Abstract:

The allelopathy in the mixture of Chinese Pine (Pinus tabulaeformis)and Liaotung Oak (Quercus liaotungensis) is studied. The results show that:The leachates of litter, half decaying litter and surface layer soil under Pineoak mixture and each pure stand have significant effect on seed germination, seedling radicle and stem growth of Chinese Pine and other plants.Generally, the leachates of higher concentration show significant inhibitory effect and those of lower ones show stimulate effect or no effect. In laberatory, pine seed germination, seedling radicle and stem growth treated by oak litter leachate(1:10)were showed to be reduced by 40.4%, 25.5% and 12.8 %.The inhibitory effect of litter in mixture (1:10) is lower than those of two pure stands. Studies indicate that mixed planting of Pine and Oak can lead to accumulating heavily of allelopathic chemicals in the stand in some conditions(such as drought, no proper mixture proportion and pattern). This can cause poor growth of Chinese Pine and forest production reduced. The phenomenon of nature Pine-Oak mixed stands is explained and Scientific basis for planting Pine-Oak mixture is provided.

Key words: Allelopathy, mixture, Chinese pine, Liaotung Oak, Leachate