| 1. |
- Abdalla, M., et al.
(författare)
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Simulation of CO2 and Attribution Analysis at Six European Peatland Sites Using the ECOSSE Model
- 2014
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Ingår i: Water, Air and Soil Pollution. - : Springer Science and Business Media LLC. - 1573-2932 .- 0049-6979. ; 225:11, s. 2182-2182
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Tidskriftsartikel (refereegranskat)abstract
- In this study, we simulated heterotrophic CO2 (Rh) fluxes at six European peatland sites using the ECOSSE model and compared them to estimates of Rh made from eddy covariance (EC) measurements. The sites are spread over four countries with different climates, vegetation and management. Annual Rh from the different sites ranged from 110 to 540 g C m(-2). The maximum annual Rh occurred when the water table (WT) level was between -10 and -25 cm and the air temperature was above 6.2 degrees C. The model successfully simulated seasonal trends for the majority of the sites. Regression relationships (r(2)) between the EC-derived and simulated Rh ranged from 0.28 to 0.76, and the root mean square error and relative error were small, revealing an acceptable fit. The overall relative deviation value between annual EC-derived and simulated Rh was small (-1 %) and model efficiency ranges across sites from -0.25 to +0.41. Sensitivity analysis highlighted that increasing temperature, decreasing precipitation and lowering WT depth could significantly increase Rh from soils. Thus, management which lowers the WT could significantly increase anthropogenic CO2, so from a carbon emissions perspective, it should be avoided. The results presented here demonstrate a robust basis for further application of the ECOSSE model to assess the impacts of future land management interventions on peatland carbon emissions and to help guide best practice land management decisions.
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| 2. |
- Laudon, Hjalmar, et al.
(författare)
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Linking variability in soil solution dissolved organic carbon to climate, soil type, and vegetation type
- 2014
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Ingår i: Global Biogeochemical Cycles. - 0886-6236 .- 1944-9224. ; 28, s. 497-509
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Tidskriftsartikel (refereegranskat)abstract
- Lateral transport of carbon plays an important role in linking the carbon cycles of terrestrial and aquatic ecosystems. There is, however, a lack of information on the factors controlling one of the main C sources of this lateral flux, i.e., the concentration of dissolved organic carbon (DOC) in soil solution across large spatial scales and under different soil, vegetation, and climate conditions. We compiled a database on DOC in soil solution down to 80cm and analyzed it with the aim, first, to quantify the differences in DOC concentrations among terrestrial ecosystems, climate zones, soil, and vegetation types at global scale and second, to identify potential determinants of the site-to-site variability of DOC concentration in soil solution across European broadleaved and coniferous forests. We found that DOC concentrations were 75% lower in mineral than in organic soil, and temperate sites showed higher DOC concentrations than boreal and tropical sites. The majority of the variation (R2=0.67-0.99) in DOC concentrations in mineral European forest soils correlates with NH4+, C/N, Al, and Fe as the most important predictors. Overall, our results show that the magnitude (23% lower in broadleaved than in coniferous forests) and the controlling factors of DOC in soil solution differ between forest types, with site productivity being more important in broadleaved forests and water balance in coniferous stands.
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| 3. |
- Peichl, Matthias, et al.
(författare)
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A 12-year record reveals pre-growing season temperature and water table level threshold effects on the net carbon dioxide exchange in a boreal fen
- 2014
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 9:5
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Tidskriftsartikel (refereegranskat)abstract
- This study uses a 12-year time series (2001-2012) of eddy covariance measurements to investigate the long-term net ecosystem exchange (NEE) of carbon dioxide (CO2) and inter-annual variations in relation to abiotic drivers in a boreal fen in northern Sweden. The peatland was a sink for atmospheric CO2 in each of the twelve study years with a 12-year average (+/- standard deviation) NEE of -58 +/- 21 g C m(-2) yr(-1). For ten out of twelve years, the cumulative annual NEE was within a range of -42 to -79 g C m(-2) yr(-1) suggesting a general state of resilience of NEE to moderate inter-annual climate variations. However, the annual NEE of -18 and -106 g C m(-2) yr(-1) in 2006 and 2008, respectively, diverged considerably from this common range. The lower annual CO2 uptake in 2006 was mainly due to late summer emissions related to an exceptional drop in water table level (WTL). A positive relationship (R-2 = 0.65) between pre-growing season (January to April) air temperature (Ta) and summer (June to July) gross ecosystem production (GEP) was observed. We suggest that enhanced GEP due to mild pre-growing season air temperature in combination with air temperature constraints on ecosystem respiration (ER) during the following cooler summer explained most of the greater net CO2 uptake in 2008. Differences in the annual and growing season means of other abiotic variables (e.g. radiation, vapor pressure deficit, precipitation) and growing season properties (i.e. start date, end date, length) were unable to explain the inter-annual variations of NEE. Overall, our findings suggest that this boreal fen acts as a persistent contemporary sink for atmospheric CO2 that is, however, susceptible to severe anomalies in WTL and pre-growing season air temperature associated with predicted changes in climate patterns for the boreal region.
