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Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A number of national environmental objectives have been decided on by the Swedish parliament. In this paper, a measure of willingness to pay for attaining these objectives is outlined in terms of an “environmental budget”, which can be disaggregated. Based on a nationwide contingent valuation survey, the average environmental budget was estimated and then disaggregated on specific “green” indicators. This paper focuses especially on protection of forest land for biodiversity purposes. Multiple bounded dichotomous choice questions were employed in the survey, allowing respondents to express uncertainty in their valuations. The effect of different question formats and valuation scenarios on the disaggregation of the environmental budget was investigated. Consideration of uncertainty had a significant impact on willingness to pay estimates. Willingness to pay varied between different levels of forest land protection when uncertainty was explicitly introduced. When valuation estimates were aggregated on the national level, the value of forest land protection exceeded the costs by a small margin. Plusieurs objectifs environnementaux ont été arrêtés par le Parlement suédois pour l’ensemble du pays. La mesure du consentement à payer pour atteindre ces objectifs constitue l’objet de cet article. Cette mesure est présentée en terme de budget environnemental qui peut être décomposé. tabli à partir d’un sondage réalisé avec la méthode d’évaluation contingente à l’échelle du pays, le budget environnemental moyen a été estimé puis décomposé selon des indicateurs « verts »spécifiques. Cet article met une emphase particulière sur la protection du territoire forestier pour des fins de biodiversité. Des questions contraintes par des choix de réponses multiples dichotomiques ont été utilisées lors du sondage pour permettre aux répondants d’exprimer de l’incertitude à propos de leurs évaluations. L’effet des différentes formulations des questions et des différents scénarios d’évaluation proposés sur la décomposition du budget environnemental a été étudié. Le fait de considérer l’incertitude a un impact significatif sur les estimations du consentement à payer. Le consentement à payer varie selon le niveau de protection du territoire forestier lorsque l’incertitude est explicitement introduite. Lorsque les estimations des valeurs sont regroupées à l’échelle nationale, la valeur de la protection du territoire forestier excède légèrement les coûts. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Changing climate in the Arctic is expected to have significant effects on the pattern and distribution of terrestrial vegetation. Species characteristic of specific zones in the mountains of northern Sweden have been shown to migrate up- and down-slope with changes in climate over the Holocene. This study evaluates the potential for Scots pine (Pinus sylvestris L.) to become a treeline dominant at Fennoscandian treelines, replacing mountain birch (Betula pubescens subsp. czerepanovii (Orlova) Hämet-Ahti). Data from paired mountain birch and Scots pine tree-ring chronologies for eight locations in northern Sweden are used to develop climate - tree ring width index (RWI) relationships. Modeled climate-RWI relationships are then used to predict the relative RWI values of the two species under a suite of climate-forcing scenarios using an ensemble of three global climate models. Results indicate that mountain birch and Scots pine RWI are both correlated with summer temperatures, but Scots pine is more likely than mountain birch to be influenced by moisture conditions. Predictions of RWI under future climate conditions indicate that mountain birch is unlikely to be replaced by Scots pine within the next century. Les changements climatiques en cours dans l'arctique devraient avoir des effets importants sur le patron et la distribution de la végétation terrestre. Il a été démontré que les caractéristiques des espèces dans des zones spécifiques des montagnes du nord de la Suède ont migré vers le haut et vers le bas de la pente en fonction des changements climatiques survenus au cours de l'holocène. Cette étude évalue la possibilité que le pin sylvestre (Pinus sylvestris L.) devienne dominant à la limite des arbres en Fennoscandie et remplace le bouleau pubescent (Betula pubescens subsp. czeropanevii (Orlova) Hämet-Ahti). Des données dendrochronologiques appariées du bouleau pubescent et du pin sylvestre provenant de huit endroits dans le nord de la Suède ont été utilisées pour établir des relations entre le climat et un indice de largeur des cernes annuels (ILC). Les relations modélisées entre le climat et l'ILC ont ensuite été utilisées pour prédire les valeurs relatives de l'ILC de ces deux espèces en fonction d'une suite de scénarios de forçage climatique à l'aide de trois modèles du climat global. Les résultats indiquent que les ILC du bouleau et du pin sont corrélés avec les températures estivales mais que le pin est plus susceptible d'être influencé par les conditions d'humidité que le bouleau. Les prédictions de l'ILC basées sur les conditions climatiques futures indiquent qu'il est peu probable que le pin sylvestre remplace le bouleau pubescent au cours du prochain siècle. [ABSTRACT FROM AUTHOR]

