scholarly journals ABOVEGROUND DENDROMASS ESTIMATION OF JUVENILE PAULOWNIA SP.

2017 ◽  
Vol 1 (24) ◽  
Author(s):  
Tatiana Stankova ◽  
Veselka Gyuleva ◽  
Dimitar Dimitrov ◽  
Hristina Hristova ◽  
Ekaterina Andonova
Keyword(s):  
Regression Models ◽  
Goodness Of Fit ◽  
Tree Height ◽  
Early Growth ◽  
Biomass Estimation ◽  
Allometric Relationships ◽  
Tree Diameter ◽  
Breast Height ◽  
Ornamental Trees ◽  
Total Tree

Species of the genus Paulownia have been introduced to Bulgaria since the beginning of the XXthcentury and their multipurpose uses - as ornamental trees, for wood and biomass production- have been tested ever since. We present a study, which examines the early growth of four Paulowniaclones at southern locations in Bulgaria and derives biometric models for dendromass estimationof juvenile Paulownia trees.The data originated from two experimental plantations established on nursery land using one-yearoldin vitro propagated plant material. Forty six, 1 to 3 year-old saplings from two clones of P. tomentosaand two P. elongata × P. fortunei hybrids were sampled. Their stem biomass was modeledas a function of the breast height tree diameter and total tree height or the stem diameter aloneand a set of goodness-of-fit criteria was applied to select the most adequate among the 29 testedformulations. The regression models were fitted in log-transformed form to the logarithm of thestem biomass and MM correction factor for bias was applied to the back-transformed predictiondata. Two allometric relationships were derived, which adequately assess stem dendromass ofyoung Paulownia sp. from easily measurable tree characteristics. Both models are applicable forstem biomass estimation of juvenile Paulownia trees of diameter up to 5 cm and total height upto 3.5 m.

Mechanistically based, allometric models to predict tree diameter and height in even-aged monoculture of Eucalyptusregnans F. Muell.

1989 ◽  
Vol 19 (2) ◽  
pp. 270-273 ◽  
Author(s):  
P. W. West ◽  
C. L. Beadle ◽  
C. R. A. Turnbull
Keyword(s):  
Tree Height ◽  
Allometric Relationships ◽  
Allometric Models ◽  
Tree Diameter ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Vertical Stability ◽  
Structural Argument ◽  
Individual Trees ◽  
Geometrical Argument

A randomly selected sample of 22 trees was felled in a stand in a 20-year-old monoculture of Eucalyptusregnans F. Muell. in southern Tasmania. One-half of the trees were from a section of the stand that had been heavily thinned 10 years previously, and the remainder were from the unthinned section. The trees were sectioned and the fresh weights of their stems (including bark) and crowns (leaves plus branches) determined. By combining a geometrical argument about the shape of tree stems with a structural argument about their vertical stability, allometric relationships were established relating tree diameter at breast height or tree height to total aboveground weight and the ratio of crown to stem weight. These relationships were found to hold in both the thinned and unthinned sections of the experiment. When combined with a model to predict biomass of individual trees, these models can be used to predict diameter or height of individual trees in E. regnans monoculture.

Comparison of linear and mixed-effect regression models and a k-nearest neighbour approach for estimation of single-tree biomass

2008 ◽  
Vol 38 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Lutz Fehrmann ◽  
Aleksi Lehtonen ◽  
Christoph Kleinn ◽  
Erkki Tomppo
Keyword(s):  
Mixed Models ◽  
Regression Models ◽  
Tree Height ◽  
Biomass Estimation ◽  
Data Sets ◽  
Tree Biomass ◽  
Mixed Effect ◽  
Single Tree ◽  
Breast Height ◽  
Effect Regression

