Biomass functions applicable to European beech

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.

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ABOVEGROUND DENDROMASS ESTIMATION OF JUVENILE PAULOWNIA SP.

ГЛАСНИК ШУМАРСКОГ ФАКУЛТЕТА УНИВЕРЗИТЕТА У БАЊОЈ ЛУЦИ ◽

10.7251/gsf1624005s ◽

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.

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HOW TO ESTIMATE BLACK WATTLE ABOVEGROUND BIOMASS FROM HETEROSCEDASTIC DATA?

FLORESTA ◽

10.5380/rf.v51i1.65236 ◽

2020 ◽

Vol 51 (1) ◽

pp. 028

Author(s):

Thiago Wendling Gonçalves de Oliveira ◽

Vinícius Morais Coutinho ◽

Luan Demarco Fiorentin ◽

Mateus Niroh Inoue Sanquetta ◽

Carlos Roberto Sanquetta ◽

...

Keyword(s):

Aboveground Biomass ◽

Nonlinear Models ◽

Basic Density ◽

Tree Height ◽

Error Variance ◽

Total Biomass ◽

Independent Variables ◽

Independent Variable ◽

Black Wattle ◽

Total Tree

This study developed a system of equations for predicting total aboveground and component biomass in black wattle trees. A total of 140 black wattle trees at age 10 years were measured regarding their diameter at 1.30 m height above the ground (d), total tree height (h), basic wood density (branches and stem), and biomass (stem, crown, and aboveground). We evaluated the performance of linear and nonlinear allometric models by comparing the statistics of R2adj., RRMSE%, and BIC. Nonlinear models performed better when predicting crown biomass (using only d as an independent variable), and stem and aboveground biomass (using d and h as independent variables). Adding basic density did not significantly improve biomass modeling. The residuals had non-homogeneous variance; thus, the fitted equations were weighted, with weights derived from a function containing the same independent variables of the fitted biomass function. Subsequently, we used a simultaneous set of equations to ensure that the sum of each component's estimated biomass values was equal to the total biomass values. Simultaneous fitting improved the performance of the equations by guaranteeing the components' additivity, and weighted regression allowed to stabilize error variance, ensuring the homoscedasticity of the residuals.

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Seemingly Unrelated Mixed-Effects Biomass Models for Black Locust in West Poland

Forests ◽

10.3390/f12030380 ◽

2021 ◽

Vol 12 (3) ◽

pp. 380

Author(s):

Karol Bronisz ◽

Szymon Bijak ◽

Rafał Wojtan ◽

Robert Tomusiak ◽

Agnieszka Bronisz ◽

...

Keyword(s):

Black Locust ◽

Random Effect ◽

Tree Height ◽

Cross Model ◽

Diameter At Breast Height ◽

Breast Height ◽

Dependent Variables ◽

Dry Biomass ◽

Biomass Components ◽

Independent Variable

Information about tree biomass is important not only in the assessment of wood resources but also in the process of preparing forest management plans, as well as for estimating carbon stocks and their flow in forest ecosystems. The study aimed to develop empirical models for determining the dry mass of the aboveground parts of black locust trees and their components (stem, branches, and leaves). The research was carried out based on data collected in 13 stands (a total of 38 sample trees) of black locust located in western Poland. The model system was developed based on multivariate mixed-effect models using two approaches. In the first approach, biomass components and tree height were defined as dependent variables, while diameter at breast height was used as an independent variable. In the second approach, biomass components and diameter at breast height were dependent variables and tree height was defined as the independent variable. Both approaches enable the fixed-effect and cross-model random-effect prediction of aboveground dry biomass components of black locust. Cross-model random-effect prediction was obtained using additional measurements of two extreme trees, defined as trees characterized by the smallest and largest diameter at breast height in sample plot. This type of prediction is more precise (root mean square error for stem dry biomass for both approaches equals 77.603 and 188.139, respectively) than that of fixed-effects prediction (root mean square error for stem dry biomass for both approaches equals 238.716 and 206.933, respectively). The use of height as an independent variable increases the possibility of the practical application of the proposed solutions using remote data sources.

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

10.51527/v2i1.13me ◽

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.

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

Forests ◽

10.3390/f11040381 ◽

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.

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

Acta Amazonica ◽

10.1590/1809-4392201504341 ◽

2016 ◽

Vol 46 (2) ◽

pp. 133-150 ◽

Cited By ~ 8

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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Total and Merchantable Volume Equations and Taper Functions for Southwestern Ponderosa Pine

Western Journal of Applied Forestry ◽

10.1093/wjaf/3.4.123 ◽

1988 ◽

Vol 3 (4) ◽

pp. 123-125 ◽

Cited By ~ 4

Author(s):

J. P. McTague ◽

W. F. Stansfield

Keyword(s):

Pinus Ponderosa ◽

Ponderosa Pine ◽

Tree Height ◽

Stem Diameter ◽

Height Functions ◽

Breast Height ◽

Pine Trees ◽

Yellow Pine ◽

Total Tree ◽

Volume Equations

Abstract Total outside and inside bark cubic foot volume equations are presented for southwestern ponderosa pine (Pinus ponderosa) that are functions of total tree height, diameter breast height, and Girard form class. These equations are appropriate for trees of any size or age, and no distinction is made between "blackjack" and "yellow pine" trees. Equations are included to predict merchantable volume to any upper stem diameter or merchantable height. Taper and merchantable height functions are indirectly derived from the merchantable volume equations. West. J. Appl For. 3(4):123-125, October 1988.

