近自然生态条件下千年桐竞争关系的研究

以近自然生态条件下千年桐直播造林林分为研究对象，研究其种内种间竞争关系。结果表明：直播造林林分中千年桐胸径＜8 cm时，千年桐种内竞争较弱，胸径在8～13 cm时，其竞争指数增长特别快，种内竞争非常大；当胸径＞13 cm时，种内竞争指数逐渐减少；其种间竞争中与杉木的竞争最为强烈。千年桐种内竞争与距离的关系表现为当其距离＜1.0 m时，其竞争指数最高，种内竞争最为激烈；距离在2.0～3.5 m时，种内竞争指数较为稳定；当其距离超过3.5 m后，千年桐种内竞争指数逐渐变小，竞争强度逐渐减弱。

Study on the Competitive Relationship of Vernicia montana in Close-to-nature

The Intraspecific and interspecific competition of Vernicia montana forest planted by direct seeding afforestation in close-to-nature. The results showed that the intensity of intraspecific competition is negligible when DBH smaller than 8 cm. The competition index increases rapidly when DBH increase from 8 cm to 13 cm, while decreased when DBH greater than 13 cm. The interspecific competition of V. montana was most intensive with Cunninghamia lanceolata. The competition index between these two species changed with the spacing of trees. The competition index is high with spacing less than 1.0 m and is relatively constant at spacing between 2.0~3.5 m, while the index decreases when spacing larger than 3.5 m.