محسن شرافتمندراد

Litter is the main source of energy which provides nutrients as absorbable form for vegetation. The reaction of plant species to the amount of litter is different. This study aimed to measure litter production and soil carbon of four species (Artemisa aucheri Boiss, Astragalus gossypinus Fisch, Stipa barbata Desf. and Hyparrhenia hirta (L.) Stapf) under litter treatments (removing and adding). Four litter treatments (0%, 50 %, 100% and 200% litter) were applied in 20 plots for each species, and then plots were marked. Litter quantity and quality, soil carbon and moisture were measure in fall season. The four species were significantly different in terms of the litter quantity and quality. Response of litter production of the four species to adding and removing litter was different. For all the species, soil carbon were significantly reduced with the removal of litter and increased significantly with the increase of litter (p<0.05). Structural equation model indicated that litter removal was the most important driver of litter production directly (p<0.01). Litter removal had a significant effect on litter production indirectly through the effect on soil moisture (P<0.05). The addition of litter also had a significant effect on litter production indirectly through the effect on soil carbon (p<0.05). The findings of this study indicate the importance of maintaining litter (at least 50 %) for the next year's litter production of plants, which should be considered in the sustainable management of rangelands.