CFS: Second-growth Forest Douglas-fir
History
Dating back to 1865, Point Grey was harvested by Vancouver Island Spar, Lumber and Sawmill Company (later Hastings Sawmill Company). The giant Douglas-fir and western redcedar that once dominated this area were felled by cross-cut saw and axe as the loggers stood on narrow spring boards.1 Because of the butt-swell and butt-rot at the bottom of these large old-growth trees, the trees were cut several meters above the ground, leaving large stumps.
In 1910 the tip of Point Grey was chosen as the site for the University of British Columbia. The provincial forest branch started issuing timber licenses to clear the space. In 1912, 65 timber sale licenses were issued to clearcut the second-growth timber and dead and down timber. In 1919 a serious brush fire broke out near Camosun Bog and this blaze burned 200 hectares.
General
Elevation: 86 m above sea level
Aspect: Southwest
Adjacency: Main road (16th Ave W)
Canopy Cover: 82 %
Major Tree Species by Volume: Douglas-fir (Fd)
Minor Tree Species by Volume: Western redcedar (Cw)
Average Height of Trees: 25 m
Soil
Forest Floor
Litter Layer:
Depth: 0.01 m
Structure: Loose
There is no indication of root, mycelial, or fecal matter in the litter layer.
Fermentation Layer:
Depth: 0.05 m
Structure: Matted
There are plenty of fine-sized roots, mycelial, and fecal matter in the fermentation layer.
Humus Layer:
Depth: 0.09 m
Structure: Friable
There are very few roots in this layer with no indication of mycelial or fecal matter.
Mineral Soil
Soil Order: Humo-ferric Podzol
Nutrient Regime: Rich
| Horizon Type | Depth (m) | Colour | Texture | Course Frag. % (G/C/S) | Course Frag. Shape | Root Abundance/size | Structure Class | Structure Kind |
|---|---|---|---|---|---|---|---|---|
| Ae | 0.05 | 10YR 3/2 | Sand | 1/0/0 | Sub-angular Blocky | Very Few/Fine | Very Fine | Granular |
| Bf | 0.46 | 10YR 4/6 | Sand | 5/2/1 | Sub-angular Blocky | Few/Medium | Very Fine | Granular |
| Bfj | 0.25 | 10YR 3/6 | Sand | 7/3/15 | Sub-angular Blocky | Very Few/Medium | N/A | Single Grain |
| C | 0.76+ | 2.5YR 7/1 | Massive | N/A | N/A | None | Massive | Cemented |
Tree Layers
This second growth forest has a thick canopy layer dominated by Douglas-fir. The canopy is beginning to open up as sub-dominant trees die, leaving tall, widely spaced dominant trees. Bigleaf maples are about 22m in height and are the major species in canopy gaps. Western redcedar is also present in the mid-canopy. Growing abundantly under the mature trees are the shade-tolerant western hemlock. These hemlocks are often seen growing on old stumps and nurse logs because they can tolerate nutrient poor conditions.
These graphs show the heights and diameters of the ground vegetation and trees. Graph 1 shows the relationship between tree height and diameter (DBH). As DBH increases, so does tree height. Tree heights are hard to measure. Knowing this relationship allows foresters to predict heights of trees once they know the diameter. In this stand we can see that the Douglas-fir are not only dominating the canopy, but they have the largest DBH as well. Tree volume is calculated from DBH and height, and by looking at this graph we can see that Douglas-fir is the major species.
Graph 2 shows the average height of the ground vegetation. Salmonberry is tall in the canopy gaps and grows taller than salal or thimbleberry.
Wildlife Trees and Large Woody Debris
The standing dead trees in this area vary in species and size. Some shorter hemlocks have a symptom called witches' broom. This symptom can be caused by many diseases, such as rust, and can also caused by the parasitic plant, dwarf mistletoe. Witches brooms are clusters of short, weak shoots that form on branches and often lead to abnormal thickening of the main branch axes.
Wildlife
There are a lot more indicators of animal presence in this area of the forest than in most. This second-growth forest is home to birds, some smaller mammals, and amphibians. It can be hard to see birds when they are high in the canopy or hidden in the understory, but you will probably hear them singing. Keep a lookout for the spotted towhee, a year-round resident of these forests!
Critical Thinking
When you first look at this stand, what do you see? How are the trees spaced? where does the crown start on the stems? What species do you see?
Being aware of these traits will help a foresters understand the site and what kind of products can be made from it.
This area was harvested about 100 years ago, before the fire disturbance. Can you see any indicators of logging? Can you see what kind of techniques they used?