scholarly journals INTENSIDADE ÓTIMA DE PODA EM Eucalyptus dunnii PARA A PRODUÇÃO DE MADEIRA LIVRE DE NÓS

FLORESTA ◽  
2015 ◽  
Vol 45 (4) ◽  
pp. 791
Author(s):  
Mário Dobner Jr. ◽  
Rudi Arno Seitz
Keyword(s):  
Tree Height ◽  
Annual Increment ◽  
Clear Wood ◽  
Diameter Increment ◽  
Eucalyptus Dunnii ◽  
Normal Diameter ◽  
Absolute Length ◽  
Current Utilization ◽  
Total Tree ◽  
Subtropical Species

Eucalytpus dunnii é uma espécie subtropical e tem seu cultivo indicado para regiões onde há ocorrência de geadas. Apesar de ser atualmente utilizada para a produção de papel, carvão e chapas, o uso sólido da madeira para fins mais nobres é conhecido, desde que práticas silviculturais como podas e desbastes sejam consideradas. O presente estudo teve como objetivo analisar o crescimento de indivíduos dominantes de E. dunnii submetidos a diferentes intensidades de poda. Foram testadas quatro diferentes intensidades de poda, mantendo uma copa remanescente de 100, 80, 50 e 20% da altura total de árvores dominantes. Foi utilizado um delineamento inteiramente casualizado com 10 indivíduos por tratamento. Passados 20 meses da realização da poda, a manutenção de até 50% da copa foi suficiente para manter um crescimento em diâmetro considerado normal. Mais importante que a proporção de copa remanescente, é o comprimento absoluto das mesmas. Conclui-se que são necessários, no mínimo, 4 m de copa remanescente para que as árvores mantenham um incremento periódico anual acima de 4 cm (média anual durante o período de 17 a 37 meses). Ao ultrapassar este limite, perdas na ordem de 50% do incremento em diâmetro são esperadas.AbstractOptimum pruning intensity in Eucalytpus dunnii for clear wood producing. Eucalyptus dunnii is a subtropical species, indicated for areas where frosts occur. Besides its current utilization for paper, coal and boards production, the potential for nobler solid-uses are recognized, provided that silvicultural practices such as pruning and thinning are regarded. The objective of this study was to analyze the growth of dominant E. dunnii trees subjected to four different pruning intensities: 100, 80, 50 and 20% of the total tree height of remained canopy. Experimental design was fully randomized, with 10 replications per treatment. After 20 months of pruning, maintaining 50% of canopy was sufficient to allow a normal diameter growth. More important than the proportion, was the absolute length of remained canopy. It was concluded that it is necessary to keep, at least, 4 m of remained canopy in order to maintain a periodic annual increment over 4 cm (average during the 17-37 months period). When this threshold is exceeded, lost in the order of 50% in diameter increment are expected.Keywords: Forest Management; Multiple-uses.

Development of comandra blister rust on lodgepole pine

1990 ◽  
Vol 20 (2) ◽  
pp. 159-165 ◽  
Author(s):  
Brian W. Geils ◽  
William R. Jacobi
Keyword(s):  
Lodgepole Pine ◽  
Tree Height ◽  
Infection Site ◽  
Canker Disease ◽  
Susceptibility To Infection ◽  
Blister Rust ◽  
The Mean ◽  
Central Rocky Mountains ◽  
Stem Cankers ◽  
Total Tree

