Hopp til hovedinnholdet

Publications

NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.

1998

Abstract

Intra-specific relationships between growth traits and nitrogen economy were studied for seedlings of mountain birch (Betula pubescens ssp. tortuosa) originating from three climatically different regions within the northern forest margin in subarctic Fennoscandia. The experiment was carried out using potted seedlings grown in Abisko, northern Sweden, through two complete growing seasons. The seedlings were grown in peat and assigned to two different temperature and fertilization treatments according to a factorial design. The treatments were ambient and ca. 2.5oC elevated temperature (passive greenhouse), and soil nutrient fertilization corresponding to 1 and 10 g nitrogen m-2 season-1. Significant differences among provenances were found in almost all growth and nitrogen economy traits studied. The differences in growth rate, which reached 47%, were explained primarily by leaf weight ratio (biomass allocation to leaves) and secondly by leaf area productivity (biomass production per unit leaf area). Both the nitrogen productivity and residence time of nitrogen (with respect to above-ground nitrogen losses) varied between provenances; no significant relationship was found between these two traits. Differences in residence time of nitrogen were more related to biomass loss ratio (leaf biomass losses per unit total plant biomass production) than to nitrogen concentration of abscised leaves. The intra-specific variation in nitrogen economy between mountain birch provenances is discussed with respect to the possibility of significant genotype x environment interaction.