杉木-拟赤杨人工混交林种内、种间竞争强度研究

Intraspecific and Interspecific Competition Intensity in Mixed Forest Plantation of Cunninghamia lanceolata and Alniphyllum fortunei

将林木竞争影响空间划分为两部分:距离对象木最近的一圈竞争木所围成的面积称为内圈,主要包括地上部分对光源的竞争和地下部分对土壤资源的竞争;除内圈外,其它6m以内的竞争木所围成的面积记为外圈,主要包括地下部分对土壤资源的竞争。在此基础上,采用Hegyi提出的单木竞争指数模型CI=Nj=1∑(Dj/Di)1Lij对福建省建瓯东安林场的杉木与拟赤杨混交林中种内、种间竞争强度进行定量分析。结果表明:无论是内圈还是外圈杉木种内、种间竞争强度随林木径级的增大而减小;竞争强度顺序为:内圈杉木种内>内圈杉木与拟赤杨种间>外圈杉木种内>外圈杉木与拟赤杨种间。从而为生态学研究植物竞争关系提供了新的思路。

Two plots with 30 m×30 m each in Dong'an plantation of Cunninghamia l anceolata and Alniphyllum fortunei in Jian'ou, Fujian Province, were used for in vestigation, and 30 representative individuals of C. lanceolata in each plot wer e chosen as objective trees to measure diameter at breast height, plant height, branch height and crown diameter. Such measurements were also taken for all comp etitive trees within 6 m from the objective tree, as well as their distances to the objective tree. Within an area with radius of 6 m, two circles were divided, theinner one was composed of competitive trees which were nearest to the objective tree, while the outer one was composed of the rest competitive trees. Hegyi's si mple competition indexes were used. The intraspecific and interspecific competit ion intensities either in the inner circles, or the outer, reduced with the incr ease of diameter class of the trees. The competition intensitites were in the or der of intraspecific competition of C. lanceolata in innercircles > interspecific competition between C. lanceolata and A. fortunei in inn er circles> intraspecific competition of C. lanceolata in outer circles > inters pecific competition in outer circles.