|Black spruce / Woodland horsetail - Labrador tea|
|Picea mariana / Equisetum sylvaticum - Ledum palustre ssp. decumbens|
|n = 53|
|I.A.2.f / 3.d. Woodland to Open Black Spruce Forest|
|Ecosystems: Discharge Slope, Relict Lakebed / Drainageway, Kettle, Depression|
Although black spruce (Picea mariana) / woodland horsetail (Equisetum sylvaticum) - Labrador tea (Ledum palustre ssp. decumbens) is very common on the Kenai lowlands, it is not mentioned in the literature. It is similar to the Black spruce / Labrador tea / feathermoss (Hylocomium splendens) type described for interior Alaska floodplains (Viereck, 1989; but on a different landscape on the Kenai), and the Black spruce / Labrador tea community described on this website, but with a dense woodland horsetail component, distinctive to the Kenai lowlands.
The black spruce / woodland horsetail- Labrador tea community occurs on foot and toeslopes where the organic horizon thins above a peatland, usually just above the black spruce / Labrador tea zone. This zone frequently occupies the groundwater discharge slope edges of low relief kames.
An open-to-woodland canopy tops an often dense Labrador tea shrub layer. Woodland horsetail cover can be nearly continuous and is distinctive to this type. Crowberry (Empetrum nigrum) is present, and frequently abundant, as is cloudberry (Rubus chamaemorus). Dwarf birch (Betula nana) and bog blueberry (Vaccinium uliginosum) are usually present, but at lower abundances. Rarely, field horsetail (Equisetum arvense) substitutes for woodland horsetail as a co-dominant.
Organic horizons are thinner, often not qualifying as an organic soil (40 cm). The water table was encountered within 30 cm (one foot) of the surface at about half the sites. The pH was measured at only four sites, and varied from moderately to extremely acid. Thirty-six of the 53 sites fit the soils criteria for a jurisdictional wetland.
Another community occasionally occurring as a narrow band on mineral soil groundwater discharge slopes, that is not named separately in this classification, and will key to this type, is the Black spruce / Barclay's willow / Field horsetail type. It frequently has lingonberry as an associate. On the Kenai Lowlands, it is a northern equivalent of the more southern Lutz spruce / Barclay's willow / Field horsetail community.
|Black spruce / Barclay's willow / Field horsetail|
Table 1. Frequency of occurrence and hydric status of soil series named at NRCS holes. Bold type indicates soils on the NRCS Alaska hydric soils list.
|STARICHKOF||9||1, 2B2, 3|
|1Proposed series, definitely hydric|
|2Proposed series, hydric status unknown|
Table 2. Summary of plant frequency and average cover for plants occurring in more than 50% of plots.
|Wetland Indicator Status|
|Picea mariana||1.0||19.7||FACW||FACW-, FACW
|Empetrum nigrum||1.0||18.9||FAC||FACU, FACW
|Ledum palustre ssp. decumbens||1.0||13.5||FACW||FACW
|Betula nana||0.9||8.6||FAC||FAC, OBL
|Vaccinium uliginosum||0.9||7.1||FAC||FACU+, FACW|
|Equisetum sylvaticum||0.9||16.3||FACU||FACU, FACW
|Calamagrostis canadensis||0.5||2.3||FAC||FAC, OBL|
|Contact: Mike Gracz Kenai Watershed Forum PO Box 15301 Fritz Creek, AK 99603 907-235-2218||
Alaska Natural Heritage Program
and Natural Resource Institute
707 A Street, Suite 101
Anchorage, Alaska 99501
04 May 2007 09:53