This is not my stuff and not sure exactly what models are here, but it's a Timber Jack Processor and a forwarder doing CTL (cut to length) logging. The processor fells and limbs, bucks and bunches young secondgrowth thinnings which are then picked up by the forwarder and transported to a truck usable road where they are either stacked for hot loaded on a truck for delivery to a mill or pulp wood facility.
This management practice provides the remaining trees with 'room to grow' which they take advantage of. Although the thinning is fairly tedious, Growing trees isn't terribly different from growing carrots. If they are too thick non of them grow up until some die out. Research suggests that land can grow about 'so much' wood per acre, and within reason, it can be on a lot of stems for a few stems, so thinning if you can do it at a profit makes sense because the trees are 'free trees' in that you grow as much wood per acre per year after the harvest as before.