| 1. |
- Bergsten, Urban, et al.
(författare)
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Frost Heaving of Picea abies Seedlings as Influenced by Soil Preparation, Planting Technique, and Location along Gap-Shelterwood Gradients
- 2009
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Ingår i: Silva Fennica. - : Finnish Society of Forest Science. - 0037-5330 .- 2242-4075. ; 43, s. 39-50
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Tidskriftsartikel (refereegranskat)abstract
- The effects or soil preparation, planting technique and location along gap-shelterwood gradients (position and orientation) oil frost heaving damage to seedlings were studied in Vindeln Experimental Forests, northern Sweden. The forest was harvested in a grid pattern in winter 2004-2005, forming gaps and shelterwood areas of 30x40 m each. Gap-shelterwood gradients were delimited in four orientations and subdivided into five positions: 7 ill and 15 m into the gap and shelterwood, and at the gap edge. At each position, three replicates of three soil preparations were made: exposed E and B horizons and HuMinMix (milled vegetation and humus layers mixed with surface mineral soil). In early October 2005, one-year-old containerized Picea abies (L.) Karst. seedlings were planted using four techniques: normal and deep planting, and mobile and fixed experimental containers. After one winter, frost heaving damage was highest for seedlings oil B horizon combined with the mobile container (51 +/- 6%) and normal planting (43 +/- 6%). Normal- or deep-planted seedlings in HuMinMix had the least damage (5-6.6 +/- 2.5%). Compared to normal planting, deep planting reduced frost heaving damage only on B horizon. When considering the orientation, seedlings in the experimental containers had more or similar frost heaving damage than normal- or deep-planted seedlings. Along the eastern gradient, seedlings incurred more frost heaving damage in the center of the gap than under the canopy.
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| 2. |
- Bergvall, Martin, et al.
(författare)
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Modeling subsurface transport in extensive glaciofluvial and littoral sediments to remediate a municipal drinking water aquifer
- 2011
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Ingår i: Hydrology and Earth System Sciences. - : Copernicus GmbH. - 1027-5606 .- 1607-7938. ; 15, s. 2229-2244
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Tidskriftsartikel (refereegranskat)abstract
- Few studies have been carried out that cover the entire transport process of pesticides, from application at the soil surface, through subsurface transport, to contamination of drinking water in esker aquifers. In formerly glaciated regions, such as Scandinavia, many of the most important groundwater resources are situated in glaciofluvial eskers. The purpose of the present study was to model and identify significant processes that govern subsurface transport of pesticides in extensive glaciofluvial and littoral sediments. To simulate the transport processes, we coupled a vadose zone model at soil profile scale to a regional groundwater flow model. The model was applied to a municipal drinking-water aquifer, contaminated with the pesticide-metabolite BAM (2,6-dichlorobenzoamide). At regional scale, with the combination of a ten-meter-deep vadose zone and coarse texture, the observed concentrations could be described by the model without assuming preferential flow. A sensitivity analysis revealed that hydraulic conductivity in the aquifer and infiltration rate accounted for almost half of the model uncertainty. The calibrated model was applied to optimize the location of extraction wells for remediation, which were used to validate the predictive modeling. Running a worst-case scenario, the model showed that the establishment of two remediation wells would clean the aquifer in four years, compared to nine years without them. Further development of the model would require additional field measurements in order to improve the description of macrodispersion in deep, sandy vadose zones. We also suggest that future research should focus on characterization of the variability of hydraulic conductivity and its effect on contaminant transport in eskers.
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| 3. |
- Casetou, Sophie, et al.
