Operations Research Models and the Management of Agricultural and Forestry Resources: A Review and Comparison
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paper_title: Farm-Level Economic Analysis Incorporating Stochastic Environmental Risk Assessment

paper_content:

A farm-level risk programming framework is presented which evaluates income/ environmental risk tradeoffs. This framework uses a time-series of environmental risk indices to incorporate the stochastic, multiattribute characteristics of environmental outcomes associated with agricultural production practices. The model is applied to a representative farm in the Oklahoma Panhandle region of the Central High Plains. Results indicate that expected income is sensitive to nitrate loading restrictions, and relatively less sensitive to pesticide loading restrictions. Results also indicate that prescriptions derived using deterministic environmental risk measures may ignore significant probabilities of exceeding an environmental standard.
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paper_title: Complementary instruments to EEC nitrogen policy in non-sensitive areas: A case study in Southern Spain

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Abstract Current EC nitrogen legislation stipulates for the non-sensitive areas a preventive approach via the development of ‘best management practices’ (BMPs) within a context of voluntary implementation. Under existing technologies, the adoption of BMPs leads to economic losses. A crop simulation model (NTRM) and a mathematical mixed multi-objective programming model (NISE) are used to assess the effects of nitrogen price increase and drainage water reduction in inducing adoption of BMPs. The model shows that increasing nitrogen price cannot be used to stimulate farmers to adopt BMPs. On the other hand, imposing a tax on drainage water could lead to a reduction of up to 37% on the quantity of nitrogen leached with a decreased of only 1·5% in gross margin. However, above this level, drainage water is no longer a useful instrument to reduce and control nitrogen losses, and could lead to inefficient solutions in terms of gross margin and nitrates pollution.
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paper_title: Modeling joint production of wildlife and timber

paper_content:

Abstract Production of marketed commodities and protection of natural systems often conflict. A focus on only one goal can result in large losses in other goals and may result in inefficient and unsustainable outcomes. In this paper, we develop a method that combines economic and ecological models in a dynamic and spatial analysis to evaluate land use decisions and find cost-effective alternatives for which it is not possible to do better on one objective without harming another objective. The method is demonstrated using timber production and species conservation on a forested landscape over a 100-year planning horizon. Current land use strategies are simulated and compared with cost-effective alternatives. The approach is compared to a static reserve approach, similar to previous studies, and found to produce substantially more efficient management strategies for the case study landscape.
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paper_title: On Aggregating Linear Programming Models of Production

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T HIS PAPER presents some aggregation results for linear programming models of the firm. It is assumed that the production decision problem for each firm in some regional, industrial, or typical firm aggregate can be represented by a linear programming model. By means of the duality theorem for dual linear programs, it is shown that under suitable conditions a single linear programming model for the aggregate is equivalent to a direct aggregation of the solutions of a set of individual firm models. Conditions sufficient for this equivalence are proportional variations of resources1 and behavioral "bounds"; proportional variation of net return expectations among all firms in the aggregate; and, finally, common technical coefficients which appear in the constraints on the firms' decisions. It is shown that imperfections in an atomistic market introduced by imperfect knowledge, uncertainty, or government policies may increase the number of aggregate models needed to describe an entire industry such as agriculture. An example is explored and implications of the model for equilibrium of an "open" economy sketched out.
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paper_title: Aggregation of Heterogeneous Firms in Mathematical Programming Models

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Serious aggregation errors may arise in mathematical programming sector models when aggregation is not properly done. Existing aggregation literature mostly focuses on exact aggregation of homogenous groups of firms. However, homogeneity rarely holds in real problem situations. Moreover, theoretical aggregation developments are generally based on the assumption of availability of full information about the firms to be aggregated. Such full information is hardly a plausible assumption when modeling the agricultural sector. This paper discusses an empirical aggregation approach based on decomposition theory, which may be particularly helpful while aggregating heterogenous firms under the absence of full information. Copyright 1989 by Oxford University Press.
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paper_title: Spatial Equilibrium and Quadratic Programming

