|Balsam poplar / Thinleaf alder|
|Populus balsamifera / Alnus incana ssp. tenuifolia|
|n = 6|
|I.B.1.c. Closed Balsam Poplar Forest|
Balsam poplar / thinleaf alder has been described by many other Alaskan workers. Viereck, et. al. (1992) cite at least eight other classifications that describe a type identical to the one found on the lowlands. However, the most similar type documented in nearby Chugach National Forest is a black cottonwood (Populus trichocarpa) / Sitka alder (Alnus viridis ssp. sinuata) type with devil's club (Echinopanax horridum) and salmonberry (Rubus spectabilis) (DeVelice et. al., 1999; and Boggs, 2000).
Balsam poplar (Populus balsamifera) / thinleaf alder (Alnus incana ssp. tenuifolia) is found on the large floodplain of the Fox River, at the head of Kachemak Bay, where cattle grazing is common and probably affects the composition and structure of those stands. This community is probably also present in a few places along the Anchor River, Deep Creek, Kasilof and Kenai Rivers. Another plot, near Nikiski, with Sitka alder (Alnus viridis ssp sinuata) in lieu of thinleaf alder was included in this summary.
A closed poplar canopy shades a tall dense alder thicket, with an abundant tall bluejoint grass (Calamagrostis canadensis) layer. Several forbs are present at low abundance: baneberry (Actea rubra), fireweed (Chamerion angustifolium), ladyfern (Athyrium felix-femina), and fragrant bedstraw (Galium triflorum), along with trace amounts of arctic starflower (Trientalis europea), red currant (Ribes triste), and monkshood (Aconitum delphinifolium). The plot near Nikiski had a significant devil's club (Oplopanax horridus) component.
The organic mat is thin, although the plot near Nikiski supported an organic layer nearly a meter thick, and the water table is deep. When this community occurs on floodplains with occasional to frequent flooding it may qualify as a jurisdictional wetland.
Table 1. Frequency of soil series occurrence and hydric status at NRCS holes.
Table 2. Summary of plant frequency and average cover for plants occurring in more than 50% of plots.
|Wetland Indicator Status|
|tall Populus balsamifera||1.0||63.4||FACU||FACU, FACW
|Alnus incana2 ssp. tenuifolia||1.0||70.0||FAC||FACU, FACW
|Ribes triste||1.0||0.5||FAC||FAC. OBL
|Rubus idaeus||0.6||4.7||FAC||UPL, FAC|
|Calamagrostis canadensis||1.0||84.0||FAC||FAC, OBL
|Actaea rubra||1.0||5.3||FAC*||UPL, FAC*
|Chamerion angustifolium||1.0||4.9||FACU||FACU, FAC|
|Athyrium filix-femina||1.0||3.7||FAC||FAC, FAC+
|Galium triflorum||1.0||2.4||FACU||FACU, FACU+
|Trientalis europaea||1.0||0.6||FAC||FAC*, FAC
|Equisetum arvense||0.8||14.4||FAC*||FAC*, FACW-
|Dryopteris expansa||0.6||0.5||FACU||FACU, FACW|
|Heracleum maximum||0.6||0.5||FACU||FACU-, OBL|
|2Plant with known physiological adaptation for occurrence in wetlands (USACE, 1987)|
|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 09:54