Stand heterogeneity of total carbon and nitrogen, and C/N ratio in soil of mountain meadows

This study was aimed at monitoring the relative and absolute stand heterogeneity of total carbon, total nitrogen and C/N ratio in Ah-Ae-Btg-Bt horizons of Gleyic Luvisol on one mountain meadow divided into two study plots: one moderately (once a season) mown (plant community of the Nardo-Callunetea class) and one abandoned for about 12 years (plant community of the Molinio-Arrhenatheretea class). The heterogeneities were evaluated more than 2 months after the mowing of the moderately mown meadow at the end of July 2005. Relative stand heterogeneity was expressed using coefficient of variation (CV), absolute stand heterogeneity using the differences between maximum and minimum value. When both meadows were taken into account, the relative stand heterogeneity of total carbon in individual horizons was < 65%, < 73% (total nitrogen), and < 93% (C/N). Lower relative and absolute stand heterogeneity of these parameters was mostly on the abandoned meadow. Relatively higher differences of stand heterogeneity between the meadows were evident in deeper parts of the soil (horizon Btg) and the lowest mainly in horizon Ah (or Bt). The accelerated accumulation of dead organic matter in the autumn caused the natural difference of these inputs not to be substantially eliminated by the presence or absence of mowing. Accelerated eluviation of organic compounds of higher nitrogen content significantly (P < 0.05) decreased the C/N ratio in the Bt horizon (n = 6-8) of the abandoned meadow.