Equations for predicting sapwood area at crown base in southwestern Oregon Douglas-fir

1987 ◽  
Vol 17 (3) ◽  
pp. 236-241 ◽  
Author(s):  
Douglas A. Maguire ◽  
David W. Hann

Two basic taper models were analyzed for their ability to predict sapwood area at crown base. Sapwood areas were estimated on stem cross sections by measuring sapwood radii on the longest and perpendicular to longest axes and by assuming conformity to an ellipse. These data were collected on 2 to 14 points along the stems of 72 Douglas-fir trees in southwestern Oregon. Across the range in diameter at breast height, total height, and height to crown base, quadratic–quadratic segmented polynomials (T. A. Max and H. E. Burkhart. 1976. For. Sci. 25: 283–289) provided more consistent monotonie taper from breast height to crown base than F. A. Bennett and B. F. Swindel models (1972. USDA For. Serv. Res. Note SE-179). A model for predicting breast height sapwood area from only diameter at breast height, total height, and height to crown base is also presented.

1995 ◽  
Vol 25 (12) ◽  
pp. 1928-1943 ◽  
Author(s):  
Risto Ojansuu ◽  
Matti Maltamo

The heartwood and sapwood of Pinussylvestris L. were analysed using simultaneous taper models for stem without bark and for heartwood. Sapwood area tapered monotonically from the base to the top of the stem. Below crown base the stem tapered more slowly than in the crown. The proportion of heartwood in the tree stem was higher in dense sample plots than in sparse ones and also decreased significantly with increasing relative size of a tree in a plot. Height at crown base correlated significantly with the proportion of heartwood, stand density, and relative size. Height at crown base was the most effective additional independent variable for predicting sapwood basal area at crown base when diameter at breast height and tree height were measured. Connected with diameter at breast height and tree height measurements, width of the sapwood at breast height explained significantly better sapwood and heartwood volumes than height at crown base.


1988 ◽  
Vol 18 (6) ◽  
pp. 803-806 ◽  
Author(s):  
W. G. Thies ◽  
E. E. Nelson

Eight treatments involving stump removal by bulldozing in combination with nitrogen fertilization were applied to 0.04-ha circular plots in a clear-cut on the Olympic Peninsula, Washington. Treatments included stump removal (either all stumps removed or the plot left undisturbed) and broadcast fertilization with ammonium nitrate (0, 336, 672, or 1345 kg N ha−1). Diameter at breast height and height of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings, planted several months after treatment, were recorded five and eight seasons after outplanting. The results showed that either bulldozing stumps from the site or fertilizing with ammonium nitrate increased growth of seedlings through their eighth growing season. After eight growing seasons, bulldozing had increased seedling height by 23% and diameter at breast height by 43%; fertilizing produced increases of 13% in height and 17% in diameter at breast height.


1996 ◽  
Vol 26 (5) ◽  
pp. 849-863 ◽  
Author(s):  
Douglas A. Maguire ◽  
João L.F. Batista

Sapwood dimensions lend insight into the functional and ecophysiological structure of trees and can therefore be profitably applied in various types of growth analyses and simulation models. Ten taper models were fitted to sapwood data from the stems of 134 Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) trees and were compared by various fit statistics, residual behavior, and validation performance on 21 additional trees. The recommended model was a variable exponent model with six parameters and three basic tree-level predictors: diameter, height, and height to crown base. The resulting equation can be applied for estimating sapwood area at crown base, leaf area, sapwood volume, and vertical foliage distribution on standing trees. Ten sample plots are examined to demonstrate that sapwood taper models allow more explicit portrayal of stand structure in dimensions that have a direct functional link to various growth and developmental processes.


