Interspecific competition and other factors influencing the performance of Douglas-fir saplings in the Oregon Coast Range

1991 ◽  
Vol 21 (6) ◽  
pp. 829-835 ◽  
Author(s):  
Robert G. Wagner ◽  
S. R. Radosevich
Keyword(s):  
Interspecific Competition ◽  
Prescribed Burning ◽  
Douglas Fir ◽  
Tree Size ◽  
Volume Index ◽  
Tree Age ◽  
Stem Volume ◽  
Minor Importance ◽  
Individual Tree ◽  
Animal Damage

Regression models describing total height, stem diameter, stem volume index, and crown volume index of individual 4- to 9-year-old saplings of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were developed from a retrospective analysis of two site-preparation experiments. The models, which accounted for between 64 and 73% of the variation in individual tree size, integrate environmental and morphological factors that can influence the performance of Douglas-fir saplings into one set of equations. Interspecific competition and amount of animal damage were negatively correlated with tree size. Tree age, 1st-year height, and the use of prescribed burning were positively correlated with tree size. When factors were held constant, trees were largest on steep southeast slopes. The models indicated that tree age, competing vegetation, animal damage, and initial seedling size had a dominant influence on the performance of Douglas-fir saplings, while prescribed burning and topography were of relatively minor importance.

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.

Neighborhood predictors of interspecific competition in young Douglas-fir plantations

1991 ◽  
Vol 21 (6) ◽  
pp. 821-828 ◽  
Author(s):  
Robert G. Wagner ◽  
Steven R. Radosevich
Keyword(s):  
Interspecific Competition ◽  
Woody Plants ◽  
Woody Species ◽  
Spatial Arrangement ◽  
Douglas Fir ◽  
Stem Diameter ◽  
Tree Age ◽  
Percent Cover ◽  
Competition Index ◽  
Neighborhood Models

Neighborhood models describing the effect of interspecific competition on the height and stem diameter of 4- to 9-year-old saplings of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were developed from site-preparation experiments in the Oregon Coast Range. The influence of abundance measures, height, distance, arid spatial arrangement of nonconiferous woody plants surrounding individual saplings was examined. Optimum neighborhood heights and radii were defined. The best interspecific competition index for predicting Douglas-fir height and stem diameter was total percent cover for all woody species within a 2.1-m radius. Visual estimates of neighbor cover were superior to objective measures of crown area. The cover of woody species equalling or exceeding the height of the tree provided the best prediction for tree height. Woody species cover equalling or exceeding one-half the height of the tree provided the best index for predicting stem diameter. Accounting for the spatial arrangement of neighboring woody plants did not improve the competition index. Interaction between the competition index and tree age indicated that the negative effect of interspecific competition on Douglas-fir size increased with time. The age-adjusted competition index accounted for 11% of the variation in height and 19% of the variation in stem diameter. Douglas-fir stem diameter was more sensitive to neighboring woody plants than was height.

scholarly journals I. Early Loblolly Pine Stand Response to Tillage on the Piedmont and Upper Coastal Plain of Georgia: Mortality, Stand Uniformity, and Second and Third Year Growth

2002 ◽  
Vol 26 (4) ◽  
pp. 181-189 ◽  
Author(s):  
R.E. Will ◽  
M.J. Wheeler ◽  
D. Markewitz ◽  
M.A. Jacobson ◽  
A.M. Shirley
Keyword(s):  
Loblolly Pine ◽  
Coastal Plain ◽  
Growing Season ◽  
Tree Size ◽  
Soil Tillage ◽  
Volume Index ◽  
Soil Series ◽  
Individual Tree ◽  
The Third ◽  
No Till

