Matanuska-Susitna Wetland Mapping
WETLAND / UPLAND COMPLEX
Areas mapped as Wetland/Upland complex support wetlands mixed with uplands, but at a scale too fine to delineate. Wetlands cover at least 30% of the area. This designation is used to flag marginal areas. Although a majority of the area might qualify as upland, wetlands also occupy a significant portion, and wet conditions are to be expected not far from the surface. Different names indicate the percentage of the area occupied by wetland. For example, WU60 indicates that about 60% of the polygon's area is covered by wetlands. The most common wetland type occurring in wetland/Upland Complex polygons are Discharge Slope wetlands. These wetlands often occur over a mineral soil and are forested with paper birch and sometimes white spruce. They can be difficult to identify, and experts may even disagree about some spots, especially later in the growing season when the seasonally high water table is at its lowest. A large forested area near the headwaters of Wasilla Creek is mapped as WU. When a perplexing site is encountered an attempt is always made to classify it into another category, and reserve WU for the most difficult cases.
A Wetland / Upland Complex near Chignaki Pond, north of Wasilla.
Numbers in paraentheses indicate number of samples.
Water table depth is a one time measurement. At sites with seasonally variable water tables this measurement reflects both the conditions that year, and the time of year. If no water table was encountered, no value was recorded; use number of samples to aid interpretation. Deeper average water tables idicate higher variability.
pH measured in a shallow pit with a YSI 63 meter calibrated each sample.
Plant Prevalence Index calculated based on Alaska indicator status downloaded from the USDA PLANTS database, which may use different values than the 1988 list.
Wetland / Upland Complex Map Units:
WU: Wetland at least 30%, but total percentage not estimated
WU40: Wetland component approximately 40%.
WU50: Wetland component approximately 50%.
WU60: Wetland component approximately 60%.
WU70: Wetland component approximately 70%.