Author(s):  
V. M. Zverkovsky ◽  
O. S. Zubkova

The linear growth of forest plantations of Western Donbass’ recultivating plot №1 were studied. The established cross-sectional the area of trunks and timber reserves experimental trees.Characterized by parameters which are the volume of wood: its height, diameter at breast height and shape of the forming barrel. In diameter at breast height cross sectional area is determined and then the barrel volume is calculated. Cross sections of tree trunks are shaped like a circle or an ellipse. Knowing the volume of logs we calculated reserves of wood for trees experimental plots.The largest reserves of timber and cross-sectional area characterized planting U. pumila – 15,367 m3 and 1,9583 m2, A. platanoides – 13,328 m3 and 2,67 m2, Q. robur – 10,120 m3 and 1,452 m2, J. virginiana – 8,748 m3 and 2,106 m2. The least plantation stocks of wood characterized E. angustifolia – 1,3699 m3 and 0,3693 m2, R. pseudoacacia – 2,9478 m3 and 0,8350 m2, P. rallasiana – 3,1626 m3 and 0,3279 m2.


Author(s):  
V. M. Zverkovsky ◽  
O. S. Zubkova

The linear growth of forest plantations of Western Donbass’ recultivating plot №1 were studied. The established cross-sectional the area of trunks and timber reserves experimental trees.Characterized by parameters which are the volume of wood: its height, diameter at breast height and shape of the forming barrel. In diameter at breast height cross sectional area is determined and then the barrel volume is calculated. Cross sections of tree trunks are shaped like a circle or an ellipse. Knowing the volume of logs we calculated reserves of wood for trees experimental plots.The largest reserves of timber and cross-sectional area characterized planting U. pumila – 15,367 m3 and 1,9583 m2, A. platanoides – 13,328 m3 and 2,67 m2, Q. robur – 10,120 m3 and 1,452 m2, J. virginiana – 8,748 m3 and 2,106 m2. The least plantation stocks of wood characterized E. angustifolia – 1,3699 m3 and 0,3693 m2, R. pseudoacacia – 2,9478 m3 and 0,8350 m2, P. rallasiana – 3,1626 m3 and 0,3279 m2.


2013 ◽  
Vol 14 (1) ◽  
pp. 147-152
Author(s):  
TB Thapa ◽  
CP Upadhyaya ◽  
YP Timilsina ◽  
SK Bhandari ◽  
L Puri

Height of the trees is not only used to estimate the product available from trees and to determine the productive capacity of the particular land but also used in forest management and research activities. In this research, predictability of total height from diameter at breast height for chir-pine (Pinus roxburghii) by using nonlinear models was examined. Total height and diameter at breast height of 180 trees were measured by using Suunto Clinometer and diameter tape respectively. The measured data were subjected to previously developed robust and strong statistical models, and evaluated by using different test statistics. Among those, H = e(-0.276) D0.925 explained the greatest proportion of variations of height (R2adj.=0.910) and minimum root mean square error (RMSE=1.221) and showed desirable behavior of flexibility and robustness. Nepal Journal of Science and Technology Vol. 14, No. 1 (2013) 147-152 DOI: http://dx.doi.org/10.3126/njst.v14i1.8935


Nativa ◽  
2018 ◽  
Vol 6 (5) ◽  
pp. 517
Author(s):  
Mayara Dalla Lana ◽  
Rinaldo Luiz Caraciolo Ferreira ◽  
José Antônio Aleixo da Silva ◽  
Gustavo Pereira Duda ◽  
Carlos Frederico Lins e Silva Brandão ◽  
...  

