| 1. |
- Aronsson, Per, et al.
(författare)
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An operational decision support tool for stump harvest
- 2011
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A multi-criteria decision support tool was developed to optimise stump harvesting for energy in Sweden. The decision tool takes account of multiple, sometimes conflicting, criteria relating to stump harvest; energy and climate, economics, biodiversity, and soil and water. Data on harvested stems are used as primary input data in the tool. Such data are routinely collected in harvester computers. The tool effectively deals with mixed sets of data; quantitative harvest data are re-calculated to metric (e.g. stump biomass), and qualitative data (e.g. biodiversity implications) are incorporated. A digital terrain map derived from air-borne laser scanning provides basic data for estimating soil wetness, while digital maps of water courses, key habitats and protected areas, or other sensitive habitats, are used to identify potentially and practically harvestable stumps.In four sub-models, an index from 0 to 10 is calculated for each stump, with 0 representing ‘Not at all suitable’ and 10 ‘Highly suitable for extraction’. Through this, a stump of high value for wood-living species is assigned a low index in the biodiversity sub-model and a large, easily accessible stump is assigned a high index in the economic sub-model. When calculating the net index, the sub-indices can be weighted according to the preferences of the end-user.An energy and climate sub-model incorporates greenhouse gas (GHG) emissions from forest operations and the effect of advancing GHG emissions when stump biomass is incinerated instead of being left to decompose. In the economic sub-model the potential monetary return from each stump is calculated based on estimated revenue from harvested stump biomass and the costs of stump harvesting and forwarding operations (based on cost functions and GIS calculations of transport distances).The biodiversity sub-model considers four types of wood-dependent organisms (lichens, mosses, insects and fungi) in terms of their habitat requirements, vulnerability, sun exposure preferences, locality, etc. A panel of external experts has drawn up a grading scale of stump values for the different taxonomic groups. The proximity to key habitats and exposure to sunlight are derived from a spatial model.Soil and water issues are handled within a sub-model estimating the consequences for long-term soil fertility (nutrient cycling and soil compaction) and water (leaching of plant nutrients and mercury, and particle transport due to soil damage by heavy machinery).The tool offers the end-user possibilities to prioritise and plan for cost-effective stump harvesting, while minimising negative environmental impacts.
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| 2. |
- Bergh, Torsten, et al.
(författare)
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2+1-roads Recent Swedish Capacity and Level-of-Service Experience
- 2016
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Ingår i: Transportation Research Procedia. - : Elsevier. - 2352-1465. ; 15, s. 331-345, s. 331-345
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Tidskriftsartikel (refereegranskat)abstract
- The first Swedish 2+1 median barrier road was opened in 1998. The concept was to retrofit the standard existing two-lane 13 m paved width cross-section at 90 and 110 kph posted speed limit without widening. This design has one continuous lane in each direction, a middle lane changing direction every one to three kilometres with a median barrier separating the two traffic directions. Today over 2 700 km 2+1 median barrier roads are opened for traffic. AADT’s vary from some 3 000 to 20 000 with an average just below 10 000 nowadays normally with 100 kph.The concept has lately been enhanced also to cover the existing 9 m paved width cross-section. The design concept is the same from a driver’s viewpoint, one continuous lane in each direction with a middle lane changing direction and a separating median barrier. This is created by introducing a continuous median barrier and adding overtaking lanes within an overtaking strategy. The differences are the existence of 1+1-sections, less overtaking opportunities and a slightly more narrow cross-section. Some 15 projects are opened. The purpose of this paper is to summarize present knowledge on level-of-service issues as they are presented in Swedish design and assessment guidelines and to give an overview of field measurements and theoretical analytical and simulation studies supporting the recommendations.
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| 3. |
- Bergh, Torsten, et al.
(författare)
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Capacity Issues in Sweden - Applications and Research
- 2016
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Ingår i: Transportation Research Procedia. - : Elsevier BV. - 2352-1465. ; , s. 36-50, s. 36-50
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Konferensbidrag (refereegranskat)abstract
- This paper gives an overview of the Swedish trunk road system and present objectives, guidelines concerning capacity and level of service procedures to assess these issues in the feasibility and design procedure are also described.An important goal in Sweden is investments and speed limit changes over a 10 year time scale to decrease the C02-exposure. The long term speed limit overview with the objective to require median barriers at speed limits over 80 kph with results so far is presented. By now over 50 % of the former traffic load over 80 kph is decreased to 80 kph. Some 2,700 km have been retrofitted to 2+1 median barrier roads with speed limit mainly 100 kph.An overview is also given of the updated Swedish Highway Capacity Manual with new chapters especially on jam densities, entry lanes, weaving areas and traffic signals. Some interesting research projects are also briefly covered. These are 2+1 median barrier roads, capacities at motorway work zones, speed harmonisation with variable speed limits on motorways to increase capacity, ramp metering and Drive Me (autonomous driving full scale tests).
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| 4. |
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| 5. |
- Grelle, Achim, et al.
