TV033
Retrospective Studies of Green Tree Retention in the Pacific Northwest, 1993

CREATOR(S): Steven A. Acker, Thomas A. Spies

PRINCIPAL INVESTIGATOR(S): Thomas A. Spies

ORIGINATOR(S): Steven A. Acker

OTHER RESEARCHER(S): Thomas A. Spies, Patricia S. Muir, Bruce P. McCune

DATA SET CONTACT PERSON: Steven A. Acker

ABSTRACTOR: Steven A. Acker

METADATA CREATION DATE:

23 Jul 2003

MOST RECENT METADATA REVIEW DATE:

21 Mar 2013

KEYWORDS:

Disturbance, Primary production, Long-Term Ecological Research (LTER), silviculture, resource management, primary production, plant growth, disturbance, forests, mature forests, young forests

PURPOSE:

To estimate the effects of large residual trees on growth and yield of conifers, and to provide information on forest composition and structure for studies of the effects of large residual trees on diversity of vascular plants and on diversity of epiphytic plants.

METHODS:

Experimental Design - TV033:

Description: Sampling was based on paired, more-or- less adjacent plots, both plots within a stand of trees 60-100 years old, and on one topographic feature. One plot contained between 1 and 25 large residual trees ("non-zero-residual" plot); the other contained no large residual trees ("zero-residual" plot). A nested, circular plot design was used. The outer plot of 3000 mý (radius 30.90 m) was used to quantify the large residual trees (hence "residual plot"). The inner plot of 500 mý (radius 12.62 m) was used to quantify the younger stand, and logs and snags ("detection plot"). Plot radii were slope-corrected in the field.

Field Methods - TV033:

Description: For live residual trees, we recorded species, dbh, height, four perpendicular crown radii, bole condition, crown condition, and total height and height to base of live crown, and obtained an increment core of at least 100 years. For dead residual trees, we recorded decay class and tree position. We did obtain increment cores from dead residual trees of decay class 1 in non-zero- residual plots. For zero-residual plots, we recorded species, dbh, height, and crown radii for the closest residual trees in four quadrants around the residual plot, provided that the trees were within 61.8 m (horizontal) from the center of the plot. In order to document the location of all measured residual trees, azimuth from plot center, distance from plot center, and slope from plot center were recorded.

For live younger cohort trees in the detection plots we recorded species, dbh, bole condition, crown condition, and canopy class. For at least two trees in each combination of species and canopy class we obtained a complete increment core and measured total height and height to base of live crown. For dead younger cohort trees, we recorded decay class and tree position. In order to document the location of all measured young cohort trees, azimuth from plot center, distance from plot center, and slope from plot center were recorded. Minimum dbh for younger cohort trees was 5 cm.

Logs and snags within each detection plot were measured as follows. For all logs at least 10 cm diameter at larger end, we recorded species, decay class, diameters at both ends, and length. For logs running out of the detection plot only the portion in the detection plot was measured. For snags at least 10 cm dbh, we recorded species, decay class, and dbh. We measured height on all snags of decay classes 3, 4, or 5. For both snags and logs the length of any hollow segments were recorded.

SUPPLEMENTAL INFORMATION:

Vascular plant and epiphytic plant data from these plots are maintained under separate study codes (indicate here when these are entered).

The following record was deleted from tv0334.dbf by S. Acker, 941104. This plot contained a residual tree in the residual plot, in violation of basic study design. This was the only live young cohort tree within 18.28m (assumed radius of influence) of the offending residual tree. For per area calculations, the area of plot LO05Z should be decreased by the estimated area within the radius of influence of the residual tree. I have computed this to be at most 4 m². Thus, the area of LO05Z should be set at 496 m² (versus the nomimal 500 m²).

TAXONOMIC SYSTEM:

Garrison et al., 1976

GEOGRAPHIC EXTENT:

OR-Western Cascades, Willamette National Forest, Detroit Ranger District, Sweet Home RD, Blue River RD, McKenzie RD, Lowell RD

ELEVATION_MINIMUM (meters):

518

ELEVATION_MAXIMUM (meters):

1341

MEASUREMENT FREQUENCY:

once only

PROGRESS DESCRIPTION:

Complete

UPDATE FREQUENCY DESCRIPTION:

notPlanned

CURRENTNESS REFERENCE:

Ground condition