Abstrakt
Calamagrostis epigeios, a common aggressive grass that usually grows on many disturbed habitats. After senescence C. epigeois large proportion of litter form standing dead biomass with limited contact with a soil which limit of microbial breakdown.
Only a smaller part of litter comes directly into the soil. The main objective of this study was to assess the effect of extensive period of dead standing biomass on the nitrogen loss from the litter.
We collected both living and dead lying and standing biomass of C. epigeios at young and old sites on post mining heap near Sokolov every two month for the whole vegetation season. The content of carbon and nitrogen was analyzed in dried and mashed biomass.
We observed reabsorbtion of nitrogen from living biomass during the vegetation season namely before senescence. Content of N in standing biomass is close to the lowest values in live biomass and does not change mass during season which indicate conservation of N in dead standing biomass.
There is remarkable difference between standing and lying biomass indicating faster leaching of N in early stages of decomposition of lying biomass. We conclude that majority of N is reabsorbed before senescence then the greater losses of nitrogen was subsequently after death and then when standing dead biomass turn to laying biomass which is in contact with soil in other periods the nitrogen loss from the litter was very slow.
In younger nutrient poor site Calamagrostis reabsorb more N and N loss from litter is slower, while in older nutrient rich site N reabsorption is not so progressive and N loss from litter is much faster.