不同割草频次对松嫩平原羊草草地生产量的影响

Effect of different clipping number on Leymus chinensis grassland in the Songnen plain of China.

当年的 1次割草处理 ,可使草地生产量提高 9% ,3次割草处理则使总生产量降低 1 1 4 % .连续两年割草处理使草地生产量下降约 50 % .割草频次增加 ,草地实际收获量减少 ,各割草频次下 ,均以初次割草的收获量占总收获量的比重最大 .割草处理对次年返青后群落中羊草生长不利 ,对糙隐子草和芦苇的分蘖有促进作用 ,1次和 2次割草处理影响的差异较小 ,3次割草的影响作用明显 .各割草频次均使草地枯枝落叶的积累量明显减少 ,1次割草的时间太迟不利于枯枝落叶积累 .

The biomass of grassland is increased 9% for clipping once in a year, and decreased 11.4% for three times. Clipping for tow years running, the biomass is decreased about half. Harvesting of grassland reduced with the increase of clipping number. The first harvesting alwasy takes the biggest percentage in the whole year harvesting at the different clipping number. Clipping is disadvanced to the growth of Leymus chinensis in next year, and promotes the tillering of Cleistogenes squarrosa and Phragmites communis . Once and twice clipping make no different influences, and three times clipping has significant effects. The accumulations of litter in grassland are significantly decreased because of clipping. If once clipping are done very lately, the accumulations of litter would be prevented.