STAND DESCRIPTION
- Plot Name: Reference Stand 26 (HJA, Watershed 8)
- Plot Size: 1 ha
- Established: 1977
- Remeasurements: 1983, 1988, 1994
- Site Description
- Latitude: 44.27
- Longitude: 122.17
- Elevation: 1050 m
- Aspect: S-SE
- Slope: 15-45%
- Landform: Mid-elevation slope
- Soil Parent Material: Unknown
- Soil: Unknown
- Plant Community: Pseudotsuga menziesii/Acer circinatum-
Berberis nervosa
- Age Class: second-growth
Soils:
- No information is available
.
General Stand Description:
The Pseudotsuga manziesii/Acer circinatum-Berberis
nervosa is an earlier successional stage leading to the Tsuga
heterophylla-Abies amabilis/Acer circinatum-Berberis nervosa
climax association. The vegetation description for this plot
is taken from stem map data for the trees and from 10
reconnaissance plots in and around the reference stand for
the understory vegetation.
The tree canopy is largely composed of moderately dense
(50-65% cover) even-aged Pseudotsuga menziesii of an average
age of 145 years-old. Maximum diameter of these trees is 110
cm. In addition, remnant old-growth Douglas-fir (greater
than 450 years-old) are scattered throughout the stand.
Reproductive tree species include the major climax species,
Tsuga heterophylla, as well as Abies amabilis in small
numbers and an occasional Abies grandis.
The shrub stratum is well developed with tall shrubs
dominated by Acer circinatum and the low shrubs by Berberis
nervosa. Vaccinium parvifolium, Rubus ursinus, Rubus
nivalis, Rosa gymnocarpa, and Symphoricarpos mollis are also
common in the shrub layers. As is typical, distribution of
Acer circinatum is patchy, with some large, very dense
patches.
The herb layer is both diverse and well developed. It
is clearly dominated by patchy Linnaea borealis and Whipplea
modesta, but Viola sempervirens, Chimaphila umbellata,
Syntheris reniformis, and Pteridium aquilinum are also
common.
- Stand Structure and Composition
- Live Tree Data at Last Measurement
- Basal Area: 99.9 m2/ha
- PSME-93.9 m2/ha
- TSHE-5.8 m2/ha
- Stem Numbers: 763/ha
- PSME-335/ha
- TSHE-415/ha
- Diameter Distribution:
- median-18.5 cm
- quadratic mean-40.8 cm
- maximum-109.5 cm
- Age: not available
- Height (measurements within the last 20 years): not
available
- Volume: 1370.4 m3/ha
- PSME-1322.0 m3/ha
- TSHE-47.6 m3/ha
- Biomass: 780.8 Mg/ha
- PSME-757.6 Mg/ha
- TSHE-22.8 Mg/ha
- Coarse Woody Debris (measured in 1977):
The total volume and mass of logs is 325 m3/ha and 56
Mg/ha, respectively. The volume and mass of standing dead
trees (snags) is 158 m3/ha and 37 Mg/ha, respectively.
- Ecosystem and Population Dynamics (measurements for most recent
interval, 1988-1994)
- Net Bole Production: 6.6 Mg/ha/yr
- Annual Mortality: 1.8 Mg/ha/yr
- Percent of Trees Dying: total-0.8%/yr