scholarly journals Effects of errors in basal area and mean diameter on the optimality of forest management prescriptions

2021 ◽  
Vol 78 (1) ◽  
Author(s):  
Roope Ruotsalainen ◽  
Timo Pukkala ◽  
Annika Kangas ◽  
Petteri Packalen
Keyword(s):  
Forest Management ◽  
Net Present Value ◽  
Basal Area ◽  
Inventory Data ◽  
Present Value ◽  
Management Objectives ◽  
Mean Diameter ◽  
Stand Attributes ◽  
Relative Errors ◽  
Correct Data

Abstract • Key message Errors in forest stand attributes can lead to sub-optimal management prescriptions concerning the set management objectives. When the objective is net present value, errors in mean diameter result in greater losses than similar errors in basal area, and underestimation greater losses than overestimation. • Context Errors in forest inventory data can cause inoptimality losses in the objectives set to forest management. Losses occur when the forest is treated with management prescriptions that are optimal for erroneous data but not for correct data. • Aims We evaluate the effect of varying levels of errors in basal area and mean diameter on the inoptimality losses. • Methods Errors from 20% of overestimation to 20% of underestimation were simulated in basal area and mean diameter. For each stand, the management prescription that maximized the net present value was selected with and without errors. The inoptimality losses were calculated for different error levels. • Results The tested error levels resulted in inoptimality losses of 0.11–3.01%. Errors in mean diameter increased inoptimality losses more than similar relative errors in basal area. Simultaneous underestimation of basal area and mean diameter led to greater inoptimality losses than simultaneous overestimation of these attributes. • Conclusion If the forest is considered as an investment, using inventory data where basal area and mean diameter are underestimated causes greater losses compared with data where these attributes are overestimated. Errors in mean diameter are more important than similar errors in the basal area. Large errors in basal area and mean diameter should be avoided especially in stands where the basal area is high.

Inoptimality losses in forest management decisions caused by errors in an inventory based on airborne laser scanning and aerial photographs

2010 ◽  
Vol 40 (12) ◽  
pp. 2427-2438 ◽  
Author(s):  
Md. Nurul Islam ◽  
Mikko Kurttila ◽  
Lauri Mehtätalo ◽  
Timo Pukkala
Keyword(s):  
Input Data ◽  
Laser Scanning ◽  
Basal Area ◽  
Airborne Laser Scanning ◽  
Aerial Photographs ◽  
Stand Age ◽  
Inventory Data ◽  
Airborne Laser ◽  
Mean Diameter ◽  
The Mean

Errors in inventory data may lead to inoptimal decisions that ultimately result in financial losses for forest owners. We estimated the expected monetary losses resulting from data errors that are similar to errors in laser-based forest inventory. The mean loss was estimated for 67 stands by simulating 100 realizations of inventory data for each stand with errors that mimic those in airborne laser scanning (ALS) based inventory. These realizations were used as input data in stand management optimization, which maximized the present value of all future net incomes (NPV). The inoptimality loss was calculated as the difference between the NPV of the optimal solution and the true NPV of the solution obtained with erroneous input data. The results showed that the mean loss exceeded €300·ha–1 (US$425·ha–1) in 84% of the stands. On average, the losses increased with decreasing stand age and mean diameter. Furthermore, increasing errors in the basal area weighted mean diameter and basal area of spruce were found to significantly increase the loss. It has been discussed that improvements in the accuracy of ALS-based inventory could be financially justified.

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.

