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Measures of Successful Wetland Restoration: An Examination of Policies and Ecologies in Northern Michigan. Andrew T. Kozich. Michigan Technological University. Introduction. Regulation of Michigan’s wetlands: DEQ Much mitigation activity: Road agencies. Three key DEQ mitigation policies.
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Measures of Successful Wetland Restoration: An Examination of Policies and Ecologies in Northern Michigan Andrew T. Kozich Michigan Technological University
Introduction • Regulation of Michigan’s wetlands: DEQ • Much mitigation activity: Road agencies
Three key DEQ mitigation policies • Monitoring reports of mitigation sites must be submitted to the DEQ annually for 5 years • Wetland acreage must be placed into conservation easement • Invasive species at mitigation sites must be limited to 10% of total cover
Previous literature • Hornyak & Halvorsen (2003): 48% of mitigation permit files in the western U.P. were missing monitoring reports, conservation easement documents, or both • Invasive plant species often problematic at mitigation sites • (Balcombe et al 2005; Cole & Shafer 2002; Moore et al 1999; Spieles 2005; Spieles et al 2006)
Research Questions • Have rates of site monitoring & conservation easements changed since 2003? • Is there a relationship between site monitoring and invasive species? • Do other site factors appear to be influencing levels of invasive species? • What about creation versus restoration?
Research Design • Examine all U.P. mitigation permit files from 2003 to 2006 (69 files; 37 mitigation sites) • Examine mitigation sites constructed by road agencies between 2003 and 2006 (11 sites) • Estimate compliance with 10% invasive species limit • Releve sampling • Created wetlands versus restored wetlands
Results • Monitoring report compliance: • Michigan Dept. of Transportation: 90% • County road commissions: 30% • Other/public entities: 45% • Private entities: 50% • Overall compliance: 54% • (20 of 37 sites in compliance)
Results • Conservation easement compliance: • Michigan Dept. of Transportation: 29% • County road commissions: 38% • Other/public entities: 50% • Private entities: 60% • Overall compliance: 51% • (19 of 37 sites in compliance)
Results • Compliance with 10% invasive species limit: • 5 sites likely in compliance • 5 sites likely out of compliance • 1 site uncertain • Overall compliance: 45%
Results • Sites in compliance with invasive species: 60% had been monitored • Sites non-compliant with invasive species: 60% had been monitored Monitoring likely not related to levels of invasive species at mitigation sites
Results • Other factors influencing invasive species? • Permittee • Age of mitigation site • Proximity to nearest road
Results Number of invasive species related to mitigation site acreage R2 = 0.74 R2 = 0.74
Further... • 100% of compliant sites were wetland restorations, constructed adjacent to natural wetlands • 80% of non-compliant sites were wetland creations, constructed adjacent to upland forests
Smaller mitigation sites (mean = 1.8 acres) Simple road re-location Restoration Pre-existing wetland hydrology Fewer invasives (mean density 6.2%)
Smaller mitigation sites (mean = 1.8 acres) Large mitigation sites (mean = 4.2 acres) Simple road re-location Multiple projects Restoration Creation Pre-existing wetland hydrology Wetland hydrology questionable Fewer invasives (mean density 6.2%) More invasives (mean density 16.9%)
Red = wetland creation Green = wetland restoration Site size (acres)
Summary • Site monitoring & conservation easements: Very little change since 2003 • Site monitoring not related to invasive species, but landscape location is • Smaller restoration projects more successful than larger creation projects
No Net Loss? 74 acres lost; 185 acres gained Wetland acreage meeting performance standards for invasive species: 30%
Conclusions • Mitigation practices in the U.P. are resulting in increased acreage but decreased overall quality of wetlands • Policy efforts should emphasize the importance of mitigation site selection • Restoration is the best option!