不同剂量凋落物添加对荒漠草原生物量的影响

Effect of Different Doses of Litter Addition on the Biomass of Desert Steppe

凋落物是草地生态系统养分循环的重要组分,是土壤有机碳库主要来源。以内蒙古短花针茅荒漠草原重度退化样地为对象,于不同季节(2013年秋季、2014年春季)添加不同剂量凋落物(中度添加,即添加500 g;重度添加,即添加1000 g),测定其对2014~2017年荒漠草原植物地上生物量及功能群生物量的影响。结果表明:不同季节添加凋落物对荒漠草原2014年、2015年的地上生物量无显著影响;凋落物添加和降雨量对地上生物量及功能群生物量有显著影响,在降雨充足年份,与不添加凋落物相比,中度添加处理植物群落地上生物量和一二年生草本植物生物量显著提高。秋季凋落物添加对改变荒漠草原植物群落的作用大于春季凋落物添加。

Litter is an important component of nutrient cycling in grassland ecosystem and the main source of soil organic carbon pool.In this experiment,we focused on a severely degraded sample plot in Stipa brevi⁃flora desert steppe of Inner Mongolia.Different amounts of litter(moderate addition:500 g;heavy addition:1000 g)were applied during different seasons(autumn 2013,spring 2014),and their effects on aboveground biomass and functional group biomass of desert steppe plants from 2014 to 2017 were measured.The results showed that adding litter in different seasons had no significant impact on the aboveground biomass of desert steppe during 2014 and 2015,litter addition and rainfall had a significant impact on aboveground biomass and functional group biomass.In years with sufficient rainfall,the aboveground biomass of moderately added plant community and annual and biennial herbaceous plants had significantly increased compared with control.The effect of fall litter addition on the change of desert steppe plant community was greater than that of spring litter addition.