scholarly journals A Comparison of Herbicide and Mulch Mat Treatments for Reducing Grass, Herb, and Shrub Competition in the BC Interior Douglas-Fir Zone—Ten-Year Results

2005 ◽  
Vol 20 (3) ◽  
pp. 167-176 ◽  
Author(s):  
G. J. Harper ◽  
P. G. Comeau ◽  
B. S. Biring
Keyword(s):  
Soil Moisture ◽  
Seedling Growth ◽  
Height Growth ◽  
Douglas Fir ◽  
Effective Control ◽  
Soil Drought ◽  
Plastic Mulch ◽  
Growth And Survival ◽  
Growing Seasons ◽  
Soil Moisture Availability

Abstract We present results from a study established in 1993 in the Interior Douglas-fir biogeoclimatic zone of southwestern British Columbia to test the effectiveness of several herbicide and mulch mat treatments for reducing grass, herbaceous, and shrub competition. The effectiveness of the preplant herbicide applications of hexazinone (Velpar L) at 2.1 kg ai/ha, glyphosate (Vision) at 2.1 and 1.0 kg ai/ha, and the installation of plastic mulch mats (Tredegar 90 × 90-cm mats) for controlling competing vegetation, improving seedling growth and survival of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings and improving soil moisture availability was evaluated. Ten-year results indicate that application of hexazinone and glyphosate enhanced the survival, diameter, and height growth of planted Douglas-fir seedlings. These herbicide treatments provided effective control of grass and herbaceous vegetation for three to four growing seasons. Plastic mulch mats did result in improvements in growth and survival, but these were not statistically different from untreated seedlings. The results of soil moisture monitoring from within the various treatments indicated delay in the onset of soil drought as a key determinant of the seedling growth improvement noted. West. J. Appl. For. 20(3):167–176.

scholarly journals Laminated Root Rot and Fumigant Injection Affect Survival and Growth of Douglas-Fir

2007 ◽  
Vol 22 (3) ◽  
pp. 220-227 ◽  
Author(s):  
Constance A. Harrington ◽  
Walter G. Thies
Keyword(s):  
Tree Growth ◽  
Growth Rates ◽  
Root Rot ◽  
Survival Rates ◽  
Height Growth ◽  
Douglas Fir ◽  
Infection Level ◽  
Growth And Survival ◽  
Growing Seasons ◽  
Tree Survival

Abstract Laminated root rot caused by Phellinus weirii is a significant disease of western conifers; it is important to understand the effects of the disease on tree growth and survival and, for some management objectives, to develop treatments that will reduce those effects. This study was conducted in a 47-year-old Douglas-fir (Pseudotsuga menziesii) stand in northwest Oregon. First, we evaluated the effects of root system infection on diameter and height growth. Growth rates were lowest in trees with high infection levels; root infection level affected diameter growth more than height growth. Second, we evaluated the effects of fumigation treatments on tree growth. The nine treatments were as follows: three dosages of methylisothiocyanate (MITC), four dosages of chloropicrin (trichloronitromethane), one dosage of Vorlex [20% MITC, 80% chlorinated C3 hydrocarbons (v/v)], and a control. The fumigants were applied by inserting them into holes drilled into the base of live trees. After nine growing seasons, all three of the treatments applying different dosages of MITC and the treatment applying the lowest dosage of chloropicrin had higher tree survival rates than the untreated control, and the growth rates in those four fumigation treatments were not significantly different from growth in the surviving control trees.

