Twelfth-year response of Douglas-fir to area of weed control and herbaceous versus woody weed control treatments

2006 ◽  
Vol 36 (10) ◽  
pp. 2464-2473 ◽  
Author(s):  
Robin Rose ◽  
Lee S Rosner ◽  
J Scott Ketchum
Keyword(s):  
Weed Control ◽  
Stand Structure ◽  
Volume Growth ◽  
Woody Species ◽  
Douglas Fir ◽  
Stem Volume ◽  
Coast Range ◽  
Vegetation Control ◽  
Hardwood Species ◽  
Individual Trees

Coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii) response to eight weed control treatments was measured 12 years after planting at two Oregon sites. Treatments included four areas of weed control around individual trees (0.375, 1.49, 3.35, and 5.95 m2), no weed control (check), total vegetation control, control of herbaceous competition only, or control of woody competition only. Douglas-fir growth and woody-species invasion differed between the Coast Range site (Summit) and the Cascade Range foothills site (Marcola). Woody species reinvasion was more intense at Summit, with Douglas-fir cumulative mortality in the check treatment reaching 23% in year 12. Woody-only control improved Douglas-fir growth at Summit but had no significant effect on growth at Marcola. Total vegetation control had a profound effect on stem volume growth 12 years after planting. At Summit, total vegetation control resulted in a 355% increase in volume per hectare relative to the check. At Marcola the increase was only 63%. At Summit, growth increased with each increase in area of weed control, whereas at Marcola growth increased with increasing area of weed control up to 3.35 m2 of control. Results suggest that much of the gain in volume growth attributable to weed control may be lost if weed-control treatments are not highly efficacious. The differential response to woody control indicates that its benefit at a given site is strongly related to the abundance of competitive hardwood species, which may be predicted from the preharvest stand structure and vegetation community.

Stand structure and growing space efficiency following thinning in an even-aged Douglas-fir stand

1988 ◽  
Vol 18 (7) ◽  
pp. 859-866 ◽  
Author(s):  
K. L. O'Hara
Keyword(s):  
Stand Structure ◽  
Volume Growth ◽  
Basal Area ◽  
Stand Density ◽  
Douglas Fir ◽  
Stem Volume ◽  
Projection Area ◽  
Individual Tree ◽  
Space Efficiency ◽  
Individual Trees

The growth of individual trees from four thinning treatments in a 64-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) stand was analyzed to determine desirable residual stand structures after thinning. Dominant and codominant trees had the highest individual tree stem volume growth rates over the previous 5 years, and accounted for most stand volume growth in thinned and unthinned stands. Two measures of growing space, crown projection area and sapwood basal area (a surrogate for leaf area), were used to measure how efficiently individual trees used their growing space. Crown classes were useful in characterizing growing space efficiency (volume growth per unit of growing space) only in the unthinned treatment. In thinned treatments, tall trees with medium-sized crowns were most efficient, while in the unthinned treatment, tall trees with relatively large crowns were most efficient. A large crown in an unthinned stand was comparable in size to a medium-sized crown in a thinned stand. Results suggest growing space is not limiting individual tree growth in thinned stands and that thinning to a particular stand structure is more appropriate than thinning to a particular level of stand density.

Interaction of vegetation control and fertilization on conifer species across the Pacific Northwest

2002 ◽  
Vol 32 (1) ◽  
pp. 136-152 ◽  
Author(s):  
Robin Rose ◽  
J Scott Ketchum
Keyword(s):  
Weed Control ◽  
Pacific Northwest ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Tsuga Heterophylla ◽  
Stem Volume ◽  
Coast Range ◽  
Basal Diameter ◽  
Vegetation Control ◽  
The Pacific

An experiment evaluating three levels of vegetation competition control (no control, 1.5 m2 of vegetation control, and 3.3 m2 of vegetation control), each with two fertilization treatments (fertilization at the time of planting with complete slow-release fertilizer (Woodace® IBDU), or no fertilization), was installed at five sites. Two of these sites were planted with Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in the Oregon Coast Range, one with ponderosa pine (Pinus ponderosa Dougl. ex P. Laws. & C. Laws.) in eastern Washington, one with western hemlock (Tsuga heterophylla (Raf.) Sarg.) in the coastal hemlock zone in Oregon, and one with coastal redwood (Sequoia sempervirens (D. Don) Endl.) in northern California. At four of the five sites, mean stem volume, basal diameter, and height of seedlings increased significantly with increasing area of weed control, and the magnitude of difference between treatments increased with time. Fertilization significantly increased seedling size only at the two sites with adequate soil moisture; increases were marginally significant at a third. Response to fertilization was less than from weed control and impacted growth for only the first year, whereas the influence of weed control continued to influence growth the entire length of the study (4 years). Area of vegetation control and fertilization did not interact significantly at any site.

