scholarly journals The tree height estimated by non-power models on volumetric models provides reliable predictions of wood volume: The Amazon species height modelling issue

2020 ◽  
Vol 2 ◽  
pp. 100028
Author(s):  
Rodrigo Geroni Mendes Nascimento ◽  
Jerome Klaas Vanclay ◽  
Afonso Figueiredo Filho ◽  
Sebastião do Amaral Machado ◽  
Ademir Roberto Ruschel ◽  
...  
Keyword(s):  
Tree Height ◽  
Wood Volume ◽  
Volumetric Models ◽  
Power Models

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.

Predicting sugar maple (Acer saccharum) discoloured wood characteristics

2013 ◽  
Vol 43 (7) ◽  
pp. 649-657 ◽  
Author(s):  
Sharad Kumar Baral ◽  
Robert Schneider ◽  
David Pothier ◽  
Frank Berninger
Keyword(s):  
Acer Saccharum ◽  
Sugar Maple ◽  
Tree Height ◽  
Tree Age ◽  
Wood Volume ◽  
Nonlinear Mixed Effects Model ◽  
Crown Length ◽  
Crown Characteristics ◽  
The Relationship ◽  
Wood Columns

The presence of wound (strain) initiated discoloured wood columns in the core of sugar maple (Acer saccharum Marshall) stems reduces the proportion of white-coloured wood and, thus, lowers its commercial value. This study aimed to assess the relationship between tree characteristics and the extent and proportion of discoloured wood in sugar maple tree stems. Using 109 trees from three different sites in southern Quebec, we found that the proportion of discoloured wood increased with decreasing sapwood volume and increasing tree age. Younger trees showed a significantly lower proportion of discoloured wood volume. Discoloured wood volume increases disproportionately with tree diameter, while varying among sites. The third important factor affecting the amount of discolored wood was tree vigour as measured by crown characteristics and growth rate changes. A nonlinear mixed-effects model was used to predict discoloured wood taper. Height along the stem was used as a predictor, along with diameter at 1.3 m (DBH), the ratio of live crown length to tree height, and tree height. Although observed injury surface area was positively correlated to discoloured wood volume, injury information did not explain a large share of discoloured wood proportion variation. Overall, older and larger trees with many injuries on less productive sites are likely to have more discoloured wood.

scholarly journals Merchantable wood volume response of P. radiate D. Don post thinned plots on coated and uncoated urea fertilizers

2020 ◽  
Vol 30 (2) ◽  
pp. 36-47
Author(s):  
R. Nirola ◽  
C. Saint ◽  
J. O. Hehir ◽  
J. Liu
Keyword(s):  
South Australia ◽  
Ammonium Phosphate ◽  
Tree Height ◽  
Control Treatment ◽  
Fertilizer Treatment ◽  
Growth Stages ◽  
Wood Volume ◽  
Volume Yield ◽  
Standing Trees ◽  
Volume Response

Our study was focused on whether the optimization of nutrition at various growth stages of Pinus radiate D. Don plantation was an important factor to increase its merchantable wood volume yield in Silviculture. The present study site is located within the ‘Green Triangle’ bordering the Australian states of South Australia and Victoria. A total of 24 sampling sub-plots, averaged to 12 super plots, were established in both the sites, and all the plots, except one set aside as 'controlled plot' in each site, were treated with 5 types of coated and un-coated urea fertilizers. The data on tree-height and diameter at breast height over bark (DBHOB) of all the standing trees were measured and recorded. A five-year sampling data from the 24 sub-plots consisting of two sites, namely Picks (Site 'A') and Hollands Lane (Site 'B') in post thinned condition were analysed. The specific target was to evaluate a productivity response in terms of merchantable volumes based on fertilizer types. The statistical analysis employing ANOVA, t-test, a neural network model, decision tree and box-plot model based on fertilizer treatment determined that Di-Ammonium Phosphate Entec Urea (DAPEU) fertilizer was found to be more effective in increasing productivity. As such, the merchantable wood volume increments measured after four years of application of DAPEU were found to be 48.61 m3 ha-1 at Site 'A' and 41.97 m3 ha-1 at Site 'B', higher than the 46.71 m3 ha-1 at Site 'A' and 39.79 m3 ha-1 at Site 'B' with 'control' treatment. Hence, the application of DAPEAU was found to be effective as compared to the 'control' treatment in silviculture to increase the merchantable wood volume.

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

Forests ◽  
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.

scholarly journals Forest Structure, Wood Standing Stock, and Tree Biomass in Different Restoration Systems in the Brazilian Atlantic Forest

Forests ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 588 ◽  
Author(s):  
Danila Morena Fidéles Pontes ◽  
Vera Lex Engel ◽  
John A. Parrotta
Keyword(s):  
Forest Structure ◽  
Block Design ◽  
Standing Stock ◽  
Tree Height ◽  
Agroforestry System ◽  
Tree Biomass ◽  
Tree Plantation ◽  
Wood Volume ◽  
Trade Offs ◽  
Mixed Plantation

