A discrete Forest in a continuous Landscape Investigating Interactions between Natural Resource Management and Sustainable Development

Summary Forests are key ecosystems of the earth and associated with a large range of functions. Many of these functions are beneficial to humans and are referred to as ecosystem services. Sustainable development requires that all relevant ecosystem services are quantified, managed and monitored equally. Natural resource managementtherefore targets the services associated with ecosystems. The main hypothesis of this thesis is that the spatial and temporal domains of relevant services do not correspond to a discrete forest ecosystem. As a consequence, the services are not quantified, managed and monitored in an equal and sustainable manner. The thesis aims were therefore to test this hypothesis, establish an improved conceptual approach and provide spatial applications for the relevant land cover and structure variables. The study was carried out in western Switzerland and based primarily on data from a countrywide landscape inventory. This inventory is part of the third Swiss national forest inventoryand assesses continuous landscape variables based on a regular sampling of true colour aerial imagery. In addition, land cover variables were derived from Landsat 5 TM passive sensor data and land structure variables from active sensor data from a small footprint laserscanning system. The results confirmed the main hypothesis, as relevant services did not scale well with the forest ecosystem. Instead, a new conceptual approach for sustainable management of natural resources was described. This concept quantifies the services as a continuous function of the landscape, rather than a discrete function of the forest ecosystem. The explanatory landscape variables are therefore called continuous fields and the forest becomes a dependent and function-driven management unit. Continuous field mapping methods were established for land cover and structure variables. In conclusion, the discrete forest ecosystem is an adequate planning and management unit. However, monitoring the state of and trends in sustainability of services requires them to be quantified as a continuous function of the landscape. Sustainable natural resource managementiteratively combines the ecosystem and gradient approaches. Resume Les forets sont des ecosystemes-cles de la terre et on leur attribue un grand nombre de fonctions. Beaucoup de ces fonctions sont benefiques pour l'homme et sont nommees services ecosystemiques. Le developpement durable exige que ces services ecosystemiques soient tous quantifies, geres et surveilles de facon egale. La gestion des ressources naturelles a donc pour cible les services attribues aux ecosystemes. L'hypothese principale de cette these est que les domaines spatiaux et temporels des services attribues a la foret ne correspondent pas a un ecosysteme discret. Par consequent, les services ne sont pas quantifies, amenages et surveilles d'une maniere equivalente et durable. Les buts de la these etaient de tester cette hypothese, d'etablir une nouvelle approche conceptuelle de la gestion des ressources naturelles et de preparer des applications spatiales pour les variables paysageres et structurelles appropriees. L'etude a ete menee en Suisse occidentale principalement sur la base d'un inventaire de paysage a l'echelon national. Cet inventaire fait partie du troisieme inventaire forestier national suisse et mesure de facon continue des variables paysageres sur la base d'un echantillonnage regulier sur des photos aeriennes couleur. En outre, des variables de couverture ? terrestre ont ete derivees des donnees d'un senseur passif Landsat 5 TM, ainsi que des variables structurelles, derivees du laserscanning, un senseur actif. Les resultats confirment l'hypothese principale, car l'echelle des services ne correspond pas a celle de l'ecosysteme forestier. Au lieu de cela, une nouvelle approche a ete elaboree pour la gestion durable des ressources naturelles. Ce concept represente les services comme une fonction continue du paysage, plutot qu'une fonction discrete de l'ecosysteme forestier. En consequence, les variables explicatives de paysage sont denommees continuous fields et la foret devient une entite dependante, definie par la fonction principale du paysage. Des methodes correspondantes pour la couverture terrestre et la structure ont ete elaborees. En conclusion, l'ecosysteme forestier discret est une unite adequate pour la planification et la gestion. En revanche, la surveillance de la durabilite de l'etat et de son evolution exige que les services soient quantifies comme fonction continue du paysage. La gestion durable des ressources naturelles joint donc l'approche ecosystemique avec celle du gradient de maniere iterative.