摘要
放牧是草原生态系统最主要的干扰因子之一,影响着草地生态系统植被和土壤的生态进程。以宁夏盐池县荒漠草原区为研究对象,根据地表植被以及地表羊粪的积累量设置6个放牧干扰梯度,分别为CK、T1、T2、T3、T4、T5,运用方差分析、回归分析研究了植被和土壤对不同放牧干扰的响应。结果表明:地上生物量、枯落物、植被覆盖度随着放牧干扰强度的加大呈现先增加后减小的趋势,支持了"中度干扰理论";随着放牧干扰强度的增大,土壤水分随之增加,土壤容重则无显著变化;土壤有机碳与全氮随放牧干扰的变化趋势大致相同,二者有很强的曲线线性关系,C/N的变化趋势与有机碳的变化规律稍有不同,C/N和地上生物量都与地表羊粪量有显著的曲线线性关系,表明地表羊粪量对土壤碳氮分布及草地生产力有着很强的影响,体现了有机碳与全氮含量变化的复杂性及各因子之间的互作效应。
Grazing is one of the main interference factors on grassland ecosystem,affecting the ecological process of grassland ecosystem vegetation and soil. Taking desert grassland area in Yanchi County of Ningxia as a research object,the paper arranged 6 grazing disturbance gradients of CK,T1,T2,T3,T4 and T5 respectively according to the surface vegetation and surface accumulation of sheep manure and analyzed the response of vegetation and soil to the different grazing disturbance by using variance and regression analysis. The outcomes show that a) the biomass,litter on the ground,vegetation coverage show the trend of first increase and then decrease along with the increase of grazing disturbance,supporting the moderate interference theory; b) soil moisture increases with the increase of grazing disturbance while the soil bulk density is no significant change and; c) the changes of soil organic carbon and total nitrogen are roughly the same along with the change tendency of grazing disturbance and both of them have a strong linear relationship,the change trend of C / N and the variation law of organic carbon is slightly different,C / N and the ground biomass have remarkable linear relationship with the quantity of sheep manure on the surface. It shows that the quantity of sheep manure has a strong influence to the soil carbon and nitrogen distribution and grassland productivity and reflects the complexity of the changes of organic carbon and total nitrogen content and interaction effect between each factor.
出处
《中国水土保持》
2013年第12期19-23,33,共6页
Soil and Water Conservation in China
关键词
放牧干扰
土壤
植被
空间变异
荒漠草原
grazing disturbance
soil
vegetation
spatial variation
desert grassland
