Scale, ecosystem resilience, and fire in shortgrass steppe

Abstract

Ecological sustainability is the central goal of ecosystem management. To achieve sustainability, ecosystems must be managed for multiple organisms, and for processes that operate over a wide range of spatial and temporal scales. Organisms, populations, communities, and ecosystems are differentially affected by disturbance based on the scale at which they occupy the landscape. Resilience represents the property that sustains ecosystems in the face of disturbance or permits recovery following disturbance. Scale of observation influences perceptions about ecosystem resilience. Therefore, consideration of scale and ecosystem resilience is integral to any conceptual model of the effects of disturbance on ecosystems. There is no single correct scale at which ecological phenomena should be studied, and management decisions require the interfacing of phenomena that occur on very different scales of space and time. I experimentally examined resilience of shortgrass steppe to fire using multiple ecosystem components at multiple spatial and temporal scales. My results indicated that shortgrass steppe can be considered resilient to fire, but all components were not equally resilient at all scales of reference. Scale of observation (length of time after fire) affected perceptions about response to fire, as did fire season, the organizational unit analyzed, and the scale at which organisms inhabit the landscape. Some fire effects were immediately obvious, while other effects had a lag time between treatments and results.