A system is stable, or in equilibrium, if it can return to its previous condition at some time after disturbance. The length of time required to return to the original condition is the recovery time. The reestablishment of a forest following harvesting and the renewed production of forage following grazing both depend on the inherent stability of the affected ecosystem. The stability of an ecosystem is dependent on its components and their interrelationships. Disturbance may primarily affect one component of an ecosystem, as with salmon fishing in the Pacific Ocean. The ability of the entire ecosystem to adjust to this disturbance depends on the complexities of the interrelationships between the salmon, their predators and prey, and their competitors.
The length of the recovery time varies with the type of system, the natural disturbance interval, and the severity of the disturbance. A system is usually stable only within some bounds. If disturbed beyond these recovery limits the system may not return to its previous state but may settle into a new equilibrium. There are examples in the Mediterranean region of systems that were overgrazed in ancient times that have never returned to their previous species composition and productivity. Forest managers, farmers, fishermen, and others must understand the natural resiliency of the systems within which they work and stay within the bounds of stability in order to ensure sustainable resource utilization into the future.
Was this article helpful?