Lutz spruce / Field horsetail Bluejoint
Picea X lutzii / Equisetum arvense Calamagrostis canadensis  
n = 91
I.A.2 Open Needleleaf Forest
Ecosystem: Discharge Slope

 

Although this is one of the most common wetland types on the Kenai lowlands, it is incompletely documented elsewhere in Alaska.  DeVelice, et. al. (1999) describe both a Lutz spruce (Picea X lutzii) bluejoint grass (Calamagrostis canadensis) and a Lutz spruce field horsetail (Equisetum arvense) type.  The Lutz spruce / field horsetail bluejoint type described here has characteristics of both.  The abundance of this community on the Kenai lowlands is probably due in part to spruce bark beetle (Dendroctonus rufipennis) mortality opening the spruce canopy, and an attendant increase in bluejoint cover.

Lutz spruce / field horsetail - bluejoint grass is widespread on toeslopes, mainly south of Ninilchik.  It occurs on toeslopes adjacent to peatlands, and along terrace risers where groundwater discharge or dense till  maintains a water table near the surface.  It occurs less frequently on discharge slopes adjacent to (underfit) stream valley walls.  

A tall, open canopy of spruce shades an understory of equally abundant tall bluejoint and field horsetail.  Shieldfern (Dryopteris expansa), fireweed (Chamerion angustifolium) and woodland horsetail (Equisetum sylvaticum) are frequent associates.  Trailing raspberry (Rubus pedatus) often forms discontinuous ground cover carpets.  

Organic horizons are thin, although a few sites had layers more than 1 meter thick.  The water table varies considerably, and the presence of shallow redoximorphic features in the soil is often the only indication that these locales are wet for some time during the growing season.  pH varied widely from very strongly acid (4.5) to neutral (6.8), at the three sites where it was measured.  

A Lutz spruce / field horsetail - bluejoint community does not always indicate that the soil criteria for classification as a jurisdictional wetland are met; one or more hydric soil indicators were found at only 54 of the 91 samples.  Higher field horsetail cover generally indicates wetter conditions.

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

SPENARD  18 2B3
NIKOLAI 9 1
CHUNILNA  7 2B3
COAL CREEK 6 2B3
TLIKAKILA1  4
CLAM GULCH  3 2B3
COHOE 2  
KALIFONSKY  2 2B3
NIKOLAEVSK2  2
QUTAL  2  
STARICHKOF  2 1, 2B2, 3
TRUULI1  2
TUXEDNI2     2
BELUGA  1 2B3
CASWELL  1
DOROSHIN  1 1
FORELAND 1 2B3
JACOBSEN  1 2B3
KACHEMAK  1
KILLEY  1 2B3
KENAI 1  
KLISKON  1
KROTO  1
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

 Plant

f  Average Cover    Alaska National
Trees 
tall Picea X lutzii 0.9 35.2 np
medium Picea X lutzii   0.8 8.2 np
Shrubs/Sapling
regeneration Picea X lutzii 0.8 0.9 np
Spiraea stevenii   0.7 1.6 FAC FAC
Vaccinium ovalifolium   0.6 1.2 FAC FACU*, FAC
Low shrub
Ribes triste   0.7 0.5 FAC FAC. OBL
Herbs/Graminoid
Calamagrostis canadensis   1.0 34.9 FAC FAC, OBL
Equisetum arvense 1.0 36.8 FAC* FAC*, FACW-
Rubus pedatus   0.9 16.3 FAC* FACU*, FAC*
Dryopteris expansa   0.9 9.6 FACU FACU, FACW
Chamerion angustifolium   0.9 7.5 FACU FACU, FAC
Equisetum sylvaticum 0.8 9.2 FACU FACU, FACW
Trientalis europaea 0.8 0.7 FAC FAC*, FAC
Streptopus amplexifolius   0.8 1.6 FAC UPL, OBL
Sanguisorba canadensis 0.8 8.9 FACW FACW, FACW+
Linnaea borealis 0.7 1.5 FACU FACU-, FAC
Orthilia secunda   0.7 0.8 FACU* UPL, FAC+
Gymnocarpium dryopteris   0.7 40.0 FACU UPL, FAC
Lycopodium annotinum 0.6 2.0 FAC FACU*, FAC
Rubus arcticus 0.6 1.5 FAC FAC
Moss 1.0 47.7
Lichen 0.5 0.5
np- not on wetland indicator status list

 


 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 09:51