Abstract The effects of machine planting, disking, bedding, and bedding + subsoiling on growth of loblolly pine (Pinus taeda L.) were assessed after two and three growing seasons for seven contrasting sites on the Piedmont and Upper Coastal Plain of Georgia. Heights and groundline diameters of half the trees (50 trees) per plot, percent mortality, individual tree volume index (D2H), stand uniformity, and per hectare volume index were compared across sites and treatments. Average tree size of the treatments were ranked (from largest to smallest) bed, bed + subsoil, disk, machine, and no-till. At the end of the third growing season, the trees in the bed only treatment had a mean height, groundline diameter, and volume index of 2.3 m ± 0.06 SE, 59 mm ± 1.7 SE, and 0.0094 m3 ± 0.00066 SE, respectively. The trees of the no-till treatment had a mean height, groundline diameter, and volume index of 2.1 m ± 0.07 SE, 50 mm ± 1.6 SE, and 0.0063 3 ± 0.00056 SE, respectively. Overall, the disk, bed, and bed + subsoil treatment plots had significantly greater absolute volume growth during the third growing season than the no-till and machine plots. Most of the tree mortality within all treatments occurred during the first growing season with the disk treatment having the least mortality (13.6%) and the no-till treatment the most (24.9%). Stand height and diameter uniformity, examined using the within plot coefficient of variation, was not significantly different among treatments. Per hectare volume index was significantly greater for the bed (7.0 m3/ha) and bed + subsoil treatments (7.1 m3/ha) than for the no-till (4.5 m3/ha) and machine (5.2 m3/ha) treatments. Significant differences occurred between sites for tree size parameters, ranging between 2.7 m mean height and 64 mm mean groundline diameter for a site on a Cowarts soil series to 1.8 m mean height and 45 mm mean groundline diameter for trees growing on a Pacolet soil series. Significant interactions between tillage treatments and sites occurred for some tree size parameters at age 2, but not age 3, and for average plot mortality rate. The results of this study indicate that some early gains in tree growth can be achieved through soil tillage on upland sites. Bedding provided the most consistent, positive response, but adding subsoiling to bedding provided no benefit. Overall, the gains were relatively small and site dependent. Tillage on these Piedmont and Upper Coastal Plain soils should best be considered as part of a complete management program that includes to weed control and fertilization. South. J. Appl. For. 26(4):181–189.

Crown structure and growth efficiency of red spruce in uneven-aged, mixed-species stands in Maine

1998 ◽  
Vol 28 (8) ◽  
pp. 1233-1240 ◽  
Author(s):  
Douglas A Maguire ◽  
John C Brissette ◽  
Lianhong Gu
Keyword(s):  
Leaf Area ◽  
Volume Growth ◽  
Growth Efficiency ◽  
Tree Size ◽  
Red Spruce ◽  
Stem Volume ◽  
Mixed Species ◽  
Individual Tree ◽  
South Central ◽  
Tree Leaf

Several hypotheses about the relationships among individual tree growth, tree leaf area, and relative tree size or position were tested with red spruce (Picea rubens Sarg.) growing in uneven-aged, mixed-species forests of south-central Maine, U.S.A. Based on data from 65 sample trees, predictive models were developed to (i)estimate the amount of foliage held by individual trees from sapwood cross-sectional area and (ii)define the relationship between stem volume growth and three variables: total foliage area, relative position in the stand, and the degree of past suppression. A model that included variables representing tree size (or relative social position) and degree of past suppression (live branch whorls per unit crown length) indicated that stem volume growth first increased but later decreased over leaf area when other variables were held constant. Growth efficiency declined with increasing tree leaf area, although greater height and diameter enhanced growth efficiency and greater past suppression diminished growth efficiency. The decline in growth efficiency with greater leaf area likely is attributable to one or several of the factors previously identified as contributing to growth declines in mature, even-aged stands.

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.

Critical period of interspecific competition for northern conifers associated with herbaceous vegetation

1999 ◽  
Vol 29 (7) ◽  
pp. 890-897 ◽  
Author(s):  
Robert G Wagner ◽  
Gina H Mohammed ◽  
Thomas L Noland
Keyword(s):  
Interspecific Competition ◽  
Critical Period ◽  
Black Spruce ◽  
Volume Growth ◽  
Jack Pine ◽  
Red Pine ◽  
Volume Index ◽  
Stem Volume ◽  
White Pine ◽  
Herbaceous Vegetation