(författare)
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From source to sink : recovery of the carbon balance in young forests
- 2023
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Ingår i: Agricultural and Forest Meteorology. - : Elsevier. - 0168-1923 .- 1873-2240. ; 330
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Tidskriftsartikel (refereegranskat)abstract
- We analyzed ecosystem carbon fluxes from eddy-covariance measurements in five young forests in southernSweden where the previous stand had been harvested by clear-cutting or wind-felled: three stands with Norwayspruce (Picea abies (L.) Karst.), one with Scots pine (Pinus sylvestris) and one with Larch (Larix x eurolepis A.Henry). One of the spruce stands had the stumps harvested, one was fertilized and one without any specialtreatments. These stands returned from positive (sources) to negative (sinks) annual carbon fluxes 8–13 yearsafter disturbance, depending on site productivity and management. This corresponds to approximately 15% ofthe rotation periods at these sites. Extrapolation in combination with chronosequence data suggests thatconventionally regenerated stands reach a neutral carbon balance after approximately 30% of the rotationperiod. The lowest carbon emissions and shortest recovery time was observed in a stand where the stumps of thetrees, in addition to the stems and logging residues, were removed after harvest. This stand not only returned to acarbon sink within this time period but the total carbon gains since disturbance also equaled the total losses afteronly 11 years. These results stress that production stands in southern Sweden are carbon sources during arelatively small part of the rotation period, and that this part can be considerably shortened by measures thatincrease productivity or reduce the amount of woody debris left after disturbance.
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| 6. |
- Grumert, Ellen, 1983-, et al.
(författare)
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Effects of incidents on motorways : a proposed methodology for estimating and predicting demand, duration and capacity for incident management
- 2021
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Effective traffic incident management is important to minimize negative impacts of congestion caused by incidents. Predictions of the traffic state at the incident site and its surrounding road network, together with an estimate of incident duration, can be used to get increased knowledge about current and future incident characteristics. The aim is to propose methods for estimating capacity, duration and demand profiles in case of an incident, and to explore how the level of detail and the possibility to identify explanatory variables for incidents with similar characteristics given currently available data sources affects the proposed methods. The knowledge obtained within the project is intended to be used for incident management. The report presents a methodology for predicting capacity, traffic demand, and incident duration, when none of the parameters are known. The proposed methods can be used as input to traffic models, when the purpose is to perform scenario-based analysis and real-time predictions to be used in the decision-making processes for traffic management/control, but also for predicting travel times which can be communicated to road users.A motorway use-case study area south of Stockholm is used to propose methods for predicting incident duration, capacity and demand profiles based on the availability of data. The methodology is evaluated by using the predicted variables as input in a scenario-based analysis with two queue models.
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| 7. |
- Håkansson, Charlotta, 1971-, et al.
(författare)
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Effects of fertilization on soil CH4 and N2O fluxes in young Norway spruce stands
- 2021
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Ingår i: Forest Ecology and Management. - : Elsevier. - 0378-1127 .- 1872-7042. ; 499
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Tidskriftsartikel (refereegranskat)abstract
- Climate change mitigation strategies have increased the demand for wood products, resulting in an urgent needto increase wood production. One approach is to fertilize forest land, but this can influence greenhouse gas (GHG) fluxes within the ecosystem. The aim of this study was to examine the effects of forest N fertilization onsoil CH4 and N2O fluxes in young Norway spruce (Picea abies (L.) Karst.) stands in southern Sweden. The gasfluxes were measured using flow-through non-steady-state dark chambers. In the first, long-term, experiment,half of the stand was fertilized twice (once in 2014 and once in 2016) with 150 kg ha-1 of N, and gas fluxmeasurements were taken throughout 2014–2017. In the second, dose, experiment, 0, 150, 300, or 450 kg ha-1 of N was added to the stand in April 2016, and gas flux measurements were taken during April-December 2016.The dose experiment showed that the sink strength of CH4 decreased with increasing amounts of N; the long-termexperiment indicated that repeated fertilization decreased the CH4 sink strength over time. Additionally, thelong-term experiment indicated that, while significantly higher N2O emissions were recorded in the fertilizationyears, this was not detected in subsequent years, suggesting the effect to be short-lived. In the dose experiment,fertilization tended to increase the N2O emissions relative to the amount of fertilizer. However, despite thesignificant effects of fertilization on these GHGs, the summed fluxes were a fraction of the net uptake of C at thesites, as recorded in another study. These findings suggest that fertilizing forest land with commercial NP or NPKfertilizers corresponding to 150 kg ha-1 of N, the level used in operational forestry in Sweden today, can beconducted without changing CH4 and N2O fluxes to any great extent.
