Natural resources are raw supplies taken from the land from specific deposits. Each island has a finite number of resource types and a finite number of resource deposits for each type. These can be viewed easily by left-clicking on the top-middle city name display that appears when your view is over an island. Then you can click on each resource icon to view each location on your island.
These natural resources are found on both northern and southern islands.
Stone deposit: Harvested by stone quarries to produce stone, which is used by countless occidental buildings (every citizen, patrician, and noblemen building except hemp plantations and weaver's huts), and the oriental Bath house building.
Tree: Harvested by lumberjack's huts to produce wood, charcoal burner's huts to produce charcoal and forest glassworks' to produce potash. There is no specific deposit for Trees; they can be planted anywhere, on both southern and northern islands. Trees are automatically planted when the above production buildings are built. Therefore, you only rarely need to manually plant Trees through the build menu.
In addition to the universal resources of stone, iron, and coal, the northern islands may also contain the following.
Bear's cave: Harvested by trapper's lodges to produce furs, which are used by furrier's workshops to create fur coats, a clothing need for noblemen.
Brine deposit: Harvested by salt mines to produce brine, which is used by salt works to produce salt, which is used by three occidental buildings (tannery, butcher's shop, and furrier's workshop) to provide goods-based needs for patricians and noblemen.