Ecological yield
harvestable population growth in an ecosystem
Ecological yield is the harvestable growth of an ecosystem. It is most commonly measured in forestry - in fact sustainable forestry is defined as that which does not harvest more wood in a year than has grown in that year, within a given patch of forest.
However, the concept is also applicable to water, and soil, and any other aspect of an ecosystem which can be both harvested and renewed - the so-called renewable resources. The carrying capacity of an ecosystem is reduced over time if more than the amount which is "renewed" (refreshed or regrown or rebuilt).