The comandra blister rust parasite (Cronartiumcomandrae Pk.) causes a serious canker disease of lodgepole pine (Pinuscontorta Dougl. ex Loud. ssp. latifolia (Engelm.) Critch.) in the central Rocky Mountains. The expansion, longevity, and distribution of comandra blister rust cankers were studied by annual monitoring, reconstructing canker histories, and random sampling. In saplings, infections occur throughout the lower 80% of the crown; and branch cankers expand toward the bole at 2.5 cm•year−1, regardless of temperature, age, position, tree size, vigor, or susceptibility to infection. The proportion of branch cankers that develop into stem cankers decreases logistically both with distance from infection site to bole and with time since infection. Fewer than 50% of branch cankers that are farther than 20 cm from the bole or more than 8 years old are expected to establish stem cankers. The proportion of branch cankers that become stem cankers decreases with distance more rapidly for comandra blister rust than for other stem rusts. The mean height of stem cankers increases with total tree height, but cankers are uncommon at the top of the crown and low on the trunk of larger trees. The number of years for a canker to girdle its host equals the diameter of the stem at the center of the canker measured in centimetres. Because girdling cankers develop infrequently, slowly, and predictably, potential losses from comandra blister rust can be reduced by timely and appropriate removal of damaged trees.

scholarly journals Growth and yield of teak stands at different spacing

2018 ◽  
Vol 53 (10) ◽  
pp. 1109-1118
Author(s):  
Reginaldo Antonio Medeiros ◽  
Haroldo Nogueira de Paiva ◽  
Flávio Siqueira D’Ávila ◽  
Helio Garcia Leite
Keyword(s):  
Growth Rate ◽  
Basal Area ◽  
Tree Height ◽  
Tectona Grandis ◽  
Growth And Yield ◽  
Mean Square ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Total Tree

Abstract: The objective of this work was to evaluate the growth and yield of teak (Tectona grandis) stands at different spacing and in different soil classes. Twelve spacing were evaluated in an Inceptisol and Oxisol, in plots with an area of 1,505 or 1,548 m2, arranged in a completely randomized design with nine replicates. The teak trees were measured at 26, 42, 50, and 78 months of age. Total tree height was less affected by spacing. Mean square diameter was greater in wider spacing, whereas basal area and total volume with bark were greater in closer spacing. An increase in volume with bark per tree was observed with the increase of useful area per plant. For teak trees, growth stagnation happens earlier, the growth rate is higher in closer spacing, and the plants grow more in the Inceptisol than in the Oxisol.

scholarly journals Modeliranje višinske in debelinske rasti dominantnih dreves ter ocenjevanje indeksov produkcijske sposobnosti gozdnih rastišč

2021 ◽  
Vol 125 ◽  
pp. 1-12
Author(s):  
Andrej Bončina ◽  
Vasilije Trifković ◽  
Živa Bončina
Keyword(s):  
Growth Models ◽  
Tree Height ◽  
European Beech ◽  
Productivity Index ◽  
Silver Fir ◽  
Forest Types ◽  
Site Productivity ◽  
Beech Forests ◽  
Sessile Oak ◽  
Diameter Increment

Modeling the height and diameter growth of trees is an important part of forest management. Growth models provide the basis for determining the thinning regime, target tree dimensions and optimal proportions of developmental phases of forest stands. We developed individual height growth models for dominant Norway spruce (Picea abies (L.) Karst) and European beech (Fagus sylvatica L.) in two forest types (sessile oak-European beech forests and pre-Alpine silver fir-European beech forests). Based on the models, the site productivity index (SPI), defined as the dominant tree height at a diameter of 45 cm, was determined for spruce and beech in both forest types. Based on the diameter increment of the dominant trees, the age of trees in regard to their diameter was calculated, which was the basis for Height-Age modeling. The site productivity index (SPI) of spruce in sessile oak-beech forests and pre-Alpine silver fir-European beech forests is higher than that of beech: 31.3 and 29.7 vs 28.7 and 27.9, respectively. Estimated site indices (SI; dominant tree height at the age of 100 years) in sessile oak- European beech forests and pre-Alpine silver fir-European beech forests were 33.4 and 32.0 for spruce, and 29.0 and 27.0 for beech, respectively. Using the described procedure, it is possible to determine indices of site productivity of spruce and beech (SI and SPI) in the selected forest habitat types. Testing the procedure in other forest types and for other tree species is suggested.

