4种针叶纯林枯落叶对3种豆科灌草的化感效应

为探讨豆科灌草在针叶人工纯林改造和林草复合植被建设中的可行性，研究了油松(Pinus tabulaeformis)、侧柏(Platycladus orientalis)、落叶松(Larix principis rupprechtii)和樟子松(P.sylvestris var.Mongolica)当年枯落叶经室内混土分解培养后，所获得的枯落叶浸提液对紫穗槐(Amorpha fruticosa)、毛苕子(Vicia villosa)和草木樨(Melilotus officinalis)种子萌发和幼苗生长的化感效应。结果表明，1)油松枯落叶浸提液抑制毛苕子和草木樨种子萌发，对紫穗槐种子萌发以及紫穗槐和毛苕子幼苗生长表现为“低促高抑”；2)侧柏浸提液促进草木樨种子萌发和毛苕子幼苗以及紫穗槐幼根生长，对紫穗槐种子萌发以及草木樨幼苗生长均表现为“低促高抑”；3)落叶松浸提液抑制了紫穗槐和毛苕子种子萌发，促进了草木樨种子萌发和毛苕子幼苗以及草木樨幼根生长，对紫穗槐幼苗生长表现为“低促高抑”；4)樟子松浸提液抑制了毛苕子和草木樨种子萌发以及紫穗槐幼苗地上部生长，促进了毛苕子幼苗和紫穗槐幼根生长，对紫穗槐种子萌发表现为“低促高抑”；5)3种豆科灌草幼苗MDA含量分析结果与其幼苗生长的分析结果一致。MDA含量可能是衡量化感效应的最敏感指标。

Allelopathic effects of leaf litters from four coniferous pure forests on three leguminous shrubs and grasses

In order to investigate the feasibility of leguminous shrub and grass species applied in coniferous artificial forests renovation and silvopastoral vegetation construction, allelopathic effects of different concentrations (10, 20 and 40 mg·mL-1) of water extracts from decomposed leaf litters of P.tabulaeformis, P.orientalis, L.principis rupprechtii and P.sylvestris on seed germination and seedling growth of A.fruticosa, V.villosa and M.officinalis were studied. The results indicated that 1) P.tabulaeformis litter extracts inhibited the seed germination of V.villosa and M.officinalis, and showed the law of “lower stimulation and high inhibition” on the seed germination of A.fruticosa and seedling growth of V.villosa; 2) P.orientalis litter extracts decreased the germination rate of V.villosa, and promoted seed germination of M.officinalis and the growth of V. villosa seedling and A.fruticosa radicals, and showed the law of “lower stimulation and high inhibition” on the seed germination of A.fruticosa and the growth of A.fruticosa seedling and M.officinalis seedling; 3) L.principis rupprechtii litter extracts inhibited the seed germination of A.fruticosa and V.villosa, promoted the seed germination of M. officinalis and the growth of V.villosa seedling and M.officinalis radicals, and showed the law of “lower stimulation and high inhibition” on the seedling growth of A.fruticosa; 4) P.sylvestris litter extracts showed the law of “lower stimulation and high inhibition” on the seed germination of A.fruticosa, inhibited seed germination of V.villosa and M.officinalis and the seedling growth of A.fruticosa, while they could promote the growth of V.villosa seedling and A.fruticosa radicals, lower concentration extract promoted the seedling growth of M.officinalis significantly; 5) Analysis results of three leguminous shrub and grass seedlings MDA content and their seedling growth analysis results were consistent. MDA content might be the most sensitive indicator to measure the allelopathic effect.