Using critical-period analysis, we examined the temporal effects of interspecific competition from herbaceous vegetation on seedlings of jack pine (Pinus banksiana Lamb.), red pine (Pinus resinosa Ait.), eastern white pine (Pinus strobus L.), and black spruce (Picea mariana (Mill.) BSP) during the first 5 years after planting. The critical period is the time period during stand development when interspecific competition reduces tree growth. We found both similarities and differences in responses among tree species. Gains in stem volume index associated with increasing duration of vegetation control (expressed by weed-free curves) differed among species. In contrast, declines in stem volume index with increasing duration of competition after planting (expressed by weed-infested curves) were equal among species. Critical periods for stem volume index were shorter for shade-intolerant jack and red pine (1 and 2 years after planting) than for more shade-tolerant white pine and black spruce (1-3 years for spruce and 1-4 years for white pine). Intolerant species had greater absolute stem volume growth, but smaller relative declines from continuous association with herbaceous vegetation (85, 81, 78, and 67% for white pine, black spruce, red pine, and jack pine, respectively). Herbaceous vegetation did not affect survival and had a variable influence on height growth of all species.

Short-term effects of prescribed burning on radial growth of Douglas-fir trees in south central British Columbia

2011 ◽  
Vol 20 (7) ◽  
pp. 876
Author(s):  
M. C. Feller ◽  
W. Klenner
Keyword(s):  
British Columbia ◽  
Tree Growth ◽  
Radial Growth ◽  
Prescribed Burning ◽  
Fire Severity ◽  
Soil Nutrient ◽  
Douglas Fir ◽  
Tree Size ◽  
Radial Increment ◽  
South Central

Radial increment of Douglas-fir (Pseudotsuga menziesii var. glauca (Beissn.) Franco) trees in uncut and partially cut and grazed and ungrazed dry cool Interior Douglas-fir forests near Isobel Lake in southern central British Columbia was measured for 2-year periods before and after prescribed burning in burned and unburned (control) areas. Parameters thought to influence the effects of prescribed burning on tree growth – characteristics of the tree and its immediate environment, adjacent surface and ladder fuels, and fire effects – were also measured. Burning caused a decrease in tree radial growth. The proportional change in radial tree growth was not related to degree of cutting or the presence of cattle grazing, but was negatively correlated with preburn radial growth, tree size, and also with some fire effect variables, particularly char height, suggesting that an increasing proportional decline in radial growth was associated with increasing tree size and with increasing fire severity. Soil nutrient (N, S, P, K, Mg or Ca) level was not a significant determinant of tree growth. The best prediction model could only explain 23% of the variation in the change in radial growth. Our results show that the effects of fire on Douglas-fir radial growth are complex and difficult to predict with the variables measured.

Climate sensitive growth models for predicting diameter growth of western Canadian boreal tree species

2020 ◽  
Author(s):  
Felix O Oboite ◽  
Philip G Comeau
Keyword(s):  
Interspecific Competition ◽  
Tree Species ◽  
Growth Models ◽  
White Spruce ◽  
Tree Size ◽  
Diameter Growth ◽  
Growth Responses ◽  
Individual Tree ◽  
Negative Effect ◽  
Frost Free Period

Abstract In the face of anticipated climate change, growth models require modifications to effectively model likely future growth and survival of trees and stands. To support incorporation of climate effects in the Mixedwood Growth Model (MGM), we developed climate-sensitive mixed effects models for lodgepole pine (Pinus contorta Douglas ex Loudon), jack pine (Pinus banksiana Lamb.), trembling aspen (Populus tremuloides Michx.), balsam poplar (Populus balsamifera L.) and white spruce (Picea glauca (Moench) Voss), and examined how tree size, intra- and interspecific competition and climate will influence individual-tree diameter growth. Remeasurement data from permanent growth and yield sample plots from across the western Canadian boreal forest were used for this study. Based on the model that we developed, tree size, competition and climate had varying effects on growth, among tree species. Although intraspecific competition had a stronger negative effect on growth for deciduous and white spruce trees, interspecific competition had a stronger negative effect on the growth of pine. Deciduous trees growing in stands having longer frost-free period experienced an increase in growth but a negative effect of frost-free period was observed for conifers. In addition, higher moisture was found to increase tree growth, but the influence of available moisture on growth was dependent on competition. Overall, these results suggest that, under climate warming, between-species differences in growth responses will contribute to our understanding of the stand dynamics in the western boreal region of Canada. Climate sensitive growth models developed in this study will be useful in the recalibration of MGM and other individual-tree models, and predictions will contribute to better-informed decisions about silvicultural treatments for these economically important boreal tree species.

