Table 1 Characteristics of functional wet meadow ecosystems (modified from [ [16]])
Characteristic | Description | Assessment |
|---|---|---|
Suitable Stream Morphology | A low gradient stream with a low width:depth ratio (<12) and medium to high sinuosity (>1.2), except in meadows believed to have no natural channel (e.g. [25]) | Best evidence: Survey data on pre- and post-project stream channel morphology |
Other evidence: Photo points, high resolution aerial photography, qualitative descriptions | ||
Stable Streambanks | Streambanks with the capacity to withstand repeated high water/flooding events without significant loss of bank material (except in meadows believed to have no natural channel (e.g. [25]) | Best evidence: Survey data on post-project stream channel morphology following repeated hydrologic events |
Other evidence: Photo points taken after several seasons, qualitative descriptions of the effects of hydrologic events | ||
High Water Table | High water tables are present within the meadow for long enough periods to result in reduced soil conditions near the soil surface (i.e. water table <30cm from soil surface for a period of at least 14 consecutive days during the growing season) and that allows for the support of native wetland plant species | Best evidence: Data from water table wells and stream hydrographs; redox potential measurements taken within the top 30 cm of the soil column. |
Other evidence: Visual observations of water levels, evidence of flooding, and soil redoximorphic characteristics; evidence of a transition to hydrophytic vegetation | ||
Organic Matter Assimilation | Characterized by a high percentage of organic matter in diagnostic soil horizons and/or a high rate of organic matter accumulation (the latter may be especially important in newer restoration sites) | Best evidence: Measurements of soil organic matter content, with comparison to suitable reference sites |
Other evidence: Descriptions of soil horizons, soil color assessments using Munsell soil color charts | ||
Perennial Native Vegetation | Perennial native vegetation covers ≥75% of the streambanks and ≥ 50% of the floodplain and is comprised predominantly of native, perennial species, especially wetland graminoid species with extensive and highly fibrous root systems (e.g., Carex spp.) | Best evidence: Quantitative data on species composition, cover and biomass using accepted vegetation measurement techniques and appropriate sample sizes |
Other evidence: Quantitative data from small samples; photo points; qualitative descriptions | ||
Presence of Native Fauna | The presence and relative abundance of both aquatic and terrestrial organisms is similar to comparable reference sites | Best evidence: Quantitative data on target species using accepted techniques and sampling intensities |
Other evidence: Visual evidence of species presence and abundance |