scholarly journals Optimizing thinnings for timber production and carbon sequestration in planted teak (Tectona grandis L.f.) stands

2019 ◽  
Vol 28 (3) ◽  
pp. 3013
Author(s):  
María-Alejandra Quintero-Méndez ◽  
Mauricio Jerez-Rico
Keyword(s):  
Interest Rates ◽  
Net Present Value ◽  
Basal Area ◽  
Tectona Grandis ◽  
C Sequestration ◽  
Growth And Yield ◽  
Site Quality ◽  
Timber Production ◽  
Transport Costs ◽  
Yield Model

Aim of study: We developed an optimization model for determining thinning schedules in planted teak (Tectona grandis L.f.) stands that maximize the financial output in terms of soil expectation value (SEV) and net present value (NPV) considering a) the simultaneous optimization of timber production and carbon (C) sequestration and b) only for C sequestration.Area of study: Planted teak forests in the western alluvial plains of Venezuela.Material and methods: We integrated a stand growth and yield model with a constrained optimization model based on genetic algorithms (GA) for determining optimal thinning schedules (number, age, and removal intensity) that maximize SEV when simultaneously managing for timber production and C sequestration. The data came from permanent plots established in planted teak stands with remeasurements from 2 to 32 yr.-old. Plots differ in site quality, initial spacing, and thinning schedules. We obtained optimal thinning schedules for several scenarios combining site quality, initial spacing, interest rates, harvest and transport costs, as well as timber and C prices. The stand growth and yield model estimates timber products and C flows (storage and emissions) until most stored C is reemitted to the atmosphere.Main results: When considering simultaneously both, timber production and C sequestration, the scenario with the maximum SEV consisted of initial stand densities = 1,111 trees ha-1, site quality (SQ) I, harvest age 20 years, and four thinnings (ages 6, 10, 14, 17 with removal intensities 26 %, 28 %, 39 %, and 25 % of stand basal area respectively). For maximizing C sequestration only, the best schedule consisted of 1,600 trees ha-1, SQ I, harvest age 25 years, with no-thinning. A sensitivity analysis showed that optimal schedules and SEV were highly sensitive to changes in interest rates, growth rates, and timber prices.Research highlights:The management schedules favoring merchantable timber production are not the same that favor C sequestration.For planted teak, the objectives of maximizing timber production and carbon sequestration are in conflict because the thinning schedules that maximize financial gains from C sequestration reduce economic gains from timber and vice versa.With actual timber teak and market C prices, optimal NPVW is much larger than optimal NPVC.For C prices under 40 $US MgC optimizing simultaneously for timber production and C sequestration is the best option, as additional although sub-optimal revenues can be obtained from C payments.Lengthening the rotation, avoiding thinnings, or reducing their intensity increase carbon storage in planted teak, although, under the analyzed scenarios, after 120 yr. almost all carbon has been re-emitted to the atmosphere.Additional keywords: heuristics, genetic algorithms, operations research, forest management planning, stand level model, carbon stocks.Abbreviations used: C (Carbon); GA (genetic algorithm); NPVW, NPVC, NPVT (net present value from the cash flows of timber (wood), carbon, and total); SEV (Soil (land) expectation value); dbh (diameter at 1.3 m from the ground); G (stand basal area); Gp (potential site carrying capacity in terms of G); SQ (site quality); R (rotation, harvest age); A (age); I (thinning intensity); Vob, Vub (overbark, underbark volume); gr (basal area growth rate); r (interest rate); harvest and transport costs (Hc); Pc (C price). 

scholarly journals A Multiproduct Growth and Yield Model for the Circumboreal Aspens

1996 ◽  
Vol 13 (4) ◽  
pp. 164-170 ◽  
Author(s):  
Donald A. Perala ◽  
George E. Host ◽  
James K. Jordan ◽  
Christopher J. Cieszewski
Keyword(s):  
North America ◽  
Simulation Model ◽  
Air Temperature ◽  
Basal Area ◽  
Growth And Yield ◽  
Site Quality ◽  
Yield Model ◽  
Growth And Yield Model

Abstract A simulation model is described that grows stands of aspen of given age, site quality, and stocking from establishment to breakup. Specifying mean July air temperature allows custom application to most aspen growing regions in North America and Scandinavia. The program predicts total yields in number of trees, basal area, and biomass; and merchantable yields in cubic feet and cords for user-specified utilization standards, and in board feet, Scribner. North. J. Appl. For. 13(4):164-170.