Effects of intra- and inter-specific competition on root and shoot biomass of young Douglas-fir and red alder

1992 ◽  
Vol 22 (1) ◽  
pp. 101-110 ◽  
Author(s):  
L.J. Shainsky ◽  
M. Newton ◽  
S.R. Radosevich
Keyword(s):  
Douglas Fir ◽  
Response Surfaces ◽  
Volume Index ◽  
Stem Volume ◽  
Shoot Biomass ◽  
Total Biomass ◽  
Mixed Stands ◽  
Red Alder ◽  
Biomass Components ◽  
Root And Shoot Biomass

The effects of intra- and inter-specific competition on root and shoot biomass of 5-year-old Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) and red alder (Alnusrubra Bong.) were studied in experimentally manipulated stands. The density of each species was varied systematically in a two-way density matrix composed of five monoculture densities and 25 mixtures of all possible pairwise combinations of monoculture densities. Roots and shoots were harvested after the fourth growing season. Response surfaces for root, shoot, and total biomass per tree were generated within the matrix. Regression analysis quantified the effect of each species' density on biomass components. Alder overtopped the Douglas-fir in all mixed stands. Alder density influenced the root and shoot biomass of both species more than Douglas-fir density. Douglas-fir density interacted with red alder density to influence all biomass components. While increasing the density of each species reduced root and shoot biomass per tree, allocation of biomass to roots and shoot was not affected by competition, nor were the allometric equations relating biomass to stem diameter and stem volume index.

scholarly journals Refining tree size and dose-response functions for control of invasive Pinus contorta

2021 ◽  
pp. 1-36
Author(s):  
Carol A. Rolando ◽  
Brian Richardson ◽  
Thomas S.H. Paul ◽  
Chanatda Somchit
Keyword(s):  
Dose Response ◽  
Pinus Contorta ◽  
Tree Size ◽  
Volume Index ◽  
Mortality Data ◽  
Field Calculation ◽  
Crown Area ◽  
Crown Diameter ◽  
Crown Volume ◽  
Canopy Area

Abstract Exotic conifers are rapidly spreading in many regions of New Zealand, as well as in many other countries, with detrimental impacts on both natural ecosystems and some productive sector environments. Herbicides, in particular the active ingredient (a.i.) triclopyr, are an important tool to manage invasive conifers, yet there is a paucity of information that quantifies the amount of herbicide required to kill trees of different sizes when applied as a basal bark treatment. Two sequential experiments were conducted to define the amount of triclopyr required to kill individual invasive Pinus contorta trees of different sizes when applied in a methylated seed oil to bark (either the whole stem or base of the tree) and to determine which tree size variates (height (HT), diameter at breast height (DBH), crown diameter (CD)), or derived attributes (crown area, crown volume index) best characterised this dose-response relationship. The outcomes of the dose-response research were compared to field operations where triclopyr was applied to the bark of trees from an aerial platform. Applying the herbicide to the whole stem, as opposed to the base of the tree only, significantly increased treatment efficacy. The tree size variates DBH, CD, crown area and crown volume index all provided good fits to the tree mortality data, with >91% prediction accuracy. Of these variates, crown diameter provided the most practical measure of tree size for ease of in-field calculation of dose by an operator. Herbicide rates used in field operations were 7 to 8 times higher than lethal doses calculated from experimental data. Our results highlight the potential for substantial reductions in herbicide rates for exotic conifer control, especially if dose-response data are combined with remotely sensed quantitative measurements of canopy area or volume using new precision technologies such as unmanned aerial vehicles.

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