Using process-orientated parameters to assess degradation

Abstract

Recent advances in ecological restoration have advocated a process-orientated approach assessing ecological thresholds. Abiotic and biotic thresholds may exist at degraded sites, preventing ecosystem recovery beyond a certain level. Aiming to reinstate primary ecological processes such as hydrological function, energy capture and nutrient cycling, rather than merely composition per se, can more reliably lead to the establishment of self-sustaining ecosystems (Whisenant, 1999). Importantly, abiotic limitations of the degraded environment need to be assessed and addressed before biological restoration can commence (Whisenant, 1999; Hobbs & Harris, 2001). Comparing degraded and undisturbed ecosystems which represent the predisturbance state can give us insights into the level of degradation and allows us to assess the type of management (abiotic or biotic) required. Furthermore, using more than one degraded site or state may allow us to infer specific management requirements more accurately. A step-wise approach could be developed where several ecosystem states are identified and measured. These degraded states, along a trajectory of recovery (or disturbance), then become reference ecosystems for the most degraded sites.