Abstract: Allelopathic effect is one of the key problems which affect arbor-shrub-herb compound vegetation construction. Nine kinds of shrub-herb were planted in pots under plastic greenhouse with humus horizon soil collected from Populus simonii and Robinia pseudoacacia woodland and woodless land. The seed germination, plant seedlings growth and physiological indexes of the shrub-herb plants were measured. Then the allelopathic effects of humus horizon soil on the shrubs and grasses were studied. Results showed that the humus soil of Populus simonii woodland and Robinia pseudoacacia woodland significantly inhibited the seed germination of Medicago sativa and Hippophae rhamnoides, the biomass growth of Medicago sativa, Melilotus officinalis, Astragalus adsurgens, Coronilla varia and Amorpha fruticosa, and reduced the catalase (CAT) activities and chlorophyll contents of Coronilla varia and Amorpha fruticosa, while it improved the malondialdehyde (MDA) contents of Vicia villosa seedling. In addition, the humus soil of Populus simonii woodland significantly inhibited the seed germination of Melilotus officinalis and Astragalus adsurgens, the biomass growth of Vicia villosa, and the CAT activities of Melilotus officinalis and Hippophae rhamnoides. The humus soil of Robinia pseudoacacia woodland also reduced the germination rate of Amorpha fruticosa, while it improved MDA contents of Melilotus officinalis and Amorpha fruticosa seedling. Comprehensive analysis indicated that the humus horizon soil of Populus simonii woodland had obvious inhibition effects on Medicago sativa, Melilotus officinalis, Coronilla varia and Amorpha fruticosa, while the humus horizon soil of Populus simonii woodland had obvious inhibition effects on Melilotus officinali, Coronilla varia and Amorpha fruticosa.

Key words: Allelopathic effects, Humus horizon soil, Potting, Shrubs and grasses

摘要： 化感效应是影响乔灌草复合植被建设的关键问题之一。通过采集立地条件基本相同的小叶杨（Populus simonii）和刺槐（Robinia pseudoacacia）林地及无林荒地（对照）腐殖质层土壤，在塑料大棚内进行完全相同条件下9种灌草植物的播种盆栽试验，测定灌草种子萌发及幼苗生长过程中的各项指标，研究森林腐殖质土壤对林下灌草植物的化感效应。结果表明：小叶杨和刺槐纯林腐殖质土壤均显著抑制紫花苜蓿（Medicago sativa）和沙棘（Hippophae rhamnoides）种子萌发，抑制紫花苜蓿、草木樨（Melilotus officinalis）、沙打旺（Astragalus adsurgens）、小冠花（Coronilla varia）和紫穗槐（Amorpha fruticosa）生物量生长，降低小冠花和紫穗槐幼苗的过氧化氢酶（CAT）活性和叶绿素含量，提高毛苕子（Vicia villosa）幼苗体内丙二醛（MDA）含量。此外，小叶杨林腐殖质土壤还抑制草木樨和沙打旺种子的萌发、毛苕子的生物量生长、草木樨和沙棘CAT的活性。刺槐林腐殖质土壤降低了紫穗槐发芽率，提高了草木樨和紫穗槐幼苗体内MDA含量。应用主成分分析法对化感效应综合分析表明，小叶杨林腐殖质土壤对紫花苜蓿、草木樨、小冠花和紫穗槐，以及刺槐林腐殖质土壤对草木樨、小冠花和紫穗槐生长整体上存在明显化感抑制效应。

关键词: 化感效应, 腐殖质土壤, 盆栽, 灌草