(författare)
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Current, steady-state and historical weathering rates of base cations at two forest sites in northern and southern Sweden: a comparison of three methods
- 2020
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Ingår i: Biogeosciences. - : Copernicus GmbH. - 1726-4170 .- 1726-4189. ; 17, s. 281-304
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Tidskriftsartikel (refereegranskat)abstract
- Reliable and accurate methods for estimating soil mineral weathering rates are required tools in evaluating the sustainability of increased harvesting of forest biomass and assessments of critical loads of acidity. A variety of methods that differ in concept, temporal and spatial scale, and data requirements are available for measuring weathering rates. In this study, causes of discrepancies in weathering rates between methods were analysed and were classified as being either conceptual (inevitable) or random. The release rates of base cations (BCs; Ca, Mg, K, Na) by weathering were estimated in podzolised glacial tills at two experimental forest sites, Asa and Flakaliden, in southern and northern Sweden, respectively. Three different methods were used: (i) historical weathering since deglaciation estimated by the depletion method, using Zr as the assumed inert reference; (ii) steady-state weathering rate estimated with the PROFILE model, based on quantitative analysis of soil mineralogy; and (iii) BC budget at stand scale, using measured deposition, leaching and changes in base cation stocks in biomass and soil over a period of 12 years. In the 050 cm soil horizon historical weathering of BCs was 10.6 and 34.1 mmolc m(-2) yr(-1), at Asa and Flakaliden, respectively. Corresponding values of PROFILE weathering rates were 37.1 and 42.7 mmolc m(-2) yr(-1). The PROFILE results indi- cated that steady-state weathering rate increased with soil depth as a function of exposed mineral surface area, reaching a maximum rate at 80 cm (Asa) and 60 cm (Flakaliden). In contrast, the depletion method indicated that the largest postglacial losses were in upper soil horizons, particularly at Flakaliden.With the exception of Mg and Ca in shallow soil horizons, PROFILE produced higher weathering rates than the depletion method, particularly of K and Na in deeper soil horizons. The lower weathering rates of the depletion method were partly explained by natural and anthropogenic variability in Zr gradients. The base cation budget approach produced significantly higher weathering rates of BCs, 134.6 mmolc m(-2) yr(-1) at Asa and 73.2 mmolc m(-2) yr(-1) at Flakaliden, due to high rates estimated for the nutrient elements Ca, Mg and K, whereas weathering rates were lower and similar to those for the depletion method (6.6 and 2.2 mmolc m(-2) yr(-1) at Asa and Flakaliden). The large discrepancy in weathering rates for Ca, Mg and K between the base cation budget approach and the other methods suggests additional sources for tree uptake in the soil not captured by measurements.
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| 4. |
- Fröberg, Mats, et al.
(författare)
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Long-term effects of experimental fertilization and soil warming on dissolved organic matter leaching from a spruce forest in Northern Sweden
- 2013
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Ingår i: Geoderma. - : Elsevier BV. - 0016-7061 .- 1872-6259. ; 200-201, s. 172-179
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 5. |
- Grip, Harald
(författare)
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Sweden's first forest hydrology field study 1905-1926: contemporary relevance of inherited conclusions and data from the Rokliden Hillslope
- 2015
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Ingår i: Hydrological Processes. - : Wiley. - 0885-6087 .- 1099-1085. ; 29, s. 3616-3631
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Tidskriftsartikel (refereegranskat)abstract
- During the last decades of the 19th century, a great worry arose about forest landscape paludification in Northern Sweden. This was the original impetus for forest hydrological research in Sweden, and the Swedish Institute of Experimental Forestry established the first field research site in 1905 at Rokliden, close to Pitea in North Sweden. It comprised 8.64ha located 2km down a 3-km-long gently sloping (similar to 4%), north facing Norway spruce covered till slope, interspersed with small mires. By 1931, it was concluded that paludification was not spreading across Northern Sweden at an appreciable rate. Within the Rokliden research site, 22 groundwater wells were installed and levels measured weekly until 1926. A map with 0.5m equidistance, ten vegetation classes, and soil profiles was established. Groundwater flow velocity was estimated by tracing added sodium chloride. Hydraulic conductivity was measured on undisturbed soil cores, while mechanical and chemical analyses were carried out on other samples. Groundwater was collected and analysed for dissolved compounds including oxygen. Hydrology was found important for soil types and vegetation development. The necessary profile drainage for podzol soil development was identified as vein drainage at the bedrock surface. Modern measurements in the re-established groundwater observation network and re-analysis of old data confirmed the plausibility of these original conclusions. Partial catchment area could explain rates of both groundwater level rise and recession. Revisiting this field study reveals that many issues in contemporary hillslope hydrology were already established a century ago, even though the provenance of that knowledge is not generally recognized. Copyright (c) 2014 John Wiley & Sons, Ltd.
