The Allelopathic Effects Of Humus From Broad Leaved Tree Species On Undergrowth Medicinal Species In The Qiaoshan Area

Compound system of forest and medicinal plants in a new mode of developing forest ecological economy. Whether or not the medicinal plants can resist allelopathic effects form humus soil of forest is one of the key problem that influence the success or failure of compound system. In the research, Bupleurum chinense, Glycyrrhiza uralensis, Astragalus membranaceus, Isatis tinctoria, Saposhnikovia divaricate, Platycodon grandifloras, Polygala tenuifolia, Achyranthes bidentate, Angelica dahurica, Belamcanda chinensis and Arisaema heterophyllum, Eleven common medicinal species were planted in pots with humus horizon soils collected from Populus simonii,Robinia pseudoacacia, Quercus liaotungensis, Betula platyphyll and Acer truncatum woodland in the Qiaoshan area in the Loess Plateau. The seed germination, seedlings growth and physiological indexes of medicinal species were measured.Then the allelopathic effects of humus horizon soil on medicinal species were studied. The main conclusions are as follows:(1) The humus soil of P.simomii woodland showed allelopathic inhibition on B.chinense,G.uralensis, I.tinctoria, B.chinensis, A.heterophyllum and Polygala tenuifolia, Based on our results, these medicinal plants were not recommended to be planted in p.simomii forests,Astragalus membranaceus and Saposhnikovia divaricateare suitable to be planted with p.simomii forests. Specific performance: the humus soil of P.simomii woodland reduced the seed germination rate of the Bupleurum chinense and Saposhnikovia divaricate, the seed germination speed of S.divaricate, Arisaema heterophyllum, Glycyrrhiza uralensis,B.chinensis and Isatis tinctoria significantly, reduced the seedling height of Astragalus membranaceus, I.tinctoria and Achyranthes bidentata, the root length of A.membranaceus and I.tinctoria, root dry weight of A.heterophyllum significantly, reduced Catalase a content and Catalase b content of B.chinense, G.uralensis and I.tinctoria significantly, it significantly reduced catalase activity of Angelica dahurica and S.divaricat, reduced Peroxidase activity of I.tinctoria, improved malondialdehyde content A.bidentata and G.uralensis.(2)The humus soil of R.pseudoacacia woodland showed allelopathic inhibition on G.uralensis, B.chinense, A.heterophyllum, A.membranaceus, A.bidentata, A.dahurica and Isatis tinctoria. Based on our results, these medicinal plants were not recommended to beplanted in R.pseudoacacia forests, P.grandiflorus are suitable to be planted with R.pseudoacacia forests. Specific performance: The humus soil of R.pseudoacacia woodland inhibited the seed germination rate of G.uralensis, the seed germination S.divaricate, it significantly reduced Chl a content of the B.chinense, inhibited catalase activity of B.chinense,Platycodon grandiflorus, A.dahurica and A.heterophyllum, inhibited Peroxidase activity of the A.bidentata, A.dahurica, B.chinense and Polygala tenuifolia, improved malondialdehyde content of G.uralensis, B.chinense, Polygala tenuifolia, A.membranaceus and P.grandiflorus.(3)The humus soil of B.platyphylla woodland showed allelopathic inhibition on A.bidentata, G.uralensis, B.chinense, A.heterophyllum, A.membranaceus, I.tinctoria,B.chinensis and P.tenuifolia. Based on our results, these medicinal plants were not recommended to be planted in B.platyphylla forests, A.dahurica and P.grandifloras are suitable to be planted with B.platyphylla forests. Specific performance: The humus soil of B.platyphylla woodland significantly inhibited the seed germination of G.uralensis and S.divaricata, reduced the seedling height and the root length of A.membranaceus and I.tinctoria significantly, reduced root dry weight of A.heterophyllum significantly, improved the seeding height, the root length, the shoot dry weight and root dry weight of B.chinense,S.divaricata and Angelica dahurica significantly, inhibited catalase activity of S.divaricata and A.dahurica significantly, improved malondialdehyde content of G.uralensis and A.bidentata significantly, it significantly reduced Chl a content and Chl b content of B.chinense and G.uralensis, inhibited Peroxidase activity of the I.tinctoria.(4)The humus soil of Q.liaotungensis woodland show allelopathic inhibition on A.membranaceus, A.bidentate, I.tinctoria, P.tenuifolia, B.chinense and A.heterophyllum.Based on our results, these medicinal plants were not recommended to be planted in Q.liaotungensis forests, A.dahurica and S.divaricata are suitable to be plants with Q.liaotungensis forests. Specific performance: The humus soil of Q.liaotungensis woodland significantly inhibited the seed germination of G.uralensis, improved the seeding height,the root length, the shoot dry weight and root dry weight of B.chinense, G.uralensis,A.membranaceus, B.chinensis and A.dahurica significantly, inhibited catalase activity of B.chinense, P.grandiflorus, A.dahurica and A.heterophyllum significantly, improved malondialdehyde content of B.chinense, G.uralensis, A.membranaceus, P,grandifloras and P,tenuifolia significantly, improved Chl a content and Chl b content, P.grandiflorus and Polygala tenuifolia significantly, improved Peroxidase activity of B.chinense, G.uralensis,A.membranaceus, P.grandiflorus and P.tenuifolia.(5)The humus soil of A.truncatum woodland show allelopathic inhibition on I.tinctoria,A.heterophyllum, A.bidentata, B.chinense, B.chinensis, G.uralensis and A.membranaceus.Based on our results, these medicinal plants were not recommended to be planted in A.ginnala forests, A.dahurica are suitable to be plants with A.ginnala forests. Specific performance: The humus soil of A.ginnala woodland significantly inhibited the seed germination of A.dahurica and S.divaricata, reduced the total dry weight of I.tinctoria significantly, reduced Chl content of A.dahurica significantly, inhibited catalase activity of A.bidentata,A.membranaceus and A.dahurica significantly, improved Peroxidase activity of A.bidentata, A.membranaceus and A.dahurica, improved Peroxidase activity of I.tinctoria, S.divaricata, B.chinensis,P.grandifloras and B.chinense, improved malondialdehyde content of G.uralensis,A.bidentata, A.dahurica and P.tenuifolia.