There's some valid points and interesting questions in this tread. And I'll attempt to shed some light from my working experience with redwoods.
One is, Select cutting old growth redwood using any current forestry models is impractical. Past attempts have shown it just puts the site and reproduction back to square one. In an old growth setting it would be better to harvest the windfalls and just let the forest do the thinning naturally.
Select cutting second growth redwood is very practical as it keeps companion species at bay. And you can enter the site every twenty years and take a fifth of the trees without significant impact on the reproduction.
Redwood has it's natural range of course and on the edges of it clearcut logging invariably results in the hardwoods taking over very quickly. And on these edges the same thing will happen in select cuts if the hardwoods are not kept at bay. The take over just happens a little slower.
Although in prime habitat nothing will take over the redwood,, even if it was clearcut.
Redwood is very hardy, fast growing and long lived. That's why it gets to be so big. Of the 2 million acre redwood region the most prime specimens are in the northern parts. Just more rain and cooler environment. And though 90% of the region has been logged over, 100% of it is still growing a very fast pace.
The redwoods will be laughing at us long after we're gone.