摘要
以在华南地区危害十分严重的入侵种五爪金龙Ipomoea cairica和其主要危害的本地植物之一鸭脚木Schefflera oc-tophflla为研究对象,通过竞争实验,分析了在3个不同氮磷比(5、15、45)下两种植物的生理生态特征,三个氮磷比在3个不同营养量下重复。结果表明,氮磷比、营养量以及两者的交互作用对五爪金龙和鸭脚木的多数生理生态指标具有显著的影响。在低营养量下,氮磷比最低(5)时五爪金龙具最佳生长,入侵潜力最大;随着氮磷比的增大,五爪金龙入侵潜力下降,鸭脚木生物量、Pmax、SLA增大,有利于鸭脚木的生长;在中等营养量下,氮磷比最大时最不利于五爪金龙生长,氮磷比为15时最不利于鸭脚木的生长;在高营养量下,氮磷比最大时鸭脚木生长状况最好,而五爪金龙生物量、Pmax、SLA则减小。氮磷比的升高,更有利于鸭脚木的生长。另外,在低营养量时,随着氮磷比的升高,五爪金龙茎叶中的氮磷比反而明显下降,表明五爪金龙的生长更易受磷水平的限制。
The effects of N/P supply ratios on Ipomoea cairica and Schefflera octophylla, an widespread invasive species and one of the mainly harmed native species, were investigated by comparing the ecophysiologieal traits of the two plants under three N/P supply ratios replicated at three levels of overall nutrient supply. The results showed that the invasive species performed best, which indicates a higher invasive potential at a N/P supply ration of 15 with low overall nutrient supply, while the native species performed best at a N/P supply ratio of 45 with high overall nutrient supply. The native performed better with the increasing of the N/P supply ratios. Besides, the N/P ratios in the leaves and stems of the two plants increased with the increasing supply ratios, with exception of the low overall nutrient supply ,in which treatrnent the N/P ratios in the invasive plant tended to decrease, indicated that Ipomoea cairica was more lively to limited by phosphorus levels.
出处
《生态环境学报》
CSCD
北大核心
2009年第4期1449-1454,共6页
Ecology and Environmental Sciences
基金
国家自然科学基金项目(30670385
U0633002)
