Landscape Disturbance Models and the Long-term Dynamics of Natural Areas

• Published in: Natural areas journal Vol. 14; no. 1; pp. 3 - 11
• Main Authors: Turner, Monica G., Romme, William H., Gardner, Robert H.
• Format: Journal Article
• Language: English
• Published: Natural Areas Association 01-01-1994
• Subjects: Ecological modeling; Forest fires; Forest habitats; Forest stands; Habitats; Landscape ecology; Landscapes; Modeling; National parks; USA
• ISSN: 0885-8608; 2162-4399

The management of natural areas in disturbance-prone landscapes poses many challenges for which spatially explicit models can provide useful guidance. We have incorporated disturbance processes into simple landscape models and applied the results to two management issues. First, alternative disturbance scenarios were simulated as a function of landscape pattern and the frequency, spread, and severity of disturbance. The model simulates disturbance on random landscapes and for various levels of landscape connectivity on subsections of Yellowstone National Park. Simulation results suggest that when the habitat that is susceptible to a disturbance is well connected, the probability of disturbance spread is most important in controlling the amount of habitat disturbed. A critical threshold of habitat connectivity was observed in random landscapes, but the actual landscape maps did not exhibit this threshold effect for the particular frequency and spread values used here. For a given proportion of the landscape occupied by susceptible habitat, the variability in the amount of habitat affected by simulated disturbances was much greater in the real landscapes than in the random landscapes. This difference suggests a strong interaction between the spatial configuration of susceptible habitat and the point of initiation of the disturbances. Second, the results of a model that incorporates disturbance and recovery dynamics suggest that qualitative shifts in landscape behavior (e.g., from steady state to nonequilibrium) may occur, with important implications for natural area management.