scholarly journals Allometric Models for Estimating Site Index of Teak (Tectona grandis Linn F.) in Kanya Forest Plantation, Kebbi State, Nigeria

2019 ◽  
pp. 1-7
Author(s):  
A. Dantani ◽  
S. B. Shamaki ◽  
M. A. Gupa ◽  
M. Sa’idu ◽  
R. B. Mukhtar ◽  
...  
Keyword(s):  
Basal Area ◽  
Tectona Grandis ◽  
Site Index ◽  
Growth And Yield ◽  
Site Quality ◽  
Forest Plantation ◽  
Age Classes ◽  
Total Height ◽  
Yield Values ◽  
Predicted Height

This study aims to develop site index for Teak (Tectona grandis) in Kanya Forest Plantation, Nigeria. Site index is defined as the total height of the dominant or co-dominant trees at an arbitrary index age, it is a method used for quantifying site quality for pure even-aged stands which is essential in growth and yield modelling. The data used in this study were obtained from six different age classes. Five sample plots each were selected across all age classes in which a total of 712 trees were measured, variables measured include total height, diameter at the base, middle, top, and diameter at the breast height were taken from 30 temporary sampled plots of 25x25m approximately from the centre, 180 dominant trees were selected from 712 trees. Basal area and volume of sampled trees were computed. Yield values obtained from the dominant trees are (B = 249.312 m3/ha, D = 196.128 m3/ha, F = 134.976 m3/ha, C = 119.328 m3/ha, E = 100.320 m3/ ha and A = 86.976 m3/ha). The results showed that B was the best and A was the poorest. Seventeen models were generated and paired sampled t-test was used for model validation, comparing the actual and predicted height. Two out of 17 were rejected (significant P<0.05). The first model Hd=12075.346-354.809(Age)+3.448(Age)2-135193.126(1/Age) is the recommended height estimation of Teak in Kanya Forest plantation for its best performance.

scholarly journals A Dynamic Stand Growth Model System for Loblolly Pine Responding to Mid-Rotation Treatments

Forests ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 556
Author(s):  
Mauricio Zapata-Cuartas ◽  
Bronson P. Bullock ◽  
Cristian R. Montes ◽  
Michael B. Kane
Keyword(s):  
Growth Model ◽  
Loblolly Pine ◽  
Basal Area ◽  
Model System ◽  
Growth And Yield ◽  
Site Quality ◽  
Response To Treatment ◽  
Plantation Management ◽  
Vegetation Control ◽  
Dominant Height

Intensive loblolly pine (Pinus taeda L.) plantation management in the southeastern United States includes mid-rotation silvicultural practices (MRSP) like thinning, fertilization, competitive vegetation control, and their combinations. Consistent and well-designed long-term studies considering interactions of MRSP are required to produce accurate projections and evaluate management decisions. Here we use longitudinal data from the regional Mid-Rotation Treatment study established by the Plantation Management Research Cooperative (PMRC) at the University of Georgia across the southeast U.S. to fit and validate a new dynamic model system rooted in theoretical and biological principles. A Weibull pdf was used as a modifier function coupled with the basal area growth model. The growth model system and error projection functions were estimated simultaneously. The new formulation results in a compatible and consistent growth and yield system and provides temporal responses to treatment. The results indicated that the model projections reproduce the observed behavior of stand characteristics. The model has high predictive accuracy (the cross-validation variance explained was 96.2%, 99.7%, and 98.6%; and the prediction root mean square distance was 0.704 m, 19.1 trees ha−1, and 1.03 m2ha−1 for dominant height (DH), trees per hectare (N), and basal area (BA), respectively), and can be used to project the current stand attributes following combinations of MRSP and with different thinning intensities. Simulations across southern physiographic regions allow us to conclude that the most overall ranking of MRSP after thinning is fertilization + competitive vegetation control (Fert + CVC) > fertilization only (Fert) > competitive vegetation control only (CVC), and Fert + CVC show less than additive effect. Because of the model structure, the response to treatment changes with location, age of application, and dominant height growth as indicators of site quality. Therefore, the proposed model adequately represents regional growth conditions.