Growth and Water Relations of Douglas Fir (Pseudotsuga menziesii) Seedlings under Different Weed Control Regimes

Weed Science ◽  
1988 ◽  
Vol 36 (5) ◽  
pp. 653-662 ◽  
Author(s):  
Michael Newton ◽  
David S. Preest
Keyword(s):  
Weed Control ◽  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Stem Volume ◽  
Tree Seedlings ◽  
Coast Range ◽  
Oregon Coast Range ◽  
Growing Seasons ◽  
Control Growth ◽  
The Difference

Growth of Douglas fir [Pseudotsuga menziesii (Mirb.) Franco] was increased by controlling grasses and broadleaf herbs with eight herbicide regimes during the first 3 yr after planting on a well-drained moist site in the Oregon Coast Range. The greatest growth occurred if weeds were controlled in the same growing season that tree seedlings were transplanted to the field; smaller increments came from second- and third-year weed control. Growth increases attributable to early weed control continued through the fifth year, indicating that conditions during establishment strongly influenced later growth. Plots with no herbaceous vegetation had more available soil water than those with competing vegetation, and tree seedlings on these plots experienced less water stress. Irrigation in the third year increased stem diameter of seedlings in that year but had no effect thereafter. Increases in average seedling stem volume at 5 yr after transplanting were linearly related (r2 = 0.77) to the difference in observed xylem potential during the first three growing seasons after transplanting and the xylem potential at which photosynthesis ceased, −2 MPa.

Synergistic stem volume response to combinations of vegetation control and seedling size in conifer plantations in Oregon

2006 ◽  
Vol 36 (4) ◽  
pp. 930-944 ◽  
Author(s):  
Lee S Rosner ◽  
Robin Rose
Keyword(s):  
Weed Control ◽  
Pacific Northwest ◽  
Analysis Of Covariance ◽  
Stem Volume ◽  
Conifer Species ◽  
Basal Diameter ◽  
Vegetation Control ◽  
Seedling Size ◽  
Volume Response ◽  
Stock Types

There are few published studies examining the effects of the interaction of seedling size and vegetation control on the growth of Pacific Northwest conifer species. Data from two vegetation management studies encompassing five planting sites, four conifer species, and two stock types were analyzed to determine the relative effects of seedling size at planting and intensity of vegetation control on subsequent seedling growth. Study 1 tested eight combinations of annual broadcast weed control or no weed control applied over the course of 5 years. Study 2 tested spot herbicide applications of differing area, as well as herbaceous-only and woody-only control treatments. The effect of seedling size was determined by analysis of covariance, with basal diameter as the covariate. Both seedling size and weed control increased growth of all conifer species through 4, 5, or 12 years, but responses varied by species and site. Diameter and height responses to weed control and seedling size were additive, whereas volume differences between treatments increased with increasing seedling size. The implication for management is that the volume return from increased weed control is maximized by planting the largest possible seedlings; conversely, the volume from increased seedling size is maximized at the highest weed control intensities.

scholarly journals Root Volume and Growth of Ponderosa Pine and Douglas-Fir Seedlings: A Summary of Eight Growing Seasons

1997 ◽  
Vol 12 (3) ◽  
pp. 69-73 ◽  
Author(s):  
R. Rose ◽  
D. L. Haase ◽  
F. Kroiher ◽  
T. Sabin
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Douglas Fir ◽  
Stem Volume ◽  
Coast Range ◽  
Root Volume ◽  
Growth And Survival ◽  
Growing Seasons ◽  
Early Results

Abstract This is the final summary of two studies on the relationship between root volume and seedling growth; early results were published previously. Survival, growth, and stem volume were determined for 2+0 ponderosa pine (Pinus ponderosa) and Douglas-fir (Pseudotsuga menziesii) seedlings after 8 growing seasons. For each species, seedlings from three seedlots were assigned to one of three root-volume categories [<4.5 cm3 (RV1), 4.5-7 cm3 (RV2), and >7 cm3 (RV3) for ponderosa pine; <9 cm3 (RV1), 9-13 cm3 (RV2), and >13 cm3 (RV3) for Douglas-fir]. On a dry harsh ponderosa pine site on the eastern slopes of Mt. Hood in Oregon, where gopher and cattle damage decreased the number of seedlings, more seedlings in the highest root-volume category survived (70%) than in the smaller root-volume categories (62% and 50%). Douglas-fir on a good site in the Coast Range of Oregon showed significantly greater height and stem volume for the largest root-volume category, whereas annual shoot growth and survival did not differ. Root volume is one of several potentially useful criteria for predicting long-term growth and survival after outplanting. West. J. Appl. For. 12(3):69-73.