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| 6. |
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| 7. |
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| 8. |
- Grip, Harald
(författare)
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Water chemistry and runoff in forest streams at Kloten
- 1982
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Natural variability of stream water composition and discharge was studied in the Kloten area, Central Sweden, by means of statistical methods and simulation technique. The effects of Urea (155 kgN ha-1) and ammonium nitrate (AN, 160 kgN ha-1) fertilization and clear-cutting were studied by comparing treated and reference streams before and after management.The concentrations of the chemical constituents and runoff were mostly inhomogeneous in space and time and the coefficients of variation were considerable.Urea fertilization had a more prolonged nitrogen leaching and a total of 750 kgN km-2 compared with AN treated areas (500 kgN km-2). The difference was due to higher nitrate leaching. Base cation leaching was larger and pH increased after Urea fertilization. pH decreased after AN fertilization.Runoff increased 180 mm year-1 after clear-cutting, while no significant change was found after fertilization. The immediate effect of clear-cutting on stream water chemistry was an increase in dissolved organic matter, followed by increased leaching of ammonia (10x), nitrate (9x) and potassium (4.8x). The total excess leaching of nitrogen was 1 040 kgN km-2 during the first three years after clear-cutting.A Norwegian hydrochemical model, that explained stream water composition, was modified and parameterized (40 parameters) for two catchments to analyse differences between them.The differences in parameters between the catchments were interpreted as differences in slopes close to the drainage net, dilution due to different evaporation, differences in standing biomass and current annual increment and slightly different mineral composition of the soils. pH at high flows could be deduced from stand characteristics.
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| 9. |
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| 10. |
- Hedwall, Per-Ola, et al.
(författare)
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Effects of clear-cutting and slash removal on soil water chemistry and forest-floor vegetation in a nutrient optimised Norway spruce stand
- 2013
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Ingår i: Silva Fennica. - : Finnish Society of Forest Science. - 0037-5330 .- 2242-4075. ; 47
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Tidskriftsartikel (refereegranskat)abstract
- Fertilisation with nutrient optimisation has in Sweden resulted in large increases in volume growth in young stands of Norway spruce. There are, however, environmental concerns about repeated fertilisation and one is the risk of nutrient leakage to ground water resources and aquatic ecosystems after clear-cutting of such forests. The present study followed soil-water chemistry in optimised fertilised stands after clear-cutting, as well as effects of harvest of slash on nutrient leakage. Parts of a 30-year-old stand of Norway spruce, which had been subject to a nutrient optimisation experiment for 17 years, were clear-cut. A split-plot design with whole-tree harvesting as the sub-plot treatment was applied. Lysimeters were installed and soil-water sampled at nine occasions during the following four years. No significant effects of fertilisation on nitrate leaching were found, while harvest of slash affected the concentration of Ca, DOC, DON, K, Mg, ammonium and nitrate, as well as pH in the soil solution. While no effects of fertilisation could be seen on the soil water concentration of N, the results indicate an interaction between fertilisation and harvest of slash on the concentration of nitrate in the soil solution. The results indicate that forest-floor vegetation plays an important role in the retention of N after clear-cutting of fertilised forests.
