刈割和养分回添对羊草草原植物群落生物量及其构成的影响

The Effect of Mowing and Nutrient Adding Back on the Biomass and Compositions of Leymus Chinensis Grassland Plant Community

基于2011年开始的养分回添控制试验,研究锡林郭勒盟草原羊草+克氏针茅+糙隐子草群落在不同肥料(氮、植物割取部分和有机质)对羊草割草场植物群落地上生物量的影响。结果表明:与不刈割相比,刈割+有机质回添、刈割+植物回添和刈割处理显著降低了植物群落地上生物量,但刈割+N素回添处理生物量并没有显著降低。4种处理均增加杂类草和一、二年生植物的地上生物量。与单纯刈割相比,刈割+植物回添处理可增加根茎禾草生物量;刈割+N素回添处理显著增加丛生型禾草地上生物量。与单纯刈割相比,刈割+植物回添处理增加了羊草(Leymus chinensis)种群地上生物量,刈割+N素回添处理增加克氏针茅(Stipa krylovii)种群地上生物量并显著增加糙隐子草(Cleistogenes squarrosa)生物量。这说明养分回添对植物群落地上生物量的影响,不仅与所施肥料种类和施肥量有关,还与该草原植物群落物种组成有关。

Based on the control test of nutrient adding back starting in 2011,the effect of different fertilizers（nitrogen,mowing parts of plants and organic matters）on the above-ground biomass of Leymus chinensis plus Stipa krylovii plus Cleistogenes squarrosa communities of XilinGol League mowing grassland was studied.The result showed：compared with the no-mowing,the mowing plus organic matter adding back,mowing plus plant adding back and mowing treatment significantly reduced the above-ground biomass of plant community,but mowing plus N element adding back showed no obvious reduction in biomass.The above-ground biomass of broad-leaved herbs and annuals and biennials all increased in four treatments.Compared with mowing only,mowing plus plant adding back increased the biomass of rhizomatous grasses and the above-ground biomass of Leymus chinensis community,and mowing plus N element adding back showed an obvious increase in the above-ground biomass of bunch-type grasses and Stipa krylovii and the biomass of Cleistogenes squarrosa,which indicated the effect of nutrient adding back on the above-ground biomass of plant community was not only associated with types and amount of fertilizers,but also related to the species composition of the grassland plant community.