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| 4. |
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| 5. |
- Peichl, Matthias
(författare)
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Analysis of nitrogen controls on carbon and water exchanges in a conifer forest using the CLASS-CTEMN+ model
- 2011
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Ingår i: Ecological Modelling. - : Elsevier BV. - 0304-3800 .- 1872-7026. ; 222, s. 3743-3760
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Tidskriftsartikel (refereegranskat)abstract
- A carbon (C) and nitrogen (N) cycle-coupled model, CLASS-CTEMN+ was developed by incorporating soil and plant N cycling algorithms in the Canadian Land Surface Scheme (CLASS) and the Canadian Terrestrial Ecosystem Model (CTEM), used in the Canadian Global Climate Model. Key soil and plant N cycling processes incorporated in the model include biological fixation, mineralization, nitrification, denitrification, leaching and N controls on plant photosynthesis capacity. The model was used to analyse N controls on C and water exchanges in a 70-year-old temperate conifer forest in southern Ontario, Canada from 2003 to 2007. The simulated values of soil-plant N contents and fluxes - including N2O flux - were generally in good agreement with observations. When N controls on C and water cycling were included in the model, simulated daily gross ecosystem productivity (GEP), ecosystem respiration (R-e), net ecosystem productivity (NEP) and evapotranspiration (ET) fluxes showed improved agreement with eddy covariance flux measurements. The five-year mean annual NEP predicted by the N-coupled model was 121 g C m(-2) yr(-) for 2003-2007, compared to 273 g C m(-2) yr(-1), which was simulated by the model when N controls were switched off (non-N model). N-coupled model estimates compared well with the measured five-year mean (+/- standard deviation) annual NEP of 136 +/- 59 g C m(-2) yr(-1). Simulated annual mean ET over five-years was 384 mm yr(-1) for the N-coupled model, and 433 mm yr(-1) for non-N model, compared with the measured five-year mean annual value of 405 +/- 44 mm yr(-1). Model results confirmed that a proper representation of N controls on photosynthetic uptake and canopy conductance could result in more plausible simulations of observed C and water fluxes. The model results also suggested that N limitations in spring and early summer were generally more important in controlling NEP. Discrepancies between simulated and measured annual variations of C exchanges occurred in years that included extreme weather periods (e.g. low soil water content and warm spring/summer temperatures). (C) 2011 Elsevier B.V. All rights reserved.