EQUAÇÕES DE BIOMASSA PARA ESPÉCIES DA CAATINGA O objetivo deste trabalho foi determinar as proporções de fuste, galhos e folhas em relação a biomassa total seca acima do solo e ajustar modelos estatísticos para estimativa da biomassa das principais espécies arbustivo-arbóreas em uma área de Caatinga. O número de indivíduos abatidos e com a biomassa aérea total determinada foi de 15 para Anadenanthera colubrina, Aspidosperma pyrifolium, Cnidoscolus quercifolius, Mimosa ophthalmocentra, Mimosa tenuiflora, Poincianella bracteosa e, de 30 para Bauhinia cheilantha e Croton heliotropiifolius. Para ajuste dos modelos foram utilizados os dados de biomassa total seca acima do solo coletados como variável dependente e as variáveis independentes foram o diâmetro à altura do peito e a altura total dos indivíduos por espécie. Foram testados oito modelos para cada uma das espécies e para todas as espécies agrupadas. Para a seleção da melhor equação utilizou-se os tradicionais critérios estatísticos. As proporções de biomassa das espécies foram quantificadas, tanto para os seus compartimentos, quanto para o total e apresentaram uma grande variação entre espécies e indivíduos da mesma espécie. Equações de biomassa aérea seca foram ajustadas com boas estatísticas de precisão, podendo ser utilizadas para a sua estimativa de biomassa de maneira confiável em regiões de Caatinga.Palavras-chave: Análise de regressão, diâmetro à altura do peito, altura total. ABSTRACT:The objective of this work was to determine the proportions of stem, branches and leaves in relation to total dry aboveground biomass and adjust statistical models to estimate the biomass of the main species in an area of Caatinga. The number of trees cut and with the determined total aboveground biomass was 15 for Anadenanthera colubrina, Aspidosperma pyrifolium, Cnidoscolus quercifolius, Mimosa ophthalmocentra, Mimosa tenuiflora, and Poincianella bracteosa, and 30 for Bauhinia cheilantha and Croton heliotropiifolius. The data of total dry aboveground biomass were used as dependent variables and the diameter at breast height and total height of individuals per species were used as the independent variables for adjusting the models. Eight models were tested for each species and for all grouped species. Traditional statistical criteria was used for selecting the best equation. The proportions of the species were quantified for both their biomass compartments and for the total biomass, showing great variation between species and individuals of the same species. Dry aboveground biomass equations were developed with good precision statistics and can therefore be used for estimating biomass in Caatinga regions.Keywords: Regression analysis, diameter at breast height, total height.


Author(s):  
S.E. Bassey ◽  
S. Ajayi

This research estimated aboveground tree stand level Biomass in Erukot Forest of Oban Division, Cross River National Park. A total of 872 individual trees were identified and measured for diameter at breast height and total height (dbh ≥ 5cm). The 872 individual trees spread across 51 species belonging to 25 different tree families. Simple random sampling was used with sampling intensity of 0.3% to lay 15 nested plots (7m x 7m, 25m x 25m and 35m x 35m). Diameter at breast height, total height and specific density of each wood species were used to determine aboveground biomass for each tree. Conversion factors were applied to estimate stand level green and dry biomass, sequestered carbon and carbon dioxide (CO2) emission in the study area. Simple linear regression models were fitted into the stand level growth data for the forest (basal area and volume). The mean diameter at breast height and mean total height were 38.5cm and 18.5m respectively. Mean basal area of 39.8 m2 ha-1 was obtained with a mean volume of 177.3 m3 ha-1 . Average green biomass, dry biomass, carbon stock and carbon-dioxide emission of 521.8113 ton ha-1 , 341.5880 ton ha-1 , 183.196 ton ha-1 and 694.2067 ton ha-1 respectively were obtained in the study area. Stand level biomass model developed for the forest showed that common logarithm of volume per hectare is significantly related to common logarithm of stand biomass (R2 = 58%). The actual and predicted biomasses were not significantly different (Paired T-test at p ˂ 0.05). Estimated bias of 0.10% for the stand biomass model means that the developed model can be used to predict the aboveground biomass of the study area without any adjustment. The research has provided easy to use regression model for determining aboveground biomass at stand level. This is very useful for carbon trade and assessment of carbon-dioxide emissions through deforestation in the study area. The model is also a tool for assessing the wood productivity of the study area and for better management of the park. Keyword: Sequestered carbon, aboveground biomass, dry biomass, conversion factor


2000 ◽  
Vol 15 (1) ◽  
pp. 34-36 ◽  
Author(s):  
James S. Hadfield ◽  
Paul T. Flanagan

Abstract Fresh attacks of Douglas-firs (Pseudotsuga menziesii) by Douglas-fir beetles (Dendroctonus pseudotsugae) were found in a campground that had trees pruned to remove Douglas-fir dwarf mistletoe (Arceuthobium douglasii) infections. All Douglas-firs with a diameter at breast height (dbh) of at least 12.7 cm were examined. Beetle attacks were found on 41% of the pruned trees and 5% of the unpruned trees. Among pruned trees, both the average number of branches pruned and the average dbh were greater in trees attacked by Douglas-fir beetles than in unattacked trees. West. J. Appl. For. 15(1):34-36.


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