Other than coming up with the mana needed, it's not hard. Wood Ghosts, Wind Chimes, and Treant Sprouts are
not required to reach those productions.
Just finish researching Forest Glade.
You might have to hover, unhover, and re-hover over the same things to get the tooltip cache to clear, but it's easy to see.
EDIT: PPs are short for "Portal Profits". They're spells that you'll find in all the places you don't want to find them in, which will fill up your capped settlement goods by a percentage of your portal's maximum capacity.
I'm at the moment in Orcs, but for you, it'll show up for you as the aforementioned Woodelves goods, but the idea remains the same.
Woodelves is also one of those few chapters where you can get away with researching just the portal and burning Portal Profits to get the portal straight to level 4, then burn a whack ton more Portal Profits to exit the chapter without ever researching the needed manufactories or making the required goods the normal way.
You still have to get the Mana some other way
EDIT2: Hot damn,
@Lelanya ,
you were right about upgrading the Forest Glade. Even though I was looking right at it at some point in my writeup. I feel a bit silly now