Chung, W. 2002. Eight heuristic planning techniques applied to three increasingly diffi cult wildlife planning problems. Silva Fennica 36(2): 561-584.As both spatial and temporal characteristics of desired future conditions are becoming important measures of forest plan success, forest plans and forest planning goals are becoming complex. Heuristic techniques are becoming popular for developing alternative forest plans that include spatial constraints. Eight types of heuristic planning techniques were applied to three increasingly diffi cult forest planning problems where the objective function sought to maximize the amount of land in certain types of wildlife habitat. The goal of this research was to understand the relative challenges and opportunities each technique presents when more complex diffi cult goals are desired. The eight heuristic techniques were random search, simulated annealing, great deluge, threshold accepting, tabu search with 1-opt moves, tabu search with 1-opt and 2-opt moves, genetic algorithm, and a hybrid tabu search / genetic algorithm search process. While our results should not be viewed as universal truths, we determined that for the problems we examined, there were three classes of techniques: very good (simulated annealing, threshold accepting, great deluge, tabu search with 1-opt and 2-opt moves, and tabu search / genetic algorithm), adequate (tabu search with 1-opt moves, genetic algorithm), and less than adequate (random search). The relative advantages in terms of solution time and complexity of programming code are discussed and should provide planners and researchers a guide to help match the appropriate technique to their planning problem. The hypothetical landscape model used to evaluate the techniques can also be used by others to further compare their techniques to the ones described here.

The effective implementation of sustainable forest management depends largely on carrying out forest operations in a sustainable manner. Climate change, as well as the increasing demand for forest products, requires a re-thinking of forest operations in terms of sustainability. In this context, it is important to understand the major driving factors for the future development of forest operations that promote economic, environmental and social well-being. The main objective of this paper is to identify important issues concerning forest operations and to propose a new paradigm towards sustainability in a changing climate, work and environmental conditions. Previously developed concepts of forest operations are reviewed, and a newly developed concept - Sustainable Forest Operations (SFO), is presented. Five key performance areas to ensure the sustainability of forest operations include: (i) environment; (ii) ergonomics; (iii) economics; (iv) quality optimization of products and production; and (v) people and society. Practical field examples are presented to demonstrate how these five interconnected principles are relevant to achieving sustainability, namely profit and wood quality maximization, ecological benefits, climate change mitigation, carbon sequestration, and forest workers' health and safety. The new concept of SFO provides integrated perspectives and approaches to effectively address ongoing and foreseeable challenges the global forest communities face, while balancing forest operations performance across economic, environmental and social sustainability. In this new concept, we emphasize the role of wood as a renewable and environmentally friendly material, and forest workers' safety and utilization efficiency and waste management as additional key elements of sustainability.

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Thermochemical biomass conversion systems have the potential to produce heat, power, fuels and other products from forest biomass at distributed scales that meet the needs of some forest industry facilities. However, many of these systems have not been deployed in this sector and the products they produce from forest biomass have not been adequately described or characterized with regards to chemical properties, possible uses, and markets. This paper characterizes the producer gas, biochar, and activated carbon of a 700 kg h −1 prototype gasification system and a 225 kg h −1 pyrolysis system used to process coniferous sawmill and forest residues. Producer gas from sawmill residues processed with the gasifier had higher energy content than gas from forest residues, with averages of 12.4 MJ m for forest residues. Biochars produced have OPEN ACCESSEnergies 2013, 6 165 similar particle size distributions and bulk density, but vary in pH and carbon content. Biochars from both systems were successfully activated using steam activation, with resulting BET surface area in the range of commercial activated carbon. Results are discussed in the context of co-locating these systems with forest industry operations.

Forest operations generate large quantities of forest biomass residues that can be used for production of bioenergy and bioproducts. However, a significant portion of recoverable residues are inaccessible to large chip vans, making use financially infeasible. New production systems must be developed to increase productivity and reduce costs to facilitate use of these materials. We present a comparison of two alternative systems to produce biomass fuel (i.e., ''hog fuel'') from forest residues that are inaccessible to chip vans: (1) forwarding residues in fifth-wheel end-dump trailers to a concentration yard, where they can be stored and then ground directly into chip vans, and (2) grinding residues on the treatment unit and forwarding the hog fuel in high-sided dump trucks to a concentration yard, where it can be stored and then reloaded into chip vans using a frontend loader. To quantify the productivity and costs of these systems, work study data were collected for both systems on the same treatment unit in northern Idaho in July 2009. With standard machine rate calculations, the observed costs from roadside to loaded chip van were $23.62 per bone dry ton (BDT) for slash forwarding and $24.52 BDT À1 for in-woods grinding. Results indicate that for harvest units with conditions similar to the test area, slash forwarding is most appropriate for sites with dispersed residues and long-distance in-woods grinder mobilization. For sites with densely piled roadside residues, in-wood grinding is likely to be a more productive and less costly option for residue recovery. Forest operations for timber harvest, precommercial thinning, fuels management, and other vegetation treatments generate large quantities of treatment residues (also called ''slash''), including tops, limbs, cull sections, and unmerchantable roundwood. These by-products are a promising source of biomass for the production of energy, fuels, and products because they are widespread, renewable, and can be used to produce products that offset the use of fossil fuels and reduce greenhouse gas emissions (Jones et al. 2010). Use of forest residues can also improve the financial feasibility of some silvicultural prescriptions by reducing site preparation costs and can improve air quality in areas where open burning is a common method of residue disposal (Gan and Smith 2007, Jones et al. 2010). The most prevalent use of forest residues is as hog fuel for combustion boilers used in the generation of heat and electricity. In this article, the term ''hog fuel'' denotes woody biomass fuel produced from forest residues, fuelwood, and wood waste by all methods of comminution, including grinding, chipping, and shredding. Combustion of hog fuel and other by-products by the forest industry accounts for more than 50 percent of all biomass energy in the United States (US Department of Energy 2011). In some regions, electric utilities, industrial boilers, and institutions with wood-fired heating systems represent additional hog fuel demand outside the forest sector.

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Fuel treatments have been widely used as an effective fire management tool to mitigate catastrophic wildland fire risk in forested landscapes. Fire research efforts of the last two decades have significantly advanced fire behavior modeling and fuel treatment effects analysis, but integrated fuel treatment planning and optimization models have yet to be extensively developed and used, mainly due to the complexity of the planning problem. This paper describes the problem complexity in terms of essential considerations when deciding where, when, and how to perform fuel treatments. Previous studies published in mainstream peer-reviewed journals are summarized and identified by their unique contributions, assumptions, and simplifications. Only a handful studies assessed fuel treatment effects in spatial and temporal contexts and incorporated them into the optimization framework. Most of these existing studies introduced optimization approaches as proof of concept with limited applications. It is hoped that future studies will build on these previous efforts and develop more efficient and integrated optimization approaches that can address multiple concerns simultaneously while producing effective fuel treatment plans for field implementation.