<P> In population dynamics and population ecology , overshoot occurs when a population temporarily exceeds the long term carrying capacity of its environment . The environment usually has mechanisms in place to prevent overshoot . For example , plants are only able to regenerate and regrow a few times after being consumed before completely dying off . The consequence of overshoot is called a collapse , a crash or a die - off in which there is a decline in population density . The entire sequence or trajectory undergone by the population and its environment together is often termed ' overshoot - and - collapse ' . </P>
when does a dieback or population crash occur
when a population temporarily exceeds the long term carrying capacity of its environment