| 1. |
- Alger, David, et al.
(författare)
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Skattning av areal organogen mark för alla ägoslag
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Torvmark lagrar stora mängder organiskt kol som kan emitteras i samband med brukande. Vidare kan lustgas och metan släppas ut från torvmark och därför anses variabeln viktig ur ett klimatperspektiv. Vi har valt att definiera torvmark som att ”mer än halva arealen täcks av torv”. Riksskogstaxeringen har en mer detaljerad definition men normalt ska torvlagret vara djupare än 30 cm. Riksskogstaxeringen mäter alltid torvmark på ägoslagen Skogsmark, Naturbete, Myr, Fjällbarrskog och Annat klimatimpediment (men periodvis har mätningar även förekommit på andra ägoslag). Därmed saknas variabeln för vissa ägoslag. Om provytan är delad i mer än ett ägoslag mäts variabeln per delyta. Internt i nuvarande klimatrapportering redovisas torvmark utifrån en inventering per omdrev (2003-2007) fast variabeln registreras vid varje återinventering av samma provyta. Tanken är att undvika variation orsakad av personlig bedömning i fält samtidigt som vi tror att variabeln sällan ändras. Det finns nu en möjlighet att grovt komplettera variabeln torvmark för ägoslag där densamma inte registrerats av Riksskogstaxering. Tanken är att använda SGUs jordartskarta för ändamålet. Uppgiften går ut på att komplettera de provytor som saknar bedömning av variabeln torvmark med uppgifter från ett nyproducerat kartskikt. Vidare kommer en kontinuerlig registrering av variabeln torvmark per inventeringstillfälle vägas mot att, som idag, enbart basera mätningen på ett inventeringstillfälle.
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| 2. |
- Berglund, Örjan, et al.
(författare)
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Land use on organic soils in Sweden – a survey on the land use of organic soils within agriculture and forest lands during 1983-2014
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Data from the Geological Survey of Sweden (SGU), the Swedish Board of Agriculture and the Swedish National Forest Inventory were used in a GIS analysis to evaluate the distribution of organic soils (OS) used for agriculture and forestry in Sweden. The status of agricultural soils and agricultural land use changes were also studied, based on the most recent data available from the SGU. The total surface area of OS in Sweden was estimated to be 6 207 284 ha (15.2% of the land surface area), which is less than reported in previous assessments (Berglund and Berglund, 2008; Berglund et al., 2009). Of the total OS area 98.2% was peat, of which 4.7% was shallow peat and 2.5% 40K peat (peat determined using gamma radiation data). The remaining 1.8% were gyttja soils. Total agricultural area under EU regulations (i.e. on the EU agriculture block map) in Sweden was 3 232 039 ha (7.9% of the land surface area) and most of this was arable land (82.8%). Pasture occupied approx. 16% of the area, the land use on the remaining 1.2% is unknown. Agricultural area on OS (AOS) based on SGU-data and the EU agriculture block map was estimated to be 225 722 ha which is 7% of the total agricultural area based on EU agriculture block maps and 9.0% based on the national maps over agricultural land areas provided by the Swedish Board of Agriculture. More than 50% of AOS was arable land whereas approx. 40% was divided between pasture and unmanaged arable land. The remaining area was wetland, unknown or other land use type. In comparison to previously studies in 2003 (Berglund and Berglund, 2008) and 2008 (Berglund et al., 2009), both the total agricultural area and AOS area have decreased, probably due to structural changes in agriculture. The decline has been sharper for the surface area of AOS than for the total agricultural area. Among the Swedish National Forest Inventory plots, 12.3% were located on OS. Land use changes recorded on the Forest Inventory plots were mostly from arable land to other land uses rather than from other land uses to arable land both in total area and in OS.
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| 3. |
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| 4. |
- Bolinder, Martin, et al.
(författare)
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Fånggrödor och rötrester i ICBM
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Målsättningen med detta utvecklingsprojekt var att göra en förstudie om tillgänglig statistik för fånggrödor och rötrester. Data med tidsserier för fånggrödor som används i andra modelleringsprojekt på SLU kan anpassas relativt enkelt för att inkluderas i kolbalansmodellen ICBM på länsnivå. För rötrester finns det också potentiella källor med tidsserier, men de skulle kräva lite mer förbehandling innan de kan användas. Båda dataserierna sträcker sig så pass långt bak i tiden att de representerar ganska bra den tidpunkten från och med att dessa två faktorer blir relevanta att ha med i markkolsmodelleringen. Modellparametrar (utöver areal fånggrödor och mängd rötrester), som man skulle behöva justera rör framför allt allometriska funktioner för fånggrödor och humifieringskoefficienten för biogödsel.
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| 5. |
- Bolinder, Martin, et al.
(författare)
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Implementing a new version of ICBM in NIR
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In the sector Land Use, Land-Use Change and Forestry (LULUCF, CRF sector 4) within the national greenhouse gas inventory (NIR), Sweden is applying a Tier 3 method for estimating the loss or gain of soil organic carbon (SOC) stocks for cropland on mineral soils to a depth of 0.25 m. The Introductory Carbon Balance Model (ICBM) is used for calculating stock change rates in eight agricultural production regions and results are aggregated to the national level. Calculations involves yearly agricultural census data and daily weather records, as well as results from a national soil-monitoring program (SMP) on soil carbon contents. Initially, only data from the first sampling of the national SMP were used for initializing ICBM. Since the first soil inventory, two additional samplings within the SMP have become available. Simultaneously, we have also gained more knowledge about SOC dynamics. In a development project last year, we were re-analyzing the complete records of data from the last two decades of the SMP confirming that SOC stocks are increasing, and we were starting to calibrate a new version of ICBM. The purpose of the project this year was to implement the new ICBM version in the NIR system.The results show that the new version of ICBM simulates increasing SOC stocks for the period 1990 to 2018, which is thereby more consistent with estimates from the national SMP data than results obtained using the previous ICBM version. The ICBM and SMP assessment methods of SOC stock changes are complementing each other, and both have their inherent limitations. Our analysis with both methodologies are still not fully completed. There remain some fine-tuning in the new ICBM version. Furthermore, we are continuously working on improving the interpretation regarding SOC stocks in the current database from the national SMP. Maintaining the latter and repeating the sampling at least once more would also substantially improve the value of this database.
