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He, H., Meyer, A., Jansson, P.-E., Svensson, M., Rutting, T. & Klemedtsson, L. (2018). Simulating ectomycorrhiza in boreal forests: implementing ectomycorrhizal fungi model MYCOFON in CoupModel (v5). Geoscientific Model Development, 11(2), 725-751
Open this publication in new window or tab >>Simulating ectomycorrhiza in boreal forests: implementing ectomycorrhizal fungi model MYCOFON in CoupModel (v5)
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2018 (English)In: Geoscientific Model Development, ISSN 1991-959X, E-ISSN 1991-9603, Vol. 11, no 2, p. 725-751Article in journal (Refereed) Published
Abstract [en]

The symbiosis between plants and Ectomycorrhizal fungi (ECM) is shown to considerably influence the carbon (C) and nitrogen (N) fluxes between the soil, rhizosphere, and plants in boreal forest ecosystems. However, ECM are either neglected or presented as an implicit, undynamic term in most ecosystem models, which can potentially reduce the predictive power of models. In order to investigate the necessity of an explicit consideration of ECM in ecosystem models, we implement the previously developed MYCOFON model into a detailed process-based, soil-plant-atmosphere model, Coup-MYCOFON, which explicitly describes the C and N fluxes between ECM and roots. This new Coup-MYCOFON model approach (ECM explicit) is compared with two simpler model approaches: one containing ECM implicitly as a dynamic uptake of organic N considering the plant roots to represent the ECM (ECM implicit), and the other a static N approach in which plant growth is limited to a fixed N level (nonlim). Parameter uncertainties are quantified using Bayesian calibration in which the model outputs are constrained to current forest growth and soil C / N ratio for four forest sites along a climate and N deposition gradient in Sweden and simulated over a 100-year period. The "nonlim" approach could not describe the soil C / N ratio due to large overestimation of soil N sequestration but simulate the forest growth reasonably well. The ECM "implicit" and "explicit" approaches both describe the soil C / N ratio well but slightly underestimate the forest growth. The implicit approach simulated lower litter production and soil respiration than the explicit approach. The ECM explicit Coup-MYCOFON model provides a more detailed description of internal ecosystem fluxes and feedbacks of C and N between plants, soil, and ECM. Our modeling highlights the need to incorporate ECM and organic N uptake into ecosystem models, and the nonlim approach is not recommended for future long-term soil C and N predictions. We also provide a key set of posterior fungal parameters that can be further investigated and evaluated in future ECM studies.

Place, publisher, year, edition, pages
Copernicus Gesellschaft MBH, 2018
National Category
Soil Science
Identifiers
urn:nbn:se:kth:diva-224694 (URN)10.5194/gmd-11-725-2018 (DOI)000426389000001 ()2-s2.0-85042705699 (Scopus ID)
Funder
Swedish Research Council Formas
Note

QC 20180323

Available from: 2018-03-23 Created: 2018-03-23 Last updated: 2018-03-23Bibliographically approved
He, H., Jansson, P.-E., Svensson, M., Meyer, A., Klemedtsson, L. & Kasimir, Å. (2016). Factors controlling Nitrous Oxide emission from a spruce forest ecosystem on drained organic soil, derived using the CoupModel. Ecological Modelling, 321, 46-63
Open this publication in new window or tab >>Factors controlling Nitrous Oxide emission from a spruce forest ecosystem on drained organic soil, derived using the CoupModel
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2016 (English)In: Ecological Modelling, ISSN 0304-3800, E-ISSN 1872-7026, Vol. 321, p. 46-63Article in journal (Refereed) Published
Abstract [en]

High Nitrous Oxide (N2O) emissions have been identified in hemiboreal forests in association with draining organic soils. However, the specific controlling factors that regulate the emissions remain unclear. To examine the importance of different factors affecting N2O emissions in a spruce forest on drained organic soil, a process-based model, CoupModel, was calibrated using the generalized likelihood uncertainty estimation (GLUE) method. The calibration also aims to estimate parameter density distributions, the covariance matrix of estimated parameters and the correlation between parameters and variables information, useful when applying the model on other peat soil sites and for further model improvements. The calibrated model reproduced most of the high resolution data (total net radiation, soil temperature, groundwater level, net ecosystem exchange, etc.) very well, as well as cumulative measured N2O emissions (simulated 8.7±1.1kgN2Oha-1year-1 (n=97); measured 8.7±2.7kgN2Oha-1year-1 (n=6)), but did not capture every measured peak. Parameter uncertainties were reduced after calibration, in which 16 out of 20 parameters changed from uniform distributions into normal distributions or log normal distributions. Four parameters describing bypass water flow, oxygen diffusion and soil freezing changed significantly after calibration. Inter-connections and correlations between many calibrated parameters and variables reflect the complex and interrelated nature of pedosphere, biosphere and atmosphere interactions. This also highlights the need to calibrate a number of parameters simultaneously. Model sensitivity analysis indicated that N2O emissions during growing seasons are controlled by competition between plants and microbes for nitrogen, while during the winter season snow melt periods are important. Our results also indicate that N2O is mainly produced in the capillary fringe close to the groundwater table by denitrification in the anaerobic zone. We conclude that, in afforested drained peatlands, the plants and groundwater level have important influences on soil N availability, ultimately controlling N2O emissions.

