The process:
Industries need resources, therefore trees would be cut down.
Industries --> Trees (Wood cutting plugin could be used or code it to just disappear, if it is easier and better)
Trees used as resources
1 block of trees = 2/4 block of industrial zone (cut down is per month or 1 month and 15 days)
No trees = no industry production = no jobs = industries close down = no product
No product = no need to sell, therefore, no commercial
No product = commercial close down
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Since I saw smaller trees. Trees need to grow.
Plant a tree = baby tree will be planted = not capable to be used as resources.
3 months or 5 months = planted baby trees grow = Adult tree = can be used as resources
Tree planting's price, that depends on the makers.
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This would give challenges to players in terms of:
1. Land space for forest/trees growth
2. Resources Management
3. Zoning Management
4. Environment/Pollution Management
5. Maintenance
At the same time, the game would also teach people how to protect and conserve the environment in a slight realistic way.
I think it is too much work to do though.
(but i dont want to give it to all of my cities only to my tests cities)