engleski

Influence of soil type on pedunculed oak (Quercus robur l.) nutrition

Introduction:Peduncled oak (Quercus robur L.) represents the most valuable and most important species of forest trees in Croatia. With the practice of natural regeneration the forest soil is preserved as the most perfect and important part of the ecosystem, which by its physical and chemical properties differs from soils outside the forest. This paper, therefore, compares the concentrations of biogenic elements both in soil and in plant material of peduncled oak stands, established on the principle of natural reforestation, with the stands directly planted on the out-of-forest areas. Material and Methods: The analysis of elements content required sample drying, grinding and wet digestion. N was determined by the Kjeldahl method, P was determined through UV/VIS spectrophotometer, K through flame photometer and Ca and Mg by AAS according to AOAC (1996). Chemical analyses of soil included determination of pH in water and 1M KCl, total carbonate, carbon, total nitrogen, nitrate and ammonia forms or nitrogen and physiologically active P and K. Results and Conclusions: Concentrations and values for the aforementioned elements and parameters are presented through the whole vegetation period at two different depths of sampling for both stand types. The paper also presents the cycling changes in the concentrations of nitrogen, phosphorus, potassium, calcium and magnesium in foliage throughout the whole of the vegetation period for naturally and artificially raised stands. On the basis of the results of the analysed plant material a cycling trend of concentrations of particular elements becomes evident. Thus, the concentrations of nitrogen, phosphorus and potassium are highest at the beginning of the vegetation period, but show a gradual decline towards the end of the vegetation period. During the vegetation period concentrations of calcium in foliage gradually increased. By means of regression analysis, correlation was determined between some analysed variables.. Average biomass of the above-ground part of peduncled oak tree in natural stands amounted to 24.36 kg, and in the cultures 21.16 kg.. Furthermore, it has been determined that the nutrient concentrations in oak foliage fall into the class of optimal supply, on the basis of which it can be concluded that the state of nutrition of both stands is satisfactory regardless of the manner of origin. However, biomass of a mean stand tree of naturally cultivated peduncled oak stands, indicates the greater productive possibility of preserved forest soils. References: Berger TW, Glatzel G, 1994: Deposition of atmospheric constituents and its impact on nutrient budgets of oak forests (Quercus petraea and Quercus robur) in lower Austria. Forest Ecology and Mamagement, Vol. 70 (1-3): 183-193. Bergmann W, 1992: Nutritional Disorders of Plants. Gustav Fischer Verlag Jena. De Vries W, GJ Reinds, MS. van Keerkvoorde, CMA. Hendriks EEJM. Leeters, C.P. Gross, J.C.H. Voogd, E.M. Vel., 2000: Intensive Monitoring of Forest Ecosystems in Europe, FIMCI, EC-UN/ECE, Brussels, Geneva, 191 pp. Komlenović N. 1981: Sezonske promjene sadržaja hraniva u biljkama hrasta lužnjaka (Quercus robur L.) i kitnjaka (Quercus petraea Liebl.). Anali za šumarstvo, 10/2, : 43-57, Zagreb. Mengel K, Kirkby E.A, 1987: Principles of Plant Nutrition. International Potash Institute Bern, Switzerland. Van Den Burg J, 1990: Foliar analysis for determination of tree nutrient status- acompilation of literature data. 2. Literatute 1985-1989. “ De Dorschkamp” , Institute for Forestry and Urban Ecology, Rapport Nr. 591, Wageningen, The Nederlands.

pedunculed oak; nutritional status; natural stand; cultures

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