it decays, it forms peat. Because peat persists for a long time, it can be used for dating plant communities form the past. Samples taken at Wagner show that it has been peatland for about 4,700 years.
Shorebirds don't seem to be attracted to the fens very much, although you might see sandpipers, yellowlegs and snipe. The surrounding forest has more, and we listened for the calls of the white-throated sparrow and the ruby-crowned kinglet.
Zone 7. As we left the ponds, the trail changed again and we were walking through the dark moist interior of the black spruce forest. There were few plants, partially because of the early season, but also because of the acidic soil and the deep shade. Labrador tea, fine sedges and round-leaved orchids will be along later, but for the time being the undergrowth below the spruce is pretty scarce.
There will also be three different kinds of feather mosses: stairstep, big-red-stem and knight's plume – they do well here in the moist soil, and can cope with lower light levels. Like the lichens, they survive where others can't.
In the same way, black spruce can tolerate waterlogged soil, while white spruce can't. As we walked farther down the trail we could distinguish where the water levels changed by looking for the short, dark cones of the back spruce and the long narrow cones of the white. We also came across one area, once covered in white spruce, where they'd been killed off by a higher water table – many deadfalls, but the black spruce was starting to move in.
The horsetail ferns will soon be up, too. More closely related to mosses and ferns, since they reproduce by spores rather than by seed, ferns are another plant that likes moist places. As a family they are very old; fossils from the Carboniferous Period (275-200 million years ago) show some ferns from the Calamites family.
Zone 8. As the forest opened up we began to get into a transitional zone. Unlike the hard line where we'd entered the forest, this was a gradual change from forest to meadow. The trees got thinner and smaller, and the bigger trees moved back away from the trail. Small clumps of young poplar along the edges, and the higher grasses moving in. Black spruce, willows and birch will be along, but they move into open space more slowly. After a succession of changes, a community is established that doesn't change much unless it is disturbed by fire, or by man.
Zone 9. Getting back into the meadows again, looking for yellow lady's-slipper orchids. Not up quite yet, but they should be out in the next few weeks. Never pick an orchid – their tiny seeds have no food reserves, and they can only thrive by developing a relationship with fungi in the soil. Establishing them in an area can be precarious, and they grow slowly. Even when taking photos, try to give them some room.
It was a short walk back to the parking lot. Unlike our usual pace, we took the time on this walk to stop and investigate, to check the books, and to look at our research notes. The benefit should be obvious – we saw more, learned more, looked at our world more closely, and had a great morning out.