阴山北麓浅耕翻季节对草地植被和土壤的影响

为探求退化草地适宜的生态修复技术，于2010年春季和夏季在希拉穆仁草原开展了浅耕翻处理对草地植被和土壤影响作用的研究。结果表明：1）春季浅耕翻造成了严重的风蚀和土壤粗质化；夏季浅耕翻不会引起风蚀和土壤粗质化。2）春季浅耕翻样地植被稀疏，许多根茎和幼苗干枯死亡或被风吹走。夏季降水增加，植被以一年生植物猪毛菜（Salsola collina）、刺藜（Chenopodium aristatum）、黄花蒿（Artemisia annua）、绳虫实（Corispermum declinatum）等为主，植被盖度30%；夏季浅耕翻样地耕翻后经过几次降水，羊草（Leymus chinensis）迅速生长，重要值高达0.7，成为绝对优势种，植被盖度62%。3）生长季末，春季浅耕翻样地枯落物很少，盖度不足10%，土壤有机质下降约1/3；夏季浅耕翻样地枯落物较多，盖度约30%，土壤有机质增加8%。4）2011年春季对两块样地返青情况的调查表明， 夏季浅耕翻样地明显好于春季浅耕翻样地。综合而言，夏季浅耕翻对草地的恢复作用大于春季。

Effect of Shallow tillage during different season on grassland vegetation and soil in the Xilamuren region of North Yin Mountains

An experiment was conducted to investigate the effect of spring and summer shallow tillage on grassland vegetation and soil in the Xilamuren region of North Yin Mountains to find the optimal technology for restoration of degraded grassland.This study showed the spring shallow tillage resulted in severe wind erosion and soil roughness and the summer shallow tillage did not cause wind erosion and soil roughness.The vegetation treated by the spring shallow tillage was sparse because many seedlings and rootstalk were dead or blew by wind,where annual herbs,such as Salsols collina,Corispermum declinatum,Chenopodum aristatum,Artimisia annua became dominant with cover of 30%;however,the vegetation cover treated by the summer shallow tillage was 62% because the Leymus chinensis grew rapidly after several rain and its important value was 0.7.At the end of growth season,the litters cover of grassland treated by the spring shallow tillage was below 10%,and the soil organic matter decreased by 33%;while the litters cover of grassland treated by the summer shallow tillage was 30%,and the soil organic matter increased by 8%.In spring of 2011,the recovery-green of the spring shallow tillage was worse than that of the summer shallow tillage.This study suggested that the summer shallow tillage was better than spring shallow tillage.