Allometric biomass models for individual trees are typically specific to site conditions and species. They are often based on a low number of easily measured independent variables, such as diameter in breast height and tree height. A prevalence of small data sets and few study sites limit their application domain. One challenge in the context of the actual climate change discussion is to find more general approaches for reliable biomass estimation. Therefore, nonparametric approaches can be seen as an alternative to commonly used regression models. In this pilot study, we compare a nonparametric instance-based k-nearest neighbour (k-NN) approach to estimate single-tree biomass with predictions from linear mixed-effect regression models and subsidiary linear models using data sets of Norway spruce ( Picea abies (L.) Karst.) and Scots pine ( Pinus sylvestris L.) from the National Forest Inventory of Finland. For all trees, the predictor variables diameter at breast height and tree height are known. The data sets were split randomly into a modelling and a test subset for each species. The test subsets were not considered for the estimation of regression coefficients nor as training data for the k-NN imputation. The relative root mean square errors of linear mixed models and k-NN estimations are slightly lower than those of an ordinary least squares regression model. Relative prediction errors of the k-NN approach are 16.4% for spruce and 14.5% for pine. Errors of the linear mixed models are 17.4% for spruce and 15.0% for pine. Our results show that nonparametric methods are suitable in the context of single-tree biomass estimation.

scholarly journals Biomass functions applicable to European beech

2012 ◽  
Vol 51 (No. 4) ◽  
pp. 147-154 ◽  
Author(s):  
E. Cienciala ◽  
M. Černý ◽  
J. Apltauer ◽  
Z. Exnerová
Keyword(s):  
Tree Height ◽  
European Beech ◽  
Biomass Estimation ◽  
Managed Forests ◽  
Independent Variables ◽  
Breast Height ◽  
Allometric Functions ◽  
Branch Biomass ◽  
Independent Variable ◽  
Total Tree

This material describes parameterization of allometric functions applicable to biomass estimation of European beech trees. It is based on field data from destructive measurements of 20 full-grown trees with diameter at breast height (dbh) from 5.7 to 62.1 cm. The parameterization was performed for total tree aboveground biomass (AB; besides stump), stem and branch biomass, respectively. The allometric functions contained two or three parameters and used dbh either as a single independent variable or in combination with tree height (H). These functions explained 97 to 99% of the variability in the measured AB. The most successful equation was that using both dbh and H as independent variables in combination with three fitted parameters. H, as the second independent variable, had rather a small effect on improving the estimation: in the case of AB, H as independent variable improved prediction accuracy by 1–2% whereas in the case of branch biomass by about 5%. The parameterized biomass equations are applicable to tree specimens of European beech grown in typically managed forests.

INDIRECT ESTIMATION OF SOUTHERN PINE BEETLE (COLEOPTERA: SCOLYTIDAE) GALLERY LENGTH UTILIZING HOST CHARACTERISTICS

1981 ◽  
Vol 113 (3) ◽  
pp. 199-203
Author(s):  
T. E. Nebeker ◽  
O. P. Hackney ◽  
R. R. Hocking
Keyword(s):  
Tree Height ◽  
Southern Pine Beetle ◽  
Sample Period ◽  
Bark Thickness ◽  
Tree Diameter ◽  
Breast Height ◽  
Pine Beetle ◽  
Time Of Year ◽  
Total Tree ◽  
Host Characteristics

AbstractA technique is presented that requires no direct measurement of gallery length to estimate the total gallery length. Required to obtain the estimate are: (1) an appropriate model for time of year, sample period, and host, (2) tree diameter at breast height, (3) length of infested bole, (4) total tree height, and (5) inner bark thickness. The technique is accurate, less time consuming, and less expensive than direct estimation techniques.

scholarly journals Taper and Volume Models for Some Terminalia Tree Species

2021 ◽  
pp. 106-125
Keyword(s):  
Tree Species ◽  
Goodness Of Fit ◽  
Tree Height ◽  
Coefficient Of Determination ◽  
Diameter At Breast Height ◽  
Breast Height ◽  
Regression Parameters ◽  
Absolute Residual ◽  
Total Tree ◽  
Volume Models

