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TP073
Plant succession and biomass dynamics following logging and burning in Watersheds 1 and 3, Andrews Experimental Forest, 1962 to Present

PRINCIPAL INVESTIGATOR: Charles B. Halpern
ORIGINATOR: C. Ted Dyrness
OTHER RESEARCHER: James A. Lutz, C. Ted Dyrness, Jerry F. Franklin
DATA SET CONTACT PERSON: Charles B. Halpern
ABSTRACTOR: Charles B. Halpern, James A. Lutz
FORMER INVESTIGATOR: Alfred B. Levno
METADATA CREATION DATE:
17 Apr 2003
MOST RECENT METADATA REVIEW DATE:
8 Apr 2019
KEYWORDS:
Disturbance, Organic matter, Primary production, communities, community structure, Long-Term Ecological Research (LTER), plant ecology, canopy cover, biomass, community composition, trophic structure, succession, primary production, disturbance, burning, timber harvest, clearcutting, nutrients, organic matter, canopies, plants, trees, understory vegetation
PURPOSE:
Characterize plant succession on a range of plant communities and soil types following logging and burning. Data will be used to analyze change in community composition, structure, biomass and nutrients with time and the role of initial disturbance on long-patterns of community development.
METHODS:
Experimental Design - TP073:
Description:

A total of 194 permanent vegetation sampling plots were established (133 plots on watershed 1, 61 plots on watershed 3). The undisturbed vegetation present on these plots was recorded during the summer of 1962. Herbage cover of shrubs and trees was estimated by species on a milacre (6.6 feet square) plot. Cover of herbs and grasses was estimated on nine 1.1-foot-square plots at each location. Percent cover and frequency were computed for each plant species present. Prior to logging, plots were assigned to one of the six plant communities and one of six soil types, reflecting parent material, depth, and profile development (Rothacher et al. 1967, Dyrness 1969). Both watersheds were logged and broadcast burned: WS1 over a 4-yr period (1962-1966) and WS3 in 1962-1963 (see site description).

Circular plots of 250 m sq were established in 1979 (WS3) and 1980 (WS1), 16 and 14 yr after broadcast burning. Plot centers coincided with the locations of permanent understory quadrats established in 1962, prior to harvest (Dyrness 1973, Halpern 1988, 1989). In WS1, 133 plots were spaced at 30.5-m intervals along six widely spaced transects oriented perpendicular to the main stream channel. In WS3, 61 plots were similarly spaced along two to four transects per harvest unit. Because the objective was to characterize development of upland forests, plots that fell in perennial stream channels were not established, nor were plots that fell on rock outcrops or on roads in WS3. Sample plots comprise ~4% of the harvested areas of the two watersheds. Circular plots include one central subplot (2 by 2 m) consistently measured from 1962 to present, and 4 square subplots on outer edge of circular plot were measured from 1979-1987.

Plot locations were determined in 2004 using a differentially corrected Trimble GPS. Direct readings were made on 91 plots and the remaining locations were interpolated. Elevation, aspect, and slope were determined from GPS locations and a 10-m digital elevation model and later a 1-m LIDAR coverage. (Lienkaemper 2005, Valentine 2009). Mean annual insolation, considering both topographic shading and cloud cover, was extracted from earlier modeling work by Jonathan Smith (2002).

Citation:

Rothacher, Jack; Dyrness, C. T.; Fredriksen, Richard L. 1967. Hydrologic and related characteristics of three small watersheds in the Oregon Cascades. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 54 p.

Lutz, James A. 2005. The contribution of mortality to early coniferous forest development. Seattle, WA: University of Washington. 95 p. M.S. thesis.

Field Methods - TP073 :
Description:

On each subplot ocularly estimate cover of trees (less than 20 m), shrubs (< 2 m) herbs, logs, litter, ground, stones. For all woody shrubs and trees, stems are tagged and counted,and diameters measured at ground level or at DBH (depending on tag location which is based on stem size).

SUPPLEMENTAL INFORMATION:

For Plant community and Soil Type definitions see:

Rothacher, Jack; Dyrness, C. T.; Fredriksen, Richard L. 1967. Hydrologic and related characteristics of three small watersheds in the Oregon Cascades. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 54 p.

For further soil type descriptions see: Dyrness, C. T. 1969. Hydrologic properties of soils on three small watersheds in the western Cascades of Oregon. Res. Note PNW-111. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Forest and Range Experiment Station. 17 p.

SITE DESCRIPTION:
The topography of these 100-ha basins is characteristic of much of the western Cascade Range, with steep dissected slopes separated by intermittent or perennial stream channels. Elevations range from 442 to 1082 m. Soils are primarily volcanic, originating from andesites, tuffs, breccias, and basalt flows. WS1 and 3 lie within the Tsuga heterophylla zone (Franklin and Dyrness 1988). Prior to logging, forests were dominated by old-growth (300-500 yr old) and mature (125 yr old) Pseudotsuga menziesii, with Tsuga heterophylla and Thuja plicata of a variety of sizes and ages. Common sub-canopy species included the shade-tolerant conifer, Taxus brevifolia and the hardwoods, Acer macrophyllum, Cornus nuttallii, and Castanopsis chrysophylla. Six plant communities were defined prior to disturbance, reflecting a strong gradient in soil moisture availability. From “dry” to “moist” these were: Corylus cornuta – Gaultheria shallon, Rhododendron macrophyllum – Gaultheria shallon, Acer circinatum – Gaultheria shallon, Acer circinatum – Berberis nervosa, Coptis laciniata, and Polystichum munitum (compiled in Lutz 2005)&amp;amp;lt;p&amp;amp;gt; History of disturbance: The timing of logging and broadcast burning differed between sites. The entire 96 ha of WS1 was clearcut over a 4-yr period (1962 -1966); logs were yarded with sky-line cables that required no road construction within the watershed. Slash was broadcast burned in October 1966. In WS3, three harvest units (5, 9, and 11 ha; 25% of the watershed) were cut over a single winter (1962-1963). A high-lead cable system was used to yard logs to three roads constructed within the watershed. Slash was broadcast burned in September 1963, thus initiating succession 3 yr earlier than in WS1. Reforestation also differed between sites. In WS1, Pseudotsuga menziesii was aerially seeded in October 1967 and 10 ha were reseeded in October 1968. Early establishment was generally poor and in April and May 1969, 2-yr-old Pseudotsuga were planted at 3-m spacing. Because of poor survival, 40 ha of the south-facing slope were replanted at 2.4 m spacing in April 1971. In WS3, 3-yr-old Pseudotsuga were planted between March and May 1964. Despite aerial seeding and planting, most Pseudotsuga regenerated through natural seeding (Lutz 2005).
TAXONOMIC SYSTEM:
Garrison et al., 1976
GEOGRAPHIC EXTENT:
Watersheds 1 and 3 lie within the H. J. Andrews Experimental Forest (HJA), 80 km east of Eugene, Oregon.
ELEVATION_MINIMUM (meters):
460
ELEVATION_MAXIMUM (meters):
970
MEASUREMENT FREQUENCY:
6 years
PROGRESS DESCRIPTION:
Active
UPDATE FREQUENCY DESCRIPTION:
asNeeded
CURRENTNESS REFERENCE:
Ground condition
RELATED MATERIAL:
Lutz, James A.; Halpern, Charles B. 2006. Tree mortality during early forest development: a long-term study of rates, causes, and consequences. Ecological Monographs. 76(2): 257-275.