Analysis of hierarchical characteristics of landscapes in Ontario : detecting emergent levels of organizaton

Abstract

Hierarchy theory suggests that complex systems such as ecosystems will develop hierarchical structure that can be reflected in multiple emergent levels of organization in landscape patterning. Emergent levels of organization are defined as the scales where non-random patterning of forest landcovers occur. Forest policy initiatives that address sustainable forest ecosystems, as opposed to sustainable fibre yield, provide direction for the emulation of natural landscape patterns when allocating timber harvest blocks. Emergent levels of organization and scale-dependent structure o f landscapes are new issues, which until recent advances in technology, have been difficult to tackle. I use thematic landcover maps, derived from satellite imagery, to evaluate the hypotheses that among regions divided by boundaries that are based on broad-scale climatic processes, emergent levels of organization within landscape structure do not exist, and if they do, that they do not differ among regions. I use lacunarity and landscape statistic analyses on sample plots of 400 km2 and 5,625 km2 to detect and compare emergent levels of organization. Hierarchical characteristics, in the form of multiple emergent levels of organization, were not consistently detected in the 400 km2 sample plots. In contrast, multiple emergent levels of organization were detected in the 5,625 km2 sample plots located in northwestern Ontario but not in northeastern Ontario. The hierarchical characteristics detected in northwestern Ontario were in both mature overstory forest and recent fire disturbance. Current landscape patterns are a result of recent historic disturbance regimes. The results indicate that by emulating current patterns at fine-scales through forest harvest, the resulting landscape patterns could be mature forests with hierarchical characteristics similar to natural systems. Broad-scale patterns in the form of emergent levels of organization exist within and among individual forest management units. The results indicate that if sustainable ecosystems are an objective of natural resource management, management strategies that include multi-scale analyses and planning techniques are necessary.