Reliable estimates of tree growth and wood yield are fundamental to support the management of restored forests and better reconcile the objectives of recovering biodiversity with the provision of ecosystem services. In this study, wood standing volumes and tree biomass stocks were estimated in different ecological restoration systems and at two sites with contrasting soil fertility, in order to evaluate the potential trade-offs between biodiversity and forest production. At each site, a complete randomized block design, with three replications of six treatments, was established in 1997–1998: direct seeding (DIRS), high-diversity tree plantation (HDIV), modified “Taungya” agroforestry system (AFS), mixed plantation with timber and firewood species (MIX), managed agroforestry system (AFSm) and managed mixed plantation (MIXm). We inventoried all trees with diameter at breast height (DBH) ≥ 5 cm in 450 m2 per treatment per plot, 19–20 years after establishment, using site-specific allometric models. Significant site effects were found for tree height, tree density and wood volume. Restoration systems (treatments) affected forest structure and forest productivity. Higher wood stock and biomass tree were observed in the less complex system (DIRS), while AFSm and HDIV reconciled higher species richness and diversity with good wood volume yields and tree biomass.

scholarly journals Contribution of some Savannah tree species in carbon sequestration

2021 ◽  
pp. 69-82
Keyword(s):  
Carbon Sequestration ◽  
Wood Density ◽  
Carbon Stock ◽  
Tree Height ◽  
Expansion Factor ◽  
Wood Volume ◽  
Biomass Expansion Factor ◽  
Diameter At Breast Height ◽  
Crown Diameter ◽  
Breast Height

Improvements in above ground biomass estimation can help account for changes in carbon stock in forest areas that may potentially participate in the clean development mechanism. The main objective of this study was to assess potential of some selected forest variables for modeling carbon sequestration for Combretum hartmannianum, Terminalia brownii, and Lanea fruitcosa. A total of 10 sample trees for Lanea fruitcosa and 8 sample trees for each of the other two species were selected for biomass and carbon determination were selected 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 presented 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. 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.

Konkurrenz zwischen Stieleiche und Buche auf Lothar-Sturmflächen | Competition between pedunculate oak and European beech on Lothar windthrow areas

2009 ◽  
Vol 160 (5) ◽  
pp. 114-123 ◽  
Author(s):  
Daniel Otto ◽  
Sven Wagner ◽  
Peter Brang
Keyword(s):  
Large Scale ◽  
Early Stage ◽  
Tree Height ◽  
European Beech ◽  
Threshold Value ◽  
Test Methods ◽  
Permanent Plots ◽  
Pedunculate Oak ◽  
Competitive Pressure ◽  
Competition Index

The competitive pressure of naturally regenerated European beech (Fagus sylvatica) saplings on planted pedunculate oak (Quercus robur) was investigated on two 1.8 ha permanent plots near Habsburg and Murten (Switzerland). The plots were established with the aim to test methods of artificial oak regeneration after large-scale windthrow. On both plots, 80 oaks exposed to varying levels of competitive pressure from at most 10 neighbouring beech trees were selected. The height of each oak as well as stem and branch diameters were measured. The competitive pressure was assessed using Schütz's competition index, which is based on relative tree height, crown overlap and distance from competing neighbours. Oak trees growing without or with only slight competition from beech were equally tall, while oaks exposed to moderate to strong competition were smaller. A threshold value for the competition index was found above which oak height decreased strongly. The stem and branch diameters of the oaks started to decrease even if the competition from beech was slight, and decreased much further with more competition. The oak stems started to become more slender even with only slight competition from beech. On the moderately acid beech sites studied here, beech grow taller faster than oak. Thus where beech is competing with oak and the aim is to maintain the oak, competitive pressure on the oak must be reduced at an early stage. The degree of the intervention should, however, take the individual competitive interaction into account, with more intervention if the competition is strong.

Spray Volume, Canopy Density, and Other Factors Involved in Thinner Efficacy

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 553d-553
Author(s):  
C.R. Unrath
Keyword(s):  
Tree Height ◽  
Tree Canopy ◽  
Tree Size ◽  
Water Volume ◽  
Canopy Density ◽  
The North ◽  
Run Off ◽  
Tree Canopies ◽  
Average Water ◽  
Water Volumes

Historically, most airblast chemical applications to apple orchards used a single “average” water volume, resulting in variability of coverage with tree size and also the greatest variable in chemical thinning. This coverage variability can be eliminated by properly quantifying the tree canopy, as tree row volume (TRV), and relating that volume to airblast water rate for adequate coverge. Maximum typical tree height, cross-row limb spread, and between-row spacing are used to quantify the TRV. Further refinement is achieved by adjusting the water volume for tree canopy density. The North Carolina TRV model allows a density adjustment from 0.7 gal/1000 ft3 of TRV for young, very open tree canopies to 1.0 gal/1000 ft3 of TRV for large, thick tree canopies to deliver a full dilute application for maximum water application (to the point of run-off). Most dilute pesticide applications use 70% of full dilute to approach the point of drip (pesticide dilute) to not waste chemicals and reduce non-target environmental exposure. From the “chemical load” (i.e., lb/acre) calculated for the pesticide dilute application, the proper chemical load for lower (concentrate) water volumes can be accurately determined. Another significant source of variability is thinner application response is spray distribution to various areas of the tree. This variability is related to tree configuration, light, levels, fruit set, and natural thinning vs. the need for chemical thinning. Required water delivery patterns are a function of tree size, form, spacing, and density, as well as sprayer design (no. of nozzles and fan size). The TRV model, density adjustments, and nozzle patterns to effectively hit the target for uniform crop load will be addressed.

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