A competition index for predicting the vigour of planted Douglas-fir in southwestern British Columbia

1986 ◽  
Vol 16 (1) ◽  
pp. 23-29 ◽  
Author(s):  
David G. Brand
Keyword(s):  
Basal Area ◽  
Ground Cover ◽  
Douglas Fir ◽  
Relative Height ◽  
Competition Index ◽  
Tree Crown ◽  
Growth Vigour ◽  
Relative Production ◽  
Relative Production Rate ◽  
Tree Vigour

To provide a method of quantifying brush competition in coastal Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) plantations, data from 124 planted trees, 1–5 years old, were used to derive a competition index for predicting changes in tree vigour measured as a relative production rate. The index, including measures of brush proximity, relative height, and percent ground cover, appears to act as a measure of light interception around the tree crown. Tree vigour was found to be largely a function of the age of the tree from planting and the competition index (r2 = 0.71). Foliage-based measures of growth vigour were more strongly related to the index than basal area or height measures. The index has potential for assessing interspecific competition problems in young Douglas-fir plantations.

Competition-induced changes in developmental features of planted Douglas-fir in southwestern British Columbia

1986 ◽  
Vol 16 (2) ◽  
pp. 191-196 ◽  
Author(s):  
David G. Brand
Keyword(s):  
Basal Area ◽  
Douglas Fir ◽  
Developmental Expression ◽  
Competition Index ◽  
Resource Limitations ◽  
Developmental Characteristics ◽  
Individual Trees ◽  
Induced Changes ◽  
Relationship Of ◽  
Developmental Features

One- to five-year-old Douglas-fir, planted operationally, were measured for various developmental characteristics indicative of competition-induced acclimation to resource limitations. Characteristics were tested against a competition index based on measures of the brush canopy surrounding individual trees. The most promising developmental characteristics for assessing competition stress were the specific leaf area of foliage, the allometric relationship of height to basal area, and bud production on nodal shoots. Measures of foliar nitrogen status and leaf internode length were less well correlated with the competition index. Comparing these results with those of controlled laboratory studies gives an indication that on the sites studied, brush competition effects on planted trees are expressed through developmental acclimation to reduced light intensity. Developmental expression of changing nutrient or moisture availability was less evident, but may be confounded by reduced demand or secondary brush canopy effects.

Preliminary DRIS norms for coastal Douglas-fir soils in Washington and Oregon

1995 ◽  
Vol 25 (2) ◽  
pp. 208-214 ◽  
Author(s):  
J.S. Shumway ◽  
H.N. Chappell
Keyword(s):  
Basal Area ◽  
Site Index ◽  
Douglas Fir ◽  
Integrated System ◽  
N Fertilizer ◽  
Soil Test ◽  
Fertilizer Response ◽  
Response Data ◽  
Limiting Nutrient ◽  
Diagnostic Work

The Diagnosis and Recommendation Integrated System (DRIS) has been used successfully in agricultural crops and holds promise for use in forest stands. This study used soil tests to develop DRIS norms and evaluate their effectiveness in coastal Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) forests. DRIS norms for nitrogen, phosphorus, potassium, and calcium were developed using soil test and site index data from 72 soil series that commonly support Douglas-fir in western Washington. The norms were tested using soil test and stand basal area growth response data from 20 thinned and 30 unthinned N fertilizer test sites in coastal Washington and Oregon. Response to urea fertilizer in thinned stands averaged 34% and 43% for 224 and 448 kg N•ha−1, respectively, when N was identified as the most limiting nutrient. When N was not the most limiting nutrient, N response averaged 8% and 10% for 224 and 448 kg N•ha−1, respectively. Results were similar in unthinned stands and thinned stands, although response to fertilizer appeared to be slightly less in unthinned stands when N was the most limiting nutrient. DRIS correctly classified 25 of the 33 sites (76%) where N fertilizer increased growth by more than 15%. More importantly, 13 of the 17 (76%) sites that responded by less than 15% were correctly identified by DRIS. The results clearly indicate that N fertilizer response is dependent on the interactions (balance) between soil nutrients at a given site. Future soil diagnostic work needs to focus on techniques, like DRIS, that provide an assessment of these interactions.

