Measures of Successful Wetland Restoration:

An Examination of Policies and Ecologiesin 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

ResultsNumber of invasive species related to

mitigation site acreage

R2 = 0.74

0 1 2 3 4 5 6 70

1

2

3

4

5

6

7

8

Site size (acres)

# of

inva

sive

spe

cies

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

Simple road re-location

Restoration

Fewer invasives(mean density 6.2%)

Pre-existing wetland hydrology

Smaller mitigation sites (mean = 1.8 acres)

Smaller mitigation sites (mean = 1.8 acres)

Large mitigationsites (mean = 4.2 acres)

Simple road re-location

Restoration

Pre-existing wetland hydrology

Multiple projects

Wetland hydrology questionable

More invasives(mean density 16.9%)

Creation

Fewer invasives(mean density 6.2%)

0 1 2 3 4 5 6 70

5

10

15

20

25%

cov

er in

vasi

ve s

peci

es

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!

Questions?