The
sustainable yield of
natural capital is the
ecological yield that can be extracted without reducing the base of capital itself, i.e. the
surplus required to maintain
ecosystem services at the same or increasing level over time. This yield usually varies over time with the needs of the
ecosystem to maintain itself, e.g. a
forest that has recently suffered a
blight or
flooding or
fire will require more of its own ecological yield to sustain and re-establish a mature forest. While doing so, the sustainable yield may be much less.