Matanuska-Susitna Wetland Mapping

Cook Inlet Wetlands

KETTLE  ECOSYSTEM Wetlands

A 2004 satellite image map showing Kettle wetlands and lakes southeast of Big Lake.

Kettle Ecosystem wetlands are peatlands occupying depressions created when pockets of underlying ice melted at the end of the last glacial advance (ice-block depressions). They have a wetland or stream connection to Cook Inlet, unlike Depression and Spring Fen ecosystem wetlands, which also formed in ice-block depressions. Depressions and Spring Fens are surrounded by uplands.

A Kettle west of Blodgett Lake.

Explanation:

All data from wetlands throughout the Cook Inlet Lowlands, not just from the Matanuska-Susitna Valley. Headwater fens are realtively uncommon.

Numbers in paraentheses indicate number of samples.

Peat depth is a minimum, because some sites had thicker peat deposits than the length of the auger used (between 160 - 493 cm).

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.

Redox features with deep depths typically indicate deeper peat deposits, which mask redox indicators so the depth corresponds to the peat thickness.

pH and specific conductance measured in surface water or 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.

Kettle Ecosystem Wetland Map Components:

K1: Kettle pond. If larger than 20 acres, the kettle is classified as a Lake.

K2: Water table at or very near the surface, often sedge-dominated.

K3: Deeper, more variable water table, often shrub dominated.

K4: Seasonally high water table, forested.