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| 6. |
- Peichl, Matthias
(författare)
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Carbon and greenhouse gas balances in an age sequence of temperate pine plantations
- 2014
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Ingår i: Biogeosciences. - : Copernicus GmbH. - 1726-4170 .- 1726-4189. ; 11, s. 5399-5410
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated differences in the magnitude and partitioning of the carbon (C) and greenhouse gas (GHG) balances in an age sequence of four white pine (Pinus strobus L.) afforestation stands (7, 20, 35 and 70 years old as of 2009) in southern Ontario, Canada. The 4-year (2004-2008) mean annual carbon dioxide (CO2) exchanges, based on biometric and eddy covariance data, were combined with the 2-year means of static chamber measurements of methane (CH4) and nitrous oxide (N2O) fluxes (2006-2007) and dissolved organic carbon (DOC) export below 1m soil depth (2004-2005). The total ecosystem C pool increased with age from 46 to 197 t C ha(-1) across the four stands. Rates of organic matter cycling (i.e. litterfall and decomposition) were similar among the three older stands. In contrast, considerable differences related to stand age and site quality were observed in the magnitude and partitioning of individual CO2 fluxes, showing a peak in production and respiration rates in the middle-age (20-year-old) stand growing on fertile post-agricultural soil. The DOC export accounted for 10% of net ecosystem production (NEP) at the 7-year-old stand but < 2% at the three older stands. The GHG balance from the combined exchanges of CO2, CH4 and N2O was 2.6, 21.6, 13.5 and 4.8 t CO2 equivalent ha(-1) year(-1) for the 7-, 20-, 35-and 70-year-old stands, respectively. The maximum annual contribution from the combined exchanges of CH4 and N2O to the GHG balance was 13 and 8% in the 7- and 70-year-old stands, respectively, but < 1% in the two highly productive middle-age (20- and 35-year-old) stands. Averaged over the entire age sequence, the CO2 exchange was the main driver of the GHG balance in these forests. The cumulative CO2 sequestration over the 70 years was estimated at 129 t C and 297 t C ha(-1) year(-1) for stands growing on low-and high-productivity sites, respectively. This study highlights the importance of accounting for age and site quality effects on forest C and GHG balances. It further demonstrates a large potential for net C sequestration and climate benefits gained through afforestation of marginal agricultural and fallow lands in temperate regions.
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| 7. |
- Peichl, Matthias
(författare)
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Changes in ecosystem carbon stocks in a grassland ash (Fraxinus excelsior) afforestation chronosequence in Ireland
- 2014
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Ingår i: Journal of Plant Ecology. - : Oxford University Press (OUP). - 1752-9921 .- 1752-993X. ; 7, s. 429-438
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Tidskriftsartikel (refereegranskat)abstract
- AimsGovernment policy in Ireland is to increase the national forest cover from the current 10% to 18% of the total land area by 2020. This represents a major land use change that is expected to impact on the national carbon (C) stocks. While the C stocks of ecosystem biomass and soils of Irish grasslands and coniferous forests have been quantified, little work has been done to assess the impact of broadleaf afforestation on C stocks.MethodsIn this study, we sampled a chronosequence of ash (Fraxinus excelsior) forests aged 12, 20, 27, 40 and 47 years on brown earth soils. A grassland site, representative of the pre-afforestation land use, was sampled as a control.Important FindingsOur results show that there was a significant decline (P < 0.05) in the carbon density of the soil (0-30 cm) following afforestation from the grassland (90.2 Mg C ha(-1)) to the 27-year-old forest (66.7 Mg C ha(-1)). Subsequently, the forest soils switched from being a C source to a C sink and began to sequester C to 71.3 Mg C ha(-1) at the 47-year-old forest. We found the amount of C stored in the above- and belowground biomass increased with age of the forest stands and offset the amount of C lost from the soil. The amount of C stored in the above-and belowground biomass increased on average by 1.83 Mg C ha(-1) year(-1). The increased storage of C in the biomass led to an increase in the total ecosystem C, from 90.2 Mg C ha(-1) at the grassland site to 162.6 Mg C ha(-1) at the 47-year-old forest. On a national scale, projected rates of ash afforestation to the year 2020 may cause a loss of 290 752 Mg C from the soil compared to 2 525 936 Mg C sequestered into the tree biomass. The effects of harvesting and reforestation may further modify the development of ecosystem C stocks over an entire ash rotation.
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| 8. |
- Peichl, Matthias
(författare)
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Convergence of potential net ecosystem production among contrasting C-3 grasslands
- 2013
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Ingår i: Ecology Letters. - : Wiley. - 1461-023X .- 1461-0248. ; 16, s. 502-512
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Tidskriftsartikel (refereegranskat)abstract
- Metabolic theory and body size constraints on biomass production and decomposition suggest that differences in the intrinsic potential net ecosystem production (NEPPOT) should be small among contrasting C-3 grasslands and therefore unable to explain the wide range in the annual apparent net ecosystem production (NEPAPP) reported by previous studies. We estimated NEPPOT for nine C-3 grasslands under contrasting climate and management regimes using multiyear eddy covariance data. NEPPOT converged within a narrow range, suggesting little difference in the net carbon dioxide uptake capacity among C-3 grasslands. Our results indicate a unique feature of C-3 grasslands compared with other terrestrial ecosystems and suggest a state of stability in NEPPOT due to tightly coupled production and respiration processes. Consequently, the annual NEPAPP of C-3 grasslands is primarily a function of seasonal and short-term environmental and management constraints, and therefore especially susceptible to changes in future climate patterns and associated adaptation of management practices.