Place, publisher, year, edition, pages
Elsevier, 2016
Keywords
CoupModel, Drained organic soil, Emission controlling factor, Generalized likelihood uncertainty estimation (GLUE), Nitrous Oxide, Spruce forest
National Category
Soil Science
Identifiers
urn:nbn:se:kth:diva-180921 (URN)10.1016/j.ecolmodel.2015.10.030 (DOI)000368866600005 ()2-s2.0-84947966885 (Scopus ID)
Note

QC 20160126

Available from: 2016-01-26 Created: 2016-01-25 Last updated: 2017-11-30Bibliographically approved
Fröberg, M., Grip, H., Tipping, E., Svensson, M., Strömgren, M. & Kleja, D. B. (2013). Long-term effects of experimental fertilization and soil warming on dissolved organic matter leaching from a spruce forest in Northern Sweden. Geoderma, 200-201, 172-179
Open this publication in new window or tab >>Long-term effects of experimental fertilization and soil warming on dissolved organic matter leaching from a spruce forest in Northern Sweden
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2013 (English)In: Geoderma, ISSN 0016-7061, E-ISSN 1872-6259, Vol. 200-201, p. 172-179Article in journal (Refereed) Published
Abstract [en]

Nitrogen deposition and increasing temperature are two of the major large-scale changes projected for coming decades and the effect of this change on dissolved organic matter is largely unknown. We have utilized a long-term fertilization and soil warming experiment in Northern Sweden to study the effects of increased nutrient levels and increased temperature on DOC transport under the O horizon. The site is N limited and mean annual temperature 2. °C. Experimental fertilization with ammonium nitrate and a physiological mixture of other macro- and micro-nutrients has been going on for 22. years and soil warming, 5. °C above ambient soil temperature for 14. years, prior to the study. Experimental plots have been irrigated to avoid drying and we also studied the effect of this long-term irrigation on DOC by establishing control plots receiving no irrigation.DOC concentrations and fluxes under the O horizon were approximately 50% higher in fertilized plots than in non-fertilized control plots. We did not find any statistically significant effect of soil warming. There was a statistically significant effect of long-term irrigation on DOC with higher DOC concentration and fluxes in irrigated plots than in plots without irrigation. There were no major effects on DOC quality measured by specific UV absorbance. Fertilization approximately doubled soil organic matter stocks in the O horizon, whereas there were no such effects of warming or irrigation on soil organic matter amounts. There was no statistically significant treatment effect on DOC collected from the B horizon. We hypothesize that the positive effect of fertilization on DOC is related to increased soil C stocks.

Keywords
Dissolved organic carbon, Forest soils, Nitrogen, Soil moisture, Temperature
National Category
Soil Science
Identifiers
urn:nbn:se:kth:diva-134276 (URN)10.1016/j.geoderma.2013.02.002 (DOI)000318057100020 ()2-s2.0-84875494081 (Scopus ID)
Funder
Formas
Note

QC 20131122

Available from: 2013-11-22 Created: 2013-11-20 Last updated: 2017-12-06Bibliographically approved
Svensson, M., Jansson, P.-E., Gustafsson, D., Berggren Kleja, D., Langvall, O. & Lindroth, A. (2008). Bayesian calibration of a model describing carbon, water and heat fluxes for a Swedish boreal forest stand.. Ecological Modelling, 213(3-4), 331-344
Open this publication in new window or tab >>Bayesian calibration of a model describing carbon, water and heat fluxes for a Swedish boreal forest stand.
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2008 (English)In: Ecological Modelling, ISSN 0304-3800, E-ISSN 1872-7026, Vol. 213, no 3-4, p. 331-344Article in journal (Other academic) Published
Abstract [en]

