Ecological functionality of landscapes with alternative rehabilitations of depleted aggregate sites

Abstract

To explore the implications of surrounding landscape context on the ecological effects of rehabilitation, we assessed three alternative ways of rehabilitating depleted Ontario sites with measures of habitat patterns and cumulative costs (landscape resistance). Alternative rehabilitations focused on (a) economics, (b) biodiversity protection and (c) a compromise of economics and biodiversity. We measured the landscape effects of the different rehabilitations within a 10 km radius of several depleted aggregate sites. A cost-surface model showed that the biodiversity protection alternative achieved lower landscape resistance than the other alternatives, and importantly that this effect could extend well beyond the site. Measuring four attributes of landscape pattern the differences among alternatives showed that the biodiversity alternative offered the best habitat patterns over the economic alternative. Yet for some sites a compromise alternative could achieve similar ecological consequences while balancing competing interests. Broad inclusion of nearby landscape context when designing rehabilitation can substantially affect the ecological outcomes of rehabilitation, and the effects can be quite extensive.

Keywords:

• cost-surface models
• fragstats
• ecological design
• surface extraction
• species-at-risk

Acknowledgements

Funding for this research was provided to the authors by The Ontario Aggregate Resources Corporation. The authors thank research assistants Nina Pulver, Erik Coleman and Natasha Kenny for data preparation and analysis.