密度、施肥和刈割对青藏高原混播人工草地物种竞争力和竞争等级的影响  

Effect of density, fertilization, and clipping on the competitive ability and hierarchy of cultivated grassland in the Qinghai-Tibetan plateau

作　　者：顾梦鹤[1] 王涛[1] 杜国桢[2] 

机构地区：[1]中国科学院寒区旱区环境与工程研究所,兰州730000 [2]兰州大学干旱与草地生态教育部重点实验室,兰州730000

出　　处：《兰州大学学报（自然科学版）》2011年第6期62-67,74,共7页Journal of Lanzhou University(Natural Sciences)

基　　金：国家重点基础研究发展计划(973计划)项目(2009CB421308);甘肃省科技支撑计划项目(1104FKCA152);中国博士后基金项目(20100480729)

摘　　要：选用三种高寒草甸常见牧草垂穗披碱草、中华羊茅和羊茅在青藏高原高寒地区进行物种竞争力的研究.试验主区设计四个密度梯度和六种播种组合,两个施肥水平和三个刈割水平为裂区设计,野外研究历时三年.利用地上生物量计算三种混播组合中的竞争参数相对产量总和和竞争率,据此分析了三物种在混播中的竞争力和竞争等级.结果表明:在草地建植第二年,垂穗披碱草竞争力最强,中华羊茅次之,羊茅最差;在草地建植第三年,垂穗披碱草竞争力最强,羊茅次之,中华羊茅最差.密度、施肥和刈割对三物种竞争参数的显著性分析表明:在草地建植第二年,密度对垂穗披碱草+羊茅混播草地中的相对产量总和和竞争率以及中华羊茅+羊茅混播草地中的竞争率有显著影响,施肥和刈割对相对产量总和和竞争率均无显著影响;在草地建植第三年,密度对中华羊茅+羊茅混播草地中的竞争率有显著影响,施肥对垂穗披碱草+中华羊茅混播草地中的相对产量总和有显著影响,其他因子对相对产量总和和竞争率无显著影响,密度、施肥和刈割没有改变物种在混播中的竞争等级.Three of perennial grasses, Elymus nutans, Festuca sinensis and Festuea ovina, which are widely distributed in the east of Qinghai-Tibetan alpine region, were selected for a field experiment that was designed to test the competitive hierarchy of the three species （4 densities, 2 fertilization, 3 clipping, and 6 seeding combinations）. The relative yield total （RYT） and competitive ratio （CR） based on the harvested shoot biomass were measured for the three species in three mixtures in three growing seasons. The results showed that E. nutans was the strongest competitor among the three species, with F. sinensis following, and F. ovina as the weakest in the second growing season. In the third growing season, the competitive ability of F. ovina increased and it was the second in the competitive hierarchy. E. nutans was still the strongest competitor and F. sinensis became the weakest competitor in mixture grassland. ANOVA of density, fertilization, and clipping showed that fertilization and clipping had no significant effect on RYT and CR in the second year after the grassland establishment. Density had significant effect on RYT and CR of E. nutans/F, ovina mixture and CR of F. sinensis/F, ovina mixture. In the third year, density had significant effect on CR of F, sinensis/F, ovina mixture. Fertilization had significant effect on RYT of E. nutans/F, sinensis mixture. However, density, fertilization and clipping did not change the competitive hierarchy of the three species in mixtures.

关 键 词：人工草地 竞争力 竞争等级 青藏高原 

分 类 号：Q945[生物学—植物学]