摘要
通过对牦牛放牧率与小嵩草Kobrecia parva高寒草甸暖季草地地上、地下生物量相关分析得出,牦牛放牧率对小嵩草高寒草甸地上、地下生物量有显著的影响.随着放牧率的增加, 总地上生物量和优良牧草地上生物量及其比例减小,杂类草比例增加;总地上生物量和优良牧草地上生物量与放牧率呈线性回归关系, 杂类草地上生物量与放牧率呈二次回归关系,且当放牧率为2.30头/hm2时, 1998年杂类草的地上生物量达到最大;放牧率为2.04头/hm2时, 1999年杂类草的地上生物量达到最大.各土壤层地下生物量与放牧率呈线性回归关系;1998和1999年对照组0～30 cm地下生物量分别是轻度、中度和重度放牧的1.1,1.4,1.5倍和1.1,1.6,1.7倍;1998年各放牧处理不同土壤层地下生物量占0～30 cm地下生物量的比例为:0～10 cm占87.18%～88.38%,10～20 cm占8.19%～9.55%,20～30 cm占2.87%～3.44%;1999年各放牧处理0～10 cm地下生物量占0～30 cm总地下生物量的88.04%～89.37%,10～20 cm占7.14%～9.34%,20～30 cm占2.25%～3.5%;另外,1999年各处理组0～10 cm地下生物量的比例均高于1998年,而10～20和20～30 cm地下生物量的比例均低于1998年.不同土壤层地下生物量与地上生物量呈线性回归关系.
Stocking rates of yaks had obvious effects on above and underground biomass in Kobrecia parva alpine meadow. With the increase of stocking rates, total aboveground biomass, aboveground biomass of high desirable forage and its percentage composition decreased, while percentage composition of weeds increased. There was a linear regression relationship between total aboveground biomass, aboveground biomass of high desirable forage and stocking rates. There was a second degree regression relationship between aboveground biomass of weeds and stocking rates, and aboveground biomass of weeds reached to the maximum value respectively when stocking rate were 2.30 heads/hm 2 in 1998 and 2.04 heads/hm 2 in 1999. There was a linear regression relationship between underground biomass of different soil stratums and stocking rates, underground biomass in 0～30 cm of control group were 1.1 and 1.1 times of light grazing group, 1.4 and 1.6 times of moderate grazing, 1.5 and 1.7 times of heavy grazing in 1998 and 1999, respectively. The percentage of underground biomass of different soil stratum for different grazing treatments were: 87.18%～88.38% in 0~10 cm, 8.19%～9.55% in 10～20 cm, 2.87%～3.44%% in 20～30 cm in 1998, and 88.04%～89.37% in 0~10 cm,7.14%～9.34%in 10～20 cm,2.25%～3.5% in 20～30 cm in 1999. Besides, the percentage of underground biomass in 0~10 cm for different grazing treatments was higher in 1999 than in 1998, and lower for 10~20 and 20~30 cm. There was a positive correlation relationship between aboveground biomass and underground biomass, and its linear regression equation was:Y=a+bx (b>0).
出处
《草业科学》
CAS
CSCD
2005年第5期65-71,共7页
Pratacultural Science
基金
青海省"九.五"攻关项目(96 N 112)
国家"十.五"攻关项目(2001BA606A 02)
关键词
牦牛放牧率
小嵩草高寒草甸
暖季草场
地上生物量
地下生物量
相关分析
stocking rate of yak
Kobrecia parva alpine meadow
warm-season pasture
aboveground biomass
underground biomass
correlative analysis
