中文摘要：

采集黄土高原丘陵区和残塬区典型油松（Pinus tabulae ormis）纯林和荒地腐殖层土壤对10种常见植物进行盆栽试验,跟踪测定植物种子萌发、幼苗生长和生理活性等指标.结果表明：丘陵区油松纯林土壤显著抑制苜蓿（Medicago sativa）和草木樨（Melilotus of ficinalis）种子萌发,显著降低紫穗槐（Amorpha fraticosa）、苜蓿和毛苕子（Vicia villosa）的苗高、根长和生物量生长,以及紫穗槐和草木樨的叶片叶绿素含量、过氧化氢酶（CAT）活性,且显著提高刺槐（Robinia pseudoacacia）、胡枝子（Lea pedeza bicolor）、毛苕子和沙打旺（Astragalus adsurgens）叶片丙二醛（MDA）含量.残塬区油松纯林土壤显著抑制沙棘和苜蓿种子萌发,以及胡枝子、小冠花（Coronilla varia）和苜蓿的苗高和生物量生长,降低了草木樨、苜蓿的叶绿素含量和柠条（Caragana korshinskii）、草木樨的CAT活性,显著提高柠条、紫穗槐、小冠花和毛苕子的MDA含量.表明黄土丘陵区油松纯林腐殖层土壤对紫穗槐、苜蓿、草木樨、毛苕子、刺槐和沙打旺以及黄土残塬区油松纯林腐殖层土壤对沙棘（Hippophae rhamnoides）、苜蓿、和沙打旺综合表现为化感抑制作用.

英文摘要：

Humus soils in Pinus tabelaeformis forests from three regions （hilly,gully areas and wasteland） of Loess Plateau were sampled separately for pot experiment with 10 common species of plants.Seed germination,seedlings growth and physiological indexes were measured during the whole experiment process.The results showed that in the hilly area of Loess Plateau,the humus soil of P.tabelaeformis forest significantly inhibited the seed germination rates of Medicago sativa and Melilotus officinalis,reduced the seedling heights,root lengths and biomass growths of Amorpha fraticosa,M.sativa and Vicia villosa,and reduced the leaf chlorophyll contents and catalase activities （CAT） of A.fraticosa and M.officinalis,whereas the humus soil significantly improved the malondialdehyde contents （MDA） of Robinia pseudoacacia,Leapedeza bicolor,V.villosa and Astragalus adsurgens.In the gully area of Loess Plateau,the humus soil of P.tabelaeformis forest significantly inhibited the seed germination rates of Hippophae rhamnoides,M.sativa,Lespedeza davurica and Coronilla varia and the heights and biomass growths of Medicago sativa,reduced the chlorophyll contents of Melilotus officinalis and Medicago sativa and the hydrogen peroxide activities of Caragana korshinskii and Melilotus officinalis,whereas significantly improved the MDA contents of Caragana korshinskii,Amorpha fruticosa,Coronilla varia and Vicia villosa.According to the comprehensive analysis,the humus soil of P.tabelaeformis forest in the hilly area showed obvious allelopathic inhibition on Amorpha fraticosa,M.sativa,Melilotus of ficinalis,Vicia villosa,Robinia pseudoacacia,and Astragalus adsurgens.And in the hilly area humus soil showed obvious allelopathic inhibition on Hippophae rhamnoides,Astragalus adsurgens and M.sativa.