scholarly journals Crown structure of Picea omorika trees in the plantation

2012 ◽  
Vol 64 (2) ◽  
pp. 605-611 ◽  
Author(s):  
M. Krstic ◽  
N. Stavretovic ◽  
V. Isajev ◽  
I. Bjelanovic
Keyword(s):  
Tree Height ◽  
Tree Crown ◽  
Crown Length ◽  
Crown Structure ◽  
Parabolic Function ◽  
Picea Omorika ◽  
Serbian Spruce ◽  
The Relationship ◽  
Total Tree ◽  
Stand Conditions

The study was carried out in Serbian spruce (Picea omorika Panc/Purkyn?) plantations in the western Serbia. The paper presents results of the analysis of crown development. The following elements were analyzed: total tree height, height of the crown base, absolute and relative crown length, maximal crown diameter, coefficient of crown spreading and degree of crown girth. We discuss approaches to the modeling of tree crown growth and development, growing under favorable environmental and stand conditions, without anomalies in development. In order to establish the relationship between analyzed factors, regression analyses were applied. Data fitting was by the analytic method, by the implementation of Prodan?s functions of growth, linear and parabolic function. Received models can be used for the simulation of various growth and developing processes in forest.

scholarly journals Comparison of Planted Loblolly and Slash Pine Performance in Southeast Texas

1993 ◽  
Vol 17 (1) ◽  
pp. 26-31 ◽  
Author(s):  
J. David Lenhart ◽  
Gary D. Kronrad ◽  
Michael S. Fountain
Keyword(s):  
Loblolly Pine ◽  
Tree Height ◽  
Pinus Elliottii ◽  
Slash Pine ◽  
Volume Index ◽  
Fusiform Rust ◽  
Tree Diameter ◽  
Stem Straightness ◽  
Southeast Texas ◽  
Total Tree

Abstract The performance of young (less than 10 yr) loblolly (Pinus taeda L.) and slash (Pinus elliottii Engelm.) pine trees was compared on planted sites in southeast Texas. Performance was compared for: total tree height; tree diameter; height to live tree crown; tree volume index,; incidenceof fusiform rust (Cronartium quercuum [Berk.] Miyabe ex Shirai f. sp. fusiforme); crookedness of stems; and survival rates. For these young trees, slash pine tended to perform better in southeast Texas than loblolly pine in total tree height, tree diameter, stem size, height to first livebranch and stem straightness. However, loblolly pine was less susceptible to fusiform rust than slash pine, and its mortality rate was lower than slash pine. However, based on the performance of these young plantations, a recommendation on the preferred pine species to plant in southeast Texasmight be premature. South. J. Appl. For. 17(1):26-31.

scholarly journals Height-Diameter Equations for Thirteen Midwestern Bottomland Hardwood Species

2002 ◽  
Vol 19 (4) ◽  
pp. 171-176 ◽  
Author(s):  
Kenneth C. Colbert ◽  
David R. Larsen ◽  
James R. Lootens
Keyword(s):  
Tree Height ◽  
Average Height ◽  
Bottomland Hardwood ◽  
Bottomland Hardwood Forests ◽  
Des Moines ◽  
Hardwood Species ◽  
Riparian Tree ◽  
Regression Techniques ◽  
Using Data ◽  
Total Tree

Abstract Height-diameter equations are often used to predict the mean total tree height for trees when only diameter at breast height (dbh) is measured. Measuring dbh is much easier and is subject to less measurement error than total tree height. However, predicted heights only reflect the average height for trees of a particular diameter. In this study, we present a set of height-diameter equations for 13 riparian tree species using data obtained from bottomland hardwood forests along the Mississippi, Missouri, Illinois, and Des Moines rivers. Nonlinear regression techniques were used to develop the equations. The resulting equations provide a reasonable means of predicting unknown tree heights, given dbh, for these species.

scholarly journals Harvester efficiency in trunk utilisation and log quality of early thinning pine trees

