title: Performance of two Picea abies (L.) Karst. stands at different stages of decline : VI. Nutrient concentration.
abstract: A declining Picea abies (L.) Karst. stand produced as much foliage and branches as a healthy stand but less stemwood at a similar leaf area index and climate. Nutrient analyses revealed that most biomass components at the declining site had lower concentrations of calcium and magnesium, but similar nitrogen and potassium (except for lower potassium in younger needles) and higher phosphorus, manganese and aluminum than the respective components at the healthy site. Comparison of these data with the results from studies on the nutrition and growth of P. abies seedlings (Ingestad 1959) led to the conclusion that the healthy stand is in a balanced nutritional state, while trees at the declining stand have only 56% of the foliar magnesium concentration required to permit growth at a rate which could be achieved at their nitrogen status. It appears that acidic deposition, which involves an input of nitrogen and a leaching of cations from the soil, causes an imbalance in the availability of nitrogen and magnesium. Growth is eventually reduced as magnesium becomes limiting.
authors.affiliation: School of Forestry and Environmental Studies, Duke University, 27706, Durham, NC, USA.
authors.forename: R
authors.initials: R
authors.lastname: Oren
authors.affiliation: Lehrstuhl Pflanzenökologie der Universität Bayreuth, Postfach 101251, 8580, Bayreuth, Federal Republic of Germany.
authors.forename: K S
authors.initials: KS
authors.lastname: Werk
authors.forename: E-D
authors.initials: ED
authors.lastname: Schulze
authors.forename: J
authors.initials: J
authors.lastname: Meyer
authors.affiliation: Lehrstuhl Bodenkunde, der Universität Bayreuth, D-8580, Bayreuth, Federal Republic of Germany.
authors.forename: B U
authors.initials: BU
authors.lastname: Schneider
authors.affiliation: Zentrales Analytiklabor des Bayerischen Staatsministeriums für Landesentwicklung und Umweltfragen, 8042, Neuherberg, Federal Republic of Germany.
authors.forename: P
authors.initials: P
authors.lastname: Schramel
keywords: Forest decline, Spruce (Picea abies); Magnesium; Nitrogen