Integrating variable retention systems into strategic forest management to deal with conservation biodiversity objectives

For the past few decades, the integration of biodiversity conservation into forest management has constituted an important challenge, since the new forest management models should make conservation objectives compatible with production issues. In many countries, timber production is no longer the main ecosystem service provided, thus other aspects such as biodiversity conservation are taken into account. One of the strategies developed to do so is to define, at the stand level, areas where final cuttings are not allowed. These areas can be found dispersed or aggregated (comprised of multiple stands) throughout the forest, helping to maintain a percentage of mature forest that fulfils conservation goals. In this study, we have developed a strategic forest planning model that allows us to integrate several retention systems compared to the business-as-usual treatment traditionally used. Production, technical and environmental criteria have been considered in order to analyse the degree of conflict between them by designing a pay-off matrix. Using multicriteria techniques conflicting objectives were assessed, and decision makers interactions have been introduced. These interactions range from criteria selection to the allocation of preferential weights to each criterion until the best solution among a set of possible alternatives is identified. The presented analytical procedure is based on the extended goal programming method applied in an exemplary forest in central Spain. Our results show that the proposed methodology allows deriving solutions that are acceptable for decision makers while estimating physical and economic opportunity costs of conservation measures in timber volume and Euros respectively.