A New Index Representing Individual Tree Competitive Status

1973 ◽  
Vol 3 (4) ◽  
pp. 495-500 ◽  
Author(s):  
James A. Moore ◽  
Carl A. Budelsky ◽  
Richard C. Schlesinger
Keyword(s):  
Spatial Distribution ◽  
Strong Correlation ◽  
Basal Area ◽  
Tree Size ◽  
Competition Index ◽  
Individual Tree ◽  
Silvicultural Practices ◽  
Basal Area Growth ◽  
Hardwood Species ◽  
Area Growth

A new competition index, modified Area Potentially Available (APA), was tested in a complex unevenaged stand composed of 19 different hardwood species. APA considers tree size, spatial distribution, and distance relationships in quantifying intertree competition and exhibits a strong correlation with individual tree basal area growth. The most important characteristic of APA is its potential for evaluating silvicultural practices.

scholarly journals Competition Indexes to Evaluate Tree Growth in a Semi-Deciduous Seasonal Forest

2019 ◽  
Vol 26 (4) ◽  
Author(s):  
Ilvan Medeiros Lustosa Junior ◽  
Renato Vinícius Oliveira Castro ◽  
Ricardo de Oliveira Gaspar ◽  
Juliana Baldan Costa Neves Araújo ◽  
Fabiana de Gois Aquino
Keyword(s):  
Tree Growth ◽  
Basal Area ◽  
Natural Forests ◽  
Competition Index ◽  
Radius Of Influence ◽  
Fixed Radius ◽  
The Subject

ABSTRACT Most of the studies that analyze the behavior of tree competition approach even-aged plantations. Therefore, it is possible to notice a lack of this kind of information regarding natural forests with high biodiversity. The objective of this study was to evaluate the competition in a fragment of Semi-Deciduous Seasonal Forest, according to the ecologic group, light depending and non-depending groups for all species sampled in the fragment. The Distance Independent Competition Index and Semi-Distance Independent Competition Index were applied in this study. The basal area in larger trees index, without the radius of influence, was the most efficient to analyze how the competition affects the growth of the specimens in the studied fragment. It was stated that evaluating the competition per ecologic group is more efficient. The results confirm that the forest competition cannot be determined by considering only a fixed radius of influence that embraces the neighbors and the subject tree.

Stand growth responses after fertilization for thinned lodgepole pine, Douglas-fir, and spruce in forests of interior British Columbia, Canada

2019 ◽  
Vol 49 (11) ◽  
pp. 1471-1482
Author(s):  
Woongsoon Jang ◽  
Bianca N.I. Eskelson ◽  
Louise de Montigny ◽  
Catherine A. Bealle Statland ◽  
Derek F. Sattler ◽  
...  
Keyword(s):  
British Columbia ◽  
Picea Glauca ◽  
Lodgepole Pine ◽  
Basal Area ◽  
Stand Density ◽  
Site Index ◽  
Douglas Fir ◽  
Picea Sitchensis ◽  
Growth And Yield ◽  
Growth Responses

This study was conducted to quantify growth responses of three major commercial conifer species (lodgepole pine (Pinus contorta Douglas ex Loudon var. latifolia Engelm. ex S. Watson), interior Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. glauca (Beissn.) Franco), and spruce (white spruce (Picea glauca (Moench) Voss) and hybrid spruce (Picea engelmannii Parry ex. Engelm. × Picea glauca (Moench) Voss × Picea sitchensis (Bong.) Carrière))) to various fertilizer blends in interior British Columbia, Canada. Over 25 years, growth-response data were repeatedly collected across 46 installations. The fertilizer blends were classified into three groups: nitrogen only; nitrogen and sulfur combined; and nitrogen, sulfur, and boron combined. The growth responses for stand volume, basal area, and top height were calculated through absolute and relative growth rate ratios relative to a controlled group. Fertilizer blend, inverse years since fertilization, site index, stand density at fertilization, and their interactions with the fertilizer blend were used as explanatory variables. The magnitude and significance of volume and basal area growth responses to fertilization differed by species, fertilizer-blend groups, and stand-condition variables (i.e., site index and stand density). In contrast, the response in top height growth did not differ among fertilization blends, with the exception of the nitrogen and sulfur fertilizer subgroup for lodgepole pine. The models developed in this study will be incorporated into the current growth and yield fertilization module (i.e., Table Interpolation Program for Stand Yields (TIPSY)), thereby supporting guidance of fertilization applications in interior forests in British Columbia.

