Wetlands: Monitoring plants
Plants exhibit many qualities that make them ideal for indicating wetland condition, or health. Other than a handful of free-floating species, plants are confined to the location where they first root and therefore are fully exposed to disturbances. They are also found in almost all wetland habitats and are readily identifiable. Most importantly, individual species and wetland plant communities as a whole respond in predictable patterns to human induced environmental stress. These stressors include hydrologic alterations that disrupt natural wetland water dynamics; excess sediment and nutrient loading; and chemical pollution. Depending on the context, exotic invasive plant species, such as Narrowleaf cattail (Typha angustifolia), can act both as a response and a cause of stress to native wetland communities.
Since 1995, the Minnesota Pollution Control Agency has worked to characterize wetland plant community responses across a gradient of human stressors. This work has primarily focused on developing plant Indices of Biological Integrity (IBIs) for depressional wetlands (wetlands within a depression in the landscape that have emergent marsh or shallow open water/aquatic plant communities). Depressional wetland IBIs have been fully developed and validated in the Mixed Wood Plains (i.e., North Central Hardwood Forest) and Temperate Prairies Ecoregions. A preliminary IBI has also been developed in the Mixed Wood Shield Ecoregion. In addition to IBI development, the MPCA has worked to develop the Floristic Quality Assessment (FQA) and landscape scale wetland condition indicators that rely on remote sensing data and Geographic Information Systems (GIS).
Wetland plant community data and IBIs can be used for a variety of wetland management applications including:
- Ambient condition monitoring (status and trends)
- Best Management Practices (BMP) effectiveness monitoring
- Problem investigation monitoring
- Mitigation and restoration effectiveness monitoring
- Permit issuance
- TMDL investigations including, listing, delisting, and implementation effectiveness.
- Status and Trends of Wetlands in Minnesota — Depressional Wetland Quality Baseline
- Survey Design of Minnesota's Depressional Wetland Quality Assessment (November 2007)
- Floristic Quality Assessment for Minnesota Wetlands (May 2007)
- A Comprehensive Wetland Assessment, Monitoring and Mapping Strategy for Minnesota (July 2006)
- Assessing the Quantity and Quality of Depressional Wetlands in the Redwood River Watershed Utilizing a Probabilistic Sampling Design (June 2006)
- Development and Validation of Indices of Biological Integrity (IBI) for Depressional Wetlands in the Temperate Prairies Ecoregion, (May 2006)
- Defining Wetland Condition Assessment Processes (December 2004) For subsequent information regarding this process, see also 2008 Wetland Assessment Documentation.
- Indexes of Biological Integrity for Large Depressional Wetlands in Minnesota (May 2002)
Omernik Level II Ecoregions and MPCA Wetland Monitoring Sites