【摘要】 文中依托中国农业科学院草原研究所锡林浩特试验基地的放牧控制试验平台,测定了大针茅+羊草草原不同放牧强度下枯落物量及厚度,采用分解袋法测定了不同放牧小区内的枯落物残留率和分解速率,研究了短期放牧时间内,放牧强度对大针茅+羊草草原枯落物分解的影响。研究结果表明:1)不同放牧强度下枯落物现存量存在极显著差异(p <0. 01),且随放牧强度的增加而减少,极重度放牧下枯落物现存量比CK减少了95. 49%;2)不同放牧强度下枯落物厚度存在显著差异(p <0. 05),且随放牧强度的增加而减少,比CK减少了25. 93%~93. 22%;3)分解第一年,枯落物质量损失率最大,为45. 75%~53. 1%,尤其是分解的前90天(6~8月),水热条件较好,有利于土壤微生物的生长和繁殖,对枯落物的分解具有促进作用,枯落物质量损失率达到20%左右。分解第二年枯落物分解变慢,质量损失率为12. 55%~20. 8%。4)放牧不同程度的加快了枯落物的分解,轻度和中度放牧强度下分解速率最快,其次为重度和极重度放牧,围封对照区枯落物分解最慢,说明适度放牧更有利于枯落物分解。更多还原

【Abstract】 Based on a short-term litter decomposition experiment carried out on Xilinhot grazing experiment platform that is set by Grassland Research Institute of Chinese Academy of Agricultural Sciences,litter mass and litter decomposition rate under different grazing intensities were measured using field litterbag experiment. The effect of different grazing intensities on litter decomposition of Leymus chinensis and Stipa grandis steppe during short-term grazing were studied. The result showed that:1) There is a significant difference in litter mass under different grazing intensity. The litter mass decreases with the increase of grazing intensity. The litter mass in EG is reduced by 95. 49% compared with CK. 2) There is a significant difference in litter thickness under different grazing intensity,and it decreases with the increase of grazing intensity. It decreases by 25. 93 ~ 93. 22% compared with that in CK. 3) In the first year of decomposition,the litter quality loss rate is from 45. 75% to 53.1%,especially in the first 90 days,the water-heat condition is better,which is beneficial to the growth and reproduction of soil microorganisms,and can promote the litter decomposition. In this period,the litter quality loss rate reach about 20%. In the second year of decomposition,the litter decomposition become slow,and the litter quality loss rate is about 12. 55% to 20. 8%. 4) Grazing can accelerate litter decomposition rate in different degrees. Litter decomposition rates in LG and MG are faster than that in other treatments. Moderate grazing is more conducive to litter decomposition.更多还原