Effects of Site Preparation on Douglas-Fir Seedling Growth and Survival

1990 ◽  
Vol 5 (2) ◽  
pp. 49-51 ◽  
Author(s):  
Don Minore ◽  
Howard G. Weatherly
Keyword(s):  
Pseudotsuga Menziesii ◽  
Seedling Growth ◽  
Height Growth ◽  
Site Preparation ◽  
Douglas Fir ◽  
Progeny Test ◽  
Seedling Height ◽  
Soil Humus ◽  
Growth And Survival ◽  
Mechanical Site Preparation

Abstract The effects of five yarding-slash treatment combinations on Douglas-fir (Pseudotsuga menziesii) growth and survival were compared by obtaining seedling heights, potential seedling heights, survival percentages, soil-penetration resistances, and the occurrence of visible soil-humus for 149 progeny-test plantations in western Oregon. Survival was not improved by mechanical site preparation, and seedlings grown on the compacted, low-humus soils associated with piling slash off site did not grow as tall during their first 5 years as seedlings growing on similar sites where slash had been broadcast-burned. Tilling (disking or ripping) did not benefit seedling height growth. West. J. Appl. For. 5(2):49-51, April 1990.

scholarly journals Early Height Growth and Site Index of Lodgepole Pine Under Wet and Dry Soil Moisture Regimes in British Columbia

1997 ◽  
Vol 12 (1) ◽  
pp. 5-8
Author(s):  
Gordon D. Nigh
Keyword(s):  
Soil Moisture ◽  
Pinus Contorta ◽  
Lodgepole Pine ◽  
Site Index ◽  
Height Growth ◽  
Moisture Regimes ◽  
Indicator Variables ◽  
Soil Moisture Availability ◽  
A Site ◽  
Growth Intercept

Abstract The objective of this study was to determine whether the relationship between site index and early height growth of lodgepole pine (Pinus contorta var. latifolia) is the same on wet and dry sites. If the height growth/site index relationship is the same for different site types, then only one growth intercept model is required to estimate site index. Indicator variables in nonlinear regression were used to incorporate soil moisture availability into a growth intercept model. One set of parameters in a site index/early height growth model was adequate for both wet and dry sites. This result was supported graphically. Therefore, only one growth intercept model is necessary for the sites examined in this study. West. J. Appl. For. 12(1):5-8.

Boron and Magnesium Fertilization of a Coastal Douglas-Fir Plantation

1993 ◽  
Vol 8 (2) ◽  
pp. 48-53 ◽  
Author(s):  
R. N. Green ◽  
R. E. Carter
Keyword(s):  
Height Growth ◽  
Douglas Fir ◽  
Boron Deficiency ◽  
Growing Seasons ◽  
Foliar Symptoms ◽  
Foliar Concentrations ◽  
A Site ◽  
Coastal British Columbia ◽  
Severe Growth

Abstract This study examines the role of boron and magnesium nutrition in the occurrence of severe growth distortion symptoms in Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) in the Skwawka River valley of south coastal British Columbia. Four fertilizer treatments including boron (2.25 kg B/ha), magnesium (42 kg Mg/ha), boron plus magnesium, and a control, were applied in conjunction with planting on a site believed to be deficient in these nutrients. After 5 growing seasons, only treatments containing boron (B and B+Mg) showed improved height growth over the control trees. The incidence of leader dieback, swollen leading shoots, and foliage distortion was significantly related to treatment with virtually no occurrence in plots treated with boron. Seedling uptake of applied boron was high, with foliar concentrations of 45 ppm found after the second growing season. Foliar B levels declined to 13-15 ppm after 5 growing seasons. No significant increase in foliar magnesium levels was detected for either of the magnesium treatments. The reduction in the incidence of leader dieback and shoot and foliar symptoms in seedlings treated with B indicate that these symptoms were the result of boron deficiencies. This is the first study to verify boron deficiency in coastal Douglas-fir through fertilizer trials. West. J. Appl. For. 8(2):48-53.