2019 ◽  
Vol 80 (1) ◽  
pp. 45-53
Author(s):  
Piotr S. Mederski ◽  
Konrad Werk ◽  
Mariusz Bembenek ◽  
Zbigniew Karaszewski ◽  
Mariusz Brunka ◽  
...  
Keyword(s):  
Management Practice ◽  
Tree Height ◽  
Maximum Height ◽  
Tree Trunk ◽  
Pine Trees ◽  
Expected Length ◽  
Set Up ◽  
Total Tree ◽  
Very High

Abstract Obtaining high harvester efficiency in young pine stands during early thinning is achallenging management practice. One of the difficulties lies in achieving the optimal use of the tree trunk for assortments and obtaining satisfactory timber quality. The objective of this research was to find out 1) how much of the tree trunk can be processed by a harvester to produce logs, and 2) the quality of the assortments in terms of log length accuracy and delimbing quality. The work was carried out in a 31-year-old pine stand in northern Poland with the Vimek 404 5T harvester with the Keto Forst Silver head for early thinning. Eighty sample plots were set up within the stand for detailed tree analysis after harvesting. The total length of the assortments from each tree was measured as well as the minimal top diameter (under bark). Additionally, the lengths of the bottom, middle and top logs were measured as well as the height of the knots after delimbing. On average, 70% of the total tree height was used for assortments and logs were processed up to a mean top diameter of 5.3 cm under bark. The length accuracy was very high: 90% of the logs had the expected length, more than 9% had a commercially acceptable length, while only 0.7% of the logs were too long. After delimbing, the knots were of a maximum height of 2 cm. Using the Vimek 404 5T harvester in the 31-year-old pine stand was an effective solution for trunk processing and obtaining quality assortments.

scholarly journals A new model for predicting the total tree height for stems cut-to-length by harvesters in Pinus radiata plantations

2019 ◽  
Vol 32 (1) ◽  
pp. 21-41 ◽  
Author(s):  
Chenxi Shan ◽  
Huiquan Bi ◽  
Duncan Watt ◽  
Yun Li ◽  
Martin Strandgard ◽  
...  
Keyword(s):  
Pinus Radiata ◽  
Generalized Method Of Moments ◽  
Tree Height ◽  
Predictor Variables ◽  
Parameter Estimates ◽  
Mathematical Form ◽  
New Model ◽  
Data Space ◽  
Nonlinear Form ◽  
Total Tree

AbstractA new model for predicting the total tree height for harvested stems from cut-to-length (CTL) harvester data was constructed for Pinus radiata (D.Don) following a conceptual analysis of relative stem profiles, comparisons of candidate models forms and extensive selections of predictor variables. Stem profiles of more than 3000 trees in a taper data set were each processed 6 times through simulated log cutting to generate the data required for this purpose. The CTL simulations not only mimicked but also covered the full range of cutting patterns of nearly 0.45 × 106 stems harvested during both thinning and harvesting operations. The single-equation model was estimated through the multiple-equation generalized method of moments estimator to obtain efficient and consistent parameter estimates in the presence of error correlation and heteroscedasticity that were inherent to the systematic structure of the data. The predictive performances of our new model in its linear and nonlinear form were evaluated through a leave-one-tree-out cross validation process and compared against that of the only such existing model. The evaluations and comparisons were made through benchmarking statistics both globally over the entire data space and locally within specific subdivisions of the data space. These statistics indicated that the nonlinear form of our model was the best and its linear form ranked second. The prediction accuracy of our nonlinear model improved when the total log length represented more than 20% of the total tree height. The poorer performance of the existing model was partly attributed to the high degree of multicollinearity among its predictor variables, which led to highly variable and unstable parameter estimates. Our new model will facilitate and widen the utilization of harvester data far beyond the current limited use for monitoring and reporting log productions in P. radiata plantations. It will also facilitate the estimation of bark thickness and help make harvester data a potential source of taper data to reduce the intensity and cost of the conventional destructive taper sampling in the field. Although developed for P. radiata, the mathematical form of our new model will be applicable to other tree species for which CTL harvester data are routinely captured during thinning and harvesting operations.

