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(P0.05),but no significant different under over grazing disturbance intensity(P0.05).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(P0.05).All community properties showed a negative correlations with the distribution of soil available P and K.