Natural Resources
Conservation Service
Ecological site R236XY204AK
Subarctic Low Scrub Loamy Glaciated Hill Depressions
Last updated: 2/13/2024
Accessed: 11/21/2024
General information
Provisional. A provisional ecological site description has undergone quality control and quality assurance review. It contains a working state and transition model and enough information to identify the ecological site.
MLRA notes
Major Land Resource Area (MLRA): 236X–Bristol Bay-Northern Alaska Peninsula Lowlands
The Bristol Bay-Northern Alaska Peninsula Lowland Major Land Resource Area (MLRA 236) is located in Western Alaska. This MLRA covers approximately 19,500 square miles and is defined by an expanse of nearly level to rolling lowlands, uplands and low to moderate hills bordered by long, mountain footslopes. Major rivers include the Egegik, Mulchatna, Naknek, Nushagak, and Wood River. MLRA 236 is in the zone of discontinuous permafrost. It is primarily in areas with finer textured soils on terraces, rolling uplands and footslopes. This MLRA was glaciated during the early to middle Pleistocene. Moraine and glaciofluvial deposits cover around sixty percent of the MLRA. Alluvium and coastal deposits make up a large portion of the remaining area (Kautz et al., 2012; USDA, 2006).
Climate patterns across this MLRA shift as one moves away from the coast. A maritime climate is prominent along the coast, while continental weather, commonly associated with Interior Alaska, is more influential inland. Across the MLRA, summers are general short and warm while winters are long and cold. Mean annual precipitation is 13 to 50 inches, with increased precipitation at higher elevations and areas away from the coast. Mean annual temperatures is between 30 and 36 degrees F (USDA, 2006).
The Bristol Bay-Northern Alaska Peninsula MLRA is principally undeveloped wilderness. Federally managed land includes parts of the Katmai and Aniakchak National Parks, and the Alaska Peninsula, Becharof, Togiak and Alaska Maritime National Wildlife Refuges. The MLRA is sparsely populated. Principal communities include Dillingham, Naknek, and King Salmon. Commercial fishing in Bristol Bay and the Bering Sea comprises a major part of economic activity in the MLRA. Other land uses include subsistence activities (fishing, hunting, and gathering) and sport hunting and fishing (USDA, 2006).
Classification relationships
Alaska Vegetation Classification:
Open low scrubland (II.C.2 - level III) / Open low sweetgale-graminoid bog (II.C.2.j - level IV)
(Viereck et al., 1992)
Circumboreal Vegetation Map – Alaska-Yukon Region:
Southern Alaska Alder-Willow-Dwarf Birch Scrub
(Jorgensen and Meidinger, 2015)
BioPhysical Settings: 7617230 – Aleutian Wet Meadow and Herbaceous Peatland - Complex
(LANDFIRE, 2009)
Ecological site concept
This ecological site is in glaciated hill and plain depressions. Site elevation is typically between 200 and 700 feet above sea level. Slopes are gentle (2 - 8 percent). Soil hydrology is the major factor shaping the vegetation in this landform. Soils are young and very poorly drained, with a water table throughout the growing season that selects for facultative wet to obligate wetland species.
The reference state supports one community. The reference plant community is characterized as an open low scrubland (Viereck et al., 1992). It is composed of a facultative to obligate wetland shrubs, graminoids and forbs atop groundcover of mosses and surface water.
Associated sites
| R236XY124AK |
Subarctic Tall Scrub Loamy Convex Hillslopes R236XY124AK describes tall scrubland communities on well drained plains and hill backslopes. It can be found surrounding the ecological site described by R236XY204AK, which is in plain and hill depressions. |
|---|---|
| R236XY131AK |
Subarctic Tussock-Scrub Frozen Plains R236XY131AK describes a low scrubland on glaciated plains. The plain depressions described by R236XY204AK are found across glaciated plains. |
Similar sites
| R236XY129AK |
Subarctic Low Scrub Peat Coastal Plains Both are depression sites supporting facultative to obligate wetland shrubs and graminoids. R236XY129 is restricted to coastal plain depressions. The influence of coastal spray and coastal storm surges create a unique reference plant community. These influences are not found in R236XY204AK. |
|---|---|
| R236XY144AK |
Subarctic Scrub Peat Terraces R236XY144AK describes terraces and depressions on terraces. There is some overlap in vegetation between that site and R236XY204AK. R236XY144AK describes two communities distinguished by ponding frequency and length. Ponding does not occur in R236XY204AK and the reference plant community is stable. |
Table 1. Dominant plant species
| Tree |
Not specified |
|---|---|
| Shrub |
(1) Myrica gale |
| Herbaceous |
(1) Carex |
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