The influence of grazing on C and N storage in relation to biomass allocation (Case study: south-facing slopes of Sabalan mountain)

Grazing is The most common use of Ranglands, which can affect grassland vegetation composition, net primary production, shoot to root ratio and nutrient cycling in the ranglands. The aim of this research, was to investigate the effect of grazing on the allocation of carbon and nitrogen in aerial and belowground biomass of Artemisia aucheri and Festuca ovina in southern slope of Sabalan ranglands. The study areas were selected based on natural resources and local views in three grazing conducted intensity light, medium and heavy. Vegetation and soil sampling were swith randomized-systematic method on 3 parallel transects with the length of 200 meters and 1×1 m2 plots was carried out at intervals of 50 meters. Soil samples were obtained based on soil depth and breadth of root from the depths of 0-15, 15-30 and 30-45 cm. To determine aerial and belowground biomass, sampling was obtained from full aerial and belowground biomass. To determine the relationship between characteristics of aboveground and belowground biomass in each of the areas the linear regression was used. Analysis of variance and Tukey's test were conducted using spss software to plant biomass, carbon and nitrogen. Contents The results showed that different intensities of grazing on aboveground and underground biomass of two species had significant effect. Analysis of variance showed that the effect of grazing on the amount of nitrogen stored in the aerial biomass of A. aucheri was significant. Also, the grazing on carbon storage in underground biomass had a significant effect. Also results showed the effects of different grazing intensities on the amount of carbon and nitrogen in aerial and underground biomass F. ovina was significant. The results of this research and the relationship between the allocation of nutrients and grazing can be used in grazing pasture management. Keywords: aboveground, underground, biomass plant allocation, grazing, carbon, nitrogen