Relationships between tree crown, stem, and stand characteristics in unthinned loblolly pine plantations

1987 ◽  
Vol 17 (6) ◽  
pp. 534-538 ◽  
Author(s):  
Peter T. Sprinz ◽  
Harold E. Burkhart
Keyword(s):  
Loblolly Pine ◽  
Basal Area ◽  
Projection Area ◽  
Diameter Growth ◽  
Tree Crown ◽  
Basal Area Growth ◽  
Area Growth ◽  
Mean Diameter ◽  
Stand Attributes ◽  
Stand Characteristics

Empirical and theoretical relationships between tree crown, stem, and stand characteristics for unthinned stands of planted loblolly pine (Pinustaeda L.) were investigated. Readily measured crown variables representing the amount of photosynthetic area or distance of the translocation process were identified. Various functions of these variables were defined and evaluated with regard to efficacy in predicting stem and stand attributes. Linear models were used to evaluate the contribution of the crown variables in predicting stem and stand characteristics. The stem attributes modeled included basal area, basal area growth, diameter at breast height, and diameter growth, while the stand attributes modeled were basal area, basal area growth, arithmetic mean diameter, and mean diameter growth. Crown diameter and crown projection area were particularly important in contributing to model fit and prediction of individual stem characteristics, while sum of crown projection areas was found especially important in stand level equations. As these crown measures developed over time so did corresponding stem and stand attributes.

scholarly journals Economic analysis of sustainable management of candeia

CERNE ◽  
2010 ◽  
Vol 16 (3) ◽  
pp. 335-345 ◽  
Author(s):  
Antonio Donizette de Oliveira ◽  
Ivonise Silva Andrade Ribeiro ◽  
José Roberto Soares Scolforo ◽  
José Márcio de Mello ◽  
José Luiz Pereira de Rezende
Keyword(s):  
Forest Management ◽  
Economic Analysis ◽  
Sustainable Management ◽  
Net Present Value ◽  
Oil Production ◽  
Planning Horizon ◽  
Economic Feasibility ◽  
Present Value ◽  
Production Methods ◽  
The Interest Rate

Candeia wood (Eremanthus erythropappus) is widely used for production of essential oil and its active ingredient, alpha-bisabolol, is consumed by both the cosmetics and pharmaceutical industry. This study aimed to determine the productivity and operating costs associated with exploration, transportation and commercialization of candeia timber obtained from sustainable management systems and used for oil production; to determine the gross income or revenue obtained from the sale of candeia timber; to analyze the economic feasibility of sustainable management of candeia. For the economic analysis, Net Present Value, Net Present Value over an infinite planning horizon, and Average Cost of Production methods were used. Results indicated that the most significant costs associated with candeia forest management involve transportation and exploration. Together they account for 64% of the total management cost. Candeia forest management for oil production is economically feasible, even in situations where the interest rate is high or timber price drops to levels well below currently effective prices. As far as candeia forest management is concerned, shorter harvest cycles allow higher profitability. However, even in situations where the harvest cycle is relatively long (30 years), the activity is still economically feasible.

scholarly journals The pertinent role of forest inventory in making choice of silvicultural operations in community forests of Nepal

2018 ◽  
pp. 65-75 ◽  
Author(s):  
S. G. Baral ◽  
H. Vacik ◽  
B. B. K. Chhetri ◽  
K. Gauli
Keyword(s):  
Time Series ◽  
Forest Management ◽  
Forest Inventory ◽  
Sustainable Forest Management ◽  
Forest Stand ◽  
Inventory Data ◽  
Community Forests ◽  
Management Objectives ◽  
Management Plans ◽  
Stand Conditions

This paper explores the application of forest inventory to design silvicultural operations and its implementation to community forests. Four-time series forest inventory data (2005, 2010, 2013 and 2016) of Terai community forests were analysed, focusing on the type and size of tree removals from the forests. In addition, content analysis of the management plans of the forests was carried out and consultations were held with key informants. Though the forest inventory was prepared during the preparation of management plans, the results did not provide proper guidance on the selection of silvicultural operations, which were decided without a clear definition of the management objectives. They were very generic and largely ignored site-specific forest stand conditions. Most commonly practised silvicultural operations were cleaning and selective harvesting, which were similar for all forest blocks, though they varied in respect of forest stand conditions. The time series analysis of the inventory data showed that pole-sized trees were consistently removed in all four periods and emphasis was on extracting good quality trees without considering its effects on the stand. The study concludes that the current forest inventory is not very relevant in making a choice about silvicultural operations and the current practices might cause economic and ecological losses. Hence, we argued for identifying minimum forest management requirement necessary for the sustainable forest management that the silvicultural operations should be decided based on the management objectives and conditions of the forest, considering the ecological and economic value of the forest. Banko JanakariA Journal of Forestry Information for Nepal Special Issue No. 4, 2018, Page : 65-75