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 Fine roots and ectomycorrhizal colonization in black spruce subjected to reductions in soil moisture

Botany ◽  
2016 ◽  
Vol 94 (1) ◽  
pp. 23-30 ◽  
Author(s):  
Sergio Rossi ◽  
Éliane Couture ◽  
Xavier Plante ◽  
Hubert Morin
Keyword(s):  
Soil Moisture ◽  
Tree Species ◽  
Fine Roots ◽  
Environmental Changes ◽  
Black Spruce ◽  
Root Tips ◽  
Transparent Plastic ◽  
Growth And Survival ◽  
Growing Seasons ◽  
Mature Stands

Growth and survival of boreal tree species depends on fungal symbionts, namely mycorrhizas. Owing to their rapid turnover, fine roots and their symbionts can be prompt and sensitive indicators of the effects of environmental changes on forest ecosystems. We investigated how a reduction in soil moisture influences the fine roots and ectomycorrhizas (ECM) of black spruce [Picea mariana (Mill.) BSP] after 3 years of rain exclusion in four mature stands of the boreal forest of Quebec, Canada. Rain was excluded with transparent plastic under-canopy covers installed during the growing seasons 2010–2012. Soil moisture was strongly affected by the treatment, with water content being reduced from 40% to 21% on average. As expected, the experimental trees showed a decrease in the proportion of vital root tips and ECM with respect to controls. The proportion of vital ECM was also globally reduced from 73.8% to 68.6%, but the effects of the treatment were only significant in two sites. The expected drier conditions due to current warming will likely influence the presence of mycorrhizas, with potential consequences on the root vitality of boreal tree species.

scholarly journals Juvenile growth of provenances and open pollinated families of four Russian larch species (Larix Mill.) in Swedish field tests

2011 ◽  
Vol 60 (1-6) ◽  
pp. 165-177 ◽  
Author(s):  
L. Karlman ◽  
A. Fries ◽  
O. Martinsson ◽  
J. Westin
Keyword(s):  
Russian Far East ◽  
Far East ◽  
Field Tests ◽  
Height Growth ◽  
Poor Growth ◽  
Growth And Survival ◽  
Early Evaluation ◽  
Growing Seasons ◽  
Larch Species ◽  
The Family

Abstract Four Russian larch species; (Larix sukaczewii Dyl., L. sibirica Ledeb., L. gmelinii Rupr. and L. cajanderi Mayr.) were tested in combined provenance-progeny tests on three sites in Sweden. 29 provenances, two seed orchards and four seed stands-material were assessed for juvenile height growth and survival after five growing seasons in the field. Genetic parameters were also determined on the family level. The results show that provenances of L. sukaczewii originating from western Russia have the highest survival. Compared to the closely related L. sibirica, L. sukaczewii show better adaptation, a pattern that has also been observed in Finland and Iceland. Provenances of L. gmelinii from the Russian Far East demonstrate best juvenile height growth on all three sites. L. cajanderi from northern interior Siberia failed on all three sites. Both climatic and geographical variables showed strong correlation with survival and height. At this early evaluation it seems like provenances of L. sukaczewii can be transferred northward with satisfactory survival whereas southern transfer or transfer from strongly continental areas in Russia to the semi maritime climate in Sweden results in poor growth. CVA values suggested relatively high genetic variation in height for L. sukaczewii and L. sibirica. The heritabilities for height growth and survival were at this early evaluation generally low (h2 < 0.10) and often non-significant.

Ten-year growth and survival of Douglas-fir seedlings treated with plant growth regulating substances at transplant

2000 ◽  
Vol 30 (11) ◽  
pp. 1778-1787 ◽  
Author(s):  
C F Scagel ◽  
R G Linderman ◽  
R K Scagel
Keyword(s):  
Plant Growth ◽  
Root Growth ◽  
Douglas Fir ◽  
Growth Responses ◽  
Indole Butyric Acid ◽  
Growth And Survival ◽  
Growing Seasons ◽  
Tree Survival ◽  
Stock Types ◽  
The Cost

