Investigating litter production of shrub and grass species in semi-arid rangeland using structural equation model

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, Astergalus gossipinus fisch, Stipa barbata Desf. and Hyparrhenia hirta(L.) Stapf) under litter treatments (Removing and adding). Four litter treatments (۰%, ۵۰ %, ۱۰۰% and ۲۰۰% litter) were applied in ۲۰ plots for each species, and then plots are marked. Litter quantity, litter qualify and soil carbon and moisture were measure in fall season. Four species are significantly different in terms of the litter quantity and qualify. Response of litter production of four species to add and remove litter was different. For all three species, soil carbon were significantly reduced with the removal of litter and increased significantly with the increase of litter (p<۰.۰۵). Structural equation model indicated that litter removal was the most important driver of litter production directly (p<۰.۰۱). Litter removal had a significant effect on litter production indirectly through the effect on soil moisture (P<۰.۰۵). The addition of litter also had a significant effect on litter production indirectly through the effect on soil carbon (p<۰.۰۵). The findings of this study indicate the importance of maintaining litter (at least ۵۰ %) for the next year's litter production of plants, which should be considered in the sustainable management of rangelands.

کلیدواژه ها:

Manipulated litter ، Litter Production ، Soil carbon ، legume