Thinleaf alder / Bluejoint

Alnus incana ssp. tenuifolia/ Calamagrostis canadensis 

n=15

II.B.1.b: Closed Tall Alder Shrub

Ecosystem:Discharge Slope

 

Tall alder shrub types are well known and described for Alaska.  Thinleaf alder (Alnus incana ssp. tenuifolia) types have been described by Hanson (1953), Hogan and Tande (1983) and VanCleve et. al. (1971).  However, thinleaf alder was not identified nearby in Chugach National Forest (DeVelice, et. al., 1999) or on the Copper River (Boggs, 2000).††

 

On the Kenai lowlands, thinleaf alder / bluejoint (Calamagrostis canadensis) sites are found at toeslope positions near the coast north of Clam Gulch, and along the bluffs above the north shore of Kachemak Bay.  Thinleaf alder bluejoint is a variable type within this uniform landscape position, but all sites have tall alder (greater than 2 m), typically as a closed canopy, with abundant bluejoint cover.† Sites with a more open alder canopy, have greater bluejoint cover.Jacobís ladder (Polemonium acutiflorum) and water horsetail (Equisetum fluviatile) are frequently present.

 

Around Seward, thinleaf alder is replaced by Sitka alder (Alnus viridis ssp. sinuata) in a similar community, often in floodplain wetlands and on more recent river terraces.

 

Standing water is sometimes encountered, but the water table was 210 centimeters below the surface at one site.Organic layers are typically thin, although two plots had an organic layer greater than 1 meter thick.pH is neutral to slightly alkaline, averaging 7.0, with one coastal site measuring 7.6.† Eleven of the 15 plots sampled could be classified as jurisdictional wetlands.

 

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.

 

  Soil Series

n

Hydric Criteria Number

STARICHKOF 3

1, 2B2, 3

COAL CREEK 2

2B3

SUSITNA

2

 

NIKOLAI 1

1

SLIKOK 1

2B3, 3

KILLEY 1

2B3

MOOSE RIVER

1

2B3

†††††††††††

Table 2.  Summary of plant frequency and average cover for plants occurring in more than 50% of plots.

 

 

 

 

Wetland Indicator Status

 Plant

f

 Average Cover 

 

Alaska

National

Shrubs

Alnus incana2 ssp. tenuifolia

1.0

60.0

 

FAC

FACU, FACW

Salix barclayi

0.6

1.3

 

FAC

FAC, FACW

Herbs/Graminoid

 

 

 

 

 

Calamagrostis canadensis

1.0

47.0

 

FAC

FAC, OBL

Polemonium acutiflorum

0.8

2.9

 

FAC

FAC

Chamerion angustifolium

0.6

6.3

 

FACU

FACU, FAC

Trientalis europaea

0.6

0.5

 

FAC

FAC*, FAC

Rubus arcticus

0.6

0.5

 

FAC

FAC

Moss

0.6

0.5

 

 

 

1 Plant with known morphological adaptation for occurrence in wetlands (USACE, 1987)
2Plant with known physiological adaptation for occurrence in wetlands (USACE, 1987)

 


 Introduction and Key to Plant Communities  

Introduction and Key to Ecosystems

    Kenai Hydric Soils    Map Unit Summary    Methods    Glossary


Contact: Mike Gracz
Kenai Watershed Forum 
PO Box 15301
Fritz Creek, AK  99603
907-235-2218
The Alaska Natural Heritage Program
Environment and Natural Resource Institute
University of Alaska, Anchorage
707 A Street, Suite 101
Anchorage, Alaska  99501

04 May 2007 09:36