杉木-观光木人工混交林种内和种间竞争研究

Intraspecific and Interspecific Competition in Cunninghamia lanceolata and Tsoongiodendron odorum Mixed Artificial Forest

采用Hegyi单木竞争指数模型对杉木一观光木人工混交林种内、种间及全林分竞争强度进行定量研究。结果表明，以杉木为对象木时，3种不同类型的竞争强度均随着对象木个体的增大而减弱，并且除6～9cm径级外，种内竞争均大于种间及全林分竞争；以观光木为对象木时，3种不同类型的竞争强度均随着对象木个体的增大而减弱，除18-21cm与24-27cm径级外，其种间竞争均大于种内及全林分竞争。利用对象木竞争强度与胸径关系进行预测的结果显示，杉木和观光木在胸径分别达到36和39cm之前应进行密度控制措施。

The competition intensities of intraspecific,interspecific and total stand in Cunninghamia lanceolata and Tsoongiodendron odorum mixed artificial forest were quantitatively analyzed by applying Hegyi＇s competition index model for individual tree. The results showed that for the Cunninghamia lanceolata object tree, three kind of competition intensities decreased gradually with the increase of the diameter scale of object tree. In addtion,except the diameter of 6-9 cm, the competition intensity of intraspecific Cunninghamia lanceolata was larger than that of interspecific and total stand. For the Tsoongiodendron odorum object tree,three kind of competition intensities also decreased gradually with the increase of the diameter scale of object tree. However,except the diameter of 18-21 and 24-27 cm,the competition intensity of in- terspecific Tsoongiodendron odorum was larger than that of intraspecific and total stand. Significant exponential relation was presented between competitive intensity and the diameter of object tree in the mixed artificial forest. Therefore, it could be used to predict competition intensity. The results indicated that for Cunninghamia lanceolata,the density management should be conducted before its diameter grew up to 36 cm, while for the Tsoongiodendron odorum, the corresponding measures need to carry out before its diameter grew up to 39 cm.