STAND DESCRIPTION

Plot Name: Reference Stand 24 (Hagan Block RNA)
Plot Size: 1.0 ha
Established: 1977
Remeasurements: 1983, 1988, 1994
Site Description
Latitude: 44.17
Longitude: 122.42
Elevation: 610 m
Aspect: NW
Slope: 45-60%
Landform: Lower 1/3 slope off a midslope subridge
Soil Parent Material: Unknown
Soil: Unknown
Plant Association: Pseudotsuga menziesii/Polystichum munitum- Oxalis oregana
Age Class: Second-growth

Soils:

No information at present.

General Stand Description:

This is a stand of second-growth Douglas-fir, 75 to 105 years old, which came in after a fire. This is a seral forest community leading to the climax association, Tsuga heterophylla/Polystichum munitum-Oxalis oregana. Characteristic species of the oxalis community are numerous here. They include Blechnum spicant, Adiantum pedatum, Athyrium filix-femina, Montia sibirica, and Thalictrum occidentale, all common to very wet microclimates. The vegetation of this reference stand is closely similar to that of the coastal Oxalis habitat types.
The tree layer is dominated by a dense canopy of Pseudotsuga menziesii with 75-80% cover. The primary reproducing tree species of the site is Tsuga heterophylla. Local areas also have considerable Alnus rubra cover (mostly adjacent to the wetter areas and depressions near a stream channel on one side of the plot).
RS 24 has a well developed shrub layer dominated by the tall shrub Acer circinatum and the low shrub Berberis nervosa (and sometimes Gaultheria shallon). The shrub layer of the more typical old-growth TSHE/POMU-OXOR stand located on footslopes and low elevation sideslopes of notherly aspects includes only spotty and minor cover of these shrub species.
The herb layer of RS 24 is typical of the oxalis community in having high diversity, as well as dominance by the two diagnostic species, Polystichum munitum and Oxalis oregana.
Stand Structure and Composition
Live Tree Data at Last Measurement
Coarse Woody Debris (measured in 1977):
Ecosystem and Population Dynamics (measurement for most recent interval, 1988-1994)
Net Bole Production: 5.9 Mg/ha/yr
Annual Mortality: 0.9 Mg/ha/yr
Percent of Trees Dying: total-0.8%/yr