Commercially available plant growth regulators (PGRs) or moisture retention gels, applied to the roots of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) before planting, can modify indole-3-acetic acid (IAA) levels in roots, root growth responses, and tree survival. We treated two different 1+0 stock types (PSB313B and PSB323) of Douglas-fir with indole-butyric acid (IBA), ethephon (Ethrel®), alginate, or a combination of IBA and alginate. New root growth and IAA levels in roots were measured 2 weeks after planting, and aboveground growth and tree survival were monitored over 10 growing seasons after planting. Treatment with IBA or the combination of IBA and alginate increased IAA conjugate and free IAA levels in roots, root growth, and tree survival. Alginate treatment alone increased new root growth and tree survival, but did not increase free IAA levels in roots. Ethrel® treatment increased free IAA levels and root growth, but had no effect on IAA conjugates or tree survival. A cost analysis suggests that use of certain PGRs or alginate decreases the cost required to attain target stocking and increased tree size. Our results suggest that application of PGRs or other root-promoting materials to the roots of Douglas-fir before planting has the potential to be a cost-beneficial method for increasing root growth and tree survival.

Effects of contrasting light and soil moisture availability on the growth and biomass allocation of Douglas-fir and red alder

2003 ◽  
Vol 33 (1) ◽  
pp. 106-117 ◽  
Author(s):  
Samuel S Chan ◽  
Steven R Radosevich ◽  
Amy T Grotta
Keyword(s):  
Soil Moisture ◽  
Biomass Allocation ◽  
Competitive Ability ◽  
Field Capacity ◽  
Douglas Fir ◽  
Red Alder ◽  
Moisture Availability ◽  
Biomass Components ◽  
Soil Moisture Availability ◽  
Moisture Conditions

We examined growth and biomass allocation of individual Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and red alder (Alnus rubra Bong.) seedlings grown for 3 years under contrasting combinations of light and water. Alder growth was always greater than Douglas-fir. Full sunlight and soil moisture at field capacity caused large differences in size between the two species. With limited light and water, differences were smaller. Under full light and limited water, Douglas-fir allocated a high portion of its biomass to roots, whereas red alder allocated a high percentage to aboveground biomass components. Under light and water resource-limiting situations, red alder allocated more mass to stem, whereas Douglas-fir allocated more to roots. Red alder growth responded negatively to water limitation, whereas Douglas-fir did not. Red alder exhibited greater foliage plasticity to light. Species differences in size and allocation in response to resource availability may determine pathways by which Douglas-fir and red alder interact in a mixed community. Our findings support the hypothesis that the potential of species to use growth-limiting resources is an indicator of competitive ability. We suggest that red alder and Douglas-fir can co-exist under conditions of full light and limiting soil moisture availability. Furthermore, when contrasted with red alder, Douglas-fir's relatively greater tolerances to low light allow it to better persist in the understory. Red alder's rapid early growth and competitive ability will be superior under full light and nonlimiting soil moisture conditions.

An index of photosynthesis for comparing forest sites in western Oregon

1977 ◽  
Vol 7 (1) ◽  
pp. 165-174 ◽  
Author(s):  
William H. Emmingham ◽  
Richard H. Waring
Keyword(s):  
Soil Moisture ◽  
Carbon Fixation ◽  
Unit Area ◽  
Carbon Assimilation ◽  
Forest Productivity ◽  
Douglas Fir ◽  
Soil Drought ◽  
Forest Sites ◽  
Annual Carbon ◽  
Soil Temperatures

An index was developed that takes into account the combined influence of air and soil temperatures, light, and the availability of soil moisture upon photosynthesis by a unit area of fully exposed foliage of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco). The index is derived from a summation of daily estimates of carbon assimilation (milligrams CO2 assimilation per decimeter per day) for an entire year. In a comparison of forest environments in western Oregon the index was correlated to a measure of forest productivity (r2 = 0.99). Furthermore, it suggests that much of the annual carbon fixation occurs during the mild winters characteristic of the region. The ability to assess the effects of frost, soil drought, and other variables separately was valuable in explaining differences between coastal, valley, and mountainous sites.

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