STAND DESCRIPTION

Plot Name: Reference Stand 21 (HJA)
Plot Size: 1.0 ha
Established: 1977
Remeasurements: 1983, 1988, 1993
Site Description:
Latitude: 44.25
Longitude: 122.14
Elevation: 1190 m
Aspect: SW
Slope: 5-10%
Landform: very gently sloping bench on the upper one-third of a prominent ridge
Soil Parent Material: Unknown
Soil: Unknown
Plant Association: Abies amabilis/Tiarella unifoliata
Age class: Old-growth

Soils:

No information available at the present time.

General Stand Description:

This stand is an upper-middle-elevation example of this community and represents the dry end of the type. The more moist higher-elevation example of the type is represented by Reference Stand 4. The stand occurs at the western tip of a large homogeneous tract of the ABAM/TIUN habitat type.
The stand was oriented within the forest to show a transition from old-growth forest between 450 and 500 years old to very old forest greater than 500 years old. The age is reflected by stem maps which show a dominance by old Pseudotsuga menziesii and Tsuga heterophylla in the north- northwest corner gradually shifting to dominance by Abies amabilis and Tsuga heterophylla in the south-southwest corner. The overall dominant tree species at this time is Pseudotsuga menziesii.
The shrub layer is poorly developed with only a small amount of Acer circinatum in the tall shrubs and less than 8% cover of other shrubs in the low shrub stratum. Shrub layer density increases in the older portions of the reference stand where the tree canopy is more broken by the loss of large dominant Pseudotsuga menziesii and seral Pinus monticola.
The herb layer has greater than 50% cover total and is clearly dominated by Tiarella unifoliata, Cornus canadensis, and Linnaea borealis. Other important species include Clintonia uniflora, Viola sempervirens, Smilacina stellata, and Achlys triphylla. Twenty-six other herbs occur in small amounts to yield a high-diversity herb layer.
Stand Structure and Composition
    Live Tree Data at Last Measurement
      Basal area: 106.0 m2/ha
      PSME-74.7 m2/ha
      TSHE-24.7 m2/ha
      Stem numbers: 569/ha
      PSME-42/ha
      TSHE-219/ha
      ABAM-305/ha
      Diameter distribution:
      median-12.7 cm
      quadratic mean-48.7 cm
      maximum-197.6 cm
      Age: not available
      Height (measurements within the last 20 years): not available
      Volume: 2024.1 m3/ha
      PSME-1480 m3/ha
      TSHE-489.7 m3/ha
      ABAM-61.3 m3/ha
      Biomass: 1106.8 Mg/ha
      PSME-854.8 Mg/ha
      TSHE-222.8 Mg/ha
      ABAM-28.4 Mg/ha
    Coarse Woody Debris: not available
Ecosystem and Population Dynamics (measurements for most recent interval 1988-1993)
Net Bole Production: 5.7 Mg/ha/yr
Annual Mortality: 1.3 Mg/ha/yr
Percent of Trees Dying: Total-1.4%/yr (17.1% were uprooted)