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| 11. |
- Kellner, Erik
(författare)
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Surface Energy Exchange and Hydrology of a Poor Sphagnum Mire
- 2001
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Mires surface energy and water budgets govern the conditions for climatic, hydrological, ecological and carbon balance processes. The components of the water and surface energy budgets were quantified over two growing seasons for an open boreal mire. The measurements of fluxes were complemented with data on the spatial variation of water content and temperature in different micro-relief elements (hummocks and hollows). Since measurements on mires are scarce, special investigations of aerodynamic properties were done as well as a calibration of TDR function for peat. The partitioning of available energy at the surface depended mainly on air temperature and relative humidity. There was a trend of falling Bowen ratio both during the day and during the season from May (monthly value 0.9) to September (0.6). The bulk surface resistance (rs) to evapotranspiration was considerable and varied little (mean rs = 160 s m-1). The cause of its relatively large value could be found in a great aerodynamic resistance within the canopy layer, and the peat wetness variation influenced little. In the scale of the whole mire, the water storage were similar over the central, open areas. On a smaller scale, the presence of a pronounced micro-topography caused a variation of the surface wetness. This was also reflected in the spatial variation of soil temperatures. The heat storage in hummock was largely influenced by lateral heat fluxes. There were considerable effects of peat elasticity and approximately 40 % of the changes in water storage was caused by swelling/shrinking of the whole peat mound. This effect should be incorporated in future models of mire-water dynamics.
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| 12. |
- Klaminder, Jonatan, et al.
(författare)
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Carbon mineralization and pyrite oxidation in groundwater : Importance for silicate weathering in boreal forest soils and stream base-flow chemistry
- 2011
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Ingår i: Applied Geochemistry. - : Elsevier BV. - 0883-2927 .- 1872-9134. ; 26:3, s. 319-324
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Tidskriftsartikel (refereegranskat)abstract
- What role does mineralized organic C and sulfide oxidation play in weathering of silicate minerals in deep groundwater aquifers? In this study, how H(2)CO(3), produced as a result of mineralization of organic matter during groundwater transport, affects silicate weathering in the saturated zone of the mineral soil along a 70 m-long boreal hillslope is demonstrated. Stream water measurements of base cations and delta(18)O are included to determine the importance of the deep groundwater system for downstream surface water. The results suggest that H2CO3 generated from organic compounds being mineralized during the lateral transport stimulates weathering at depths between 0.5 and 3 m in the soil. This finding is indicated by progressively increasing concentrations of base cations-, silica- and inorganic C (IC) in the groundwater along the hillslope that co-occur with decreasing organic C (OC) concentrations. Protons derived from sulfide oxidation appear to be an additional driver of the weathering process as indicated by a buildup of SO(4)(2-) in the groundwater during lateral transport and a delta(34)S parts per thousand value of +0.26-3.76 parts per thousand in the deep groundwater indicating S inputs from pyrite. The two identified active acids in the deep groundwater are likely to control the base-flow chemistry of streams draining larger catchments (>1 km(2)) as evident by delta(18)O signatures and base cation concentrations that overlap with that of the groundwater.
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| 13. |
- Klaminder, Jonatan, et al.
(författare)
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Estimating the mean residence time of lead in the organic horizon of boreal forest soils using 210-lead, stable lead and a soil chronosequence
- 2006
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Ingår i: Biogeochemistry. - : Springer Netherlands. - 0168-2563 .- 1573-515X. ; 78:1, s. 31-49
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Tidskriftsartikel (refereegranskat)abstract
- Knowledge about the residence time of lead in the organic horizon (mor layer; O-horizon) overlaying forest mineral soils is important for the prediction of past and future lead levels in the boreal environment. To estimate the mean residence time (MRT) of lead in the mor layer, we use in this study from Northern Sweden three different approaches: (1) lead-210 is applied as a tracer of lead migration; (2) estimations of loss rates of stable lead (concentrations and 206Pb/207Pb ratios) from the mor layer at an undisturbed forest setting, and (3) a study of lead in a soil series with sites of different age (a chronosequence of 20–220 years). In the last two approaches we compared measured inventories in the soil with estimated inventories derived using analyses of lake sediments. The results suggested a MRT of about 250 years in the mor layer in the mature forest and in the older parts of the chronosequence it was at least >170 years. The agreement between the three different approaches gives good credibility to this estimate. It is also supported by a modeling of trends in the 206Pb/207Pb ratio both between single cores and with depth in the mor layer. Our results suggest that it will take centuries for the deeper parts of the mor layer of undisturbed boreal forest soils to fully respond to decreased atmospheric lead pollution. However, data from the chronosequence indicate that the response could be much faster (MRT<50 years) in the mor layer at early stages of forest succession where graminoid and broadleaved litter fall dominates over conifer litter.
