Linking Surface Hydrological Connectivity Patterns with Landscape Functionality in Semiarid Australian Ecosystems

摘要

Water-limited ecosystems generally show self-organized spatial patterns as mosaic-like structures of. sources and sinks of water runoff and sediments with variable interconnection. Variations in climate and. land uses can disrupt the spatial organization of vegetation and change hydrologic response, causing a substantial loss of water and soil resources by increasing landscape hydrological connectivity and, hence, affecting ecosystem functionality. We explore the connectivity patterns (i.e. flowlength probability distribution) obtained from the coupled analysis of satellite images and digital elevation models from several well preserved and degraded semiarid Mulga landscapes with banded vegetation. Our analysis reveals a major role of surface connectivity in ecosystem function. Indeed, actual connectivity patterns are tightly linked to the spatial organization of vegetation while, at the same time, show a high sensitivity to degradation processes, suggesting a threshold behaviour upon landscape functionality. These results highlight connectivity patterns as practical indicators for monitoring the landscape health in drylands.