Nitrogen net mineralization in mixed and pure stands of European beech (Fagus sylvatica) and Norway spruce (Picea abies) in the Solling-Hills (Lower Saxony)

Alfeld

2007

S. 41-45

3 Abb., 2 Tab., zahlr. Lit. Ang.

Artikel aus einer ZeitschriftUnselbständiges Werk

200138515

In situ nitrogen net mineralization was studied during one vegetation period in a pure beech stand, a pure spruce stand and in a mixed stand of both species. The stands are located in the Solling-Hills (Lower Saxony) forming a block of neighbouring woodlots. All sites are characterized by an oligotrophic acid brown soil with a moder humus-type. In the mixed stand three types were selected (spruce-dominated, beech-dominated, equal frequency of both). Concentration based nitrogen (N) mineralization shows a decrease in plots dominated by spruce. However, when N mineralization is expressed per soil surface area, this decrease is compensated due to the high accumulation of organic matter in spruce stands. Totoal N mineralization amounted to 104 to 124 kg ha-1 during the vegetation period for all stands. Although the review of a large number of in-situ and ex-situ studies gives clear evidence that N mineralization on acid soils decreased by planting spruce on former beech forests, a linear relationship between N mineralization and the proportion of beech and spruce in mixed stands was not found.