A Growth and Yield Model for Improved Eastern Cottonwood Plantations in the Lower Mississippi Delta

1991 ◽  
Vol 15 (4) ◽  
pp. 213-216 ◽  
Author(s):  
Quang V. Cao ◽  
Kenneth M. Durand
Keyword(s):  
Populus Deltoides ◽  
Mississippi Delta ◽  
Basal Area ◽  
Site Index ◽  
Growth And Yield ◽  
Annual Increment ◽  
Yield Model ◽  
Eastern Cottonwood ◽  
Volume Yield ◽  
Growth And Yield Model

Abstract A compatible growth and yield model was developed based on remeasurement data collected from 183 plots on unthinned improved eastern cottonwood (Populus deltoides Bartr.) plantations in the lower Mississippi Delta. The Sullivan and Clutter (1972) equation form was selected for predicting cubic-foot volume yield and projecting volume from site index and initial age and basal area. Yield equations explained 97% and 94%, respectively, of the variations in total outside bark and merchantable inside bark volumes. Mean annual increment of merchantable volume culminated between 8 and 15 years, depending on site index and initial basal area. South. J. Appl. For. 15(4):213-216.

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 Stand-Level Components of a Growth and Yield Model for Nothofagus Mixed Forests from Southern Chile

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 810
Author(s):  
Sebastian Palmas ◽  
Paulo C. Moreno ◽  
Wendel P. Cropper ◽  
Alicia Ortega ◽  
Salvador A. Gezan
Keyword(s):  
Forest Type ◽  
Geographical Area ◽  
Basal Area ◽  
Forest Growth ◽  
Model Systems ◽  
Growth And Yield ◽  
Permanent Plots ◽  
Stand Age ◽  
Yield Model ◽  
Mixed Forests

Reliable information on stand dynamics and development is needed to improve management decisions on mixed forests, and essential tools for this purpose are forest growth and yield (G&Y) models. In this study, stand-level G&Y models were built for cohorts within the natural mixed second-growth Nothofagus-dominated forests in Chile. All currently available (but limited) data, consisting of a series of stratified temporary and permanent plots established in the complete range of this forest type, were used to fit and validate these models. Linear and nonlinear models were considered, where dominant stand age, number of trees, and the proportion of basal area of Nothofagus species resulted in significant predictors to project future values of stand basal area for the different cohorts (with R2 > 0.51 for the validation datasets). Mortality was successfully modeled (R2 = 0.79), based on a small set of permanent plots, using the concept of self-thinning with a proposed model defined by the idea that, as stands get closer to a maximum density, they experience higher levels of mortality. The evaluation of these models indicated that they adequately represent the current understanding of dynamics of basal area and mortality of Nothofagus and companion species in these forests. These are the first models fitted over a large geographical area that consider the dynamics of these mixed forests. It is suggested that the proposed models should constitute the main components of future implementations of G&Y model systems.

scholarly journals A Growth and Yield Model Incorporating Hardwood Competition for Natural Loblolly Pine Stands in the Georgia Piedmont

1999 ◽  
Vol 23 (3) ◽  
pp. 179-185 ◽  
Author(s):  
Stacey W. Martin ◽  
Graham H. Brister
Keyword(s):  
Loblolly Pine ◽  
Basal Area ◽  
Growth And Yield ◽  
Parameter Estimates ◽  
Yield Model ◽  
Pinus Taeda L ◽  
Projection Equations ◽  
Georgia Piedmont ◽  
The Impact ◽  
Over Time

Abstract Using 5 yr remeasurement data from even-aged natural loblolly pine (Pinus taeda L.) stands in the Georgia Piedmont, a system of growth equations was developed to project pine yield over time that accounts for hardwood competition. In this system, the increase in the proportion of hardwood basal area over time is estimated, then the projected pine basal area and trees per acre are adjusted inversely to account for this increase. The parameter estimates for this system ensure compatibility between volume prediction and projection equations and the proportion of hardwood basal area, pine basal area, dominant height, and trees per acre projection equations. The whole-stand growth and yield system developed here coupled with published merchantable yield equations allow for the evaluation of the impact of hardwoods on future stand yield and product distributions. The results indicate that the impact of hardwood competition on pine yield is substantial and occurs mainly as a reduction in sawtimber volume. South. J. Appl. For. 16(3):179-185.

scholarly journals Financial and risk analysis of African mahogany plantations in Brazil

