title: Nitrogen relations of ruderal communities (Rumicion alpini) in the Northern Calcareous Alps.
abstract: The total nitrogen and nitrate turnovers of three plots of plant communities typical of cattle resting sites in the Bavarian Alps were investigated. Annual net N mineralisation of the soil and N content of the above-ground phytomass at maximum development are low in the Senecio cordatus dominated community "W" at 1,450 m altitude (80 and 57 kg N/ha respectively) and highest in the nearly pure Rumex alpinus stand "K" (1,240 m) (156 and 148 kg N/ha). The subalpine mixed Rumex alpinus community "S" (1,790 m) is intermediate with low mineralisation but high N content in the aboveground parts (69 and 128 kg N/ha). In general the mineralisation values are below those from other comparable plant communities. The main component of N mineralisation is nitrification in all three plots.The nitrate content in the phytomass at full development increases from 0.1 g/m2in W to 0.3 g/m2in S and to 1.0 g/m2in K. With one exception (Adenostyles alliariae) no species showed a real nitrate accumulation in the leaf laminae towards the end of the growing season.
authors.affiliation: Institut für Botanik und Mikrobiologie der Technischen Universität München, Arcisstr. 21, D-8000, München 2, Federal Republic of Germany.
authors.forename: H
authors.initials: H
authors.lastname: Rehder