Environmental effects on soil NO concentrations and root N uptake in beech and spruce forests |
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| Authors: | Fang Dong Judy Simon Michael Rienks Jürgen Schäffer Klaus von Wilpert Heinz Rennenberg |
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| Affiliation: | 1. Chair of Tree Physiology, Institute of Forest Sciences, University of Freiburg, Georges‐K?hler‐Allee 53/54, 79110 Freiburg, Germany;2. Plant Physiology and Biochemistry, Department of Biology, University of Konstanz, Universit?tsstrasse 10, 78457 Konstanz, Germany;3. Forest Research Institute Baden‐Württemberg, Department of Soil and Environment, Wonnhaldestra?e 4, 79100 Freiburg, Germany |
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| Abstract: | This study aimed to investigate the shifts in net nitrogen (N) uptake and N compounds of fine roots over the vegetation period (i.e., spring, summer, autumn) and correlate this with NO concentration in the soil. Soil NO concentration was measured using gas lysimeters for collection and a chemiluminescence analyzer for quantification. Net N uptake by the roots was determined using the 15N enrichment technique. N pools were quantified using spectrophotometric techniques. Soil NO concentrations at beech and spruce forest sites were highest in spring (June), and lowest in winter (December). Total N of the roots was similar during the seasons and between the two years under study despite considerable variation of different N compounds. Net N uptake generally increased with higher N supply. Correlation analysis revealed a positive relationship between soil NO concentration and net N uptake only for spruce trees. This relationship seemed to be modulated by environmental factors and tree species. |
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| Keywords: | amino acids ammonium field experiment gas lysimeters N compounds nitrate |
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