Plant Community Structure and Composition in Uneven-aged Stands of Loblolly-Shortleaf Pine at Four Basal Area Levels

1995 ◽  
Vol 19 (2) ◽  
pp. 84-88 ◽  
Author(s):  
Philip A. Tappe ◽  
Michael D. Cain ◽  
T. Bently Wigley ◽  
Derik J. Reed
Keyword(s):  
Community Structure ◽  
Plant Community ◽  
Basal Area ◽  
Ground Cover ◽  
Control Treatment ◽  
Plant Community Structure ◽  
Shortleaf Pine ◽  
Single Tree ◽  
Single Tree Selection ◽  
Four Levels

Abstract The effects of overstory pine basal area on plant community structure and composition were assessed in uneven-aged stands of loblolly and shortleaf pines (Pinus taedaL. and P. echinata Mill.) in southern Arkansas. Basal area treatments were 40, 60, 80, and 100 ft2/ac for the merchantable pine component (>3.5 in. dbh) and were maintained on a 6 yr cutting cycle using single-tree selection. Assessments of plant communities were made 10 yr after a single hardwood control treatment. The four levels of pine basal area had no effect on percent ground cover of most plants <3 ft tall, but ground cover from graminoids decreased as pine basal area increased. Vertical cover above loft height increased 33% as overstory basal area increased from 40 to 100 ft2/ac, but basal area had no effect on horizontal cover in height zones between 0 and 10ft. It is concluded that uneven-aged stands of loblolly-shortleaf pine with merchantable basal areas of from 40 to 100 ft²/ac may support similar plant species in the understory and consequently probably provide similar habitat requirements for a variety of game and nongame wildlife. South. J. Appl. For. 19(2):84-88.

Long-term patterns of diameter and basal area growth of old-growth Douglas-fir trees in western Oregon

2002 ◽  
Vol 32 (7) ◽  
pp. 1232-1243 ◽  
Author(s):  
Nathan J Poage ◽  
John C Tappeiner, II
Keyword(s):  
Large Diameter ◽  
Basal Area ◽  
Douglas Fir ◽  
Slope Aspect ◽  
Site Factors ◽  
Old Growth ◽  
Site Class ◽  
Basal Area Growth ◽  
Area Growth ◽  
Age Range

Diameter growth and age data collected from stumps of 505 recently cut old-growth Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) trees at 28 sample locations in western Oregon (U.S.A.) indicated that rapid early and sustained growth of old Douglas-fir trees were extremely important in terms of attaining large diameters at ages 100–300 years. The diameters of the trees at ages 100–300 years (D100–D300) were strongly, positively, and linearly related to their diameters and basal area growth rates at age 50 years. Average periodic basal area increments (PAIBA) of all trees increased for the first 30–40 years and then plateaued, remaining relatively high and constant from age 50 to 300 years. Average PAIBA of the largest trees at ages 100–300 years were significantly greater by age 20 years than were those of smaller trees at ages 100–300 years. The site factors province, site class, slope, aspect, elevation, and establishment year accounted for little of the variation observed in basal area growth at age 50 years and D100–D300. The mean age range for old-growth Douglas-fir at the sample locations was wide (174 years). The hypothesis that large-diameter old-growth Douglas-fir developed at low stand densities was supported by these observations.

Dynamics of Forest Clumps on Chenier Plains, Cobourg Peninsula, Northern Territory

1990 ◽  
Vol 38 (6) ◽  
pp. 593 ◽  
Author(s):  
DMJS Bowman ◽  
WJ Panton ◽  
L Mcdonough
Keyword(s):  
National Park ◽  
Field Experiments ◽  
Calcareous Soils ◽  
Basal Area ◽  
Woody Species ◽  
Acacia Auriculiformis ◽  
Tree Crown ◽  
Bos Javanicus ◽  
Preferred Habitat ◽  
Monsoon Forest

