Yeah I'm starting to lean toward the forest. At this point, I really should have enough provinces to cover for any population issues and with the wood production bonus, I can put 25% more villagers to work in the iron mines while getting the same wood production that would come from using 25% more villagers in the lumber mill in a plains province. Wait... that might not be quite right. I feel a brain vomit coming on...
Basic production of 1000 villagers is: 100 wood, or 20 iron, or 50 stone, or 50 gold.
example in plains: 1000 villagers = 100 wood,
in plains w/ forest: 800 villagers = 100 wood
**At first I was thinking 750 villagers would do it but here's my math on the bonus...
800villagers =80 wood + (0.25 bonus x 80 wood) = 100 wood;
*or if you add the bonus to the villager numbers*
800 villagers + (0.25 bonus x 800 villagers) = 1000 villagers = 100 wood
So it actually looks like the 25% production bonus somehow means that 20% fewer workers will yield the same results. I think that's right but it's screwing with my head.**
So now, if I have 1000 villagers, I can use 200 of them to produce 4 iron while making the same amount of wood
-and-
take away 10% of that population due to the forest growth rates and 900 villagers will still make 100 wood and 2 iron
Of course, in reality I would divide the workers up differently depending on the current trade rates or army needs but the point is that the forest is clearly going to win the production battle.
-annoying afterthought... a statistician, which I'm not, could probably argue that the population growth bonus % has a compounding effect while the production bonus is fixed thereby making all those numbers useless once you account for time.
...Whatever
Screw the whole thing! I'm going with the forest because my map will look cooler if I do!