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This work aimed to tackle a timber harvest scheduling problem by simultaneously integrating into the analysis two forestry products derived from the same species: the timber and the pine nut. For this purpose, three management scenarios were proposed: two in which each of the productions is maximised separately, and a third mixed where, in each management unit, the product to which the silvicultural effort should be devoted is decided. After defining a set of objectives, and optimising the rotation length, a multi-criteria model based on goal programming was considered since no feasible solutions have been obtained when employing linear programming. The results in our case study show how the feasible solutions reached can be more attractive for the manager. Specifically, the area to be devoted to timber and cone/pine-nut production was computed in a scenario where the optimal silviculture (oriented towards timber or pine nuts) in each stand was selected, and it was concluded that the area allocated to pine nuts should be notably greater. This situation is the opposite of the current management.

This paper characterizes the sustainability of the European paper industry. To undertake this task the sustainability of each country is defined by using fourteen indicators of a diverse nature (economic, environmental and social). These indicators are aggregated into a composite or synthetic index with the help of a compromise programming model. In order to associate different weights with each indicator, a survey among international experts has been carried out. In this way, a ranking of seventeen European countries analysed in terms of the sustainability of the European paper industry has been established, where Finland is the most sustainable paper industry in Europe except when the most balanced solution is chosen. Also, the results are robust when different preferential weights are attached. Finally, this methodology can be applied at a more disaggregated level and other indicators can be introduced.

Spatially explicit, tactical forest planning is a necessary but challenging task in the management of plantation forests. It involves harvest scheduling and planning for road access and log transportation over time and space. This combinatorial problem can be formulated into the fixed-charge transportation problem (FCTP), in which the sum of fixed and variable costs is minimized while meeting harvest volume requirements and allowing necessary road maintenance and log hauling activities. The problem can be solved using general optimization methods such as mixed-integer linear programming (MILP), but the computational efficiency of the MILP-based approach quickly drops as the size and complexity of the problem increases. We developed a new optimization procedure that partitions the large planning problem into smaller subproblems. We applied a hybrid optimization approach using both MILP and heuristic rules to efficiently solve the large FCTP that otherwise may not be solvable using traditional methods. We applied our approach to an industrial plantation forest in Brazil. Our applications demonstrate the performance of the new optimization procedure and the benefit of solving large forest planning problems that integrate harvest scheduling with road access and transportation. Key words: forest management planning, mixed-integer linear programming, heuristics, optimization. La planification forestiere tactique, spatialement explicite, est une tache necessaire quoique difficile pour l'amenagement des forets de plantation. Cela implique l'etablissement d'un echeancier de recolte et la planification des chemins d'acces et du transport des billes dans le temps et l'espace. Ce probleme combinatoire peut etre formule comme un probleme de transport a charge fixe (PTCF), ou la somme des couts fixes et variables est minimisee tout en satisfaisant les exigences de volume de recolte et en permettant l'entretien necessaire des chemins ainsi que le debardage des billes. Le probleme peut etre resolu a l'aide de methodes generales d'optimisation, telles que la programmation lineaire partiellement en nombres entiers (PLNE), mais l'efficacite de calcul de l'approche fondee sur la PLNE diminue rapidement a mesure que la taille et la complexite du probleme augmente. Nous avons elabore une nouvelle procedure d'optimisation qui consiste a diviser le gros probleme de planification en en sous-problemes plus petits. Nous avons applique une approche d'optimisation hybride utilisant la PLNE et des regles heuristiques afin de resoudre efficacement le gros PTCF qui ne pourrait autrement etre resolu avec les methodes traditionnelles. Nous avons applique notre approche a une vaste foret de plantation industrielle au Bresil. L'application de notre approche demontre la performance de la nouvelle procedure d'optimisation et l'avantage qu'elle presente pour resoudre de gros problemes de planification forestiere qui integrent l'etablissement d'un echeancier de recolte avec les chemins d'acces et le transport. Mots-cles: amenagement forestier, programmation lineaire partiellement en nombres entiers, heuristique, optimisation., Introduction It has been a common practice among industrial forest plantation companies in Brazil to implement hierarchical, top-down planning approaches to develop forest plans at various spatial and temporal scales [...]

We present an approach based on several quantitative techniques to derive a ranking of sustainable Eucalyptus plantations. A list of indicators was defined and applied to a set of heterogeneous Eucalyptus globulus plantations located in the northwest of Spain. These indicators were aggregated into a synthetic index with the help of a binary goal programming model. This model has been fed with the responses of 45 stakeholders to find out the preferential weights and targets attached to each indicator. In addition, we have analyzed the causes behind the level of sustainability achieved by each plantation. This task was carried out by taking the composite sustainability indexes as endogenous variables and a tentative set of economic, environmental, and social variables as explanatory variables. The link between endogenous and exogenous variables was made with the help of a statistical analysis. The results show how some variables such as altitude or distance to pulp mills are statistically significant, whereas others such as certification are not statistically significant. Key words: forest plantations, sustainability, stakeholders, goal programming. Nous presentons une approche soutenue par plusieurs techniques quantitatives pour obtenir un classement des plantations d'Eucalyptus fonde sur leur durabilite. Une liste d'indicateurs a ete definie et appliquee a un ensemble de plantations heterogenes d'Eucalyptus globulus Labill. situees au nord-ouest de l'Espagne. Ces indicateurs ont ete regroupes dans un indice synthese a l'aide d'un modele binaire de programmation des objectifs. Ce modele a ete alimente par les reponses de 45 parties prenantes pour determiner les poids et cibles preferentiels relies a chaque indicateur. De plus, nous avons analyse les causes du degre de durabilite atteint par chaque plantation. Ce travail a ete realise en prenant les indices composites de durabilite comme variables endogenes, et un ensemble provisoire de variables economiques, environnementales et sociales comme variables explicatives. Le lien entre les variables endogenes et exogenes a ete effectue a l'aide d'une analyse statistique. Les resultats montrent comment certaines variables, telles que l'altitude ou la distance des usines de pates, sont statistiquement significatives alors que d'autres, comme la certification, ne le sont pas. [Traduit par la Redaction] Mots-cles : plantations forestieres, durabilite, parties prenantes, programmation des objectifs., 1. Introduction Sustainability has been a basic ingredient of forest management for over 250 years (Schraml and Detten 2010). In fact, this concept was conceived in forestry (Carlowitz (1713) in [...]

An expert or panel of experts suggests a set of targets or desirable levels of achievement for 'm' indicators of sustainability. A method based upon goal programming with zero-one decision variables, which is a powerful tool for determining the overall sustainability, attached to each forestry system is described.