The MPCA employs a probabilistic monitoring approach to track the overall status and trends of wetland quality in Minnesota. Probabilistic monitoring simply refers to the process of randomly selecting sites to monitor; from which, an unbiased estimate of the resource can be made. Trends about wetland quality are determined by repeating probabilistic surveys over time. The process is similar to that of an opinion or political poll where the results of an overall population can be estimated and tracked over time by randomly surveying a limited number of individuals over several iterations.
The MPCA is a leader in developing and implementing wetland probabilistic monitoring. It is the primary wetland monitoring activity at the MPCA, and several efforts have been completed or are currently in progress.
- It started with a pilot project in the Redwood River watershed (2006): Assessing the Quantity and Quality of Depressional Wetlands in the Redwood River Watershed Utilizing a Probabilistic Sampling Design: Condition of depressional wetlands using IBIs in the Redwood River watershed
- A group of state and federal agencies collaborated to create a broadly understood, scientifically sound strategy for monitoring and assessing status and trends in wetland quantity and quality statewide: A comprehensive wetland assessment, monitoring, and mapping strategy for Minnesota
MPCA is currently engaged in two ongoing projects to monitor wetland quality status and trends on a statewide basis.
Depressional wetland condition assessment
From 2007-09, more than 150 randomly selected depressional wetlands were sampled to provide the first status estimate of wetland quality for each of Minnesota's major ecoregions and statewide. In 2012, an additional 100 depressional wetland were sampled in the central and former prairie regions of the state (where most depressional wetlands occur) to measure wetland quality trends for the first time. Invertebrate and plant IBIs are the primary indicators used in the Depressional Wetland Quality Assessment (DWQA). With two rounds of the DWCA now complete, results show that depressional wetland quality is stable from 2007 to 2012.
Minnesota wetland condition assessment
From 2011-12, the MPCA conducted sampling for the Minnesota Wetland Condition Assessment (MWCA), which is a statewide survey that includes all wetland types (not just depressional wetlands). The MWCA measures plant community condition using the Floristic Quality Assessment and is being done in conjunction with EPA's National Wetland Condition Assessment. MWCA results reveal that Minnesota’s wetlands overall have high vegetation quality, but there is a large disparity between the northern region (that has a large share of high quality wetlands) and the central and former prairie regions (where wetland vegetation is largely degraded).
How are Minnesota's wetlands doing?
To see the latest wetland status and trend results, visit the How are Minnesota's wetlands doing page.
Future monitoring cycles
Subsequent rounds of the MWCA and DWQA will be synchronized with EPA's National Wetland Condition Assessment five-year rotating schedule, with the next sampling iteration to begin in 2016. This provides a sustained ability to monitor wetland quality status and trends to complement the DNR's wetland quantity status and trends survey and ultimately, help determine whether Minnesota is meeting the no net loss wetland policy.
- Status and Trends of Wetlands in Minnesota — Vegetation Quality Baseline
- Status and trends of wetlands in Minnesota — Depressional Wetland Quality Assessment (2007–2012)
- Status and Trends of Wetlands in Minnesota — Depressional Wetland Quality Baseline
- Survey design of Minnesota's depressional wetland quality assessment
- Assessing the quantity and quality of depressional wetlands in the Redwood River Watershed utilizing a probabilistic sampling design
For more information
For more information about wetland monitoring and assessment at the MPCA, contact Michael Bourdaghs at 651-757-2239