刈割制度对围封羊草草地群落特征及生物量的影响

以呼伦贝尔草甸草原围封羊草(Leymus chinensis)草地群落为研究对象,对不同刈割制度(连续刈割、隔年刈割)对围封羊草草地的影响进行分析。结果表明,在刈割干扰下,植被群落盖度和地上生物量都会显著降低(P0.05)。隔年刈割和连续刈割两种制度相比,在植被群落数量特征及生物量上,隔年刈割要优于连续刈割,植被群落的平均高度、盖度等数量特征及地上生物量均表现出随着刈割频次的增加而降低的趋势。植被群落的α-多样性在封育下最低,表现出随刈割频次的增加而变大的趋势。在不同刈割方式下,植被群落组成发生了变化且群落中各物种的重要值变化幅度很大,建群种羊草的重要值在连续刈割下低于隔年刈割,而寸草苔(Carex duriuscula)重要值在连续刈割下最大,且群落中其它伴生种的重要值也随刈割频次增加而降低。

The effects of different mowing system on plant community characteristics and biomass in fenced Leymus chinensis grassland

The influence of different mowing system (continuous mowing and biennial mowing) on fenced Leymus chinensis grassland in Hulunbeier were studied. The results showed that community coverage and aboveground biomass significantly decreased under mowing treatment. The biennial mowing was better than continuous mowing in quantitative characteristics of community and biomass. The community average height, coverage and the aboveground biomass of community decreased with the increase of mowing frequency whereas the plant community α-diversity index increased with the increase of mowing frequency which was the lowest in fenced grassland without mowing. The composition of plant community and the important value of each species in the community changed a lot under different mowing system. The important value of L. chinensis under continuous mowing was lower than that under biennial mowing, however, the important value of Carex duriuscula was the highest under continuous mowing. The important value of other associated species decreased with mowing frequency.