The effects of sample plot selection strategy and the number of sample plots on inoptimality losses in forest management planning based on airborne laser scanning data

2019 ◽  
Vol 49 (9) ◽  
pp. 1135-1146 ◽  
Author(s):  
Roope Ruotsalainen ◽  
Timo Pukkala ◽  
Annika Kangas ◽  
Jari Vauhkonen ◽  
Sakari Tuominen ◽  
...  
Keyword(s):  
Forest Management ◽  
Laser Scanning ◽  
Net Present Value ◽  
Training Data ◽  
Selection Strategy ◽  
Sample Plot ◽  
K Nearest Neighbors ◽  
Management Planning ◽  
Forest Management Planning ◽  
Stand Attributes

In forest management planning, errors in predicted stand attributes might lead to suboptimal decisions that result in decreased net present value (NPV). Forest inventory data will have higher value if the amount of suboptimal decisions can be decreased. Therefore, the value of information can be measured through the decrease in inoptimality losses, which are the NPV differences between the optimal and suboptimal decisions. In this study, four alternative sample plot selection strategies with different numbers of sample plots were compared in terms of expected mean inoptimality losses. Stand-level mean inoptimality losses varied between €41.1·ha–1 and €80.7·ha−1, depending on the sample plot selection strategy and the number of sample plots used as training data in the k-nearest neighbors imputation method. Mean inoptimality losses decreased substantially when the number of sample plots increased from 25 to 100, and the decreasing trend continued until 500 sample plots. Total inoptimality losses can decrease by approximately €1 million in an inventory area of 100 000 ha when the number of sample plots is increased from 100 to 500. The measurement of more sample plots can be justified as long as the field measurement costs do not exceed the decrease in inoptimality losses.

scholarly journals Forest management decision-making using goal programming and fuzzy analytic hierarchy process approaches (case study: Hyrcanian forests of Iran)

2019 ◽  
Vol 65 (No. 9) ◽  
pp. 368-379
Author(s):  
Seyedeh Soma Etemad ◽  
Soleiman Mohammadi Limaei ◽  
Leif Olsson ◽  
Rasoul Yousefpour
Keyword(s):  
Decision Making ◽  
Environmental Economic ◽  
Forest Management ◽  
Analytic Hierarchy Process ◽  
Goal Programming ◽  
Net Present Value ◽  
Present Value ◽  
Analytic Hierarchy ◽  
Stock Level ◽  
Hierarchy Process

The aim of this study is to determine the optimum stock level in the forest. In this research, a goal programming method was used to estimate the optimal stock level of different tree species considering environmental, economic and social issues. We consider multiple objectives in the process of decision-making to maximize carbon sequestration, net present value and labour. We used regression analysis to make a forest growth model and allometric functions for the quantification of carbon budget. Expected mean price is estimated using wood price and variable harvesting costs to determine the net present value of forest harvesting. The fuzzy analytic hierarchy process is applied to determine the weights of goals using questionnaires filled in by experts in order to generate the optimal stock level. According to the results of integrated goal programming approach and fuzzy analytic hierarchy processes, optimal volume for each species was calculated. The findings indicate that environmental, economic and social outcomes can be achieved in a multi-objective forestry program for the future forest management plans.

