黄土高原主要人工林树种对几种豆科牧草的化感作用

【目的】分析黄土高原主要人工林树种枯落叶对几种豆科牧草的化感作用，为豆科牧草在人工纯林改造中的应用及林草复合植被的建设提供科学依据。【方法】采集樟子松、华北落叶松、刺槐和辽东栎等人工林树种（供体）当年枯落叶，制成不同质量浓度（0.005，0.010和0.020 g/mL）的枯落叶浸提液，定期浇灌胡枝子、沙打旺和小冠花等豆科牧草植物（受体）种子，进行室内发芽试验，观测种子萌发和幼苗生长的相关指标。【结果】樟子松和华北落叶松枯落叶浸提液对3种受体植物种子萌发及幼苗生长均无显著影响，其中樟子松枯落叶浸提液对胡枝子表现出“低促高抑”的规律，而对小冠花有微弱抑制作用；刺槐枯落叶浸提液对胡枝子和沙打旺种子萌发及幼苗生长均表现出“低促高抑”的规律，对小冠花则表现为抑制作用；辽东栎枯落叶浸提液对3种受体植物种子萌发及幼苗生长均有抑制作用。【结论】所选树种的枯落叶浸提液对3种豆科牧草的影响存在较大差异，初步认为，在樟子松人工林下可以种植沙打旺，华北落叶松人工林中这3种植物均可种植，刺槐人工林中不宜种植小冠花，辽东栎人工林中这3种植物均不宜种植。

Study on allelopathic effects of main planted forest trees in the Loess Plateau on some legumes

【Objective】The study was done on the allelopathic effects of main plantation species litter on some Legumes in the Loess Plateau,in order to provide a scientific basis for the legumes in the artificial forests renovation and construction of forest and grass vegetation combined.【Method】Pinus sylvestris,Larix principis-rupprechtii,Robinia pseudoacacia and Quercus liaotungensis plantations(donor) litter were collected in the current year to make different concentrations(0.005,0.010 and 0.020 g/mL) of aqueous extract,indoor germination test watering Leapedeza,Astragalus adsurgens and Coronilla varia seeds(receptor)were processed with aqueous extracts of litter at regular intervals,seed germination and seedling growth related indicators were determined.【Result】Pinus sylvestris and Larix principis-rupprechtii litter extract had insignificant impact on the germination and seeding growth of three kinds of legumes,and it showed the law of "low promote high-suppression" about Pinus sylvestris on Leapedeza,while there was a weak inhibition on Coronilla varia;Robinia pseudoacacia litter extract showed the law of "low promote high-suppression" on the germination and seeding growth of Leapedeza and Astragalus adsurgens.Coronilla varia showed a weak inhibition;Quercus liaotungensis litter extract showed inhibition on the germination and seeding growth of three kinds of legumes.【Conclusion】There are some differences in the effect on the litter extract of selected species on three kinds of legumes.We preliminary conclude that,Astragalus adsurgens can grow under Pinus sylvestris plantations,Larix principis-rupprechtii plantations can plant with these three plants,Robinia pseudoacacia forests should not be planted with Coronilla varia,and these three plants should not be planted in Quercus liaotungensis plantation.