摘要
在自然状态下，羊草草原枯枝落叶积累季节动态是积累量从５月出现，随着时间推移呈指数形式递增，１０月末出现最大值。当枯枝落叶输入量和分解速率保持恒定时，积累量的年变化，随着时间的进展不断增加，最后达到稳定状态，量大积累量为５７２ｇ／ｍ￣２，达９５％稳定状态时间约为７─８ａ。放牧对枯枝落叶积累有明显的抑制作用，当放牧强度达７．５８羊（只）／ｈｍ￣２时，积累量比非放牧区减少近７４％。割草对枯枝落叶积累的影响也是显著的，随着割草频度增加，积累量明显减少，当一年内刈割３次，积累量减少８３％。刈割时间对积累量的影响表现在割草期的早晚，伴随刈割时间推迟，积累量逐渐减少。
nder natural conditions,the seasonal dynamics of litter accumulation in a Leymus chi-nensis grassland was found to be in such a way that the litter accumulation started with May,then was increasing exponentially over time,and reached a maximum value by the end of Oc-tober.If the input and decomposition rates of litter were kept constant,the annual accumu-lation would be increasing continuously over time and would finally reach a steady state,with a maximum accumulation of 572g/m￣2,95%of which would take about 7─8 years.Grazing had a significantly inhibitory effect on the litter accumulation,A grazing intensity ofup to 7.58 sheeps/hm￣2 could make the accumulation decreased by nearly 74%,as comparedwith control(non-grazing area).Grass cutting had also an obvious effect on the litter accu-mulation:the more frequently cutting,the less accumulation. Three times cutting a year re-sulted in an accumulation reduced by 83%. Cutting time also affected the litter accumula-tion:the later a cutting,the less and accumulation.
出处
《生态学报》
CAS
CSCD
北大核心
1994年第3期255-259,共5页
Acta Ecologica Sinica
基金
国家自然科学基金
关键词
羊草
草原
枯枝落叶
积累
放牧
Leymus chinensis grassland,litter accumulation,grazing,grass cutting.
