外来物种金钟藤的危害现状及其原因分析

The Effect and Reasons Analysis of Damaging of M.erremia boisiana

对金钟藤在广州地区的分布与危害现状进行了调查,并进行了金钟藤的水溶性化感物质对菜心种子萌发抑制作用的实验。结果表明,金钟藤在广州地区的危害仅发现在龙洞林场太和嶂山一带,未大面积扩散,但受害地区的危害程度相当严重,比薇甘菊等外来物种危害更大,已致使约20 hm2林地4万株树木枯死;金钟藤在广州地区生长时产生了生态变异,其藤茎更为粗壮,叶片变大,叶柄和总花序变长,加重了对森林的危害;金钟藤在广州地区花期改变、较少结实,其扩散方法主要靠营养繁殖,扩散速度较慢;金钟藤的化感作用比薇甘菊、蟛蜞菊、五爪金龙等外来入侵植物强,能强烈抑制菜心种子的萌发和生长。

Merremia boisiana （Gagnep.）Oostr is a new foreign species discovered in Guangzhou which endangers environment seriously. The paper induces the harm effect to forest of Guangzhou and the allelopathic effect of different concentration aqueous extracts of Merremia boislana on seeds germination of Brassica parachunensis L. H. Bailey. The results showed that Merremia boisiana distributed only in Taihezhang Mountain in Guangzhou, but its damaging effect was more serious than Mikania micrantha. 40 000 trees in 20 ha. had died because of harm effect of Merremia boisiana. Some variation of Merremia boisiana had been discovered in Guangzhou, which foliage was bigger, petiole and inflorescence were longer than original variety, Florescence changed and flowered in 11 month to 1 month next year. The every concentration aqueous extracts of Merremia boisiana could restrain seeds germination of Brassica parachunensis, the biggest concentration was, the strongest restraining was. The inhibiting of Merremia boisiana was strongest than other exotic invading species on seeds germination in the same concentration. We have analyzed the reasons of harm effect and out forward the preventing countermeasure at oresent in the vaoer too.