Research article - Peer-reviewed, 2016
Linnebjer—A South Swedish Oak Forest and Meadow Area—Revisited after Half a CenturyAndersson, Folke; Nihlgård, Bengt
AbstractAn oak forest and three wet meadows/fens were reinvestigated after 50 years concerning tree vitality,biomass and productivity, and soil chemistry. Sulphur and nitrogen deposition has changeddramatically during these years, and the aim was to analyse the differences in both the oak forestand the open field ecosystems. Trees were re-measured and soil profiles were resampled. Importantvisible changes in the oak forest were stated concerning the vitality of oaks. Abovegroundthere was a decrease in tree biomass, production and litter fall, but a huge increase in standingdead logs. During the years, the deposition of sulphur had decreased drastically, but nitrogendeposition was still high. Soil acidification in the forest had decreased, reflected in an increasedbase saturation in the forest, in spite of slightly lowered pH-values. Strongly increased amounts ofexchangeable Ca and Mg now appeared in the forest soil, and a substantial transport of calciumand magnesium had obviously taken place from the forest soil to the meadow and fens during theyears. However, the most important soil change was the accumulation of organic matter. The increasedaccumulation of organic matter in turn meant increased amounts of colloid particles andmicrosites for ion exchange in the soil. This favoured 2-valence base cations, and especially Ca andMg that increased very much in all the studied ecosystems. Carbon as well as nitrogen had stronglyincreased in the forest, meadow and fen soils. This was interpreted as a natural result of increasedvegetation growth due to high nitrogen deposition, increased global annual temperature and increasedcarbon dioxide concentration in air. It was concluded that the decreased deposition ofsulphur had have a positive effect on soil chemistry, and that the deposition of nitrogen probablyhad stimulated vegetation growth in general, and contributed to increased amount of organicmatter in the soils. However, in this studied oak forest, the decreased vitality and many killedtrees were also suspected to be a result of high nitrogen deposition. Obviously increased treegrowth was counteracted by decreased stress resistance, and increased appearance of pathogensin the oak trees.
Published inOpen Journal of Ecology
2016, volume: 6, number: 2, pages: 74-83
Swedish University of Agricultural Sciences, Department of Ecology
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