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Evaluation of Different Calibration Approaches for Merchantable Volume Predictions of Norway Spruce Using Nonlinear Mixed Effects Model

Forests ◽

10.3390/f10121104 ◽

2019 ◽

Vol 10 (12) ◽

pp. 1104

Author(s):

Zdeněk Adamec ◽

Radim Adolt ◽

Karel Drápela ◽

Jiří Závodský

Keyword(s):

Norway Spruce ◽

Tree Height ◽

Mixed Effects ◽

Mixed Effects Model ◽

Wood Volume ◽

Nonlinear Mixed Effects Model ◽

Breast Height ◽

Stem Taper ◽

Total Tree

Research Highlights: Determination of merchantable wood volume is one of the key preconditions for sustainable forest management. This study explores accuracy of calibrated predictions of merchantable wood volume of Norway spruce (Picea abies (L.) H. Karst.) using stem taper curves (STC) in a form of a mixed model. Background and Objectives: The study is devoted to the determination of merchantable wood volume (over bark) of individual standing stems based on the integration of an STC model calibrated using upper diameter measurements. Various options of upper diameter measurement were tested and their impact on the accuracy of merchantable wood volume prediction was evaluated. Materials and Methods: To model stem taper curves, a Kozak 02 function was applied in a form of a nonlinear, mixed effects model. Accuracies of calibrated merchantable wood volume predictions obtained through remote (optical) upper diameter measurements were compared to accuracies corresponding to contact measurements by a caliper. The performance of two alternative methods used in the Czech National Forest Inventory (NFI) and forestry practice, involving diameter at breast height and total tree height as the only predictors, were also tested. The contact measurements were performed at identical stem positions after felling the respective sample tree. The calibration was done in order to account for factors inherent in particular location, and, optionally, also in a particular sample stem (within the respective location). Input data was sourced as part of a dedicated survey involving the entire territory of the Czech Republic. In total, 716 individual spruce trees were measured, felled and analysed at 169 locations. Results: In general, the best merchantable volume predictions were obtained by integrating the STC fitted (and calibrated) by minimising errors of stem cross-sectional areas instead of diameters. In terms of calibrated predictions, using single-directional, caliper measurement of upper diameter at 7 m (after felling) led to the best accuracy. In this case, the observed mean bias of merchantable volume prediction was only 0.63%, indicating underestimation. The best optical calibration strategy involved upper diameter measurements at two heights (5 and 7 m) simultaneously. Bias of this volume prediction approach was estimated at 2.1%, indicating underestimation. Conclusions: Concerning the prediction of merchantable stem volume of standing Norway spruce trees, STC calibration using two optical upper diameter measurements (at 5 and 7 m) was found to be practically applicable, provided a bias up to 3.7% can be accepted. This method was found to be more accurate than the existing national alternatives using diameter at breast height and the total tree height as the only predictors.

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Determining the Age of Streetside Trees with Diameter at Breast Height-based Multifactorial Model

Arboriculture & Urban Forestry ◽

10.48044/jauf.2008.018 ◽

2008 ◽

Vol 34 (3) ◽

pp. 137-143

Author(s):

Jan Lukaszkiewicz ◽

Marek Kosmala

Keyword(s):

Regression Coefficient ◽

Tree Height ◽

Tree Age ◽

Multifactorial Model ◽

Diameter At Breast Height ◽

Breast Height ◽

R Value ◽

The Difference ◽

Individual Trees ◽

Total Tree

This article evaluates the possibility of determining tree age based simultaneously on diameter at breast height (dbh) (1.3 m [4.3 ft]) and total tree height using common lime, common ash, and horsechestnut species. The first step was the identification and measuring groups of trees growing in similar conditions (streetside trees in Warsaw area, Poland) in which planting ages were known (mainly from archives). Next, multifactorial regression model was developed describing the growth of both tree parameters (dbh and height) over time. In the majority of cases, plotting tree age against diameter and height yielded a regression coefficient r value and determination coefficient r 2value above 0.9. For graphic interpretation of elaborated multifactorial models, nomograms were applied. This kind of graph allows explaining tree age based on both dbh and height of trees. Another step was verification. The resulting model was applied to unrelated groups of trees of known age. Mean bias values were established for each model. The difference between the actual age and mean age calculated with the model was less than ±15%. Presented model, although not meant for application to individual trees, might be useful to determine the age of groups of trees growing along streets and roads.

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