Stickstoff- und kohlenhydratspeicherung in rhizomen von Phragmites australis (Cav.) Trin. ex Steudel an unterschiedlichen aquatischen standorten oberbayerischer seen

Nitrogen and carbohydrate utilization in Phragmites australis rhizomes was investigated under natural conditions at 10 sites in 5 lakes in Upper Bavaria over a period of two years. Nitrate and ammonium of surface and interstitial water was determined. The results indicate that conditions of habitat and environment, such as climate and fluctuation of water level, lead to different adaptations of reed. These parameters had an effect on the storage of nitrogen and carbohydrate. The reed stands exposed to high water level during spring and summer have a high carbohydrate content in the rhizomes. A positive correlation was shown between the aboveground biomass and the content of storaged carbohydrates during the vegetation period. No relationship could be demonstrated between the nitrogen availability of the habitats and the type of storage of carbohydrates and nitrogen. The nitrogen content in the rhizomes can be used as an indicator of the ability of reed stands to produce new secondary shoots after shoot loss. The differently established reed genotypes are not able to compensate short-term environmental changes, such as growing leisure problems and higher shoot loss by the increasing appearance of waterfowl, from their reserve storage.