荒漠草原地区冷蒿构件及其动态规律对载畜率的响应

采用随机区组试验方法,研究了内蒙占高原荒漠草原地区不同载畜率对冷蒿构件数量特征的影响,结果表明:冷蒿生长时期和载畜率是影响冷蒿构件数量的关键因素,相同载畜率水平下,冷蒿的营养枝密度、不定根密度和匍匐茎长度为生长末期>生长盛期>生长初期,生殖枝8月最多,冷蒿生长盛期和末期,轻牧区的营养枝密度、不定根密度和匍匐茎长度显著增加(P<0.05);同一生长季节生殖枝随载畜率的增大显著下降(P<0.05),极度干旱的2005年没有形成生殖枝,说明干旱也是限制冷蒿生殖生长的关键性因子.荒漠草原地区冷蒿的繁殖格局以营养繁殖为主,占到80%以上,随载畜率的增加.冷蒿的营养枝分化率逐渐增加.

Response of Artemisia frigida Module to Stocking Rates in the Desert Steppe, Inner Mongolia

The experiment was conducted in Stipa breviflora desert steppe in Inner Mongolia located in 41°47'17"N, 111°53'46"E, altitude 1450m in 2004. The objectives were to study the influence of different stocking rates on Arternisia frigida module number characteristics with random plot group methods. The results showed that Arternisia frigida module characteristics were changed with grazing season and stocking rates. The density of vegetative shoots and reproductive shoots of Arternisia frigida were increased with the grazing season in 2004, density of reproductive shoots were highest in August. Density of vegetative shoots was highest in light grazed (LG) plot, and gradually decreased with the stocking rates increased, density of reproductive shoots were decreased significantly. Because of less raining, no repro- ductive shoots occurred in 2005. Adventitious root density and repens length were the same change like density of vegetative shoots. Spacer length was almost no change, but decreased in heavy grazed plot (HG), the result indicated that adventitious root density and repens length were increased with the same time, Artemisia frigida depends on adventitious root to get nutritious matter and live space. With the stocking rates increased, differentiation ratio of vegetative shoots of Arternisia frigida was gradually in- creased, and the reproductive patter was mostly vegetative propagation which occupy over 80%.