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| 9. |
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| 10. |
- Peichl, Matthias, et al.
(författare)
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Divergent apparent temperature sensitivity of terrestrial ecosystem respiration
- 2014
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Ingår i: Journal of Plant Ecology. - : Oxford University Press (OUP). - 1752-9921 .- 1752-993X. ; 7, s. 419-428
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Tidskriftsartikel (refereegranskat)abstract
- Aims: Recent studies revealed convergent temperature sensitivity of ecosystem respiration (Re) within aquatic ecosystems and between terrestrial and aquatic ecosystems. We do not know yet whether various terrestrial ecosystems have consistent or divergent temperature sensitivity. Here, we synthesized 163 eddy covariance flux sites across the world and examined the global variation of the apparent activation energy (Ea), which characterizes the apparent temperature sensitivity of and its interannual variability (IAV) as well as their controlling factors.Methods: We used carbon fluxes and meteorological data across FLUXNET sites to calculate mean annual temperature, temperature range, precipitation, global radiation, potential radiation, gross primary productivity and Re by averaging the daily values over the years in each site. Furthermore, we analyzed the sites with >8 years data to examine the IAV of Ea and calculated the standard deviation of Ea across years at each site to characterize IAV.Important Findings: The results showed a widely global variation of Ea, with significantly lower values in the tropical and subtropical areas than in temperate and boreal areas, and significantly higher values in grasslands and wetlands than that in deciduous broadleaf forests and evergreen forests. Globally, spatial variations of Ea were explained by changes in temperature and an index of water availability with differing contribution of each explaining variable among climate zones and biomes. IAV and the corresponding coefficient of variation of Ea decreased with increasing latitude, but increased with radiation and corresponding mean annual temperature. The revealed patterns in the spatial and temporal variations of Ea and its controlling factors indicate divergent temperature sensitivity of R-e, which could help to improve our predictive understanding of R-e in response to climate change.
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| 11. |
- Peichl, Matthias, et al.
(författare)
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Energy exchange and water budget partitioning in a boreal minerogenic mire
- 2013
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Ingår i: Journal of Geophysical Research. - 2156-2202. ; 118, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated patterns and controls of the seasonal and inter-annual variations in energy fluxes (i.e., sensible heat, H, and latent heat, lambda E) and partitioning of the water budget (i.e., precipitation, P; evapotranspiration, ET; discharge, Q; and soil water storage, Delta S) over five years (2001-2005) in a boreal oligotrophic fen in northern Sweden based on continuous eddy covariance, water table level (WTL), and weir measurements. For the growing season (May 1 to September 31), the 5 year averages (+/- standard deviation) of the midday (10:00 to 14:00 h) Bowen ratio (beta, i.e., H/lambda E) was 0.86 +/- 0.08. Seasonal and inter-annual variability of beta was mainly driven by lambda E which itself was strongly controlled by both weather (i.e., vapor pressure deficit, D, and net radiation, R-n) and physiological parameters (i.e., surface resistance). During the growing season, surface resistance largely exceeded aerodynamic resistance, which together with low mean values of the actual ET to potential ET ratio (0.55 +/- 0.05) and Priestley-Taylor alpha (0.89) suggests significant physiological constrains on ET in this well-watered fen. Among the water budget components, the inter-annual variability of ET was lower (199 to 298 mm) compared to Q (225 to 752 mm), with each accounting on average for 34 and 65% of the ecosystem water loss, respectively. The fraction of P expended into ET was negatively correlated to P and positively to R-n. Although a decrease in WTL caused a reduction of the surface conductance, the overall effect of WTL on ET was limited. Non-growing season (October 1 to April 30) fluxes of H, lambda E, and Q were significant representing on average -67%, 13%, and 61%, respectively, of their growing season sums (negative sign indicates opposite flux direction between the two seasons). Overall, our findings suggest that plant functional type composition, P and R-n dynamics (i.e., amount and timing) were the major controls on the partitioning of the mire energy and water budgets. This has important implications for the regional climate as well as for ecosystem development, nutrient, and carbon dynamics. Citation: Peichl, M., J. Sagerfors, A. Lindroth, I. Buffam, A. Grelle, L. Klemedtsson, H. Laudon, and M. B. Nilsson (2013), Energy exchange and water budget partitioning in a boreal minerogenic mire, J. Geophys. Res. Biogeosci., 118, 1-13, doi:10.1029/2012JG002073.
