Ljusk Ola Eriksson

Optimal storing, transport and processing for a forest-fuel supplier

Abstract The supplier of forest fuel has a large number of interrelated activities to coordinate on the way from raw material source to consumer. Transports, storing and intermediate processing must be decided on for a number of different raw materials. In this paper, an analysis is performed on the energy supply system of Jamtlandsbranslen, a subsidiary of the Swedish Cellulose Company. Included are several forest supply regions, one central processing site and one consumer. Optimal solutions are derived for a problem with an infinite sequence of years, where each year is divided into six periods. The problem is solved as an ordinary linear programming problem. Results are given on optimal production flows, storing and procurement. The usefulness of the applied analytical approach for deriving rules for operational planning is discussed.

Solving the stand management problem under biodiversity-related considerations

A new solution method to solve the even-aged stand management problem that results when biodiversity-related demands are taken into account is presented. The model was based on single-tree growth functions, the meta-heuristic optimisation technique: tabu search and greedy heuristics. The timing of thinnings and final harvest was recognised, and fixed entry cost included. Biodiversity considerations were expressed in terms of stand attribute targets for coarse woody debris, tree-size diversity and tree retention. The performance of the model was demonstrated with a case example, where the model was applied to simulated, mixed stands of Norway spruce and birch. The model was able to solve huge problems in a short time. Cost curves for the non-timber outputs are presented. The biodiversity considerations typically affected the time for final harvest, number of thinnings and thinning form.

Allowing for spatial consideration in long-term forest planning by linking linear programming with simulated annealing

This paper presents three approaches for including spatial considerations, in terms of continuous areas of old forest, in a long-term forest planning problem with even-flow and inventory constraints. Two of the approaches integrate linear programming with simulated annealing into one single solution procedure. Simulated annealing is used for solving the spatial dimension of the problem, while linear programming is used for solving the non-spatial dimension. The third approach uses only simulated annealing for solving the entire management problem. All three approaches are in a case study applied to a landscape consisting of 755 stands in northern Sweden. The results from this case study indicate that the approaches that use both simulated annealing and linear programming produce more effective solutions in terms of net present value and spatial layout for this landscape than the approach that only uses simulated annealing.

Climate change mitigation through increased wood use in the European construction sector—towards an integrated modelling framework

Using wood as a building material affects the carbon balance through several mechanisms. This paper describes a modelling approach that integrates a wood product substitution model, a global partial equilibrium model, a regional forest model and a stand-level model. Three different scenarios were compared with a business-as-usual scenario over a 23-year period (2008–2030). Two scenarios assumed an additional one million apartment flats per year will be built of wood instead of non-wood materials by 2030. These scenarios had little effect on markets and forest management and reduced annual carbon emissions by 0.2–0.5% of the total 1990 European GHG emissions. However, the scenarios are associated with high specific CO2 emission reductions per unit of wood used. The third scenario, an extreme assumption that all European countries will consume 1-m3 sawn wood per capita by 2030, had large effects on carbon emission, volumes and trade flows. The price changes of this scenario, however, also affected forest management in ways that greatly deviated from the partial equilibrium model projections. Our results suggest that increased wood construction will have a minor impact on forest management and forest carbon stocks. To analyse larger perturbations on the demand side, a market equilibrium model seems crucial. However, for that analytical system to work properly, the market and forest regional models must be better synchronized than here, in particular regarding assumptions on timber supply behaviour. Also, bioenergy as a commodity in market and forest models needs to be considered to study new market developments; those modules are currently missing.

Planning under uncertainty at the forest level : A systems approach

Abstract Large-scale long-range forest management problems have been successfully analysed for decades using linear programming models. Existing larger systems, such as MELA, FOLPI, FORPLAN, GAYA-LP and Spectrum, are based on a model formulation that is known as model I or the closely related model II. This paper shows how the model I formulation can be extended to incorporate stochastic phenomena. The uncertainty problem is given as a programme with recourse, i.e. the formulation takes account of the fact that the decision maker is able to observe the state of the system over time and subsequently make adaptations. Basic for the formulation is the expression of the stochastic process as a collection of scenarios. After the basic model has been formulated the implications for systems design are indicated. The approach is applied to a small sample forest where the consequences of different objectives and constraints are illustrated. The limitations of the method, among which model size is prominent, are discussed. It is also noted that not all stochastic processes are amenable to analysis with the suggested approach. The procedure requires global, not standwise, processes and there should be no feedback between actions and scenario probabilities.

