UTILIZING INFORMATION ON SITE HYDROLOGY IN GROWTH AND YIELD MODELING: PEATLAND MODELS IN THE MOTTI STAND SIMULATOR

2013 ◽  
Author(s):  
H. Hökkä & H. Salminen
Keyword(s):  
Growth And Yield ◽  
Yield Modeling ◽  
Growth And Yield Modeling

scholarly journals Forest Growth and Yield Modeling

2011 ◽  
Author(s):  
Aaron R. Weiskittel ◽  
David W. Hann ◽  
John A. Kershaw ◽  
Jerome K. Vanclay
Keyword(s):  
Forest Growth ◽  
Growth And Yield ◽  
Yield Modeling ◽  
Growth And Yield Modeling ◽  
Forest Growth And Yield

scholarly journals Use data from permanent sampling points in growth and yield modeling

2007 ◽  
Vol 31 (1) ◽  
pp. 59-69 ◽  
Author(s):  
Alexandre José Pereira ◽  
Helio Garcia Leite ◽  
João Carlos Chagas Campos ◽  
Agostinho Lopes de Souza
Keyword(s):  
Eucalyptus Grandis ◽  
Basal Area ◽  
Site Index ◽  
Minas Gerais ◽  
Growth And Yield ◽  
Western Region ◽  
Independent Variables ◽  
Yield Modeling ◽  
Sampling Points ◽  
Growth And Yield Modeling

This study was carried to evaluate the efficiency of the Bitterlich method in growth and yield modeling of the even-aged Eucalyptus stands. 25 plots were setup in Eucalyptus grandis cropped under a high bole system in the Central Western Region of Minas Gerais, Brazil. The sampling points were setup in the center of each plot. The data of four annual mesurements were colleted and used to adjust the three model types using the age, the site index and the basal area as independent variables. The growths models were fitted for volume and mass of trees. The efficiency of the Bitterlich method was confirmed for generating the data for growth and yield modeling.

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.

A simple production function model for variable density growth and yield modeling

1984 ◽  
Vol 14 (6) ◽  
pp. 783-788 ◽  
Author(s):  
Sun Joseph Chang
Keyword(s):  
Site Index ◽  
Yield Function ◽  
Variable Density ◽  
Growth And Yield ◽  
Planting Density ◽  
Annual Increment ◽  
Yield Data ◽  
Growth Functions ◽  
Basic Model ◽  
Growth And Yield Modeling

This paper proposes a logarithmic–reciprocal yield function that improves upon the function proposed by Nautiyal and Couto (J. C. Nautiyal and L. Couto. 1982. Can. J. For. Res. 12: 452–458) by allowing forest crops starting with different stocking levels to eventually approach the same volume and peaking of the current annual increment (CAI) at different ages of the stands. The function is then used to fit yield data generated from Smalley and Bailey's study (Smalley, G. W., and R. L. Bailey. 1974. U.S. For. Serv. Res. Pap. SO–96) that shows wobbles in CAI and changes in yield as a result of changes in planting density. The basic model is then expanded by incorporating site index to account for local differences in productivity. Finally, compatible growth functions that can be estimated with log differences in yield instead of instantaneous growth are also derived.

Growth and yield of okra (Abelmoschus esculentus (L.) Moench) grown in the marginal upland area of Sta. Rita, Samar as influenced by different planting densities and mulching materials

2017 ◽  
pp. 44-54
Author(s):  
Zenaida Gonzaga ◽  
Warren Obeda ◽  
Ana Linda Gorme ◽  
Jessie Rom ◽  
Oscar Abrantes ◽  
...  
Keyword(s):  
Bare Soil ◽  
Abelmoschus Esculentus ◽  
Growth And Yield ◽  
Planting Density ◽  
Rice Hull ◽  
Plastic Mulch ◽  
Lady’S Finger ◽  
Materials Used ◽  
Set Up ◽  
A Minor

Okra or Lady’s finger, botanically known as Abelmoschus esculentus (L.) Moench, is a tropical and sub-tropical indigenous vegetable crop commonly grown for its fibrous, slimy, and nutritious fruits and consumed by all classes of population. It has also several medicinal and economic values. Despite its many uses and potential value, its importance is under estimated, under-utilized, and considered a minor crop and little attention was paid to its improvement. The study was conducted to evaluate the effects of different planting densities and mulching materials on the growth and yield of okra grown in slightly sloping area in the marginal uplands in Sta. Rita, Samar, Philippines. A split-plot experiment was set up with planting density as main plot and the different mulching materials as the sub-plot which were: unmulched or bare soil, rice straw, rice hull, hagonoy and plastic mulch. Planting density did not significantly affect the growth and yield of okra. Regardless ofthe mulching materials used, mulched plants were taller and yielded higher compared to unmulched plants. Moreover, the use of plastic mulch resulted to the highest total fruit yield. The results indicate the potential of mulching in increasing yield and thus profitability of okra production under marginal upland conditions.

Response of corn (Zea mays L.) to various organic-based fertilizers in marginal upland of Sta. Rita, Samar

2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno
Keyword(s):  
Block Design ◽  
Management Strategies ◽  
Chemical Properties ◽  
Organic Fertilizers ◽  
Growth And Yield ◽  
Physical And Chemical Properties ◽  
Total N ◽  
Randomized Complete Block Design ◽  
Physical And Chemical ◽  
And Chemical Properties

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.

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