Optimal Timber Utilisation Strategies for Wik People on Cape York Peninsula

A forestry industry based on the native Darwin stringybark forests of Cape York Peninsula has been identified as a potential generator of employment and income for Wik people. Information appropriate for examining potential Wik timber utilisation strategies is scarce, necessitating primary data collection activities in north Queensland. A mixed-integer, single-period goal program is developed to produce a suite of ‘optimal’ timber utilisation strategies from the perspective of Wik people. Optimal forestry strategies predicted by the goal programming model are financially viable and suggest, in general, that relatively low-technology forestry activities are likely to best satisfy Wik forestry objectives

Optimal Timber Utilisation Strategies for Wik People on Cape York Peninsula

A forestry industry based on the native Darwin stringybark forests of Cape York Peninsula has been identified as a potential generator of employment and income for Wik people. Information appropriate for examining potential Wik timber utilisation strategies is scarce, necessitating primary data collection activities in north Queensland. A mixed-integer, single-period goal program is developed to produce a suite of 'optimal' timber utilisation strategies from the perspective of Wik people. Optimal forestry strategies predicted by the goal programming model are financially viable and suggest, in general, that relatively low-technology forestry activities are likely to best satisfy Wik forestry objectives

Thinning optimization in mixed-species forests

An approach is summarized for estimating optimal thinning and final harvest age for existing, mixed-species stands. The method involves stand-table projection with upgrowth and mortality equations, formulated as an integer-nonlinear programming problem. Random search methods are proposed for estimating optimal cutting prescriptions. Such solution methods warrant further study in forestry, since their use enables broad application of stand-specific modeling results

Approaches to integrated strategic/tactical forest planning

Traditionally forest planning is divided into a hierarchy of planning phases. Strategic planning is conducted to make decisions about sustainable harvest levels while taking into account legislation and policy issues. Within the frame of the strategic plan, the purpose of tactical planning is to schedule harvest operations to specific areas in the immediate few years and on a finer time scale than in the strategic plan. The operative phase focuses on scheduling harvest crews on a monthly or weekly basis, truck scheduling and choosing bucking instructions. Decisions at each level are to a varying degree supported by computerized tools. A problem that may arise when planning is divided into levels and that is noted in the literature focusing on decision support tools is that solutions at one level may be inconsistent with the results of another level. When moving from the strategic plan to the tactical plan, three sources of inconsistencies are often present; spatial discrepancies, temporal discrepancies and discrepancies due to different levels of constraint. The models used in the papers presented in this thesis approaches two of these discrepancies. To address the spatial discrepancies, the same spatial resolution has been used at both levels, i.e., stands. Temporal discrepancies are addressed by modelling the tactical and strategic issues simultaneously. Integrated approaches can yield large models. One way of circumventing this is to aggregate time and/or space. The first paper addresses the consequences of temporal aggregation in the strategic part of a mixed integer programming integrated strategic/tactical model. For reference, linear programming based strategic models are also used. The results of the first paper provide information on what temporal resolutions could be used and indicate that outputs from strategic and integrated plans are not particularly affected by the number of equal length strategic periods when more than five periods, i.e. about 20 year period length, are used. The approach used in the first paper could produce models that are very large, and the second paper provides a two-stage procedure that can reduce the number of variables and preserve the allocation of stands to the first 10 years provided by a linear programming based strategic plan, while concentrating tactical harvest activities using a penalty concept in a mixed integer programming formulation. Results show that it is possible to use the approach to concentrate harvest activities at the tactical level in a full scale forest management scenario. In the case study, the effects of concentration on strategic outputs were small, and the number of harvest tracts declined towards a minimum level. Furthermore, the discrepancies between the two planning levels were small

Modelling of selection and mating decisions in tree breeding programs

Hardwood trees from the temperate forests of southern Australia are an important source of timber for high quality paper. Two species in particular, Eucalyptus globulus and Eucalyptus nitens are well suited to this purpose and are now widely grown in commercial plantations. These plantations have been established by professional tree breeders using seedlings derived originally from broadly based collection of seed in natural forests. To increase productivity it is desirable to select trees that grow quickly and give high yields of top quality timber. Nevertheless it is important to maintain genetic diversity in the breeding population and thereby retain a robust capacity to adapt to changing environmental factors. In this article we formulate a number of related mathematical models for the selection and mating processes and discuss the consequences of these models. We recommend a relatively simple scheme which can be implemented on an IBM compatible PC using standard algorithms

Forest Management Zone Design with a Tabu Search Algorithm

Increased conflicts between timber production and environmental protection led some analysts to advocate land-use segregation, often referred to as forest management zoning. The objective of zoning is to create ecologically desirable non-fragmented forest reserves and group timber production areas. We formulate an integer programming model of forest zoning that explicitly addresses clustering of spatial units allocated to timber production and reserve zones while also promoting separation of these zones. A tabu search algorithm is developed, implemented and tested using a case study. The case study results indicate that up to 5% of the net financial return is sacrificed with a 'satisfactory' grouping of units within each zone. A 'good' separation between the reserves and timber production zone is achieved at the cost of further decline of the net financial return up to 11% relative to the unconstrained case.forest planning, integer programming, reserves, tabu search, timber production, zoning

An integrated MCDA software application for forest planning : a case study in southwestern Sweden

Forest planning in Sweden today translates not only into planning of timber production, but also for the provision of other functions and services. Multi-criteria decision analysis (MCDA) methods provide a way to take also non-monetary values into account in planning. The purpose of this study was to gain experience on how to use a forest decision support system combined with an MCDA tool in practical forestry. We used a new forest planning tool, PlanWise, which includes an integrated MCDA module, PlanEval. Using the software, the decision maker can compare different forest plans and evaluate them against his/her objectives in a structured and analytical manner. The analysis thus provides a ranking of the alternatives based on the individual preferences of the decision maker. PlanEval and the MCDA planning process are described in a case study, where the manager of a forest estate in southwestern Sweden used the program to compare different forest plans made for the estate. In the paper, we analyze possibilities and challenges of this approach and identify problems such as the adherence to formal requirements of MCDA techniques and the difficulty of comparing maps. Possibilities to expedite an MCDA planning process further are also discussed. The findings confirm that integration of an MCDA tool with a forest decision support system is valuable, but requires expert assistance to be successful