Quelle: Forstarchiv 78: 2, 41-45 (2007)
Autor(en): Weckesser M, Schmidt W
Abstract: In situ nitrogen net mineralization was studied during one vegetation period in a pure beech stand, a pure spruce stand and in a mixed standof both species. The stands are located in the Solling-Hills (Lower Saxony) forming a block of neighbouring woodlots. All sites are characterized byan oligotrophic acid brown soil with a moder humus-type. In the mixed stand three types of plots were selected (spruce-dominated, beech-domina-ted, equal frequency of both). Concentration based nitrogen (N) mineralization shows a decrease in plots dominated by spruce. However, when Nmineralization is expressed per soil surface area, this decrease is compensated due to the high accumulation of organic matter in spruce stands. To-tal N mineralization amounted to 104 to 124 kg ha-1during the vegetation period for all stands. Although the review of a large number of in-situ andex-situ studies gives clear evidence that N mineralization on acid soils decreased by planting spruce on former beech forests, a linear relationship be-tween N mineralization and the proportion of beech and spruce in mixed stands was not found.
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