Adding nitrogen to coniferous forests on mineral soils will increase stem-wood growth in most boreal forests. The addition of nitrogen affects soils and waters as well. This investigation was conducted to evaluate the long-term effects of nitrogen fertilization at different intensities on soil chemistry in nitrogen-limited ecosystems. The study was performed at three experimental sites that were originally established around 1980 in Scots pine (Pinus sylvestris L.) stands. Fertilization regimes with applications ranging from conceivable commercial rates to very intensive rates (3× 150 kg N·ha-1 up to 12× 150 kg N·ha-1) had been applied. Samples were collected from the FH horizon at all sites and 0-20 cm in the mineral soil at two sites and analyzed for pH and major nutrients. The carbon to nitrogen ratio in the FH horizon decreased with increasing total nitrogen application, while the concentrations and contents of nitrogen and exchangeable magnesium and phosphorus increased. The concentration and contents of exchangeable potassium decreased in both the FH horizon and the mineral soil. In general, larger effects on soil chemistry were observed with increasing fertilization intensity. L'ajout d'azote dans les forêts de conifères établies sur des sols minéraux augmentera la croissance du tronc des arbres dans la plupart des peuplements boréaux. L'ajout d'azote affecte aussi le sol et l'eau. Cette étude visait à évaluer les effets à long terme de différentes intensités de fertilisation azotée sur les caractéristiques chimiques du sol dans les écosystèmes pauvres en azote. L'étude a été effectuée dans trois stations expérimentales où les traitements initiaux ont été appliqués vers 1980 dans des peuplements de pin sylvestre (Pinus sylvestris L.). Des régimes de fertilisation avec des taux d'application variant d'un taux correspondant à une application commerciale à un taux très élevé (de 3 à 12× 150 kg N·ha-1) avaient été utilisés. Des échantillons ont été prélevés dans l'horizon FH de toutes les stations et à une profondeur de 0 à 20 cm dans le sol minéral de deux stations. Ces échantillons ont ensuite été analysés pour déterminer le pH et la concentration des principaux nutriments. Le rapport entre le carbone et l'azote de l'horizon FH diminuait avec la quantité totale d'azote qui avait été appliquée alors que la concentration et le contenu en azote, en magnésium échangeable et en phosphore échangeable augmentaient. La concentration et le contenu en potassium échangeable avaient diminué dans l'horizon FH et dans le sol minéral. D'une façon générale, l'ampleur des effets sur les caractéristiques chimiques du sol augmentait avec l'intensité de la fertilisation. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We describe the decision support system RuttOpt, which is developed for scheduling logging trucks in the forest industry. The system is made up of a number of modules. One module is the Swedish road database NVDB, which consists of detailed information of all of the roads in Sweden. This also includes a tool to compute distances between locations. A second module is an optimization routine that finds a schedule, i.e., set of routes for all trucks. This is based on a two-phase algorithm where linear programming and a standard tabu search method are used. A third module is a database storing all relevant information. At the center of the system is a user interface where information and results can be viewed on maps, Gantt schedules, and result reports. The RuttOpt system has been used in a number of case studies and we describe four of these. The case studies have been made in both forest companies and hauling companies. The cases range from 10 to 110 trucks and with a planning horizon ranging between 1 and 5 days. The results show that the system can be used to solve large case studies and that the potential savings are in the range 5%–30%. Nous décrivons le système d’aide à la décision RuttOpt, qui a été développé pour planifier le déplacement des grumiers dans l’industrie forestière. Le système est composé de plusieurs modules. La base de données des routes suédoises (NVDB), qui contient des informations détaillées sur toutes les routes de la Suède, est l’un de ces modules. Ce module contient également un outil qui permet de calculer la distance entre deux endroits. Un deuxième module est constitué d’un sous-programme d’optimisation qui permet de générer un calendrier de transport, c.-à-d. un ensemble de trajets pour tous les camions. Cette opération est réalisée à l’aide d’un algorithme à deux phases dans lequel la programmation linéaire et une méthode de recherche tabou standard sont utilisées. Le troisième module est une base de données qui permet d’emmagasiner toutes les informations pertinentes. Au cœur du système se trouve une interface utilisateur qui permet de visualiser les informations et les résultats par le biais de cartes, de graphiques de Gantt et de rapports des résultats. Le système RuttOpt a été utilisé dans le cadre de plusieurs études de cas et nous décrivons quatre de ces études. Les études de cas ont été réalisées chez des compagnies forestières et des entreprises de transport. Selon le cas, le nombre de camions varie de 10 à 110 et l’horizon de planification d’un à 5 jours. Les résultats montrent que le système peut être utilisé pour résoudre des études de cas de grande taille et que les économies potentielles sont de l’ordre de 5 % à 30 %. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Forest Research is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A method based on region growing for segmentation of tree crowns in aerial photographs is presented. By using a decision function, for including a pixel or not, in the spatial domain and in the colour domain simultaneously, the irregular contour of the tree crowns is kept in the segmentation result. Thus, contour information may be subsequently used for tree species classification. A set of possible candidate regions for each tree is evaluated, and the best region, according to a measure, is selected. The method is evaluated on a large sample of high spatial resolution aerial images in central Sweden. Almost 15 ha of natural regenerated boreal forests are included in the image material. On average, the identification of 73% of the tree crowns is in agreement with the corresponding results from the manual delineations. The estimation of the total number of stems from the 30 test images is 93% of the value obtained from the manual count. [ABSTRACT FROM AUTHOR]