The paper evaluated the performance of the current functional tree taper and volume models. The models were applied to some selected economically important natural Terminalia tree species common to central Sudan, namely, Terminalia laxiflora and, Terminalia brownii. 22 two-variable models (Diameter at breast height and total tree height or bole height) and 10 three-variables models (Diameter at ground level, Diameter at breast height and total tree height or bole height) were evaluated. The tree variables measured were the diameter at breast height (DBH, cm), diameter at the base of the tree (d0, cm), upper stem diameters (di), total tree height (H), and height to the base of the crown (Hb). Data were extracted from a natural reserved forest in the Blue Nile state. The models goodness of fit were evaluated in terms of adjusted coefficient of determination (Ra2), standard error (SE), mean absolute residual (MAR), bias (BI) Akaike’s information criterion (AIC), homogeneity of the residuals and significance of the regression parameters. Taper-17 and Taper-19 were found to be among the best two models for the two species with R2 range of 0.94 – 0.93, but with different rankings for each species. Comparison of the range of data for the tow studied species suggested that representation of various diameter at breast height (DBH, cm), diameter at the base of the tree (d0, cm), upper stem diameters (di), total tree height (H), and height to the base of the crown (Hb), had significant influence on the accuracy of prediction outside the range of the fitted data. This implies that application of the selected models is only useful at local stand level or at best in similar biological and stand structure conditions. For volume models, The results indicated that individual equations act differently in each species as there were great variations in the values of the same parameter of a given model accross the species. Some regression parameters of a given model were found to be significant in some species and insignificant in others. Comparison between the two versions of each group reveals that the replacement of the total tree height by the bole height (merchantable height) improves both the level of parameter significance and the coefficient of determination. From the first, the regression parameters of only 5 models (VOL-1, VOL-5, VOL-8, VOL-17, and VOL-20) were found to be significant at 0.05 probability level for all the tow species. The results also reveal that inclusion of variable D0 to the original two variables (DBH, Ht) to the volume equations results in insignificant improvement of the Ra2 values, while the replacement of the original model Ht variable with the Hb results in quite significant improvement of the Ra2 values. However, substantial improvement of the Ra2 values were obtained when both D0 and Hb were added. For this group of models, VOL-23, VOL-25- VOL-29 VOL30- and VOL-31were found to be the best for almost all the tow species. In general, the study concluded that taper and volume models can provide precise and accurate tree growth variables for the studied species with reasonable cost and time, but care should be taken when dealing with same model for the same species across the varying growth and management condition.

scholarly journals Contribution of some Acacia Species on Carbon Sequestration in Blue Nile State, Sudan

2021 ◽  
pp. 97-105
Keyword(s):  
Carbon Sequestration ◽  
Wood Density ◽  
Carbon Stock ◽  
Tree Height ◽  
Biomass Estimation ◽  
Expansion Factor ◽  
Wood Volume ◽  
Crown Diameter ◽  
Breast Height ◽  
Acacia Seyal

Background: The current challenge is to reduce the uncertainties in obtaining accurate and reliable data of carbon stock changes and emission factors essential for reporting national inventories. Improvements in above ground biomass estimation can also help account for changes in carbon stock in forest areas that may potentially participate in the Reducing emissions from deforestation and forest degradation and other initiatives. Current objectives for such estimates need a unified approach which can be measurable, reportable, and verifiable. This might result to a geographically referenced biomass density database for Sudanese forests that would reduce uncertainties in estimating forest aboveground biomass. The main objective: of this study is to assess potential of some selected forest variables for modeling carbon sequestration for Acacia seyal, vr. Seyal, Acacia seyal, vr. fistula, Acacia Senegal. The specific objectives include development of empirical allometric models for forest biomass estimation, estimation of carbon sequestration for these tree species, estimation of carbon sequestration per hectare and comparing the amount with that reported to the region. A total of 10 sample trees for biomass and carbon determination were selected for each of the three species from El Nour Natural Forest Reserve of the Blue Nile State, Sudan. Data of diameter at breast height, total tree height, tree crown diameter, crown height, and upper stem diameters were measured. Then sample trees were felled and sectioned to their components, and weighed. Subsamples were selected from each component for oven drying at 105 ˚C. Finally allometric models were developed and the aboveground dry weight (dwt) and carbon sequestered per hector were calculated. The results: presents biomass equations, biomass expansion factor and wood density that developed for the trees. In case of inventoried wood volume, corrections for biomass expansion factor and wood density value were done, and new values are suggested for use to convert wood volume to biomass estimates. The results also, indicate that diameter at breast height, crown diameter and tree height are good predictors for estimation of tree dwt and carbon stock. Conclusion: The developed allometric equations in this study gave better estimation of dwt than default value. The average carbon stock was found to be 22.57 t/ha.

