Renewable Resources

In ecology, resources are by definition something that can be depleted. A renewable resource is then something that can be depleted by use but also has a mechanism for resupply. There are three types of renewable resources: recycled, physical sources, and biological resources.

The difference is illustrated in the systems diagrams below.

Recycled resource

After use, some process is used to recreate the original resource. This could be a resource such as aluminum that can be returned to aluminum stock.

Physical renewable

After use, a source provides a resupply through a physical process such as rain and wind.

Biological renewable

After use, biological growth processes that have potential positive feedback, resupply the stock. Examples of this are trees, fish, mushrooms, and bacteria.

Ecosystem Services that increase water supply

Combining physical renewal processes in a forested watershed can increase the amount of water available. This is the result of increasing some flows and decreasing losses of water. This sometimes called "green water" (in contrast to "blue water" that would be lakes and rivers).