Road Ecology Center

The Washington State Department of Transportation (WSDOT) creates, restores, and enhances wetlands to mitigate for impacts that occur during highway construction projects. Monitoring data provides information on the development and success of these wetland mitigation sites. Valid monitoring data is critical to the adaptive management of site remediation and maintenance activities. In 2000, biologists surveyed wetland vegetation using two different sampling strategies on four mitigation sites in western Washington. Vegetative aerial cover data were collected using both the agency’s historical, standardized monitoring approach, and an alternative method that combines changes in sampling design with new methods of data collection. Cover estimates were calculated for each data set and compared. Post-monitoring data analysis shows the alternate methods generate more reliable aerial cover estimates for target plant populations.