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 HeightߝDiameter Equations for 12 Upland Species in the Missouri Ozark Highlands

2007 ◽  
Vol 24 (2) ◽  
pp. 149-152 ◽  
Author(s):  
James R. Lootens ◽  
David R. Larsen ◽  
Stephen R. Shifley
Keyword(s):  
Tree Species ◽  
Tree Height ◽  
Tree Diameter ◽  
Ozark Highlands ◽  
The Mean ◽  
Predicted Values ◽  
Total Tree

Abstract We calibrated a model predicting total tree height as a function of tree diameter for nine tree species common to the Missouri Ozarks. Model coefficients were derived from nearly 10,000 observed trees. The calibrated model did a good job predicting the mean heightߝdiameter trend for each species (pseudo-R2 values ranged from 0.56 to 0.88), but for a given tree diameter observed tree heights were highly variable. We also present a technique for incorporating the observed variation in tree heights in the predicted values.

scholarly journals Seemingly Unrelated Mixed-Effects Biomass Models for Young Silver Birch Stands on Post-Agricultural Lands

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 381
Author(s):  
Karol Bronisz ◽  
Lauri Mehtätalo
Keyword(s):  
Tree Height ◽  
Mixed Effects ◽  
Model System ◽  
Silver Birch ◽  
Estimation Methods ◽  
Biomass Estimation ◽  
Agricultural Lands ◽  
Cross Model ◽  
Diameter At Breast Height ◽  
Breast Height

Secondary succession that occurs on abandoned farmlands is an important source of biomass carbon stocks. Both direct and indirect tree biomass estimation methods are applied on forest lands. Using empirical data from 148 uprooted trees, we developed a seemingly unrelated mixed-effects models system for the young silver birch that grows on post agricultural lands in central Poland. Tree height, biomass of stem, branches, foliage, and roots are used as dependent variables; the diameter at breast height is used as the independent variable. During model elaboration we used restricted cubic spline: 5 knots at the quantiles (0.05, 0.275, 0.5, 0.725, and 0.95) of diameter at breast height provided sufficiently flexible curves for all biomass components. In this study, we demonstrate the use of the model system through cross-model calibration of the biomass component model using tree height measured from 0, 2, 3, and 4 available extreme trees feature in the plot in question. A different number of extreme trees were measured for final model system and our results indicated that for all analyzed components, random-effect predictions are characterized by higher accuracy than fixed-effects predictions.

scholarly journals Floristic and structure of an Amazonian primary forest and a chronosequence of secondary succession

2016 ◽  
Vol 46 (2) ◽  
pp. 133-150 ◽  
Author(s):  
Camila Valéria de Jesus SILVA ◽  
João Roberto dos SANTOS ◽  
Lênio Soares GALVÃO ◽  
Ricardo Dal'Agnol da SILVA ◽  
Yhasmin Mendes MOURA
Keyword(s):  
Structural Analysis ◽  
Basal Area ◽  
Tree Height ◽  
Intermediate Stage ◽  
Primary Forest ◽  
Breast Height ◽  
Floristic Analysis ◽  
Kolmogorov Smirnov ◽  
Total Tree ◽  
Fisher’S Alpha

ABSTRACT The analysis of changes in species composition and vegetation structure in chronosequences improves knowledge on the regeneration patterns following land abandonment in the Amazon. Here, the objective was to perform floristic-structural analysis in mature forests (with/without timber exploitation) and secondary successions (initial, intermediate and advanced vegetation regrowth) in the Tapajós region. The regrowth age and plot locations were determined using Landsat-5/Thematic Mapper images (1984-2012). For floristic analysis, we determined the sample sufficiency and the Shannon-Weaver (H'), Pielou evenness (J), Value of Importance (VI) and Fisher's alpha (α) indices. We applied the Non-metric Multidimensional Scaling (NMDS) for similarity ordination. For structural analysis, the diameter at the breast height (DBH), total tree height (Ht), basal area (BA) and the aboveground biomass (AGB) were obtained. We inspected the differences in floristic-structural attributes using Tukey and Kolmogorov-Smirnov tests. The results showed an increase in the H', J and α indices from initial regrowth to mature forests of the order of 47%, 33% and 91%, respectively. The advanced regrowth had more species in common with the intermediate stage than with the mature forest. Statistically significant differences between initial and intermediate stages (p<0.05) were observed for DBH, BA and Ht. The recovery of carbon stocks showed an AGB variation from 14.97 t ha-1 (initial regrowth) to 321.47 t ha-1 (mature forests). In addition to AGB, Ht was also important to discriminate the typologies.

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