Studying the use of forest management decision support systems: an initial synthesis of lessons learned from case studies compiled using a semantic wiki

In order to share information on the development and use of forest management decision support systems (FMDSS), a European-initiated network has established a wiki website as part of its activities. Case studies and associated lessons learned were solicited from the network using semantic structures built on the wiki. A total of 31 cases from 10 different countries and 80 associated lessons were entered into the wiki. The resulting lessons were categorized (non-exclusively) using four major themes: (1) decision support system architecture and design (40 lessons), (2) methods and models (26), (3) knowledge management processes (34) and (4) participatory processes (32). The semantic wiki proved useful for gathering case information and relating it to other information objects, such as FMDSS software descriptions; however, it was not as well suited to the task of analysis and synthesis as commercial qualitative analysis software packages. Future development possibilities for the semantic structures are suggested, and more cases are solicited from the FMDSS community.

Impacts of different forest management scenarios on forestry and reindeer husbandry

In northern Sweden, the forests are used simultaneously for both timber production and reindeer husbandry. During the winter months, lichen is the most important fodder for reindeer. Forest management operations are generally considered having a negative impact on reindeer husbandry as harvesting and dense stands remove or obscure the ground lichen cover. In this study, we simulate three different scenarios for forest management, differing in the intensity and types of harvest operations. The resulting 100-year scenarios are analyzed with respect to their estimated suitability for providing reindeer pasture areas. Suitability is determined by vegetation type, stand density and stand height. The results indicate that the current trend of a decrease in lichen area will continue if existing forestry practice prevails. Implementing continuous cover forestry as a management alternative and carrying out precommercial thinning could halt the decrease in reindeer pasture area and even lead to a future increase in pasture area, with losses of approximately 5% in the net present value of forestry.

Gendered business activities in family farm forestry: From round wood delivery to health service

Abstract The development of non-wood forest products and services has been put forward as a means for business diversification and development of rural areas. However, the well-documented male dominance in traditional family farm forestry (FFF) is considered to restrain womens involvement in forestry activities, and thus hamper new enterprising businesses. Given the gender structure in traditional forestry, it is hypothesised that women are more likely to engage in less traditional activities than men. Through a cluster analysis of data from the Swedish Farmers Associations member survey, typical combinations of forest-related business activities were identified. The representation of women and men as operational managers within each activity was assessed. Results show that traditional forestry is the main task for both male and female FFF owners, however, women engage more often than men in service-oriented business activities. The main conclusion is that the prevailing pattern on the labour market, with women predominately within service and care professions, seems to be reproduced within FFF businesses. The results are further discussed in relation to owner types and possible impact on FFF restructuring and rural development.

A Model for Predicting Productivity in Subgrade Preparation of Forest Roads by Excavator

The effect of terrain factors on productivity in subgrade preparation by excavator was studied. The data, collected in a follow-up time study of 57 road sections, was analyzed using multiple linear regression. A prediction model that has soil moisture class and boulder frequency as independent variables was derived. The results also show that productivity varies considerably among operators. It is also apparent that the effect of the terrain is partly levelled out as the quality requirements for the performance of the subgrade are normally adjusted to the terrain conditions. It is suggested that, within a certain region, a fairly simple model can be sufficient for practical use in road network planning.

Ranking Stands with Treatment Indices

Medium‐term plans give prescriptions for individual stands in each of three to five years. The long range plan, on the other hand, is based on aggregated data in the form of timber classes, and multi‐year periods. Three treatment indices for stands are developed as linkages between these plans. Several model studies are performed where the prioritizing of thinning and fertilization according to index are compared with the solution to a model based on disaggregated data. The index that is based on reduced costs computed on stand data shows the best correspondence. The index that shows the poorest results transfers the treatment assigned to the timber classes to the stand via the kinship of the initial state of the stands with that of the timber classes. It is not evident that the use of this index would perform better than a mere random selection. The third index has reduced costs computed on timber class data which are transferred to the stands via the kinship between them and the timber classes. This ind...