Red pine in mixed stands?

Last week I went downeast with Kyle Burdick to do the Fourth Machias Lake-Gasabias Lake- Nicatous Lake route. We never found the Gasabias Portage, which was a pain, but we saw some beautiful pine forests on Fourth Machias and Nicatous. White and red pine play a more dominant role here than northern Maine; if you never leave the lakes you might think pine was all that grew here. I think this goes hand in hand with the greater place of fire downeast than anywhere up north. Unfortunately, Hancock and Washington Counties are not included in the early survey records, so it is hard to demonstrate fire's historic place here. (But if anyone could ever find the surveys from Bingham's Penobscot Purchase, that would be a goldmine. For that matter, the surveys from his Kennebec Purchase would tell us a lot about pre-settlement forests in western Maine.)

Most of the red pine on the lakes is in fairly pure, even-aged clumps, as you'd expect from fire origin. But there are a fair number of mixed pine-hemlock-spruce stands, where red pine is sprinkled fairly thinly throughout. They don't look like older residuals, I think they are in the same cohort(s) as the spruce and hemlock. So how did these stands develop? Either they are fire-generated (unlikely, I think) or red pine is adapted to typical Acadian forest gap dynamics. It would be very interesting to take a closer look at red pine in mixed stands, and understand its potential recruitment pathways better. I suspect that on pine-friendly outwash sites (i.e. near Nicatous), red pine can regenerate after small partial disturbances. The picture shows some nice red pine seedlings coming up in a light (trails-only) cut near the lake.