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| 8. |
- Håkansson, Charlotta, 1971-
(författare)
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Greenhouse Gas Fluxes and Carbon Sequestration in Young Norway Spruce Stands : The Effects of Fertilization
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The enormous challenge of climate change is discussed and debated today because of its major impact on life on Earth. The forests have an important role to play as the plants absorb carbon dioxide (CO2) from the atmosphere through their photosynthesis and the growing tree retain carbon (C). Hence, the larger the growth the greater the carbon storage and climate benefit. The demand for wood and wood products is increasing as well as the ongoing debate about forest management. Therefore, alternative management methods to increase wood production is of interest and the effects these methods could have on climate change mitigation. In this context this Thesis deals with the effect of fertilization on carbon balance and growth in young forest as well as flows of the greenhouse gases, CO2, methane (CH4), and nitrous oxide (N2O) from forest land. In addition, it deals also with the reliability and comparability of different measurement methods which are compared with respect to the carbon balance.The studies have been carried out in a young mixed stand of Norway spruce (Picea abies (L.) Karst) and birch (Betula pendula and B.pubescens) on a storm-felled (Gudrun 2005) area in southern Sweden, Kronoberg county. Part of the area was fertilized with 150 kg N ha-1 everysecond year from 2014 and forward, while the other part was kept unfertilized. In the unfertilized part a dose experiment was set up where 0,150, 300, and 450 kg N ha-1 were added to investigate the impact of the different fertilizer levels on forest floor greenhouse gas fluxes. Chamber measurements of forest floor fluxes, eddy-flux measurements of stand net-fluxes and tree measurements of height, diameter and birch leaf biomass were conducted in different, occasionally overlapping, periods in the years 2013-2021.The results show that even if the flows of CO2 from the forest floor increase initially after a first standard fertilization, the effect decreases quickly. The net fluxes show that the stands become carbon sinks already eight years after the storm with a net uptake of about 18 ton CO2 ha-1 yr-1 of. The forest floor fluxes of CH4 and N2O also show a short-term effect of fertilization, however the levels are very low compared to CO2. The fertilization induced increase of total tree biomass growth increased with time. The results show that 12 and 15 years after regeneration, the fertilization compared to the control has increased the tree growth by 3.4 and 6.3 m3 ha-1 yr-1 and carbon storage by 4.7 and 8.7 ton C ha-1 yr-1 respectively.Comparison of measurement results of the Eddy-flux technique's netflows and chamber measurements of soil respiration together with tree growth shows the importance of calibrating the measurement methods when the results are later to be used in modeling future climate scenarios.
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| 9. |
- LarsOlle, Anders, et al.
(författare)
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A multi-criteria decision support model for optimal stump harvesting
- 2012
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- A multi-criteria decision support model for optimal stump harvesting Sweden was developed. The model quantifies the effect of harvesting each individual stump over a harvesting object in four criteria's: - Biodiversity (Biodiversity value index) - Economy (SEK) - Greenhouse gas emissions (CO2) - Soil and water (Soil and water preservation index) The four criteria's are sometimes in conflict to each other, and uses values that are not directly comparable. The intended use for this model is to contribute with the objective evaluation of all four criteria's in the decision in what stumps to harvest and what stumps to leave in the harvesting object. The model uses individual stump data (e.g. position, tree species and stump biomass) and harvesting object GIS data (roads, elevation map, soil map, terrain map). Primary data on individual stumps comes from the logging system in the stem harvesters: GPS and operator classification. Such data are routinely collected in harvesters. Official map data for the harvesting object are available from the Swedish mapping, cadastral and land registration authority (Lantmäteriet). This includes the topographic map and elevation maps data in 2 m resolution. Also, GIS data are collected in the inspections before harvesting the stems. The biodiversity sub-model considers different types of wood-dependent organisms (lichens, mosses, insects and fungi) in terms of their habitat requirements, vulnerability, sun exposure preferences, locality, etc. A panel of external experts has drawn up a grading scale of stump values for the different taxonomic groups. The proximity to key habitats and exposure to sunlight are derived from a spatial model. In the economic sub-model the potential net return from each stump is calculated based on estimated revenue from harvested stump biomass and the costs of stump harvesting and transport (based on cost functions and GIS calculations of transport distances). An energy and climate sub-model incorporates greenhouse gas (GHG) emissions from forest operations and the effect of advancing GHG emissions when stump biomass is incinerated instead of being left to decompose. Soil and water issues are handled within a sub-model estimating the consequences for long-term soil fertility (nutrient cycling and soil compaction) and water (leaching of plant nutrients and mercury, and particle transport due to soil damage by heavy machinery). Each criteria is evaluated in totally four sub-models. To be able to compare the resulting value from each of the criteria, a harvesting index from 0 to 1 is calculated for each stump. The value 0 represents ‘Not at all suitable for harvest’ and 1 ‘Highly suitable for harvest’. Through this, a stump of high biodiversity value is assigned a low harvesting index in the biodiversity sub-model and a large, easily accessible stump is assigned a high harvesting index in the economic sub-model. When calculating the total net index, the harvesting index from each criteria has to be weighed together using one coefficient for each criteria. The weighing coefficient for each criteria is chosen according to the preferences of the decision maker. The tool offers the end-user possibilities to prioritise and plan for cost-effective stump harvesting, while minimising negative environmental impacts.
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| 10. |
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