scholarly journals Early Selection of Douglas-Fir across South Central Coastal Oregon, USA

2006 ◽  
Vol 55 (1-6) ◽  
pp. 135-141 ◽  
Author(s):  
C. A. Dean ◽  
R. W. Stonecypher
Keyword(s):  
Genetic Correlations ◽  
Volume Growth ◽  
Douglas Fir ◽  
Early Selection ◽  
Stem Volume ◽  
Direct Selection ◽  
South Central ◽  
Coos Bay ◽  
The Individual ◽  
Age Range

Abstract Details are given of three first-generation progeny tests (CB1, CB2 and CB3) of coastal Douglas-fir (Pseudotsuga menziesii [MIRB.] FRANCO var. menziesii) planted in the Coos Bay region of south-central coastal Oregon in 1973. The three tests included 15 polymix families based on a 10-pollen mix, and 27 families openpollinated on the ortet. The present study gives heritabilities and additive genetic correlations for growth measured between two and 17 years after planting. Correlated responses are estimated for volume at 17 years from early selection for height and diameter. Between four and 17 years after planting the individual heritability (h2) of height of coastal Douglas-fir across the Coos Bay tests was quite stable between h2 = 0.18 and 0.22. The heritability of stem diameter age-forage was consistently much lower than for height. In the critical age range for early selection between five and 10 years the individual heritability of diameter ranged from h2 = 0.07 to 0.10. The additive genetic correlations involving volume-17 and height or diameter increased to high values of rA = 0.80 to 0.84 between eight to 10 years after planting. Before seven years the absolute values of juvenilemature correlations were much lower. The higher heritability of height made this trait the best criterion for early indirect selection to improve mature stem volume growth. Across these Coos Bay tests, early selection on stem height measured at 5-8 years after planting was estimated to produce almost 40% more gain per year in volume-17 compared with direct selection at 17 years on volume-17 itself. The recommendation for maximizing gain per year in mature volume of coastal Douglas-fir at Coos Bay is to select on height at 7-8 years when the mean height of trees in tests should be around 4.5 to 5.5 meters.

Five-year growth responses of Douglas-fir, western hemlock, and western redcedar seedlings to manipulated levels of overstory and understory competition

2006 ◽  
Vol 36 (10) ◽  
pp. 2439-2453 ◽  
Author(s):  
Timothy B Harrington
Keyword(s):  
Growth Rate ◽  
Nitrogen Content ◽  
Douglas Fir ◽  
Western Hemlock ◽  
Volume Index ◽  
Stem Volume ◽  
Western Redcedar ◽  
Foliar Nitrogen ◽  
Relative Growth ◽  
Vegetation Control

Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), western hemlock (Tsuga heterophylla (Raf.) Sarg.), and western redcedar (Thuja plicata Donn ex D. Don) seedlings were planted in March 2001 within three clearcut-harvested, shelterwood, or thinned stands of mature Douglas-fir near Olympia, Washington. From 2002 to 2005, areas of vegetation control of 0, 4.5, or 9 m2 were maintained with herbicides around a total 162 seedlings per species. Photosynthetically active radiation (PAR) was 34%, 62%, and 100% of full sunlight in thinned stands, shelterwoods, and clearcuts, respectively. Effects of overstory level and vegetation control on seedling growth and resource availability generally were additive. Seedling stem volume index in clearcuts averaged four to eight times that observed in thinned stands, and with vegetation control, it averaged two to four times that observed without it. In thinned stands, relative growth rate of seedling stem volume index had a positive linear relationship with PAR (R2 = 0.38). Foliar nitrogen content of Douglas-fir explained 71% of the variation in relative growth rate. Factors explaining the most variation in foliar nitrogen content differed between thinned stands (PAR, R2 = 0.34) and clearcuts or shelterwoods (midday water potential, R2 = 0.63), suggesting that light and root competition, respectively, were the primary growth-limiting factors for these overstory levels.