This study quantified major fluxes of carbon (C), heat and water, including uncertainty estimates, in a boreal forest in northern Sweden, using a process-based model (Coup-Model) and Bayesian calibration methodology. Coupled C, water and heat fluxes were described together with estimated uncertainties for all major components of the simulated C budget. Simulated mean gross primary production was 641 +/- 74 gC m(-2) yr(-1), total ecosystem respiration 570 +/- 55 gC m(-2)yr(-1) and net ecosystem productivity 71 +/- 37gCm(-2)yr(-1). Most high-resolution measurements were well described but some interesting exceptions arose between model and measurements, e.g. latent heat flux was overestimated and field layer (understory) root litter production underestimated. Bayesian calibration reduced the assumed prior parameter ranges in 30 of 33 parameters, thus reducing the uncertainty in the estimates. There was a high degree of couplings between different sub-models and processes in the model, highlighting the importance of considering parameters not as singularities but in clusters

Keywords
carbon budget, CoupModel, Markov chain Monte Carlo simulation, process-based model, uncertainty estimate
National Category
Agricultural Sciences
Identifiers
urn:nbn:se:kth:diva-6651 (URN)10.1016/j.ecolmodel.2008.01.001 (DOI)000255624900006 ()2-s2.0-41149133225 (Scopus ID)
Note
Uppdaterad från manuskript till artikel: 20100922. QC 20100922 Available from: 2006-12-15 Created: 2006-12-15 Last updated: 2017-12-14Bibliographically approved
Svensson, M., Jansson, P.-E. & Berggren Kleja, D. (2008). Modelling soil C sequestration in spruce forest ecosystems along a Swedish transect based on current conditions. Biogeochemistry, 89(1), 95-119
Open this publication in new window or tab >>Modelling soil C sequestration in spruce forest ecosystems along a Swedish transect based on current conditions
2008 (English)In: Biogeochemistry, ISSN 0168-2563, E-ISSN 1573-515X, Vol. 89, no 1, p. 95-119Article in journal (Refereed) Published
Abstract [en]

The change of current pools of soil C in Norway spruce ecosystems in Sweden were studied using a process-based model (CoupModel). Simulations were conducted for four sites representing different regions covering most of the forested area in Sweden and representing annual mean temperatures from 0.7 degrees C to 7.1 degrees C. The development of both tree layer and field layer (understory) was simulated during a 100-year period using data on standing stock volumes from the Swedish Forest Inventory to calibrate tree growth using different assumptions regarding N supply to the plants. The model successfully described the general patterns of forest stand dynamics along the Swedish climatic transect, with decreasing tree growth rates and increasing field layer biomass from south to north. However, the current tree growth pattern for the northern parts of Sweden could not be explained without organic N uptake and/or enhanced mineralisation rates compared to the southern parts. Depending on the assumption made regarding N supply to the tree, different soil C sequestration rates were obtained. The approach to supply trees with both mineralised N and organic N, keeping the soil C:N ratio constant during the simulation period was found to be the most realistic alternative. With this approach the soils in the northern region of Sweden lost 5 g C m(-2) year(-1), the soils in the central region lost 2 g C m(-2) year(-1), and the soils in the two southern regions sequestered 9 and 23 g C m(-2) year(-1), respectively. In addition to climatic effects, the feedback between C and N turnover plays an important role that needs to be more clearly understood to improve estimates of C sequestration in boreal forest ecosystems.

Keywords
boreal, carbon, CoupModel, climate, nitrogen, organic nitrogen uptake
National Category
Agricultural Sciences
Identifiers
urn:nbn:se:kth:diva-6648 (URN)10.1007/s10533-007-9134-y (DOI)000257201300008 ()2-s2.0-46249102136 (Scopus ID)
Note
Uppdaterad från manusript till artikel: 20100922 Tidigare titel: Soil C in spruce forest ecosystems in Sweden – modelling current pools and trends using different assumptions on N supply. QC 20100922Available from: 2006-12-15 Created: 2006-12-15 Last updated: 2017-12-14Bibliographically approved
Berggren Kleja, D., Svensson, M., Majdi, H., Jansson, P.-E., Langvall, O., Bergkvist, B., . . . Lindroth, A. (2008). Pools and fluxes of carbon in three Norway spruce ecosystems along a climatic gradient in Sweden.. Biogeochemistry, 89(1), 7-25
Open this publication in new window or tab >>Pools and fluxes of carbon in three Norway spruce ecosystems along a climatic gradient in Sweden.
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2008 (English)In: Biogeochemistry, ISSN 0168-2563, E-ISSN 1573-515X, Vol. 89, no 1, p. 7-25Article in journal (Refereed) Published
Abstract [en]