2018 ◽  
Vol 42 (2) ◽  
pp. 148-158
Author(s):  
Andressa Ribeiro ◽  
Carolina Souza Jarochinski e Silva ◽  
Antonio Carlos Ferraz Filho ◽  
José Roberto Soares Scolforo
Keyword(s):  
Interest Rates ◽  
Net Present Value ◽  
Financial Analysis ◽  
Initial Density ◽  
Growth And Yield ◽  
Financial Return ◽  
African Mahogany ◽  
Management Regimes ◽  
Wood Demand ◽  
Growth And Yield Modeling

ABSTRACT Wood demand is increasing in quality and quantity, and economic studies are fundamental to analyze the feasibility of forest projects. These researches are in line with management and silvicultural studies, highlighting growth and yield modeling. This paper proposes an economic evaluation of implementation of African mahogany stands in Brazil under different perspectives of forest management. Data are from plantations ranging from 1.1 to 15 years old in different Brazilian regions. Financial analysis was undertaken using Net Present Value (NPV), Internal Rate of Return (IRR) and Equal Annual Equivalent (EAE) for a 20-year period considering three thinning management regimes (A - unthinned, B - one thinning at age 10 years remaining 150 trees ha-1 and C - two thinnings, first at age 8 remaining 150 trees ha-1 and second at age 15 years remaining 75 trees ha-1) considering an initial density of 278 trees ha-1. A Monte Carlo simulation was performed considering six risk variables. Results showed that the discount rate is the variable that most influences the viability of the project. All site indexes in all management regimes lead to a feasible financial return, with NPV values ranging from 25,053 to 125,780 Brazilian reais per hectare, being regimes B and C the best ones. The probability for an unfeasible investment is almost zero, highlighting African mahogany as a great forest investment opportunity, providing high interest rates values (14% to 25%), superior to most available market rates of return.

scholarly journals A New Whole-Stand Model for Unmanaged Loblolly and Slash Pine Plantations in East Texas

2009 ◽  
Vol 33 (2) ◽  
pp. 69-76 ◽  
Author(s):  
Dean W. Coble
Keyword(s):  
Loblolly Pine ◽  
Basal Area ◽  
Pinus Elliottii ◽  
Current Data ◽  
Slash Pine ◽  
Pine Plantations ◽  
Growth And Yield ◽  
East Texas ◽  
Age Classes ◽  
Yield Model

Abstract A new compatible whole-stand growth-and-yield model to predict total tree cubic-foot volume per acre yield (outside and inside bark) was developed for unmanaged loblolly pine (Pinus taeda) and slash pine (Pinus elliottii) plantations in East Texas. This model was compared with the noncompatible whole-stand model of Lenhart (<xref ref-type="bibr" rid="B15-2127">Lenhart, 1996</xref>, Total and partial stand-level yield prediction for loblolly and slash pine plantations in east Texas, South. J. Appl. For. 20(1):36–41) and the <xref ref-type="bibr" rid="B15-2127">Lenhart (1996)</xref> model refit to current data. For the two species, all three models were evaluated with independent observed data. The model developed in this study outperformed both Lenhart models in prediction of future yield and basal area per acre for all age classes combined and by 5-year age classes. The Lenhart models consistently overestimated yield and basal area per acre. All three models predicted surviving trees per acre similarly. An example is also provided to show users how to use the new whole-stand model.

A dynamic programming algorithm for optimization of uneven-aged forest stands

1994 ◽  
Vol 24 (9) ◽  
pp. 1758-1765 ◽  
Author(s):  
David J. Anderson ◽  
B. Bruce Bare
Keyword(s):  
Dynamic Programming ◽  
Interest Rates ◽  
Net Present Value ◽  
Initial Conditions ◽  
Dynamic Programming Algorithm ◽  
Basal Area ◽  
Management Problem ◽  
Present Value ◽  
Stand Management ◽  
The Impact

A deterministic dynamic programming formulation of the transition uneven-aged stand management problem is presented. Using a previously published northern hardwoods growth model, a forward recursive, discrete, two-state problem that maximizes the net present value of harvested trees at each stage is developed. State variables represent the total number of trees and the total basal area per acre. A neighborhood storage concept previously published is used to reduce the number of states considered at each stage. Two harvest allocation rules are used to assign the harvested basal area to individual diameter classes. Terminal end point conditions and stage to stage sustainability are not required. Results from four base runs of the model are presented and compared with previously published results. Each run produces significantly different optimal paths, with one showing a higher net present value than any previously published. Sensitivity runs illustrate the impact of changes in interest rates, width of neighborhood storage class, and initial conditions. Dynamic programming offers promise for analyzing uneven-aged stand management problems.

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