Sunday, 27 May 2012

A Hike Up the Mountain

On a bright summer day I like to start in a low elevation forest and hike up to the summits. Starting a hike at low altitude adds several components to the trip. You need to start earlier in the day in order to reach your destination and return. Consequently you get more exercise, more of a workout because of the greater elevation gain, and spend more time in the outdoors. There are also components other than those associated with the exercise. There are the changes to be seen between the base of the mountain and the peak.

In coastal British Columbia there is a considerable difference in the vegetation at sea level and that on the mountain crests. Even if you do not know their names, when you look at the trees you will see that those growing on the peaks are different. The low altitude forests are mostly western hemlock (Tsuga heterophylla). They grow close together, and their thickly clustered needles stop most of the sunlight from reaching the ground. It is a shady, cool walk to start the day. Associating with the western hemlock are Douglas fir (Pseudotsuga menziesii), and western redcedar (Thuja plicata). Because of the dominance of western hemlock, these forests are called the Western Hemlock Zone.

As you ascend the slopes you will see that the lower elevation kinds of trees are gradually replaced by different types of trees. This transition begins around the 1000 metre level. By the time you reach 1200 metres almost all the trees are different species from those down below. This is called the Mountain Hemlock Zone because mountain hemlock (T. mertensiana) is the dominant tree, replacing the lower elevation western hemlock. Red cedar is replaced by yellow cedar (Chamaecyparis nootkatensis), and Douglas fir gives way to amabilis fir (Abies amabilis).

When you proceed further not only are the trees different, they are also farther apart, with little seepage areas covered by grass-like sedges. Some of the ponds are rimmed with cotton-grass (Eriophorum angustifolium), which is actually a sedge, not a grass. Sedges are related to grasses, but belong to a different family. Most of the grasses in marshes are actually sedges. Cotton-grass has fluffy seed heads, like balls of cotton. The white edges of these ponds can be spotted from a long distance away. Higher up are the open rocky summits with little soil and few trees. From such vantage points you can look down on the route your journey has taken earlier in the day. Above 1500 metres are extensive meadow slopes clothed in wildflowers. These are the subalpine meadows. Scattered here and there are small clumps of little trees. Higher still the trees give out all together. The slopes and flat areas are covered with alpine flowers, whereas the rocky ridge crests are covered by heathers, with small, needle-like leaves. They look more like little conifers than flowering plants. The reason they have needle-type leaves is the same reason that conifers have them - to conserve moisture.

The lower forest is the rainforest, or at least on the outer coast it is a rainforest. In the Lower Mainland area it does not get quite enough moisture to be a true rainforest, but the plants are essentially the same in both areas. The most noticeable difference is the mosses. They are more luxurious in the true rainforest. The most striking is the cat-tail moss (Isothecium myosuroides). In humid places it hangs from the trees in long, thin streamers.  The sea level forest is wet and snow free for most of the winter. Except for the driest part of the summer, the evergreen trees and mosses continue to grow right through the year. The upper areas are the snow forest. The snow comes to the summits in October and does not completely leave until July. This means that even after the warm spring sun shines on the tree tops, and brings re-growth to the mosses and lichens growing there, the ground remains in winter right into the early summer. The plants found here have only four months to grow, flower, and set seed. Most of our familiar plants cannot survive under such extreme conditions. This is the land of the heathers, and alpine meadows. It is a land quite different from our familiar woodlands, a land where we are just casual visitors. We spend the day struggling upwards, stop a few fleeting minutes on the peak, and then return to our homes in the lowland.

Even though you may not know their names, if you look at the mosses of the forest floor you will see that they too change as you ascend the slopes. The most common moss on the ground at low elevations is the Oregon beaked moss (Kindbergia oregana). It is shaped like a little green feather, and forms dense carpets. Also common is a pale green species - wavy leaved cotton moss (Plagiothecium undulatum). It is closely appressed to the surface and looks superficially similar to a delicate cedar twig. Also forming thick carpets is the step moss (Hylocomium splendens). It is called step moss because it forms a new step-like shoot each year, and you can count each previous year’s growth, something like counting tree rings. When you get to about the thousand metre level the ground between the blueberry bushes is often densely clothed with a completely different moss, one with shaggy, wrinkled leaves. Because of this appearance it is called pipecleaner moss (Rhytidiopsis robusta). The appearance of pipecleaner moss tells us we are approaching the summits.

With the coming of spring, memories of summer hikes return, and anticipation of seeing the mountain plants re-awakens. Even if it is a peak that has been visited many times, there are still new experiences to be had, and new things to be seen. As the snow melts back the high altitude plants, which are cold resistant, push through its edges. To see these emerging shoots is to see the emergence of summer. They say in their own way that for a few months life has again returned to the high country.

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