长期施肥对黄土区连作苜蓿草地植被特征的影响  

Effects of Long-term Fertilization on Vegetation Characteristics of Continuous Cropping Alfalfa Grasslands in Loess Plateau

作　　者：蔡志风[1] 郝明德[1,2] 吴振海[3] 史培[1] 王缠军[1] 普琼[1] 

机构地区：[1]西北农林科技大学林学院,陕西杨凌712100 [2]中国科学院水利部水土保持研究所,陕西杨凌712100 [3]西北农林科技大学生命科学学院,陕西杨凌712100

出　　处：《水土保持通报》2011年第1期46-52,共7页Bulletin of Soil and Water Conservation

基　　金：国家重点基础研究发展计划项目"主要粮食作物高产栽培与资源高效利用的基础研究"(2009CB118604);中国科学院知识创新工程重要方向项目(kzcx2-yw-424-3);中国科学院知识创新工程重大项目(KSCX-YW-09-07)

摘　　要：利用长期定位试验,对不同施肥条件的苜蓿草地植被特征变化进行了研究。结果表明,不同施肥处理下连作苜蓿草地群落物种丰富度指数变化不显著。群落盖度增大,群落高度亦明显增加。施肥可维持群落多样性和稳定性,提高苜蓿草地生产力。施肥后苜蓿种群生态位宽度明显上升,竞争力相对增强,而杂类草生态位宽度降低,竞争力相对减弱。连作施肥条件下苜蓿种群与其它物种之间没有最大的生态位重叠,杂类草之间生态位重叠较大,它们之间的竞争较为激烈且占主要地位,施肥可提高苜蓿草地质量和经济价值。狗尾草等杂草入侵是导致苜蓿人工草地退化的一个重要影响因素。The changes of the vegetation characteristics of alfalfa grasslands under different fertilization schemes were analyzed with the trial of plot experiments.The results indicate that the species richness index of the continuous cropping alfalfa grassland did not significantly change under different fertilizer treatments,along with considerably increased community coverage,and significantly raised community heights.Fertilization could maintain species diversity and community stability and enhance alfalfa grassland productivity.After the application of fertilizer,the niche breadth of alfalfa population significantly increased and the competitiveness strengthened relatively.However,the niche breadth of forbs decreased and relatively weakened.No significant niche overlap was found between alfalfa population and other species under continuous cultivation and fertilization.Greater niche overlap was found among the forbs,between which the competition was more intense and dominant.Fertilization could improve the quality and economic value of alfalfa grasslands,while the invasion of forbs functional groups such as Setaria viridis was one of the most important factors degrading the grasslands.

关 键 词：黄土区 长期施肥 连作苜蓿草地 植被特征 

分 类 号：S7[农业科学—林学]