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 Growth and Volume Estimates of Teak (Tectona grandis Linn F.) in Kanya Forest Plantation, Kebbi State, Nigeria

2019 ◽  
pp. 1-10
Author(s):  
A. Dantani ◽  
S. B. Shamaki ◽  
M. A. Gupa ◽  
A. I. Zagga ◽  
B. Abubakar ◽  
...  
Keyword(s):  
Basal Area ◽  
Tectona Grandis ◽  
Growth And Yield ◽  
Forest Plantation ◽  
Scatter Plots ◽  
Volume Production ◽  
Yield Values ◽  
Volume Estimates ◽  
Negative Relationships ◽  
Area And Volume

This study was conducted in order to estimate growth and volume production of Teak (Tectona grandis) in Kanya Forest Plantation, Nigeria. The plantation was divided in to six strata-based age classes (A=38, B=37, C=36, D=35, E=34, F=28, years). Five plots were randomly selected from each stratum. Trees within each plot were enumerated and 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 25x25 m approximately from the center, 180 dominant trees were selected from 712 trees. Descriptive statistic was used to summarize the results while inferential statistic (correlation) was used to establish relationship growth and yield variables. Basal area and volume of sampled trees were computed using Excel as well as scatter plots, correlation analysis was achieved using SPSS statistical package version 20. The results of growth and 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 (37 years) the best and A (38 years) was the poorest. The results of correlation showed positive relationships with most of the tree growth and yield characteristics but negative relationships exist between age and some parameters that is to say as the age increases those parameters are decreasing.

The growth and yield responses of a high site quality red pine plantation to seven thinning treatments and two thinning intervals

1986 ◽  
Vol 16 (3) ◽  
pp. 513-520 ◽  
Author(s):  
Hal O. Liechty ◽  
Glenn D. Mroz ◽  
David D. Reed
Keyword(s):  
Volume Growth ◽  
Basal Area ◽  
Site Index ◽  
Red Pine ◽  
Growth And Yield ◽  
Site Quality ◽  
Pine Plantation ◽  
High Site ◽  
Yield Responses ◽  
Lower Site

Seven thinning treatments with residual densities between 60 and 160 ft3/acre (13.8 and 36.8 m2/ha) of basal area were applied to a highly productive (site index, 81 ft (24.7 m); base age, 50 years) red pine (Pinusresinosa Ait.) plantation. After 10 years, periodic basal area growth was maximized over a lower and much broader range of residual densities than previously found in lower site quality stands. Total and merchantable cubic foot volume growth for the 10 year period was not significantly different between treatments. Application of these thinning treatments on a 6- compared with a 10-year interval reduced total and merchantable cubic foot volume growth while increasing the average stand diameter.

scholarly journals La qualité des stations et la productivité des plantations de pin rouge (Pinus resinosa Ait.) au Québec.

1975 ◽  
Vol 51 (1) ◽  
pp. 16-20
Author(s):  
S. Popovich
Keyword(s):  
Basal Area ◽  
Pinus Resinosa ◽  
Site Index ◽  
Red Pine ◽  
Growth And Yield ◽  
Site Quality ◽  
Average Height ◽  
Stand Volume ◽  
Factors Affecting ◽  
The Relationship

This paper presents an evaluation of site quality based on the relationship between volume per square foot of basal area and age of plantation, for planted red pine (Pinus resinosa Ait.) in Quebec.A graph for the three site index classes is included with indication for its use. There is a table showing the values of volume per square foot of basal area as a function of average height and average form quotient of a stand, permitting a rapid evaluation of stand volume of a plantation. Finally, several factors affecting growth and yield of red pine plantations for various sites in Quebec are discussed.

scholarly journals GROWTH AND YIELD OF EVEN-AGED Cupressus lusitanica PLANTATIONS IN SOUTHERN BRAZIL

FLORESTA ◽  
2021 ◽  
Vol 51 (4) ◽  
pp. 980
Author(s):  
Mário Dobner Jr.
Keyword(s):  
Basal Area ◽  
Site Index ◽  
Growth And Yield ◽  
Site Quality ◽  
Timber Species ◽  
Southern Brazil ◽  
Cupressus Lusitanica ◽  
Dominant Height ◽  
Dominant Height Growth ◽  
Quality Variation