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| 12. |
- Peichl, Matthias
(författare)
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Evaluating management effects on nitrous oxide emissions from grasslands using the process-based DeNitrification-DeComposition (DNDC) model
- 2011
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310. ; 45, s. 6029-6039
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Tidskriftsartikel (refereegranskat)abstract
- The development of agricultural mitigation strategies to reduce greenhouse gas (GHG) emissions is urgent in the context of climate change - land use interactions. In this study the DNDC biogeochemical model was used to study nitrous oxide (N(2)O) emissions from grazed grasslands in southern Ireland. The objectives of this study were: (1) to evaluate the DNDC model using a two year (2008-2009) data set of chamber measured N(2)O fluxes at eight grassland sites and (2) to investigate the impact of different management scenarios on N(2)O emissions including changes in i) inorganic nitrogen (N) fertilizer application rates ii) slurry application rates; and iii) animal density (livestock unit per hectare LU ha(-1)). The comparison of modeled daily DNDC fluxes (using a combination of measured and default soil parameters) and measured fluxes resulted in an r (coefficient correlation) = 0.48. To improve the model performance, the fluxes for 2008 were used in a calibration exercise during which the soil properties were optimized to obtain the best fit of N(2)O fluxes. This resulted in an improved model performance, with an r = 0.62. In a validation exercise using 2009 data, we used the model parameters set (e.g. soils) from the calibration exercise and this resulted in a model performance with an r = 0.57. The annual N(2)O fluxes (measured and modeled) were appreciably higher than those estimated using the IPCC emissions factor of 1.25%. In scenario analysis, the modeled N(2)O fluxes only increased/decreased on average +/-6% and +/-7% following a 50% increase/decrease of inorganic N and slurry N applications respectively. These modeled scenario % changes are much lower than the IPCC emission factor % changes of a 50% increase in N(2)O emissions for a 50% increase in nitrogen applied. An absolute change scenario (+/-50 kg) in inorganic N and slurry N resulted in greater change in N(2)O fluxes (+/-9% inorganic N and +/-17% slurry N) as compared to the relative change scenario (above). Furthermore, DNDC N(2)O flux estimates were not sensitive to changes in animal density (LU ha(-1)). The latter is a scenario limitation in the current model version. This study suggests that the calibration of soil parameters for Irish conditions is necessary for optimum simulation with DNDC and highlights the potential of management strategies for reducing N(2)O emissions from grazed grasslands. It further highlights the difference between DNDC and IPCC estimates that require further research. Published by Elsevier Ltd.
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| 13. |
- Peichl, Matthias
(författare)
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Management and climate effects on carbon dioxide and energy exchanges in a maritime grassland
- 2012
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Ingår i: Agriculture, Ecosystems and Environment. - : Elsevier BV. - 0167-8809 .- 1873-2305. ; 158, s. 132-146
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Tidskriftsartikel (refereegranskat)abstract
- This study investigated the effects of grassland management and climate on the exchanges of carbon dioxide (CO2) (i.e. net ecosystem CO2 exchange, NEE; gross ecosystem production, GEP; and ecosystem respiration, ER) and energy (i.e. latent heat flux, LE; sensible heat flux, H; and Bowen ratio, beta) in an intensively managed grassland in the maritime climate of southeast Ireland using six years (2004-2009) of eddy-covariance data. The observed effects on CO2 (reduction of net CO2 uptake (i.e. NEE), GEP and ER) and energy exchanges (LE decreased while H and beta increased) were more pronounced following harvest compared to grazing practices and were further dependent on their seasonal timing. Most importantly, a net loss of CO2 occurred for 2-3 weeks following harvest whereas net uptake continued during grazing periods. Whereas the environmental conditions were in general non-constraining and similar among years, the predominant annual management regime varied widely among years including cattle grazing, grass harvesting, kale planting, and grass re-seeding. For the years 2004-2009, the NEE was -385, -202, -109, +134, -101, and -201 g C m(-2) year(-1) (negative sign indicating uptake) and the mean growing season midday beta was 0.97, 0.66, 0.82, 1.07, 0.78 and 0.79. During similar environmental conditions, about twice as much annual CO2 uptake and greater H flux occurred under the cattle grazing regime in 2004 compared to the grass harvesting regime in 2005. Kale planting and re-seeding during the early summer likely caused the reduced annual CO2 uptake in 2006 and net emission combined with a greater beta in 2007. A 2-week drought period in summer 2006 further affected GEP, ER and energy fluxes, while its impact on NEE was limited. Recognizing additional effects from climate, this study finds that the choice of grassland management regime is a key control on grassland ecosystem carbon, water, and energy exchanges in this maritime climate region. (C) 2012 Elsevier B.V. All rights reserved.