Response of coastal Douglas-fir and competing vegetation to repeated and delayed weed control treatments during early plantation development

2009 ◽  
Vol 39 (6) ◽  
pp. 1208-1219 ◽  
Author(s):  
Douglas A. Maguire ◽  
Douglas B. Mainwaring ◽  
Robin Rose ◽  
Sean M. Garber ◽  
Eric J. Dinger
Keyword(s):  
Weed Control ◽  
Seedling Growth ◽  
Volume Growth ◽  
Douglas Fir ◽  
Optimal Regime ◽  
Competitive Effects ◽  
Competing Vegetation ◽  
Plantation Development ◽  
Age Shift

A key silvicultural decision in managing young conifer plantations is determining the number and timing of release treatments to control competing vegetation. Three coastal Douglas-fir ( Pseudotsuga menziesii (Mirb.) Franco) plantations were treated under eight alternative herbicide regimes during the first 5 years after planting to test treatment effects on vegetation dynamics and seedling growth. After termination of herbicide treatments, competing vegetation developed at a rate similar to that of check plots, reaching 40%–60% cover in the first growing season and approaching 100% by the third. Recovery of competing vegetation was slightly more rapid with greater number of previous releases. Annual volume growth of seedlings was negatively correlated with current cover of competing vegetation, but competitive effects from previous years were fully accounted for by initial tree size. Under 4 years of release, delaying treatment by 1 year reduced volume attained at the end of 5 years by about 15%. Plots receiving 5 consecutive years of weed control reached the 5 year volume of check plots in only 3.9 years, implying an age shift of 1.1 years. Increasing the number of operational release treatments significantly improved seedling growth in the short term, but long-term growth effects must be monitored to determine the economically optimal regime.

Stand structure, thinning prescriptions, and density indexes in a Douglas-fir thinning study, Western Washington, U.S.A.

1983 ◽  
Vol 13 (1) ◽  
pp. 126-136 ◽  
Author(s):  
Chadwick Dearing Oliver ◽  
Marshall D. Murray
Keyword(s):  
Stand Structure ◽  
Volume Growth ◽  
Basal Area ◽  
Stand Density ◽  
Close Relation ◽  
Douglas Fir ◽  
Volume Number ◽  
Large Trees ◽  
Before And After ◽  
Number Of Stems

A Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) thinning study was established in 1959 in a stand begun after logging in 1930. Thinnings to set basal area densities were done in 1959, 1962, 1966, and 1970. On each plot both large and small trees were removed since average basal area per tree was kept constant before and after thinning. Volume growth varied greatly between plots of the same age, initial basal area, and site because of differences in stand structure. Large trees on a plot grew more per tree and per basal area than small trees. Stand basal area, stand volume, number of stems, or number of dominant and codominant trees were not closely related to volume growth per hectare, although density indexes giving weight to larger trees showed the closest relation. The lack of close relation between stand density indexes and growth found here and elsewhere probably means the indexes do not uniquely define stand structures; it does not necessarily mean that thinning will not increase volume growth per hectare. Volume growth per hectare after thinning to a given basal area density will be greater and probably more consistent if larger trees are left and enough time is allowed for the stand to recover following thinning.

scholarly journals Ten Years of Vegetation Succession Following Ground-Applied Release Treatments in Young Black Spruce Plantations

2004 ◽  
Vol 21 (3) ◽  
pp. 123-134 ◽  
Author(s):  
Douglas G. Pitt ◽  
Robert G. Wagner ◽  
William D. Towill
Keyword(s):  
Foliar Application ◽  
Black Spruce ◽  
Volume Growth ◽  
Good Control ◽  
Deciduous Tree ◽  
Stem Volume ◽  
Woody Vegetation ◽  
Short Term ◽  
Vegetation Control ◽  
Vegetation Removal

Abstract Responses of planted black spruce [Picea mariana (Mill.) BSP] and associated vegetation were studied for 10 years after conifer release options on two northeastern Ontario sites. Six treatments were compared to untreated check plots, including directed foliar application of glyphosate herbicide, basal bark treatment with triclopyr herbicide, glyphosate capsule injection with the EZ-Ject system, spot-treatment with hexazinone herbicide, manual cutting with brushsaw, and five growing seasons of annual vegetation removal with repeat applications of glyphosate. Ten years after treatment, black spruce survival averaged 86% and varied little among treatments (P > 0.5). Annual vegetation removal treatments resulted in nearly complete domination by spruce, with treated trees exhibiting 16–55% gains in height and 112–476% gains in stem volume growth over untreated trees. Despite rigorous vegetation control on these plots, each of the vegetation groups studied were well represented at the end of the observation period, including deciduous trees, tall shrubs, low shrubs, forbs, ferns, and grasses/sedges. Directed foliar treatment provided good control of herbaceous and woody vegetation around individual crop trees, providing an 8–46% gain in height and a 43–246% gain in stem volume growth. Both spruce and hardwoods shared dominance on these plots. Spot treatments with hexazinone provided similar short-term reductions in herbaceous vegetation, but tended to release shrub species that had a negative net effect on spruce growth. The other release treatments provided only short-term reductions in woody vegetation, which ultimately led to young stands dominated by deciduous tree species. North. J. Appl. For. 21(3):123–134.

Sign in / Sign up

Export Citation Format

Share Document