刺槐对乡土植被的入侵与影响

通过样带法和小样方法于2005年在山东泰山调查刺槐繁殖扩散和对乡土植被的入侵状况。结果表明，刺槐主要以根蘖繁殖进行扩散入侵，并且根蘖繁殖能力与根系是否受伤或是否被砍伐有密切关系；刺槐通过根蘖扩散进入已有高大乔木的林内，如油松人工林和侧柏人工林；在密闭均匀的林分内，刺槐只是伴生下木，很难形成优势群体，但在林隙处可以迅速生长而成为上层木，与乡土树种形成混交林；刺槐能扩散进入灌木丛，说明耐瘠薄能力很强。调查还发现有6种乡土木本植物能在刺槐林下天然更新并且正常生长。分析比较发现，刺槐目前能与泰山低山分布的许多乡土树种形成混交林，不会侵占掉乡土树种。由于刺槐寿命短，推测刺槐混交林会被乡土植被群落替代。刺槐是荒山造林的先锋树种，只要造林前合理设计树种配置，造林后加强管理，可以减少对自然、半自然的森林生态系统产生危害。该文研究结果可为刺槐的引种栽培管理提供理论依据。 

Invasion of Robinia pseudoacacia and impacts on native vegetation

Investigations were carried out to study the diffusion and invasion of Robinia pseudoacacia into native vegetation by line plot and small plot methods in Mount Tai of Shandong Province in 2005.Results show that R.pseudoacacia invades the plantations of Pinus tabulaeformis and Platycladus orientalis by vegetative reproduction and the expanding extent is related to cutting or root injury.It is found that R.pseudoacacia is not dominant and is remained as an associated tree species in the stands with high density and even distribution.But it grows up quickly and becomes dominant in the upper layer within the stands and the invaded pure stands of native tree species subsequently become mixed stands.The capability of invading shrub indicates the high tolerance of R.pseudoacacia to soil infertility.Six native woody plant species can naturally regenerate under the canopy of R.pseudoacacia and grow well.R.pseudoacacia establishes mixed stands with native species instead of replacing and the mixed forests are finally replaced by native communities during the long process of succession due to their short life span.It is a pioneer tree for barren hills and produce no harm to native plant community with rational design of species composition and plantation management.The results provide a theoretical basis for R.pseudoacacia cultivation and management.