香港东北角吉澳群岛入侵植物调查

什么样的生态系统容易入侵是入侵生态学关心的核心问题之一。最近,我们对香港东北角吉澳群岛中的鸦洲湾、小鸦洲、鸦洲、拦船排、虎王洲、娥眉洲、往湾洲、吉澳等8个岛屿上的所有外来植物及本土植物的种类、数量和盖度进行了调查,结果表明:具有高钙低硅土壤基质的鸦洲、小鸦洲、鸦洲湾等三个小岛上分布有大量外来入侵植物的种类和数量,而具有高硅低钙土壤基质的拦船排、虎王洲、娥眉洲、往湾洲等岛屿上外来植物的种类和数量稀少,吉澳岛虽然外来植物的种类多,但外来植物的个体数量少。分析说明:钙离子可能是影响外来植物的入侵能力或生态系统的可入侵性的关键因子。此外,文章还讨论及介绍了外来植物在石灰岩生境、盐碱地、海岸沙滩、温带广布的各种钙土、地中海气候影响下形成的干旱土等钙离子丰富的生态系统中入侵情况。

A survey on the invasive plants in Kap O Islands, Northeastern Hong Kong

What type of ecosystems more vuinerabie than the others in herms of inpact of invasive species? It is one of the focuses of modern species invasion ecology. Our survey on the invasive plants on 8 islands in northeastern water of Hong Kong(114°15'~114°27'E, 22°30'~22°34'N) was carried out recently. The results shown that the islands(including Island Sai Ap Chau, Island Ap Lo Chun and Island Ap Chau) with calcium-rich soil might be more invasible than other islands (including Island Lam Shuen Pai, Island Fu Wong Chau, Island Ngo Mei Chau, Island Wong Wan Chau) with low calcium soil. Although there are may more species of invasive plants in Island Kap O, the abundance of exotic plants is low and did not cause significant harm to the natural vegetation. Based on comparison of the invasive plants and island area, human disturbance and soil component, the results presented herewith on the relstionship between calcium and the fact that limestone, saline, beach, calcic soil that widely distributed in temperate zone and arid soil formed in Mediterranean Sea Climate was easily invaded by the invasive plants.