This paper presents an integrated analysis of organic carbon (C) pools in soils and vegetation, within-ecosystem fluxes and net ecosystem exchange (NEE) in three 40-year old Norway spruce stands along a north-south climatic gradient in Sweden, measured 2001-2004. A process-orientated ecosystem model (CoupModel), previously parameterised on a regional dataset, was used for the analysis. Pools of soil organic carbon (SOC) and tree growth rates were highest at the southernmost site (1.6 and 2.0-fold, respectively). Tree litter production (litterfall and root litter) was also highest in the south, with about half coming from fine roots (< 1 mm) at all sites. However, when the litter input from the forest floor vegetation was included, the difference in total litter input rate between the sites almost disappeared (190-233 g C m(-2) year(-1)). We propose that a higher N deposition and N availability in the south result in a slower turnover of soil organic matter than in the north. This effect seems to overshadow the effect of temperature. At the southern site, 19% of the total litter input to the O horizon was leached to the mineral soil as dissolved organic carbon, while at the two northern sites the corresponding figure was approx. 9%. The CoupModel accurately described general C cycling behaviour in these ecosystems, reproducing the differences between north and south. The simulated changes in SOC pools during the measurement period were small, ranging from -8 g C m(-2) year(-1) in the north to +9 g C m(-2) year(-1) in the south. In contrast, NEE and tree growth measurements at the northernmost site suggest that the soil lost about 90 g C m(-2) year(-1).

Keywords
soil carbon, boreal ecosystems, climatic gradient, CoupModel, root litter, dissolved organic carbon
National Category
Agricultural Sciences
Identifiers
urn:nbn:se:kth:diva-6649 (URN)10.1007/s10533-007-9136-9 (DOI)000257201300002 ()2-s2.0-46249089502 (Scopus ID)
Note
Uppdaterad från manuskript till artikel: 20100922 QC 20100922Available from: 2006-12-15 Created: 2006-12-15 Last updated: 2017-12-14Bibliographically approved
Jansson, P.-E., Svensson, M., Berggren Kleja, D. & Gustafsson, D. (2008). Simulated climate change impacts on fluxes of carbon in Norway spruce ecosystems along a climatic transect in Sweden. Biogeochemistry, 89(1), 81-94
Open this publication in new window or tab >>Simulated climate change impacts on fluxes of carbon in Norway spruce ecosystems along a climatic transect in Sweden
2008 (English)In: Biogeochemistry, ISSN 0168-2563, E-ISSN 1573-515X, Vol. 89, no 1, p. 81-94Article in journal (Refereed) Published
Abstract [en]

A simulation study based on recent regional climate scenarios for Sweden investigated possible changes in carbon (C) dynamics and net ecosystem exchange (NEE) of Swedish Norway spruce forest ecosystems. Four sites, representative of well-drained soils in four regions, were included. Stand development was simulated for a 100-year rotation period using a coupled model describing abiotic and biotic processes in the soil-plant-atmosphere system. Two IPCC climate change scenarios, corresponding to a mean annual temperature increase of about 2 degrees C (A2) or 3 degrees C (B2) from the reference period 1961-1990 to a new period 2061-2090, were considered. Annual maximum snow depth decreased with the increase in air temperature, whereas maximum soil frost depth and mean annual soil temperature showed only small changes, especially for the sites in northern Sweden. Simulations suggested that in the warmer climate, gross primary production (GPP) increased by 24-32% in northern Sweden and by 32-43% in the south. In the north, the increase was related to the combined effect of air and soil temperature extending the growing season, whereas in the south it was mainly governed by increased N availability due to increased soil temperature. NEE increased by about 20% (A2) or 25% (B2) at all sites, more or less solely due to increased accumulation of C in the tree biomass (including harvest residues), since changes in soil C were small compared with the current climate. Both light use efficiency and water use efficiency were improved in the future climate scenarios, despite increases in atmospheric CO2 not being considered.

Keywords
air temperature, boreal, CoupModel, net ecosystem exchange, nitrogen, soil temperature, soil frost, soil respiration
National Category
Agricultural Sciences
Identifiers
urn:nbn:se:kth:diva-6650 (URN)10.1007/s10533-007-9147-6 (DOI)000257201300007 ()2-s2.0-46249117260 (Scopus ID)
Note
Uppdaterad från manuskript till artikel: 20100922 Tidigare titel: Climate change impacts on fluxes of carbon in Norway spruce ecosystems along a climatic transect in Sweden. QC 20100922Available from: 2006-12-15 Created: 2006-12-15 Last updated: 2017-12-14Bibliographically approved
Svensson, M. (2006). Carbon dynamics in spruce forest ecosystems - modelling pools and trends for Swedish conditions. (Doctoral dissertation). Stockholm: KTH
Open this publication in new window or tab >>Carbon dynamics in spruce forest ecosystems - modelling pools and trends for Swedish conditions
2006 (English)Doctoral thesis, comprehensive summary (Other scientific)
Abstract [en]

