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Acidification of Swedish forest soils

evaluation of data from the Swedish forest soil inventory

Iwald, Johan (2016). Acidification of Swedish forest soils. Uppsala : Sveriges lantbruksuniv.
ISBN 978-91-576-9448-5
eISBN 978-91-576-9449-2
[Licentiate thesis]

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Acidification of forest soils in Sweden has negatively affected nutrient status and caused toxic effects on biota. The aim of this thesis was to investigate potential impacts of two drivers of acidification of forest soils in Sweden: (1) tree growth with subsequent harvest and (2) deposition of sulphur and nitrogen compounds.

The magnitude of acidification by tree growth was calculated using estimates of stem wood, logging residue and stump harvesting from a national forestry impact assessment and data of cations and anions in different tree parts. Acidification by tree growth was defined as the net cation uptake.

The magnitude of acidification by deposition was estimated based on deposition data from four catchments throughout Sweden. Acidification by deposition was defined as the negative value of the acid neutralizing capacity in deposition.

The acidifying effect of tree harvesting decreases in the order Norway spruce>birch>Scots pine. Harvesting of logging residues causes more soil acidification than harvesting of stumps, despite the fact that the biomass of stumps is larger, due to the higher contents of base cations in needles and branches than in stem wood. Harvesting of Scots pine and birch causes soil acidification at a magnitude equal to recent deposition levels while harvesting of Norway spruce causes more acidification than what is caused by deposition.

To study the acidifying effects on the soil of tree growth during a forest generation and deposition, data from the Swedish Forest Soil Inventory – a large-scale inventory throughout Sweden – from the O (n=1990), B (n=1902) and C (n=1477) horizons were used. Four variables were chosen as indicators of soil acidity: pH-H₂O (pH), base saturation (BS), exchangeable calcium (Ca) and exchangeable aluminium (Al) from each horizon. The variables were analysed with respect to tree age and data of sulphur deposition, using linear and multiple regression. For tree age, a relative age concept was used to account for different tree growth rates in different parts of Sweden.

Tree growth during a forest generation and deposition of acidifying substances both affect acidity related variables in Swedish forest soils. Tree growth causes decreased pH, BS and Ca and increased Al in the O and to some extent the B horizon in the beginning of the trees’ life cycle. Deposition causes decreased pH, BS and Ca and increased Al in the O, B and C horizons throughout the deposition gradient in Sweden. The effect of deposition is most evidently expressed in deep soil layers where biological acidification have less influence.

Authors/Creators:Iwald, Johan
Title:Acidification of Swedish forest soils
Subtitle:evaluation of data from the Swedish forest soil inventory
Year of publishing :2016
Depositing date:2 November 2016
Number of Pages:46
IIwald, J., Löfgren, S., Stendahl, J. & Karltun, E. (2013). Acidifying effect of removal of tree stumps and logging residues as compared to atmospheric deposition. Forest Ecology and Management, 290, pp. 49-58.
IIIwald, J., Stendahl, J., Löfgren, S., von Brömssen, C. & Karltun, E. (2016). Spatial variations of acid-base properties in Swedish forest soils – the impact of tree growth, temperature and atmospheric deposition. Manuscript.
Place of Publication:Uppsala
Publisher:Department of Soil and Environment, Swedish University of Agricultural Sciences
ISBN for printed version:978-91-576-9448-5
ISBN for electronic version:978-91-576-9449-2
Publication Type:Licentiate thesis
Full Text Status:Public
Agris subject categories.:K Forestry > K10 Forestry production
P Natural resources > P06 Renewable energy resources
P Natural resources > P30 Soil science and management
Subjects:(A) Swedish standard research categories 2011 > 1 Natural sciences > 105 Earth and Related Environmental Sciences > Environmental Sciences (social aspects to be 507)
(A) Swedish standard research categories 2011 > 1 Natural sciences > 105 Earth and Related Environmental Sciences > Geochemistry
(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 401 Agricultural, Forestry and Fisheries > Soil Science
Agrovoc terms:forest soils, acidification, acid deposition, sulphur, nitrogen, forest trees, picea abies, betula pendula, pinus sylvestris, growth, logging residues, soil surveys, sweden
Keywords:soil acidification, tree growth during a forest generation, deposition, Sweden
Permanent URL:
ID Code:13810
Faculty:S - Faculty of Forest Sciences
Department:(NL, NJ) > Dept. of Soil and Environment
(S) > Dept. of Soil and Environment
Deposited By: Mr Johan Iwald
Deposited On:03 Nov 2016 08:48
Metadata Last Modified:10 Sep 2020 13:41

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