喀纳斯草地群落和土壤理化特征对放牧干扰的响应

对不同放牧干扰强度下喀纳斯草地植物群落数量特征、土壤理化特征的变化及土壤养分分布与植物群落间的关系进行了研究,结果表明:随放牧强度的增加,植物群落高度下降,生物量减少,盖度降低,密度则在一定放牧强度内呈增加趋势;土壤容重在0～10 cm土层随放牧强度的增加而显著增加(P<0.05),土壤含水量在0～10 cm土层随放牧强度的增加而显著下降(P<0.05),两者在重牧与极牧阶段均无差异(P>0.05);从轻牧到重牧,土壤有机质、碱解氮和有效磷在土壤表层(0～10 cm)均呈下降趋势,到极牧阶段又上升,而土壤速效钾随放牧强度的增加而增加;土壤有机质和碱解氮的分布与植物群落高度和生物量呈正相关,且土壤有机质与植物群落高度和生物量相关性显著(P<0.05),土壤有效磷、速效钾与植物群落特征均表现为负相关关系.

Effect of grazing disturbance on plant community and soil properties of grassland in Kanasi Reserve

The plant community properties,variation of soil physical and chemical properties and the relationship between plant community properties and soil nutrient distribution under different grazing disturbance levels were studied in Kanasi Reserve in 2006.The result indicated that the plant community height,coverage and biomass decreased with the increasing of grazing disturbance intensity.But the plant community density increased under the light to heavy grazing disturbance intensity.In 0 to 10 cm soil layer,soil bulk density increased and soil water content decreased with the increasing of grazing disturbance intensity.And they were significant different from light to heavy grazing disturbance intensity(P<0.05),but no significant different under over grazing disturbance intensity(P>0.05).The contents of soil organic matter,soil available N and P decreased under light to heavy grazing disturbance intensity within 0 to 10 cm soil layer,but soil available K content increased.In over grazing disturbance intensity stage,the contents of soil organic matter,soil available N and P increased.The biomass and height of plant community showed the positive correlations with the distribution of soil organic matter and soil available N.The soil organic matter content showed a significant positive relationship with the biomass and height of plant community(P<0.05).All community properties showed a negative correlations with the distribution of soil available P and K.