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作 者:张春雨[1] 魏彦波[1,2] 王德胜 夏富才[1] 赵亚洲[1] 赵秀海[1]
机构地区:[1]北京林业大学省部共建森林培育与保护教育部重点实验室,北京100083 [2]吉林省天然林保护工程管理中心,吉林130000
出 处:《林业科学》2010年第10期167-172,共6页Scientia Silvae Sinicae
基 金:国家自然科学基金项目(30940012);林业公益性行业科研专项项目(200904022;201004002);国家"十一五"科技支撑项目(2006BAD03A0804;2008BADB0B0503)
摘 要:雌雄异株植物的雌雄植株在营养和繁殖结构的大小、颜色及寿命,资源获得与分配,与群落其他物种相互作用等方面均存在差异(Delphetal.,1996;2002;Pickering,2000;Gehring et al.,1994)。种群性比是雌雄异株植物的一个重要结构指标,尽管雌树多于雄树(Opler et al.,1978;Alliende et al.,1989),Size structure,sex ratios and sex-dependent spatial distribution of dioecious Fraxinus mandshurica were tested in a secondary forest. The results showed that: 1) there were 560 F. mandshurica trees with their DBH greater than 5 cm recorded in a 5. 2 hm2 plot,among which there were 135 male trees,158 female trees and 267 undetermined trees. The sex ratio(male trees /female trees) was 0. 85,which did not significantly differ from 1 ∶ 1(Chi-square test,P = 0. 179) . 2) The average DBH of male trees and female trees was(24. 5 ± 6. 2) cm and(24. 9 ± 7. 9) cm,respectively. The difference in DBH was not significant between male trees and female trees(t-test,P 〉0. 1) . The coefficient of variation in DBH size was identical between male trees and female trees(CVfemale = CVmale = 54%) . The number of undetermined trees tended to decrease with increasing tree size. Almost all trees with their DBH larger than 35 cm were sexed. 3) Saplings(1 cm〈 DBH〈 5 cm) of F. mandshurica showed random distribution,but male and female trees mainly showed clumped distribution in space. 4) No association between saplings and female trees and male trees was detected at 0-50 m scales. A significant attraction between male and female trees at distances of 3-50 m was found under the null hypothesis of type independence. However a significant repellence was observed at very close ranges(1-5 m and 23-28 m) under the random labeling hypothesis. Different interactions were observed between different tree sizes,between male and female trees.
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