Since the mid 1990s we have been contending with a large mountain pine beetle outbreak. The control and salvage effort meant huge areas of forest were clear cut. Very common to have openings that were (are still) thousands of hectares. Most of this ground wasn’t challenging; “pine flat” was the common descriptor. This meant a shift away from forest stands dominated by steep slopes, environmental constraints (selective cut) or other tree species. We couldn’t hope to salvage all the pine so effort was put to going after the “easiest” stuff every year. And the “going after” involved mostly ramping up the feller buncher, skid to road side system.
Post salvage effort has left us with a higher proportion of difficult stands: small patches, steep slopes, selective cut, low volumes etc. So that is why these other systems are coming back. But a whole industry has grown up, invested heavily in one dominant system – so difficult now to break that mould. There are examples but even something as worldly common as commercial thinning meets with institutional resistance.