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| 14. |
- Lim, Hyungwoo, et al.
(författare)
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Boreal forest biomass accumulation is not increased by two decades of soil warming
- 2019
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Ingår i: Nature Climate Change. - : Springer Science and Business Media LLC. - 1758-678X .- 1758-6798. ; 9, s. 49-52
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Tidskriftsartikel (refereegranskat)abstract
- Increased soil organic matter decomposition with increasing temperature has been hypothesized to enhance soil nitrogen availability, consequently stimulating forest biomass production and offsetting decomposition-induced soil carbon losses(1-5). This projection, however, is based on evidence gathered from short-term studies (<= 10 years)(2,3,5). The key question for carbon sequestration is whether such responses are transient or persist over long forest rotation periods. Here we report on biomass production in a typical nitrogen-limited boreal Picea abies forest, exposed to 18 years of soil warming manipulation (+ 5 degrees C) at a plot scale (100 m(2)). We show that two decades of soil warming elicited only short-duration growth responses, thus not significantly increasing aboveground biomass accumulation. Furthermore, in combination with published work from this forest, our results suggest that increased decomposition is slight and ephemeral, and increased fine root production and turnover in deeper soil may be greater than increased decomposition, netting slightly more biomass, perhaps conserving the soil carbon stock. Thus, this long-term study does not support the notion that the projected increase in soil temperatures will cause either an increased carbon loss with decomposition or a compensatory growth increase from nitrogen mineralization.
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| 15. |
- Lövdahl, Lars, et al.
(författare)
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Effects of mulching and catch cropping on soil temperature, soil moisture and wheat yield on the Loess Plateau of China
- 2009
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Ingår i: Soil and Tillage Research. - : Elsevier BV. - 0167-1987 .- 1879-3444. ; 102, s. 78-86
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Tidskriftsartikel (refereegranskat)abstract
- Soil management can notably influence crop production under dryland farming in semiarid areas. Field experiments were conducted, from October 2001 to September 2004, with an attempt to evaluate the effects of field management regimes on thermal status at an upland site; and soil water and wheat production in a winter wheat (Triticum aestivum L) system at upland, terrace land and bottom land sites on the Loess Plateau, China. The field management regimes tested were: (i) the conventional practice (winter wheat followed by a ploughed summer bare fallow); (ii) conventional management, but a catch crop growing for certain time during fallow period used as green manure (after the wheat harvest, a catch crop were directly sown. instead of ploughing, and then incorporated into the soil roughly one month before wheat sowing); and (iii) wheat straw mulch (0.8 kg m(-2)), covering the soil throughout the year during the experimental period (no summer ploughing, straw was removed during wheat sowing). Soil temperature under catch cropping was lower during certain period of its growing by about 2 degrees C, slightly higher for short spells after incorporation and before wheat harvest, no observed effects during the rest time of a year relative to conventional practice at the upland site. Moreover, soil water storage levels under catch cropping were comparable with those of the conventional practice for all three years, but wheat yield substantially declined in the last year. Mulching showed different responses for the three land sites. At the upland site, daily mean soil temperatures under mulching at 10 cm depth were decreased in the warmer period by 0-4 degrees C, and increased in the colder period by 0-2 degrees C when compared to those of non-mulched soil. At upland and bottom land sites, mulching conserved an average of 28 and 20 mm more water in the upper 100 cm soil layer at the time of wheat sowing, respectively, than conventional practice. However, at the terrace, mulching had little effect on soil water storage, nor on wheat grain yield, relative to conventional practice. Therefore, considering the limited availability of mulch material in this region and the economic benefits, it is recommended that mulching may be beneficial to upland or bottom land, but not to terraced land. In addition, the application of catch cropping in this study did not show positive effects, the more comprehensive evaluation of this approach would be further needed. (C) 2008 Elsevier B.V. All rights reserved.
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| 16. |
- Zanchi, Giuliana, et al.
