Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2009
Authors
Svein Solberg Mathias Dobbertin Gert Jan Reinds Holger Lange Kjell Andreassen Paloma Garcia Fernandez Anders Hildingsson Wim de VriesAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Rune Slimestad Eivind Vangdal Cato BredeAbstract
No abstract has been registered
Authors
David Bredström Petrus Jönsson Mikael RönnqvistAbstract
A cost efficient use of harvesting resources is important in the forest industry. The main planning is made in an annual resource plan which is continuously revised. The harvesting operations are divided into harvesting and forwarding. The harvesting operation fells trees and put them in piles in the harvest areas. The forwarding operation collects piles and moves them to storage locations adjacent to forest roads. These operations are done by machines (harvesters, forwarders and harwarders) and these are operated by crews living in cities/villages which are within some maximum distance from the harvest areas. Machines, harvest teams and harvest areas have different characteristic and properties and it is difficult to come up with the best possible match throughout the year. The aim with the planning is to come up with a cost efficient plan The total cost is based on three parts; production cost, traveling cost and moving cost. The production cost is the cost for the harvesting and the forwarding. The traveling cost is the cost for driving back and forward (daily) to the harvest area from the home base. Moving cost is associated with moving the machines and equipment between harvest areas. The Forest Research Institute of Sweden has together with a number of Swedish forest companies developed a decision support platform for the planning. An important aspect is to come up with high quality plans within short computational time. A central part is an optimization model which integrates assignment of machines to harvest areas and scheduling of the harvest areas during the year for each machine. The problem is complex and we propose a two phase solution method where we first solve the assignment problem and in a second stage the scheduling. In order be able to control the scheduling also in phase 1, we have introduced an extra cost component which balances the geographical spread of the assignments in phase 1. We have tested the solution approach on a case study from one of the larger Swedish forest companies. This case study involves 46 machines and 968 harvest areas representing a log volume of 1,33 million cubic meters. We describe some numerical results and experiences from the development and tests.
Authors
David Bredström Petrus Jönsson Mikael RönnqvistAbstract
A cost efficient use of harvesting resources is important in the forest industry. The main planning is made in an annual resource plan which is continuously revised. The harvesting operations are divided into harvesting and forwarding. The harvesting operation fells trees and put them in piles in the harvest areas. The forwarding operation collects piles and moves them to storage locations adjacent to forest roads. These operations are done by machines (harvesters, forwarders and harwarders) and these are operated by crews living in cities/villages which are within some maximum distance from the harvest areas. Machines, harvest teams and harvest areas have different characteristic and properties and it is difficult to come up with the best possible match throughout the year. The aim with the planning is to come up with a cost efficient plan The total cost is based on three parts; production cost, traveling cost and moving cost. The production cost is the cost for the harvesting and the forwarding. The traveling cost is the cost for driving back and forward (daily) to the harvest area from the home base. Moving cost is associated with moving the machines and equipment between harvest areas. The Forest Research Institute of Sweden has together with a number of Swedish forest companies developed a decision support platform for the planning. An important aspect is to come up with high quality plans within short computational time. A central part is an optimization model which integrates assignment of machines to harvest areas and scheduling of the harvest areas during the year for each machine. The problem is complex and we propose a two phase solution method where we first solve the assignment problem and in a second stage the scheduling. In order be able to control the scheduling also in phase 1, we have introduced an extra cost component which balances the geographical spread of the assignments in phase 1. We have tested the solution approach on a case study from one of the larger Swedish forest companies. This case study involves 46 machines and 968 harvest areas representing a log volume of 1,33 million cubic meters. We describe some numerical results and experiences from the development and tests.
Authors
Erlend Nybakk Pablo Crespell Eric Hansen Anders LunnanAbstract
Increased urbanization in many societies is having a negative impact on vitality of rural areas. To maintain the vitality of these areas governments have employed a variety of policies, some of which are designed to facilitate innovation and enhance landowner innovativeness. However, little research has investigated the antecedents to landowner innovativeness and whether innovativeness positively impacts economic performance in this setting. The present study investigates these issues in the context of Norwegian forestland owners and their involvement in non-timber forest products and services (a form of ecosystem services). The authors present a conceptual model hypothesizing that social networking, entrepreneurial climate, and a learning orientation each have a direct, positive impact on landowner innovativeness and innovativeness has a direct, positive impact on economic performance. Property size is included as a moderating variable. Data were collected via a mail survey and a total of 683 useable responses were received reaching an adjusted response rate of 35%. Results show that social networking and a learning orientation positively impact innovativeness, but that entrepreneurial climate does not. Innovativeness was found to positively impact economic performance. The authors outline implications of the findings that may be used by policy makers, landowners and research. (C) 2008 Elsevier B.V. All rights reserved.
Authors
Josef Eitzinger Sabina Thaler Simone Orlandini Pavol Nejedlik Valentin Kazandjiev Tor Håkon Sivertsen Dragutin MihailovicAbstract
No abstract has been registered
Abstract
No abstract has been registered
Abstract
The study aims to estimate the effects on the sheep farm economy of reducing grazing levels necessitated due to possible overgrazing by sheep on two important mountainous range pastures in southwest Norway. The pasture range in Setesdal Vesthei is grazed by sheep from distant farms located at Jæren (south of Stavanger), while south-western Hardangervidda is grazed by sheep from local farms and distant farms located along the coast. Farmers utilizing the pasture areas combine sheep with dairy cows, off farm work or businesses, while the local farms combine it with orchards. A Linear Programming (LP) model for specialized sheep farms based on farm records has been developed to study effects of reaching various grazing capacity levels. Reducing the number of sheep in Setesdal Vesthei by 10 percent would lower farm income per breeding stock animal with € 15 to € 119 and with € 35 to € 211 for Hardangervidda. The decrease in annual income will range from € 15,00 to € 119,00 in total for the farms using Setesdal Vesthei. The economic effects depend much on meat production per ewe. Replacing unilateral sheep grazing with a mixed system involving suckling goats and heifers is discussed to deal with the problems of encroachment and increasing elevation of the alpine tree-line.
Abstract
No abstract has been registered