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| 6. |
- Bolinder, Martin, et al.
(författare)
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New calibration of the ICBM model & analysis of soil organic carbon concentration from Swedish soil monitoring programs
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- We are using the Introductory Carbon Balance Model (ICBM) within the national inventory reporting (NIR) system for estimating changes in soil organic carbon (SOC) stocks in Swedish arable land for mineral soils. The first version of ICBM was developing from a long-term experiment (LTE) in Ultuna Sweden, with a time-series of data from 1956 to 1991. The model is initialized using data from a soil database and information from Swedish soil monitoring programs (SMPs). For that purpose, it specifically uses data from the first inventory of the Swedish Environmental Protection Agency (SEPA) SMP conducted in the early 1990s. Since the 1990s, the SEPA SMP has conducted two further inventories in a 10-year cycles, with the last inventory completed in 2017. In complement to this SEPA SMP, the Swedish Board of Agriculture (SJV) was completing a spatially more detailed SMP in 2011 and 2012. In an earlier study, when the third inventory of SEPA was still not fully completed, we showed that SOC concentrations are increasing in Swedish arable mineral soils during the past two decades. Simulations with the current version of ICBM are not reproducing this long-term increasing trend.The main purposes of this project were to (i) calibrate a second version of ICBM by incorporating new knowledge gained from LTEs, (ii) evaluate the trends in SOC concentrations with the complete inventories (I, II and III) of SEPA, (iii) compare results from SEPAs last inventory (III) with that of SJV SMP conducted at approximately the same time period. A Bayesian approach was selected for calibrating the second version of ICBM, using an updated time series of data from Ultuna ending in 2017, and by also including experimental data (1996-2017) from a new sister experiment at Lanna in southern Sweden. For adequately comparing the SEPA and SJV SMPs, we were correcting data from the SJV samples so that we could express all results for SOC concentrations on a basis equivalent to dry combustion. Our analysis on the complete SEPA inventories are generally confirming our previous assessment. However, a more detailed exploration using data only from inventories II and III having identical sampling coordinates, clearly indicates that the increases in SOC concentrations were less in the last decade than in the previous one. Furthermore, when comparing SOC concentrations at different spatial scales, the positive trend in SOC concentrations is much more obvious on the scale of Swedish agricultural production regions (eight regions). Indeed, at the scale of the twenty-one Swedish counties, there are few significant differences and the increasing trend is unclear for many of the counties. This is reflecting difficulties related to the density of sampling points in the SEPA SMP; each of them roughly represents 1500 ha of arable land. Besides, only two decades or even only one decade since SEPA was regarding inventory II as a restart of their SMP, remain a short time period in detecting changes in SOC and highlight the importance of maintaining continuous SMPs.We found the comparisons between the SJV and SEPA SMPs useful but further work is necessary to refine the linkage. The overall changes in parameter values related to SOC dynamics for the calibrated second version of ICBM, will give simulations towards higher SOC stocks, compared to the current version. The main parameter explaining this differences is the increased contribution of below ground (i.e., roots) annual C inputs to soil contributing to the formation of more stable SOC. The approach we used here also offers the advantage of making a multi-site calibration and we could in the future, further refine parameter values by including other Swedish LTEs. Additionally, it allows us to include an estimate for uncertainty in the predictions of SOC stocks, which we could also develop for inclusion in the NIR system.
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| 7. |
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| 8. |
- Gustavsson, Leif, 1954-, et al.
(författare)
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Climate change effects of forestry and substitution of carbon-intensive materials and fossil fuels
- 2017
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Ingår i: Renewable & sustainable energy reviews. - : Elsevier. - 1364-0321 .- 1879-0690. ; 67:January, s. 612-624
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Tidskriftsartikel (refereegranskat)abstract
- We estimate the climate effects of directing forest management in Sweden towards increased carbon storage in forests with more land set-aside for protection, or towards increased forest production for the substitution of carbon-intensive materials and fossil fuels, relative to a reference case of current forest management. We develop various scenarios of forest management and biomass use to estimate the carbon balances of the forest systems, including ecological and technological components, and their impacts on the climate in terms of radiative forcing. The scenario with increased set-aside area and the current level of forest residue harvest resulted in lower cumulative carbon emissions compared to the reference case for the first 90 years, but then showed higher emissions as reduced forest harvest led to higher carbon emissions from energy and material systems. For the reference case of current forest management, increased harvest of forest residues gave increased climate benefits. The most climatically beneficial alternative, expressed as reduced cumulative radiative forcing, in both the short and long terms is a strategy aimed at high forest production, high residue recovery rate, and high efficiency utilization of harvested biomass. Active forest management with high harvest levels and efficient forest product utilization will provide more climate benefit, compared to reducing harvest and storing more carbon in the forest.
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