I have been playing SMAC on and off since it was released almost 20 years ago. Every few years, I play for a few months, then move on to something else, but I always come back.
I think that I long ago found "a winning formula" and now repeat it without knowing why.
The salient part is that I early on drill a borehole and an aquifer near each city. After a while, I will be getting all of my money, food, etc from satellites, so I turn the rest of the landscape over to forests, plus lost of rivers.
I have a separate question about rivers (upvoted, but no comments or answers).
This one concerns covering 95%+ of the landscape with forest. Am I doing anything wrong? Are there any disadvantages or negative effects?
Best Answer
I consider forests excellent for early game; they provide with a balanced food/production/energy output and they self-expand (e.g. they don't need your manual effort for terraforming).
Forests also seem to be a very reasonable choice for any square that seems too arid to support a good farm. In addition, Sensor arrays are best built on forests near your bases because the sensor arrays combine with the forest, unlike the other improvements (e.g., if you build a sensor in a square with a solar collector or mine, the latter will be destroyed).
After you discover more effective terraforming improvements, nothing prevents you from building them over the old forests. Forests never expand over the earlier-terraformed squares, as far as I understand.
In addition, in late phases of the game, the remaining forests help reduce pollution caused by production in nearby cities.
As I mentioned in previous posts, the ultimate goal in SMAC/SMAX is reaching the instant population boom. With it, you quickly run to overpopulated cities, with a large percentage of unhappy drones. If you manage to build a vast fleet of supply crawlers to support your cities from outland (specialized!) squares and take citizens off from working on squares near cities, then forests around the cities seem to be an additional benefit.