Long-term recovery of a restored palustrine wetland: the role of monitoring and adaptive management.
In wetland restoration, adaptive management is a rarely used but potentially effective way to test initial assumptions of factors controlling recovery and adjust ongoing management to encourage ecosystem recovery. Limited development of monitoring practices and governance approaches hinder broader adoption of adaptive management. Reports of adaptive management for small wetlands, in particular, are lacking. We report here on lessons learned from monitoring a 3-ha, restored, palustrine wetland in central Minnesota for 23 years and using this information to guide management. The restoration was undertaken to convert a drained wetland dominated by invasive species to a high-quality meadow and marsh. Invasive species were treated, the drainage-tile system disabled, and 112 native wetland species seeded or planted. We installed a staff gauge for weekly hydrologic monitoring and monuments to delineate 26 vegetation monitoring units that encompassed the entire wetland. Five vegetation surveys were conducted between 2000 and 2019, consisting of comprehensive meanders of each monitoring unit; cover was estimated within each unit for all species observed. Coordination meetings of management staff and scientists were held to review evidence from monitoring that indicated a need to adjust vegetation or water management. Hydrologic monitoring provided evidence that the ecosystem goals needed to be adjusted and vegetation monitoring informed invasive species management. However, the linkage between monitoring and management could have been strengthened with a formal adaptive management plan at the initiation of restoration and with more frequent coordination cycles.