(författare)
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A Hydrological Concept including Lateral Water Flow Compatible with the Biogeochemical Model ForSAFE
- 2016
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Ingår i: Hydrology — Open Access Journal. - : MDPI AG. - 2306-5338. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- The study presents a hydrology concept developed to include lateral water flow in the biogeochemical model ForSAFE. The hydrology concept was evaluated against data collected at Svartberget in the Vindeln Research Forest in Northern Sweden. The results show that the new concept allows simulation of a saturated and an unsaturated zone in the soil as well as water flow that reaches the stream comparable to measurements. The most relevant differences compared to streamflow measurements are that the model simulates a higher base flow in winter and lower flow peaks after snowmelt. These differences are mainly caused by the assumptions made to regulate the percolation at the bottom of the simulated soil columns. The capability for simulating lateral flows and a saturated zone in ForSAFE can greatly improve the simulation of chemical exchange in the soil and export of elements from the soil to watercourses. Such a model can help improve the understanding of how environmental changes in the forest landscape will influence chemical loads to surface waters.
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| 17. |
- Zhang, Shulan, et al.
(författare)
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Modelling the effects of mulching and fallow cropping on water balance in the Chinese Loess Plateau
- 2007
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Ingår i: Soil & Tillage Research. - : Elsevier BV. - 0167-1987 .- 1879-3444. ; 93:2, s. 283-298
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Tidskriftsartikel (refereegranskat)abstract
- To improve water use efficiency on drylands it is essential to understand the mechanisms affecting water balance partitioning in arable land ecosystems. A field experiment was conducted, from October 2001 to October 2004, to evaluate the effects of field management regimes on water balance and water use efficiency in a winter wheat (Triticum aestivum L.) system in the Loess Plateau, China. The field management regimes tested were: (i) conventional agricultural management (winter wheat followed by a ploughed summer fallow); (ii) conventional management plus a fallow crop used as green manure; (iii) application of wheat straw mulch (0.8 kg m(-2)), which was retained throughout the year (no summer ploughing). A process-oriented ecosystem model (CoupModel) was calibrated with field measurements of soil water contents, leaf area indices, plant heights and crop yields, then used to generate comparative simulations of the water balance partitioning under the wheat straw mulch, fallow crop and conventional management regimes. The simulations indicated that during the experimental period mulching increased soil water storage by 5-8%, decreased soil evaporation by 11-13%, and increased wheat transpiration by 2-5% compared with the conventional management regime, thus increasing the wheat yield and water use efficiency. Furthermore, water reached deeper horizons under mulching than under conventional practice, resulting in 15% more deep percolation in a wet year. The simulation results also indicated that growing green manure during the fallow period decreased soil water storage, leading to lower wheat yields. Mulching proved to be an efficient measure for increasing yields, and possibly contributed to groundwater recharge.
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| 18. |
- Öquist, Mats, et al.
(författare)
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Water availability controls microbial temperature responses in frozen soil CO2 production
- 2009
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Ingår i: Global Change Biology. - : Blackwell Publishing Ltd. - 1354-1013 .- 1365-2486. ; 15:11, s. 2715-22
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Tidskriftsartikel (refereegranskat)abstract
- Soil processes in high-latitude regions during winter are important contributors to global carbon circulation, but our understanding of the mechanisms controlling these processes is poor and observed temperature response coefficients of CO2 production in frozen soils deviate markedly from thermodynamically predicted responses (sometimes by several orders of magnitude). We investigated the temperature response of CO2 production in 23 unfrozen and frozen surface soil samples from various types of boreal forests and peatland ecosystems and also measured changes in water content in them after freezing. We demonstrate that deviations in temperature responses at subzero temperatures primarily emanates from water deficiency caused by freezing of the soil water, and that the amount of unfrozen water is mainly determined by the quality of the soil organic matter, which is linked to the vegetation cover. Factoring out the contribution of water limitation to the CO2 temperature responses yields response coefficients that agree well with expectations based on thermodynamic theory concerning biochemical temperature responses. This partitioning between a pure temperature response and the effect of water availability on the response of soil CO2 production at low temperatures is crucial for a thorough understanding of low-temperature soil processes and for accurate predictions of C-balances in northern terrestrial ecosystems.
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