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| 14. |
- Peichl, Matthias
(författare)
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Modeling dissolved organic carbon in temperate forest soils: TRIPLEX-DOC model development and validation
- 2014
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Ingår i: Geoscientific Model Development. - : Copernicus GmbH. - 1991-959X .- 1991-9603. ; 7, s. 867-881
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Tidskriftsartikel (refereegranskat)abstract
- Even though dissolved organic carbon (DOC) is the most active carbon (C) cycling in soil organic carbon (SOC) pools, it receives little attention from the global C budget. DOC fluxes are critical to aquatic ecosystem inputs and contribute to the C balance of terrestrial ecosystems, but few ecosystem models have attempted to integrate DOC dynamics into terrestrial C cycling. This study introduces a new process-based model, TRIPLEX-DOC, that is capable of estimating DOC dynamics in forest soils by incorporating both ecological drivers and biogeochemical processes. TRIPLEX-DOC was developed from Forest-DNDC, a biogeochemical model simulating C and nitrogen (N) dynamics, coupled with a new DOC process module that predicts metabolic transformations, sorption/desorption, and DOC leaching in forest soils. The model was validated against field observations of DOC concentrations and fluxes at white pine forest stands located in southern Ontario, Canada. The model was able to simulate seasonal dynamics of DOC concentrations and the magnitudes observed within different soil layers, as well as DOC leaching in the age sequence of these forests. Additionally, TRIPLEX-DOC estimated the effect of forest harvesting on DOC leaching, with a significant increase following harvesting, illustrating that land use change is of critical importance in regulating DOC leaching in temperate forests as an important source of C input to aquatic ecosystems.
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| 15. |
- Peichl, Matthias
(författare)
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The impact of induced drought on transpiration and growth in a temperate pine plantation forest
- 2012
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Ingår i: Hydrological Processes. - : Wiley. - 0885-6087 .- 1099-1085. ; 26, s. 1779-1791
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Tidskriftsartikel (refereegranskat)abstract
- The effects of early growing season droughts on water and carbon balances in conifer forests are poorly understood. In this study, the response of canopy transpiration (Ec) and growth rates to reduced precipitation input during the early growing season was evaluated in a 70-year old temperate white pine (Pinus strobus L.) plantation forest, in Southern Ontario, Canada. In order to induce the drought, a 20 x 20?m throughfall exclusion setup was established. Throughfall was excluded from 1 April to 3 July 2009. During this period, 270?mm of rainfall occurred (27% of annual precipitation), of which more than 90% was excluded. Sapflow, stem growth, soil moisture and soil temperature were measured in both drought and reference plots. Prior to the induced drought, both plots showed similar soil water content, transpiration rates and tree diameters. The primary control on forest water loss was vapour pressure deficit, whereas soil moisture had an effect when it reached below 0.068?m3?m-3 during the growing season. The rainfall exclusion did not negatively affect Ec until early June, approximately 54?days after drought initiation. Ec was 27% less in the drought plot compared to the reference plot when evaluated at the end of the growing season in November. Tree growth estimates at the end of the growing season indicated a 17% decrease in growth in the drought plot as compared to the reference plot. Because climate predictions foresee changes in precipitation pattern, drought spells similar to this artificial short-term rainfall manipulation may be more frequent in the future. Hence, although overall precipitation may remain the same, the short-term deficit in water supply may have important implications for forest ecosystems. The findings of this rainfall manipulation will help quantify the impacts of spring and early summer water deficit on forest ecosystems and evaluate their potential responses to future climate regimes. Copyright (C) 2012 John Wiley & Sons, Ltd.
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