اعظم خسروی مشیزی

Understanding the response of plant communities to litter removal or addition plays an important role in the sustainable management of rangelands. In this study, we investigated the effect of different litter removal and addition treatments on the annual forage production and on soil carbon and nitrogen contents of four rangeland communities in arid to semiarid areas of Iran. The results showed that litter removal reduced the contents of carbon and nitrogen in soil and the annual forage production. There was an 80% drop in annual forage production of Artemisia aucheri stand when whole litter mass was removed. The litter removal increased the annual production in Saccharum bengalense stand, and the highest forage production increment was seen when 50% of litter was removed. There was no significant difference between legume and non-legume plant stands owing to variations of soil nitrogen content. Due to the allelopathic effects in Artemisia aucheri stand, litter manipulation had no effect on the annual growth of annuals. The litter quality was more correlated to soil C and N contents and to annual forage production than to litter quantity in plant stands. Plant stands in semiarid rangelands were more sensitive to litter removal than to litter addition. Generally, short-term litter manipulation for a growing season had greater impacts on shrubland communities.