Plantation forestry in southern Brazil demands additional timber species to a higher market differentiation by providing high quality timber and exploitation of market niches. Cupressus lusitanica has long been recognized for this purpose but, until now, it was not properly region-wide quantified in terms of growth and yield. The present study delivers the lacking quantitative approach, which may encourage the commercial use of the species. With this study it was aimed at collecting and processing quantitative data from all known C. lusitanica stands in southern Brazil. Inventories were carried out (60 ha, 6-39 years of age) in order to model the development of dominant height (h100), basal area, volume and dominant diameter (d100). Dominant height was the basis for site quality evaluation, delivering site index curves, which, together with the commercial volume of the stands, allowed yield modelling. A wide amplitude of dominant height growth was detected (10-30 m at 20 years), indicating a great site quality variation. At age of 20 years, commercial volumes of 110 and 620 m³ ha-1 were observed for site indexes of 14 and 26, respectively, equivalent to a maximum of 6-31 m³ ha-1 year-1 at ages between 16-18 years. Results demonstrated in a robust manner that C. lusitanica has a high potential for cultivation in southern Brazil. Thus, offering the opportunity of market differentiation by promoting market niches whose demands timber for special solid end-uses.

Building a dynamic growth model for trembling aspen in western Canada without age data

2013 ◽  
Vol 43 (3) ◽  
pp. 256-265 ◽  
Author(s):  
Oscar García
Keyword(s):  
Populus Tremuloides ◽  
Site Occupancy ◽  
Basal Area ◽  
Site Index ◽  
Growth And Yield ◽  
Site Quality ◽  
Diameter Distribution ◽  
Stand Age ◽  
Parameter Estimates ◽  
Trembling Aspen

A biologically inspired whole-stand growth and yield model was developed for even-aged thinned or unthinned stands dominated by trembling aspen (Populus tremuloides Michx.). The estimation used permanent sample plot data from British Columbia, Alberta, Saskatchewan, and Manitoba, supplemented by published site index and young stand information. An ingrowth imputation procedure was devised to facilitate the use of plot measurements where small trees are not measured. Two published site index models were closely approximated by a simple age-base invariant equation. Good parameter estimates for mortality and basal area growth were obtained without using age observations, which were unreliable or missing. Four differential equations describe the dynamics of top height, trees per hectare, basal area, and a site occupancy factor. Current values of these variables are used to estimate total and merchantable volumes up to any diameter limit and diameter distribution parameters. When an independent source of site quality estimates is available, the final model does not require stand age knowledge for making growth and yield predictions.

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 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 A Novel Approach to Modelling Stand-Level Growth of an Even-Aged Forest Using a Volume Productivity Index with Application to New Zealand-Grown Coast Redwood

Forests ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1155 ◽  
Author(s):  
Mark O. Kimberley ◽  
Michael S. Watt
Keyword(s):  
New Zealand ◽  
Growth Model ◽  
Growth Models ◽  
Stand Density ◽  
Site Index ◽  
Growth And Yield ◽  
Productivity Index ◽  
Site Quality ◽  
Spatial And Temporal Variation ◽  
Coast Redwood

Empirical growth models are widely used to predict the growth and yield of plantation tree species, and the precise estimation of site quality is an important component of these models. The most commonly used proxy for site quality in growth models is Site Index (SI), which describes the mean height of dominant trees at a specified base age. Although SI is widely used, considerable research shows significant site-dependent variation in height for a given volume, with this latter variable more closely reflecting actual site productivity. Using a national dataset, this study develops and describes a stand-level growth and yield model for even-aged New Zealand-grown coast redwood (Sequoia sempervirens). We used a novel modelling approach that quantifies site quality using SI and a volume-based index termed the 300 Index, defined as the volume mean annual increment at age 30 years for a reference regime of 300 stems ha−1. The growth model includes a number of interrelated components. Mean top height is modelled from age and SI using a polymorphic Korf function. A modified anamorphic Korf function is used to describe tree quadratic mean diameter (Dq) as a function of age, stand density, SI and a diameter site index. As the Dq model includes stand density in its formulation, it can predict tree growth for different stand densities and thinning regimes. The mortality model is based on a simple attritional equation improved through incorporation of the Reineke stand density index to account for competition-induced mortality. Using these components, the model precisely estimates stand-level volume. The developed model will be of considerable value to growers for yield projection and regime evaluation. By more robustly describing the site effect, the growth model provides researchers with an improved framework for quantifying and understanding the causes of spatial and temporal variation in plantation productivity.

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