Offers information on Heureka research program initiated at the Forest Faculty, Swedish University of Agricultural Sciences in Sweden. Background on Swedish forestry; Information on some computer-based analyses and planning instruments for the management of forest resources developed at the university; Basic model concepts; Challenges in the development of a new generation of forest planning systems.

Focuses on a study which investigated the effects of previous fertilization with urea after final felling of a Norway spruce stand in Sweden. Materials and methods; Results; Discussion.

Investigates the single and combined effects of shelterwood, soil scarification, and feeding barriers on pine weevil (Hylobius abietis L.) damage to Norway spruce (Picea abies (L.) Karst.) seedlings in southern Sweden. Seedlings that were planted on four different sites, each consisting of two plots, one clearcut and one with shelterwood; Plots that were each subdivided into two parts, one scarified and one left untreated; Seedlings that were protected with insecticide or feeding barriers or left as unprotected controls; Damage-reducing effects of shelterwood, scarification, and physical protection that were additive; Order of effectiveness of the individual measures for reducing damage by pine weevils that was insecticide, scarification, physical protection, and shelterwood; Scarification that reduced pine weevil damage equally well on clearcuts as in shelterwoods; Effects of scarification that were more long lasting in shelterwoods.

Studies the effect of fertilization on the characteristics of Norway spruce in a nutrient optimization experiment in Sweden. Relation of the decrease in wood density with the proportion of latewood; Essence of effective timber production in practical forestry; Factors determining wood density.

Evaluates the approaches used in determining harvest timing of trees in Sweden. Use of tree-selection harvest control; Consideration for fixed cutting cycles; Importance of aggregated data to determine appropriate harvest timing.

This paper reviews the approaches to multiple objective landscape planning that have developed in Swedish forestry in the 1990s. The objectives of such planning include primarily timber production and maintenance of biodiversity, but also aspects such as aesthetics and recreation. The variety of approaches and models that have emerged is caused by regional differences in land-use history, forest conditions, recreation pressure, and ownership. We distinguish three approaches: The species approach and the naturalness approach integrate conservation aspects, while the multiple aspects approach integrates several aspects (biological, social, economic, spiritual, etc.) into commercial timber-producing forestry. The species approach is exemplified by thekey habitat--corridor model in which key habitats and corridors are preserved to support certain species. The natural landscape model illustrates an example of the naturalness approach, as it integrates natural forest features from a fire-disturbed landscape and gives examples of management implications at the landscape as well as at the stand level. The multiple aspects approach combines several objectives and defines important structures rather loosely. This approach was developed in areas where private nonindustrial forestry dominates. Nontimber and nonconservation aspects therefore become relevant to forest management. The supportive feature model exemplifies an application ofthat approach. [ABSTRACT FROM AUTHOR]