Forest clumps occur scattered throughout Sorghum plumosum grasslands on chenier plains at Gurig National Park, Cobourg Peninsula, a preferred habitat for the introduced banteng (Bos javanicus.). The clumps are dominated by Pandanus spiralis, Acacia auriculiformis, Alstonia actinophylla, Timonius timon and Casuarina equisetifolia and vary in size from the radius of one tree crown to large patches of over several hectares. Fifteen of the 32 woody species recorded in 42 clumps occurred as juveniles less than 1 cm diameter at breast height. Both the clumps and grasslands occur on uniform calcareous soils. The clumps are thought to be a stage in a succession towards monsoon forest. Field experiments showed that seedlings from a range of monsoon forest and savanna species can grow on the plains. Interpretation of aerial photography taken in 1963 and 1982 suggests that the clumps have expanded. Fire is thought to control the succession. A fire on the plains was found to kill between one and two-thirds of the basal area of Pandanus spiralis and A. auriculiformis and stimulated the establishment of six times more A. auriculiformis seedlings than in nearby unburnt clumps. Monsoon forest juveniles that invade the clumps typically resprout following fire. Stunted, fire-damaged monsoon forest species (e.g. Timonius timon, Alstonia actinophylla) occur in low densities in the grasslands. It is unclear whether banteng promotes the succession by reducing fuel loads in the grasslands and spreading A. auriculiforms seeds.

Soil disturbance and juvenile Douglas-fir growth following stump removal on moderately coarse textured soils in southwestern British Columbia: 10-year results

2019 ◽  
Vol 49 (7) ◽  
pp. 767-774
Author(s):  
Stefan Zeglen ◽  
Paul J. Courtin
Keyword(s):  
British Columbia ◽  
Tree Growth ◽  
Basal Area ◽  
Soil Disturbance ◽  
Douglas Fir ◽  
Stand Development ◽  
Site Productivity ◽  
Nutrient Analysis ◽  
Armillaria Ostoyae ◽  
Root Diseases

Mechanized treatment for root diseases such as Coniferiporia sulphurascens (Pilát) L. W. Zhou & Y. C. Dai (syn. Phellinus sulphurascens Pilát) and Armillaria ostoyae (Romagn.) Herink (syn. Armillaria solidipes Peck) is often avoided due to cost or the perception that removal of stumps creates detrimental soil disturbance or degradation that hinders site productivity. Our study tested five diseased stands that were treated by extracting stumps following harvesting and replanted with susceptible Douglas-fir. Soil disturbance surveys were conducted in treated and untreated plots, and individual planted spots were assessed and categorized for soil disturbance using existing and proposed new categories specific to disturbance caused by the stump removal. Tree measurements were taken at intervals over the first 10 years of stand development, and foliage was sampled for nutrient analysis. The percentage of total and counted disturbance was 20%–46% and 8%–11% greater, respectively, in treated versus untreated plots; however, mean tree growth in height and diameter was not statistically different between treatments and was more positive for treated plots at all sites but one. Tree nutrition and survival to age 10 was not negatively affected by stump removal. Total site productivity represented by basal area and tree volume differed widely between sites but was not significantly different between treatments.

scholarly journals Estimating the Height and Basal Area at Individual Tree and Plot Levels in Canadian Subarctic Lichen Woodlands Using Stereo WorldView-3 Images

2019 ◽  
Vol 11 (3) ◽  
pp. 248 ◽  
Author(s):  
Benoît St-Onge ◽  
Simon Grandin
Keyword(s):  
Remote Sensing ◽  
Basal Area ◽  
Ground Cover ◽  
Structural Data ◽  
Tree Level ◽  
Individual Tree ◽  
Visual Contrast ◽  
The Relationship ◽  
Height Data

Lichen woodlands (LW) are sparse forests that cover extensive areas in remote subarctic regions where warming due to climate change is fastest. They are difficult to study in situ or with airborne remote sensing due to their remoteness. We have tested a method for measuring individual tree heights and predicting basal area at tree and plot levels using WorldView-3 stereo images. Manual stereo measurements of tree heights were performed on short trees (2–12 m) of a LW region of Canada with a residual standard error of ≈0.9 m compared to accurate field or UAV height data. The number of detected trees significantly underestimated field counts, especially in peatlands in which the visual contrast between trees and ground cover was low. The heights measured from the WorldView-3 images were used to predict the basal area at individual tree level and summed up at plot level. In the best conditions (high contrast between trees and ground cover), the relationship to field basal area had a R2 of 0.79. Accurate estimates of above ground biomass should therefore also be possible. This method could be used to calibrate an extensive remote sensing approach without in-situ measurements, e.g., by linking precise structural data to ICESAT-2 footprints.

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