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This paper attempts to indicate how spatial equilibrium models of the Enke-Samuelson variety may be handled as quadratic programming problems. Assuming the existence of linear regional demand and supply relations, models are formulated and algorithms specified which may be used to obtain directly and efficiently the interregional price and flow solutions for the single and multiproduct, n region cases. For each of the specifications the existence, uniqueness and convergence characteristics are investigated and the conditions for obtaining optimum solutions are noted. Illustrative numerical examples are given to reflect the structure of the programming formulation for several alternative spatial models.
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paper_title: Market Equilibrium Computations in Activity Analysis Models

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This paper shows how an approximate competitive market equilibrium may be computed as the solution to a linear programming model, when production possibilities are described by activity analysis vectors and demand functions are locally linear. Numerical examples show that the degree of approximation may be expected to be very small in many cases. Prices and quantities of goods and resources and also incomes are explicit in the primal. The defining characteristics of a market equilibrium are written as primal constraints. Linearizations of inherently nonlinear expressions are attained by use of grid linearizations and the associated interpolation variables.
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paper_title: Coping with Risk in Agriculture

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The popular first edition of this standard text on risk analysis and management in agriculture has been almost wholly revised. The second edition includes much new material. There is a revised chapter on incorporating decision makers' preferences into the analysis of risky choices that recognizes and gives consideration to some recently published challenges to the legitimacy of the expected utility hypothesis. While it is argued that the theory is still the best way to handle risk aversion, at least in prescriptive analyses, more attention is given to the practical problems of utility function elicitation. It is shown how estimates of (or ranges of) degree of risk aversion might best be obtained and consistently applied. The new edition has a much more thorough treatment of stochastic simulation, including some novel yet simple methods for dealing to stochastic dependency between uncertain quantities. The treatment of policy aspects of risk in agriculture has been revised and extended to account for such important current issues as new approaches to crop insurance, the management of serious animal and crop diseases and food safety issues. As with the first edition, the book contains a blend of theory with simple illustrative examples to enable readers to see how the principles being discussed can be made operational using modern software.
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paper_title: GAME THEORY-AN EXTENSION OF ITS APPLICATION TO FARM PLANNING UNDER UNCERTAINTY

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Current game theoretic models for farnt planning are limited in scope and restrictive in their assumptions. This paper reviews the current status of such models, compares them to the quadratic programming model, and then combines the desirable features of the game theoretic and quadratic Programming approaches by means of parametric linear programming
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paper_title: Generalized Constrained Games in Farm Planning

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Constrained games arise when the mixed strategies of a finite rectangular game are subject to further constraints in the form of linear inequalities. Such games permit more realistic and convenient formulation of many decision problems. This paper offers a generalization of the constrained game model which widens the scope of game-theoretic approaches in farm planning. Solution procedures are proposed for Savage's minimax regret, Hurwicz's pessimism-optimism index, and the "Wald-maximax" and "Wald-Savage" criteria. It is shown that the proposed approaches can handle uncertainty in the inequality constraints. An application to a farm planning problem concludes the paper.
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paper_title: A Linear Alternative to Quadratic and Semivariance Programming for Farm Planning under Uncertainty

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Quadratic decision criteria for farm planning are theoretically appealing but difficult to handle computationally. This paper reviews the advantages of the quadratic approach and develops a linear alternative which, while retaining most of the desired features of the quadratic models, can be readily solved on conventional linear programming codes with the parametric option.
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paper_title: Goal Programming and Agricultural Planning

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Goal Programming is similar in structure to linear programming, but offers a more flexible approach to planning problems by allowing a number of goals which are not necessarily compatible to be taken into account, simultaneously. The use of linear programming in farm planning is reviewed briefly. Consideration is given to published evidence of the goals of farmers, and ways in which these goals can be represented. A goal programming model of a 600 acre mixed farm is described and evaluated. Advantages and shortcomings of goal programming in relation to linear programming are considered. It is found that goal programming can be used as a means of generating a range of possible solutions to the planning problem.
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paper_title: Multiple Criteria Analysis for Agricultural Decisions