Carbon (C) pools and fluxes in northern hemisphere forest ecosystems are attracting increasing attention concerning predicted climate change. This thesis studied C fluxes, particularly soil C dynamics, in spruce forest ecosystems in relation to interactions between physical/biological processes using a process-based ecosystem model (CoupModel) with data for Swedish conditions. The model successfully described general patterns of C and N dynamics in managed spruce forest ecosystems with both tree and field layers. Using regional soil and plant data, the change in current soil C pools was -3 g C m-2 yr-1 in northern Sweden and +24 g C m-2 yr-1 in southern Sweden. Simulated climate change scenarios resulted in increased inflows of 16-38 g C m-2 yr-1 to forest ecosystems throughout Sweden, with the highest increase in the south and the lowest in the north. Along a north-south transect, this increased C sequestration mainly related to increased tree growth, as there were only minor decreases in soil C pools. Measurements at one northern site during 2001-2002 indicated large soil C losses (-96 g C m-2 yr-1), which the model successfully described. However, the discrepancy between these large losses and substantially smaller losses obtained in regional simulations was not explained. A simulation based on Bayesian calibration successfully reproduced measured C, water and energy fluxes, with estimated uncertainties for major components of the simulated C budget. Site-specific measurements indicated a large contribution from field layer fine roots to total litter production, particularly in northern Sweden. Mean annual tree litter production was 66% higher at the most southerly site (240 g C m-2 yr-1 compared with 145 g C m-2 yr-1 in the north), but when field and bottom layers were included the difference decreased to 16% (total litter production 276 g C m-2 yr-1 and 239 g C m-2 yr-1 respectively). Regional simulations showed that decomposition rate for the stable soil C fraction was three times higher in northern regions compared with southern, providing a possible explanation why soil C pools in southern Sweden are roughly twice as large as those in the north.

Place, publisher, year, edition, pages
Stockholm: KTH, 2006. p. viii, 25
Series
Trita-LWR. PHD, ISSN 1650-8602 ; 1029
Keywords
boreal, climate, CoupModel, net ecosystem production, nitrogen, process-based model, soil carbon
National Category
Natural Sciences
Identifiers
urn:nbn:se:kth:diva-4240 (URN)978-91-7178-544-2 (ISBN)
Public defence
2006-12-19, D3, Lindstedtsvägen 5, KTH, Stockholm, 10:00
Opponent
Supervisors
Note
QC 20100922Available from: 2006-12-15 Created: 2006-12-15 Last updated: 2010-09-22Bibliographically approved
Svensson, M. (2004). Modelling soil temperature and carbon storage changes for Swedish boreal forests. (Licentiate dissertation). Stockholm: Mark och vatten
Open this publication in new window or tab >>Modelling soil temperature and carbon storage changes for Swedish boreal forests
2004 (English)Licentiate thesis, comprehensive summary (Other scientific)
Abstract [en]

With the use of a process-orientated ecosystem model andmeasurements conducted at different Swedish coniferous forestsites, abiotic and biotic interactions between tree and soilwere identified and related to governing factors. Two differentmodelling approaches to describe soil temperatures at two sitesincluding hydrological transects were tested (I). The approachin which both canopy and soil were considered proved to be amore flexible tool to describe soil temperatures, especiallyduring snow-free winter periods. Five sites along a climatetransect covering Sweden were used to describe soil carbon poolchanges during an 80-year period simulation (II). The dynamicmodelling approach, with a feedback between abiotic and bioticsub-models, was successful in describing simplified patterns offorest stand dynamics and furthermore in differentiatingbetween climate and nitrogen availability factors. The largereffect of nitrogen availability compared to climate on soilcarbon pool changes was clearly shown.

Keywords:SPAC; soil surface energy balance; Norwayspruce; canopy; LAI; climate; nitrogen; CoupModel

Place, publisher, year, edition, pages
Stockholm: Mark och vatten, 2004. p. x, 10
Series
Trita-LWR. LIC ; 2018
Keywords
SPAC, soil surface energy balance, Norway spruce, canopy, LAI, climate, nitrogen, CoupModel
Identifiers
urn:nbn:se:kth:diva-1711 (URN)91-7283-697-0 (ISBN)
Available from: 2004-03-05 Created: 2004-03-05 Last updated: 2012-03-21
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0002-0926-3304

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