摘要
Fixed sample plots were set up for researching competition relationships between Manglietia yuyuanensis and Cunninghamia lanceolata in 17-year-old M.yuyuanensis stands mixed wiht C.lanceolata. The interspecific competition intensity in different mixed stands was determined by using the competition indexes constructed with diameter of breast height, the volume of tree crown and distance between trees, through Hegyi’s Competition Index Model. The results showed that the spatial distribution of M. yuyuanensis in mixed stands was stochastic, the numbers of M. yuyuanensis and C. lanceolata around each M. yuyuanensis increased with the increase of the distance. Under the steady density, the ratios of C.lanceolata to M. yuyuanensis directly affect the interspecific competition and the growth. When the ratios of C.lanceolata to M. yuyuanensis were in the scope of 9-1 to 7-3, M. yuyuanensis had the obvious increase production trend compared with its pure stand. When the ratio was 9-1, the tree height and the diameter of breast height of M. yuyuanensis increase by 22.3% and 69.3% respectively; likewise, when the ratio was 8-2, they increase by 23.2% and 56.9% respectively, because at this ratio, the number of M. yuyuanensis in mixed stand was so low that its competition was mainly the interspecific competition from C.lanceolata. The competition index of M. yuyuanensis was 1.67 times lower than that in pure stand, especially the competition index constructed by the tree-crown volume was 21 times lower. however, when the ratios were in the scope of 6-4 to 5-5, M. yuyuanensis obviouly decreased production compared with pure stand, the intraspecific competition of M. yuyuanensis becomes stronger when its number increased. Based on the mechanism of stemwood cultivation, initial planting density of M. yuyuanensis trees should be reduced properly and higher ratio of C.lanceolata to M. yuyuanensis should be 8-2 or small higher in order to realize the cultivation goal of large timber of M. yuyuanensis .
Fixed sample plots were set up for researching competition relationships between Manglietia yuyuanensis and Cunninghamia lanceolata in 17-year-old M. yuyuanensis stands mixed wiht C. lanceolata. The interspecific competition intensity in different mixed stands was determined by using the competition indexes constructed with diameter of breast height, the volume of tree crown and distance between trees, through Hegyi' s Competition Index Model. The results showed that the spatial distribution of M. yuyuanensis in mixed stands was stochastic, the numbers of M. yuyuanensis and C. lanceolata around each M. yuyuanensis increased with the increase of the distance. Under the steady density, the ratios of C. lanceolata to M. yuyuanensis directly affect the interspecific competition and the growth. When the ratios of C. lanceolata to M. yuyuanensis were in the scope of 9 - 1 to 7 - 3, M. yuyuanensis had the obvious increase production trend compared with its pure stand. When the ratio was 9 - 1, the tree height and the diameter of breast height of M. yuyuanensis increase by 22.3 % and 69.3 % respectively; likewise, when the ratio was 8- 2, they increase by 23.2% and 56.9% respectively, because at this ratio, the number of M. yuyuanensis in mixed stand was so low that its competition was mainly the interspecific competition from C. lanceolata. The competition index of M. yuyuanensis was 1.67 times lower than that in pure stand, especially the competition index constructed by the tree-crown volume was 21 times lower, however, when the ratios were in the scope of 6 - 4 to 5 - 5, M. yuyuanensis obviouly decreased production compared with pure stand, the intraspecific competition of M. yuyuanensis becomes stronger when its number increased. Based on the mechanism of stemwood cultivation, initial planting density of M. yuyuanensis trees should be reduced properly and higher ratio of C. lanceolata to M. yuyuanensis should be 8 - 2 or small higher in order to realize the cultivation goal of large timber of M. yuyuanensis.
出处
《林业科学》
EI
CAS
CSCD
北大核心
2005年第5期201-206,共6页
Scientia Silvae Sinicae
基金
福建省科委重点科研项目"阔叶树种选育"资助项目(99-Z-173)
福建省普通高校211重点学科"森林培育学"资助项目。
关键词
乳源木莲
杉木
混交林
空间分布
生长
竞争关系
Manglietia yuyuanensis
Cunninghamia lanceolata
mixed stand
spatial distribution
growth
competition relationship