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PART ONE. MULTIPLE CRITERIA IN AGRICULTURAL DECISIONS. 1. Main Features of the MCDM Paradigm. Criticism of the traditional paradigm for decision making. Economic versus technological decisions. Multiple objectives and goals in agricultural economics. Historical origins of the MCDM paradigm. Plan of the book. 2. Some Basic Concepts. Attributes, objectives and goals. Distinction between goals and constraints. Pareto optimality. Trade-offs amongst decision making criteria. A first approximation of the main MCDM approaches. PART TWO. MULTIPLE CRITERIA DECISION MAKING TECHNIQUES. 3. Goal Programming (GP). Introductory example for handling multiple-criteria in a farm planning model. The role of deviational variables in GP. Lexicographic goal programming (LGP). Sensitivity analysis in LGP. The graphical method for LGP. The sequential linear method (SLM) for LGP. A brief comment on other LGP algorithms. Weighted goal programming (WGP). A critical assessment of GP. Some extensions of GP. 4. Multiobjective Programming (MOP). An approximation of the multiobjective programming problem. The pay-off matrix in MOP. The constraint method. The Weighting Method. The noninferior set estimation method (NISE). Multigoal programming. Some issues related to the use of MOP techniques. 5. Compromise Programming (CP). An intuitive treatment of the concept of distance measures. A discrete approximation of the best-compromise solution. Compromise programming - a continuous setting. The method of the displaced ideal. Pros and cons of goal programming, multiobjective programming and compromise programming. Relationships among different MCDM approaches. 6. The Interactive MCDM Approach. Structure of an interactive MCDM process. The STEM method. The method of Zionts and Wallenius. Interactive multiple goal programming (IMGP). An assessment of the interactive MCDM approaches. 7. Risk and Uncertainty and the MCDM Techniques. Risk programming techniques in agricultural planning within MCDM framework. Compromise-risk programming. Game theory models and the MCDM framework. Games with multiple goals and GP. Compromise games. PART THREE. CASE STUDIES. 8. A Compromise Programming Model for the Agrarian Reform Programme in Andalusia, Spain. The background. Trade-off curves for seasonal labour, employment and gross margin. Compromise sets. An approximation of the efficient set in a three-dimensional space. Concluding comments. 9. Livestock Ration Formulation and MCDM Techniques. A livestock ration formulation example. Ration formulation as a LGP problem. Ration formulation as a MOP problem. 10. Livestock Ration Formulation with Penalty Functions via GP. Penalty functions in diet formulation. Diet formulation as a WGP model with penalty functions. Diet formulation problem as an LGP model with penalty functions. An assessment. 11. Optimum Fertilizer Use via GP with Penalty Functions. 12. An LGP Model for Logistics Planning in an Agribusiness Company. The background. Data.
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paper_title: Multicriteria analysis for agricultural resource management: A critical survey and future perspectives

paper_content:

Abstract This paper reviews multicriteria analysis applied to agricultural resource management. The applications utilize either methods for selecting multiattribute discrete alternatives (including multiattribute utility theory) or methods for solving multiobjective planning problems (including goal programming). Our main purpose is to classify and evaluate the criteria (attributes, objectives) used for modeling agricultural systems and to identify the difficulties for practitioners in applying the methodology. The fields of study in agricultural decisions requiring further investigation are also discussed.
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paper_title: An Evaluation of Goal Hierarchies for Small Farm Operators

paper_content:

Considerable attention recently has been focused on the small farm sector in the United States. Regional small farm conferences were sponsored by the U.S. Department of Agriculture (USDA) during 1978 (USDA 1978b); the ESCS held a Small-Farm Workshop (USDA 1978c); and the National Small Farms Conference was sponsored by the National Rural Center (Madden and Tischbein) in February 1979. If agricultural policy is to facilitate the accomplishment of small farmers' objectives, then a central issue must be the determination of
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paper_title: Goal programming with penalty functions and livestock ration formulation

paper_content:

Abstract This paper contends that the conventional linear programming paradigm commonly used for livestock ration formulation suffers from several inherent weaknesses. One such weakness is the mathematical rigidity that must be respected to meet the minimum nutritional requirements specified in the model, thus making the paradigm inflexible and unrealistic under many situations. Goal programming techniques, on the other hand, do not impose such rigid conditions and also allow consideration of several decision criteria. This paper represents a departure from the traditional LP approach by formulating the diet formulation problem as a GP model incorporating penalty functions that make the specification of minimum levels of nutrients more flexible and realistic.
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paper_title: Multiple-criteria decision-making techniques and their role in livestock ration formulation

paper_content:

Abstract The livestock ration formulation problem is postulated within the framework of multiple-criteria decision-making techniques. This exercise is motivated by the fact that the ordinary least-cost approach can, and does, generate solutions that either cannot be implemented or supply nutritionally undesirable levels of various nutrients. This originates from using cost as the criterion for selecting the ingredients of the diet. But in fact, diet formulation problems involve several criteria and should, therefore, be solved using techniques designed for modelling such problems. This paper is an attempt at introducing these techniques to agricultural systems modellers and then demonstrating their use in livestock ration formulation. The multiple-criteria decision-making techniques covered include goal programming and its variants such as weighted and lexicographic approaches and multiple-objective programming.
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paper_title: Integration of Markov and Linear Programming Models to Assess the Farmgate and National Consequences of Adopting New Bovine Reproductive Technologies in the United Kingdom Agriculture

paper_content:

Despite many advances in biotechnology being futuristic, in some industries such technological improvements are now becoming generally available for absorption into commercial practice. The new reproductive technologies for bovine animals are such an example. For a regulated industry like agriculture, an ex ante evaluation of the impact of their adoption is the concern of policy makers. This paper describes a modelling strategy devised to assess these impacts, using a sequence of stochastic, financial and linear programming models. A set of individual farm type models were developed and later extended to a national model to simulate the interactions that occur between dairy and beef enterprises and the competition between them for resources on individual farms. Restraints reflecting national policies such as quotas on milk production and industry support through subsidies are built into the model to explore several scenarios. These models are used to assess the impact of new technologies on dairy and beef production nationally and for regions which have been identified by the Ministry of Agriculture, Fisheries and Food.
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paper_title: Using Chance-Constrained Programming for Animal Feed Formulation at Agway

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Agway uses chance-constrained programming to formulate commercial feeds for animals. The finished feeds averaged 40 percent greater nutritional consistency and were lower in cost than feeds formulated by traditional linear programming with a margin of safety. Formulating animal feeds by chance-constrained programming saves Agway, Inc. more than $250,000 per year.
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paper_title: Optimal Replacement of Mastitic Cows Determined by a Hierarchic Markov Process

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Abstract Farmers frequently have to decide whether to keep or to replace cows that suffer from clinical mastitis. A dynamic programming model was developed to optimize these decisions for individual cows within the herd, using the hierarchic Markov process technique. This technique provides a method to model a wide variety of cows, differing in age, productive performance, reproductive status, and clinical mastitis occurrence. The model presented was able to support decisions related to 63% of all replacements. Results—for Dutch conditions—showed the considerable impact of mastitis on expected income of affected cows. Nevertheless, in most cases, the optimal decision was to keep and to treat rather than to replace the cow. Clinical mastitis occurring in the previous lactation negligibly influence expected income. Clinical mastitis in current lactation, especially in the current month, however, had a significant effect on expected income. Total losses caused by clinical mastitis were US$83/yr per cow. Farm level treatment, which reduced incidence by 25% on a farm with 10 clinical quarter cases per 10,000 cow days, may cost at maximum US$27/yr per cow.
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paper_title: Timber RAM-A long-range planning methods for commercial tim-ber lands under multiple-use management

paper_content:

Esters of cyclopropyl substituted carboxylic acids, syntheses thereof, compositions thereof, and use for the control of mites and ticks.
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paper_title: Forest planning at the tactical level

paper_content:

Forest management and planning can involve large tracts of land involving numerous areal units. One approach to plan activities for a forested region over decades involves breaking down decision making into three components: strategic, tactical, and operational. Each level of the management hierarchy can involve the development and application of optimization models. These models typically aid in exploring management alternatives as well as multi-objective tradeoffs. Even though a strategic model can provide support for long term management at a broad scale, solutions may not be feasible at an operational level. Tactical level modeling helps to bridge solutions reached at a strategic level using operational planning information. This paper presents several tactical level planning models that have been developed as a part of a research effort supported by the US Forest Service. These models have been utilized in land use management and planning by the US Forest Service through a specially developed spatial decision support system. Copyright Kluwer Academic Publishers 2000
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paper_title: A model and Tabu search method to optimize stand harvest and road construction schedules

paper_content:

An important function of tactical planning in forest management is to choose spatially and temporally explicit schedules for both harvesting and road construction activities. In addition to maintaining consistency with goals of the strategic planning process, harvesting decisions are subjected to spatial, environmental constraints. At the same time, planning and cost of road access over the medium-term planning horizon must be considered. This article presents a model and heuristic solution methodology to address stand level harvest scheduling and the associated road construction scheduling problem. The model is formulated to determine minimal cost schedules, for stand harvests and road construction, that achieve recommended timber harvest volume targets and that comply with environmental regulations. The harvest decisions are made at the stand level of resolution. Graph structures are used to formulate the spatial restrictions on clearcut opening size and location. Road construction projects are scheduled to create a feasible road network at minimum net present capital cost. The optimization problem is solved using a Tabu search heuristic, which includes special constructs to cope with the complexity of this problem. An efficient frontier of solutions is produced, which may be utilized to analyze tradeoffs between lost forest productivity, due to timing of harvests, and the capital cost of road construction. Forest Science 46(2):188-203.
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paper_title: A (recursive) multiple objective approach to analyse changes in the utility function of farmers due to policy reforms

paper_content:

Multi-criteria decision-making (MCDM) methodology is used to analyse shifts in the utility function of farmers due to policy changes. The presented approach is tested for a sample farm in the loamy region in Belgium. The utility functions under the situation before and after the CAP-reform are estimated and compared. This reveals that the change from price support to direct income support has decreased the relative importance of the risk objective, while the environmental objective, almost non-existent in the situation before 1992, is gaining importance. The example shows that the multi-objective methodology can be a useful framework for a better understanding of farmers' reactions on policy reforms.
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paper_title: Linear programming and related approaches in forest planning.

paper_content:

A number of approaches to forest management planning are surveyed and analysed. A unified treatment of the various models and optimisation techniques is attempted, aiming at a better understanding of their essential characteristics and interrelationships. Ways of improving computational efficiency are examined. Structures for the forestry submodel are classified into three basic types, and interpreted in terms of network flows. A utilisation / economics submodel, comprising an objective function and constraints representing supply requirements, yield regulation, terminal conditions, and other aspects of the management problem, completes the formulation. A new criterion for yield regulation, based on irreversible investment concepts, is discussed in detail. The optimisation methods proposed in the literature for solving forest planning problems are evaluated, together with other potentially useful techniques and strategies. Topics covered include the use of standard Linear Programming packages, the prospects of decomposition and partitioning methods, the potential for utilising oldest-first and other cutting priorities, the explicit use of time structure in Dynamic Linear Programming and Optimal Control Theory algorithms, and the Hoganson-Rose procedure and its relationship to Lagrangian relaxation.
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paper_title: Long-Term Forest Ecosystem Planning at Pacific Lumber

paper_content:

In 1995, the Pacific Lumber Company contracted with VESTRA Resources to develop a 120-year, 12-period forest-eco system management plan for its properties to meet new California Board of Forestry wildlife, fisheries, and timber resource requirements and to optimize its timberland operations and profitability. VESTRA Resources developed the ecosystem planning express model, Ep(x), which seamlessly integrates geographic information systems with a database resource capability model and a policy-alternative model, providing the inputs to a linear program. The Ep(x) model uses an underlying adaptive management approach that also maximizes the knowledge base of the ecosystem through detailed sensitivity analyses. The model increased present net worth by over $398 million and generated a more optimal mix of wildlife habitat acres, including spotted-owl-nesting habitat.
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paper_title: Forest management challenges for operational researchers

paper_content:

This is an overview of operational research work that has been carried out to support strategic forest management planning, short term forest planning, forest operations, and forest fire management. It identifies important unresolved problems and new challenges that could serve as a rich source of problems for both practitioners and researchers.
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paper_title: A Three-Stage Heuristic for Harvest Scheduling with Access Road Network Development

paper_content:

In this article we present a new model for the scheduling of forest harvesting with spatial and temporal constraints. Our approach is unique in that we incorporate access road network development into the harvest scheduling selection process. Due to the difficulty of solving the problem optimally, we develop a heuristic that consists of a solution construction stage and two solution improvement stages. We call our approach INROADS and compare it to three other approaches by employing hypothetical example problems with 225 stands (or cut blocks) over a three-period planning horizon. Thirteen example forests that vary in terms of stand value and spatial dispersion are used to evaluate our heuristic, which outperforms the other approaches tested. For. Sci: 46(2):204-218.
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paper_title: Tree Bucking for Optimal Stand Value with Log Allocation Constraints

paper_content:

A bucket conveyor has buckets which are supported by transverse elements extending between two conveyor belts, each conveyor bucket being connected to the neighboring bucket at the transverse element but without pivotal movement between the buckets at this connection, flexure of the conveyor belts at drive and guide rollers being accommodated by bending of a part of one of the transverse bucket walls of reduced thickness.
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paper_title: A Heuristic System to Solve Mixed Integér Forest Planning Models

paper_content:

Implementing forest plans involves decisions regarding the geographic arrangement and timing of management activities, and the design of efficient transportation networks to provide access for these activities. These planning problems have been modeled successfully as mixed integer linear programs. However, these models are difficult to solve with commercial software due to their relatively large number of binary variables. We present a heuristic approach that has solved these problems well. The heuristic rules and a linear programming package interact within a closed system requiring no special user intervention. We describe several applications of this system for decision making in the USDA Forest Service.
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paper_title: Linking strategic and tactical forestry planning decisions

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In this paper a two-level model and optimization algorithms areintroduced to assist forestry companies in simultaneously considering strategicinvestment and tactical planning decisions. A procedure to reduce thediscrepancy produced in the aggregation and disaggregation process used to linkthese two-level decisions is also presented. This procedure is based onboth cluster analysis over economic parameters defined on “the standmacro-units to be harvested” and on the information transmittedbottom-up and top-down between the strategic and tactical models. Wealso show a new approach for solving the tactical mixed integer model.
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paper_title: New Issues in Forest Land Management from an Operations Research Perspective

paper_content:

Over the last two decades, forest land management practices have changed in response to ecological issues and the need to improve efficiency to remain competitive in emerging global markets. Decision processes have become more open and complex as information and communication technologies change. The OR/MS community is meeting these challenges by developing new modeling strategies, algorithms, and solution procedures that address spatial requirements, multiresource planning, hierarchical systems, multiple objectives, and uncertainty as they pertain to both industrial timberlands and public forests.
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paper_title: A 2-Opt tabu search procedure for the multiperiod forest harvesting problem with adjacency, greenup, old growth, and even flow constraints

paper_content:

Because of environmental concerns, modern forest harvesting plans are being modified to address aesthetics and wildlife protection issues. In the literature, the most referenced are adjacency constraints with exclusion or greenup years. Also of interest are the concepts of old growth patch size and total old growth area restrictions. Typically, harvest blocks have been defined a priori. Recently, some have proposed a more complex approach in which basic cells are defined, and the decision-making process includes forming harvest blocks from these cells. This has been called ARM (Area Restriction Model). Until now, no successful exact method has been reported for large-scale ARM problems, leaving heuristics as a viable option. In this work we present a multiperiod harvest-scheduling ARM model with these spatial constraints. A tabu search procedure with 2-Opt moves (exchanging at most 2 units) was developed. For small size instances, the procedure found the optimal solution in most cases, and for a real-size problem an 8% optimality gap is provided.
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paper_title: Modeling joint production of wildlife and timber

paper_content:

Abstract Production of marketed commodities and protection of natural systems often conflict. A focus on only one goal can result in large losses in other goals and may result in inefficient and unsustainable outcomes. In this paper, we develop a method that combines economic and ecological models in a dynamic and spatial analysis to evaluate land use decisions and find cost-effective alternatives for which it is not possible to do better on one objective without harming another objective. The method is demonstrated using timber production and species conservation on a forested landscape over a 100-year planning horizon. Current land use strategies are simulated and compared with cost-effective alternatives. The approach is compared to a static reserve approach, similar to previous studies, and found to produce substantially more efficient management strategies for the case study landscape.
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paper_title: EVALUATING THE ECONOMIC COST OF ENVIRONMENTAL MEASURES IN PLANTATION HARVESTING THROUGH THE USE OF MATHEMATICAL MODELS*

paper_content:

An important issue being discussed for Chilean pine plantation policies is the application of environmental protection measures when managing its timber areas. Typical measures, already in place in more developed countries, include imposing riparian strips and protecting fragile soils from the use of heavy machinery. While environmental protection measures have been considered vital for decades, so far there has been almost no attempt to quantify both the benefits and costs of these measures. This paper attempts to measure the costs associated with the main measures which can help both the forestry firms and the government evaluate the cost impact of the new environmental protection regulations being studied. The analysis for different environmental scenarios is carried out by modifying a mixed integer LP, currently used for tactical planning by one forestry firm.
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paper_title: Spatial optimization in ecological applications

paper_content:

Preface1. IntroductionPart I. Simple Proximity Relationships2. Sedimentation3. Stormflow Management4. Natural Regeneration in Any-aged Forest Management5. Combining Simulation with Optimization: Habitat Placement for the Northern Spotted OwlPart II. Reaction-Diffusion Models6. Characteristics of the Discrete Reaction-Diffusion Model7. The Basic Model: Habitat Placement for the Black-Footed Ferret8. Population-Dependent Dispersal: Habitat Placement for the Black-Tailed Prairie Dog9. Topography-Based Dispersal: Habitat Location for the Western Prairie Fringed Orchid10. Habitat Edge EffectsPart III. Control Models11. Strategies for Controlling Exotic Pests12. Strategies for Controlling WildfirePart IV. Using Optimization to Develop Hypotheses About Ecosystems13. Multi-Scaled Ecological Limiting Factors14. Carbon Fixation in Trees as an Optimization Process15 PostscriptReferencesIndex
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paper_title: Spatial restrictions in harvest scheduling

paper_content:

Forest resource use has traditionally been multifaceted. In order to ensure that these resources continue to be available for use by current and future generations, sustainable management practices are essential for striking a balance between the varied and often competing demands associated with forest use. This has meant that analysis incorporate specific objectives and considerations aimed at minimizing the impacts of forest activities. One such management planning approach has been the inclusion of spatial restrictions in harvest scheduling analysis. This article reviews two basic harvest scheduling models which may be used for imposing spatial restrictions. Distinctions between the alternative methods are highlighted and operational considerations are discussed. This article establishes and outlines priority areas for future harvest scheduling research.
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paper_title: Reserve design for species preservation

paper_content:

The problem of designing a natural area reserve for the preservation of species is approached as a zero-one integer program. The least-cost assemblage of parcels is sought for different numbers of species whose locales must be included within the reserve. The reserve itself is designed to include core parcels and buffer parcels which surround and protect the core. Compactness and contiguity of the reserve are promoted by the problem formulation. Solution is by a combination of a greedy heuristic followed by heuristic concentration which achieves a reduced set of variables for the zero-one program.
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paper_title: Reserve selection as a maximal covering location problem

paper_content:

Many alternative approaches have been proposed for setting conservation priorities from a database of species (or communities) by site. We present a model based on the premise that reserve selection or site prioritization can be structured as a classic covering problem commonly used in many location problems. Specifically, we utilize a form of the maximal covering location model to identify sets of sites which represent the maximum possible representation of specific species. An example application is given for vertebrate data of Southwestern California, which is then compared to an iterative solution process used in previous studies. It is shown that the maximal covering model can quickly meet or exceed iterative models in terms of the coverage objective and automatically satisfies a complementarity objective. Refinements to the basic model are also proposed to address additional objectives such as irreplaceability and flexibility.
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paper_title: Forest management challenges for operational researchers

paper_content:

This is an overview of operational research work that has been carried out to support strategic forest management planning, short term forest planning, forest operations, and forest fire management. It identifies important unresolved problems and new challenges that could serve as a rich source of problems for both practitioners and researchers.
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paper_title: Harvest scheduling subject to maximum area restrictions: exploring exact approaches

paper_content:

We consider a spatial problem arising in forest harvesting. For regulatory reasons, blocks harvested should not exceed a certain total area, typically 49 hectares. Traditionally, this problem, called the adjacency problem, has been approached by forming a priori blocks from basic cells of 5 to 25 hectares and solving the resulting mixed-integer program. Superior solutions can be obtained by including the construction of blocks in the decision process. The resulting problem is far more complex combinatorially. We present an exact algorithmic approach that has yielded good results in computational tests. This solution approach is based on determining a strong formulation of the linear programming problem through a clique representation of a projected problem.
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paper_title: The impact of environmental constraints on short term harvesting: Use of planning tools and mathematical models

paper_content:

Both in New Zealand and Chile there exist important forest industries based mostly on pine plantations. The management of harvesting requires a series of activities such as building access roads, harvesting with skidders on flat terrain and cable logging for steep terrain, transportation from forest origins to destinations, such as a port, pulp plant and sawmills.
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paper_title: A Real Options Approach to the Valuation of a Forestry Investment

paper_content:

Abstract The theory of real options is used to model the optimal tree harvesting decision. The value of the option to harvest is estimated using a dynamic programming approach and a general numerical solution technique suitable for any type of stochastic process for prices. The conditions under which the optimal harvest time is independent of price are examined. In addition, the impact of assuming future lumber prices are mean reverting is considered. It is found that option value and optimal cutting time are significantly different under the mean reversion assumption compared to geometric Brownian motion.
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paper_title: The impact of environmental constraints on short term harvesting: Use of planning tools and mathematical models

paper_content:

Both in New Zealand and Chile there exist important forest industries based mostly on pine plantations. The management of harvesting requires a series of activities such as building access roads, harvesting with skidders on flat terrain and cable logging for steep terrain, transportation from forest origins to destinations, such as a port, pulp plant and sawmills.
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Title: Operations Research Models and the Management of Agricultural and Forestry Resources: A Review and Comparison

Section 1: Introduction
Description 1: This section introduces the complexity of managing agricultural and forestry resources and the role of OR models in addressing these challenges.

Section 2: Agricultural-Planning Problems (Farm Level)
Description 2: Discusses the application of linear programming (LP) models at the farm level, their uses, and potential future applications despite existing challenges.

Section 3: Agricultural-Planning Problems (Regional-Sector Level)
Description 3: Examines the shift of analysis from the farm level to the regional sector, addressing the change in objective functions and aggregation problems.

Section 4: Modeling the Interaction Between Agriculture and the Environment
Description 4: Describes models that evaluate the economic impacts of environmental effects in agriculture to promote sustainable practices.

Section 5: Risk and Uncertainty Analysis
Description 5: Covers the various OR methods used to handle risk and uncertainty in agriculture, such as game theory, safety-first models, and stochastic programming.

Section 6: Dealing with Multiple Criteria in Agriculture
Description 6: Addresses the need for multiple-criteria decision-support models due to the conflicting objectives in agricultural management.

Section 7: Formulating Livestock Rations and Feeding Stuffs
Description 7: Reviews the use of LP models to optimize livestock diets and the extensions of this approach, including parametric LP and multicriteria models.

Section 8: Forestry
Description 8: Explores the application of OR models in forestry, from long-range harvest planning to incorporating ecological concerns in model formulation.

Section 9: Decision-Making Levels
Description 9: Outlines the different decision-making levels in forestry (strategic, tactical, operational) and the respective OR models used.

Section 10: Implementation Issues
Description 10: Discusses the factors contributing to the successful implementation of OR models in forestry and agriculture.

Section 11: The Environmental Question
Description 11: Examines the environmental considerations in forestry and the OR models developed to address various ecological constraints.

Section 12: Uncertainty and Multiple Objectives
Description 12: Analyzes how uncertainty and multiple-objective models are applied in forestry, and the challenges involved in their implementation.

Section 13: Comparative Analysis
Description 13: Compares the OR models used in agriculture and forestry, highlighting similarities and differences in their applications and data requirements.

Section 14: Conclusions
Description 14: Summarizes the effectiveness and future prospects of OR models in managing agricultural and forestry resources, with an emphasis on environmental and uncertainty considerations.