Optimal forest management under financial risk aversion with discounted Markov decision process models

2019 ◽  
Vol 49 (7) ◽  
pp. 802-809
Author(s):  
Mo Zhou ◽  
Joseph Buongiorno
Keyword(s):  
Forest Management ◽  
Risk Aversion ◽  
Net Present Value ◽  
Income Smoothing ◽  
Variance Analysis ◽  
Process Models ◽  
Financial Returns ◽  
Present Value ◽  
Markov Decision ◽  
Mean Variance

The common assumption of risk neutrality in forest decision making is generally inadequate because the stakeholders tend to be averse to fluctuations in the return criteria. In Markov decision processes (MDPs) of forest management, risk aversion and standard mean-variance analysis can be readily dealt with if the criteria are undiscounted expected values. However, with discounted criteria such as the fundamental net present value of financial returns, the classic mean-variance optimization is numerically intractable. In lieu of this, this paper (i) presents a linear-programming method to calculate the variance of discounted criteria conditional on any specific policy and (ii) adopts, as an alternative to the variance measure of risk, the “discount normalized variance” (DNV), an economically meaningful criterion consistent with income-smoothing behavior. The DNV is then used in procedures analogous to mean-variance analysis and certainty-equivalent optimization tractable by quadratic programming. The methods are applied to the management of uneven-aged, mixed-species forests in the southern United States. The results document the trade-off between the expected net present value and risk of financial returns, as well as the consequences for selected ecological criteria.

Partial Calibration of "ONTWIGS": A Forest Growth and Yield Projection System Adapted for Ontario

1994 ◽  
Vol 11 (2) ◽  
pp. 41-46 ◽  
Author(s):  
Bijan Payandeh ◽  
Pia Papadopol
Keyword(s):  
Basal Area ◽  
Forest Growth ◽  
Data Sets ◽  
Prediction Errors ◽  
Northern Ontario ◽  
Quadratic Mean ◽  
Tree Survival ◽  
Mean Diameter ◽  
Quadratic Mean Diameter ◽  
Stand Attributes

Abstract "ONTWIGS" (an adaptation of "LSTWIGS" for Ontario), was partially calibrated for permanent plots data sets from northern Ontario. Stand attributes used for calibration were quadratic mean diameter, number of trees, and basal area/ha. Simple local calibration was accomplished by adjusting tree survival and potential diameter growth coefficients so as to reduce the prediction errors to within 10% of the actual values over a 5-yr period. This resulted in prediction errors ranging from -9.9 to 6.9%, but with an overall average of only: -1.4, 1.0, and 0.2% for the spruce fir data; from -8.5 to 2.8%, but with an overall average of only -0.7, 0.5, and 0.4% for a black spruce drainage and fertilization experiment; and from -6.6 to 9.8%, but with an overall average of only -1.7, 0.0, and -1.8% for an unthinned red pine plantation for number of trees/ha, quadratic mean diameter, and basal area/ha, respectively. Results indicate that "ONTWIGS" may be locally calibrated through simple procedures to increase its prediction accuracy to ±5% of the observed stand attributes, averaging less than 3% for the major timber species in northern Ontario and for short to medium projection periods. However, the uncalibrated model should be used with caution for short terms, only and where no other projection tools are available. More extensive calibrations of "ONTWIGS" on larger and more representative data sets are currently underway. North. J. Appl. For. 11(2):41-46.

The Potential Economic Effect of Lease Hunting on Forest Management in the Southeast

1992 ◽  
Vol 16 (4) ◽  
pp. 200-203 ◽  
Author(s):  
Allan P. Marsinko ◽  
Webb M. Smathers ◽  
David C. Guynn ◽  
Gerald L. Stuckey
Keyword(s):  
United States ◽  
Forest Management ◽  
Public Relations ◽  
Net Present Value ◽  
Economic Effect ◽  
Southern United States ◽  
Forest Industry ◽  
Conservative Estimate ◽  
Present Value ◽  
Similar Survey

Abstract A survey was conducted of 1989 forest industry hunt lease programs in the southern United States. Average annual lease fees were $2.15/ac and respondents placed additional implicit values of $2.15/ac and $3.11/ac respectively for public relations and protection(access control, property damage, etc.) benefits. Contributions to net present value ranged from $22.37 for a conservative estimate of leasing alone to $96.64 for an estimate of all benefits when discounted at 6% over a 25-yr rotation. Interest in leasing by industry has increasedsince a similar survey was conducted in 1985. South. J. Appl. For. 16(4):200-203

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