Effects of green pruning on growth of Pinus radiata

2003 ◽  
Vol 33 (11) ◽  
pp. 2067-2073 ◽  
Author(s):  
W A Neilsen ◽  
E A Pinkard
Keyword(s):  
Pinus Radiata ◽  
Growth Curves ◽  
Tree Height ◽  
Radiata Pine ◽  
Stem Growth ◽  
Term Study ◽  
Diameter Increment ◽  
Long Term Study ◽  
Green Pruning

Pruning of plantation trees is completed to produce knot-free timber and veneer logs, thus increasing the value of the plantation. A long-term study (11 years) was established to investigate the effects of selective pruning on radiata pine (Pinus radiata D. Don) stem growth. The 175 stems selected for the experiment had been pruned to 2.4 m at 6 years of age. At ages 8 and 10, the trees were pruned to 45%, 60%, or 75% of tree height and growth was compared with a control (first lift pruned only). Pruning to 45% of tree height had no effect on growth to age 13 years. Responses to the other treatments were apparent soon after pruning and continued until measurements ceased at 17 years of age. Pruning to 60% or 75% of tree height at second lift reduced diameter increment, and increment decreased as pruning severity increased. There was a further separation of the growth curves following third-lift pruning to 60% or 75% of tree height. The results suggested that maintaining a live crown ratio of 55% would minimize effects of pruning on diameter growth. The effect of severe pruning on diameter increment was greater for subdominant trees than for dominant stems. Pruning had less effect on height than diameter increment, but all treatments involving pruning to 75% of height at third lift resulted in trees that were approximately 10% shorter than unpruned trees at 13 years of age. More severe second-lift pruning resulted in smaller diameter over stubs at the time of third-lift pruning. Second-lift pruning to 60% of total height produced acceptable diameter over stubs. Implications for management are discussed.

Incorporating intertree competition into an ecosystem model

1995 ◽  
Vol 25 (3) ◽  
pp. 413-424 ◽  
Author(s):  
R.L. Korol ◽  
S.W. Running ◽  
K.S. Milner
Keyword(s):  
Process Model ◽  
Basal Area ◽  
Stand Density ◽  
Tree Height ◽  
Ecosystem Model ◽  
Growth And Yield ◽  
Maintenance Respiration ◽  
Tree Diameter ◽  
Diameter Increment ◽  
Individual Trees

Current research suggests that projected climate change may influence the growth of individual trees. Therefore, growth and yield models that can respond to potential changes in climate must be developed, TREE-BGC, a variant of the ecosystem process model FOREST-BGC, calculates the cycling of carbon, water, and nitrogen in and through forested ecosystems. TREE-BGC allocates stand-level estimates of photosynthesis to "each tree using a competition algorithm that incorporates tree height, relative radiation-use efficiency, and absorbed photosynthetically active radiation, TREE-BGC simulated the growth of trees grown in a dense and an open stand of interior Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) near Kamloops, B.C. The competition algorithm dynamically allocated stand estimates of photosynthesis to individual trees, and the trees were grown using an allometric relationship between biomass increment and height and diameter increment. Asymptotic height growth and the changes in the height–diameter relationship with competition were also incorporated in the model algorithms. Sapwood and phloem volume were used to calculate maintenance respiration. Predicted reductions in diameter growth with stand density were similar to those observed in the study stands. Although the carbon balance of individual trees was not tested, simulated tree diameter increments and height increments were correlated with the actual measurements of tree diameter increment (r2 = 0.89) and tree height increment (r2 = 0.78) for the 5-year period (n = 352). Although the model did not work well with trees that had diameters <5 cm, the model would be appropriate for a user who required an accuracy of ± 0.03 m3•ha−1 for volume, ± 0.02 m2•ha−1 for basal area, or ± 0.4 m for tree height over a 5-year period.

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