Sunday, July 27, 2014

Uphill and downhill of forest management in British Columbia


On the west of Vancouver Island facing the Pacific Ocean lies a slope that extends from the sea to a ridge line of about 3000 feet in elevation. Over the past sixty years loggers have worked their way through the virgin forest leaving behind well stocked young forest. Some old growth remains near some parts of the ridge line. It is the last to go because it is at the top of the hill and was much smaller in stature than the previous old growth that once existed downhill.

The human footprint on the slope bears witness to the supremacy of industrial forest management in the landscape. It was supported by a tenure system of harvesting rights held by forest corporations in public forests. There was a strategic vision of replacing decadent old growth with vigorous young stands. The system of taking virgin timber from the forest has worked its way up the hill and is now looking at its future.

At the top of the slope there is another footprint, a little testimony to the notion that public forests should not just be about growing timber. A long trail was located and developed by volunteers along the ridge line. Parts of the trail go through the remaining old growth. Although the trees are smaller than the now vanished lower elevation old growth, a moist environment of Mountain Hemlock and Yellow Cedar gives a rich interesting ecosystem. The remaining old growth is not protected. Its previous protection lay in the fact that it was the least desirable timber in the landscape. Now the Yellow Cedar and Mountain Hemlock make acceptable pickings in comparison to the young trees downhill.

The trail takes the visitor through an interesting old growth environment as shown in the picture:
The trail is adequate for the low volume of foot traffic it presently receives, but since it was located by amateurs there is little control of gradients along the route. Note the rope in the picture supplied as an aid on a steep section. If the trail gets a higher level of traffic it would become gouged, eroded and unsustainable. Even the loggers have seen the light on the need for gradient control on forest roads for at least half a century, but steep eroding foot trails are a feature in BC landscapes. Some protect areas in BC Parks have steep eroding foot trails.

Meanwhile the loggers have been improving the road up the hill. Ditches have been cleaned out and new culverts have been installed. It is a 30 kilometer log haul from the top of the hill to the water, so it pays to improve the road. Improved ditches and culverts make the roads sustainable and reduce erosion. Forest practices codes and guidelines have brought some improvement in practice, but there is a strong hint that old attitudes prevail. The sign marking the trail at the road was totally obscured by a big pile of rocks and soil cleaned out of the roadside ditch.

The road downhill from the ridge goes through second growth that gets progressively taller and older as you work your way down the hill. Near the bottom of the hill, the harvest of the brave future is underway. Parked beside the road near the bottom is this thing:

The tree falling machine is quite a technological achievement with considerable hydraulic prowess and probably some computer assisted stabilization. The old time tree faller of half a century ago would probably describe it as "A bean pole snips that looks like a vulture's ass in a power dive".
Using these machines on the steep slopes of coastal BC will be more costly than in other areas where these machines can be used on flat or gentle terrain.

A little farther down the hill is an area of young forest that has been harvested with bean pole snips:

The machine did not harvest the trees from the big stumps. It would be too small to grab the tree and if it could the mass of the tree would over-topple the big machine. The big stumps remain from previous virgin forest harvest, sixty or seventy years ago. They are like rotting wooden markers in a graveyard, a reminder of the once majestic forests that stood here. They will probably be gone in another sixty or seventy years after the next harvest of relatively small young trees.

"Work with nature or you will be defeated" is an old forestry notion. On the hills and mountains of coastal BC, nature grew big valuable trees over time periods of 200 or more years. We are trying to grow smaller less valuable trees in sixty or seventy years in service to one notion of economics. Science knows that it takes about 100 years for all the biological components of an old growth forest ecosystem to re-establish. Other than some minor root rot problems, there is little experience of negative effects with short rotations. We do not know if short rotation industrial forest management in these landscapes is sustainable over the long term. By quickly harvesting our old growth in favor of short rotations, we have put most of our eggs in one basket.

No comments:

Post a Comment

We encourage comments and questions