Ecological Goals and Wetland Preservation Choice

Canada's multilayered wetland policies promote the preservation of "significant" wetlands, but the criteria for identifying these wetlands are not clearly defined partially because wetlands are a source of multiple ecological outputs, such as abating sediment and providing wildlife habitat. This study adapts a GIS-based, hydrologic, and economic model to examine the trade-offs between agricultural interests and ecological benefits in the Eramosa Watershed, located in southwestern Ontario, Canada. While preserving a wetland enhances both water quality and wildlife habitat goals, and the costs of preservation increase at an increasing rate as expected, the ranking of wetlands, and so the choice of "significant" wetlands, varies considerably depending upon the wetland benefit chosen as the policy goal. The trade-off between wetland benefits and drainage is diminished if there is an alternative means to abate sediment. Since conservation tillage is a lower cost means of improving water quality than wetland preservation, its inclusion can achieve comparable environmental benefits at decreased agricultural cost.