内蒙古不同草地类型针茅属植物对放牧强度和气候因子的响应  

Response of Stipa to grazing intensity and climate factors in different grasslands of Inner Mongolia

作　　者：秦洁[1] 韩国栋[1] 乔江[1,2] 武倩[1] 

机构地区：[1]内蒙古农业大学生态环境学院,呼和浩特010018 [2]中国农业科学院草原研究所,呼和浩特010010

出　　处：《生态学杂志》2016年第8期2066-2073,共8页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(31270502);内蒙古科技攻关项目"不同生态类型区域生态监测与评估及风险预测技术研究"和研究生科研创新项目(B20151012906Z)资助

摘　　要：以内蒙古草甸草原、典型草原、荒漠草原为研究对象,设置轻度、中度、重度以及对照4个放牧梯度,经过连续5年野外调查试验,研究针茅属植物在不同放牧强度及不同水热条件下的变化趋势,为针茅属植物为建群种的草地管理提供理论基础。结果表明:1)草甸草原的贝加尔针茅相对生物量随着放牧强度的增加呈下降趋势,即使降水波动较大,依然保持该趋势;2)典型草原大针茅受降水的影响较大,在对照样地中相对生物量与降水呈显著正相关(r=0.326),在轻度放牧样地中则为负相关(r=-0.319),在干旱年份大针茅相对生物量在轻度放牧强度中显著高于对照样地,所以放牧对大针茅的影响随降水的不同而不同;3)荒漠草原的短花针茅相对生物量随放牧强度增加而降低,但差异不显著,短花针茅受降水和温度的影响较大,与降水呈显著负相关(r=-0.440^-0.583),与温度呈显著正相关(r=0.282~0.299)。综上所述,在水分不受限制的草甸草原,即使降水温度有较大波动也不会对群落建群种产生较大影响,放牧成为草甸草原退化的主要因子;而在降水较少的典型草原和荒漠草原,气候逐渐成为除放牧以外的主要制约因子。A consecutive five-year experiment was conducted to study the responses of relative bio- mass of Stipa species in meadow steppe, typical steppe and desert steppe to different grazing in- tensifies （ no, light, moderate or heavy grazing） in Inner Mongolia in relation to precipitation and air temperature patterns over time. The relative biomass of Stipa baicalensis was inversely related to grazing intensity in meadow steppe, irrespective of precipitation. In contrast, the relative bio- mass of S. grandis in typical steppe increased with precipitation （r= 0.326） in the control plots, yet it decreased （r=-0.319） with precipitation in the light grazing plots and was significantly greater than that of the control plots in dry years. S. breviflora＇ s relative biomass decreased with grazing intensity in desert steppe, but the differences among treatments were not statistically sig- nificant. S. breviflora＇s relative biomass was also negatively correlated with precipitation in non- grazing （ r = -0.459）, light grazing （ r = -0.583 ）, and moderate grazing plots （ r = -0.440）, yet positively with air temperature in all treatments （r = 0.282-0.299） except for heavy grazing. In conclusion, in meadow steppe where water was not a limiting factor, fluctuations in precipitation and air temperature had no great influence on the dominant species in the community, while gra- zing was the main factor of grassland degradation. Fluctuations in precipitation and air tempera- ture became the key factors of grassland degradation in typical and desert steppe where the pre- cipitation was less.

关 键 词：草地 退化 放牧梯度 针茅 

分 类 号：S812[农业科学—草业科学]