珠海淇澳岛次生植被特征及物种多样性

Characteristics and Species Diversity of Secondary Vegetation on Qi'ao Island,Zhuhai

次生植被是珠海淇澳岛主要的植被类型之一,为揭示岛上次生植被特征及物种多样性特点,采用标准样方法进行植被调查,从地理成分、叶性质、生活型谱和物种多样性四个方面进行分析研究。结果显示:(1)15个样方共有维管束植物46科69属86种,科与属的地理成分均以热带亚热带成分占优势。(2)叶性质特征表现为:叶型以单叶植物占优势(71.8%),叶缘以全缘叶植物(65.9%)多于非全缘叶植物,叶质以革质叶植物(52.9%)为主,叶级比例构成中以小型叶植物的占比具优势(45.3%);且淇澳岛与临近陆地区域的地带性植被差异大,叶功能性状是对淇澳岛干季生长环境(高光且干燥)的适应结果。(3)淇澳岛植物生活型因受人为因素干扰(人工引进植物进行群落构建)与植被演替阶段影响,以小型(33.72%)和矮小型(23.26%)高位芽植物为主。(4)受海风及海岛土壤贫瘠等不利因素影响,乔木层的物种多样性低于灌木层,植被中各群落Shannon-Wiener多样性指数较低(1.84～2.65),为不成熟的群落构成,群落演替至稳定状态还需要一定时间。

The secondary vegetation is one of the typical and dominant vegetation type in Qi ao Island,Zhuhai City,Guangdong Province.In this study,flora characteristics and family and genus areal types were investigated based on the recorded species of quadrat method.The quadrat method as well was applied to investigate the community characteristics and life-form spectrum,and to analyze species diversity to reveal the typical characteristics of the secondary vegetation in Qi ao Island.The result showed:(1) a total of 86 species of vascular plants belonging to 69 genera and 46 families were found in 15 quadrants.The geographical elements of the families and genera are both mainly composed of tropical and subtropical types.(2) The leaf characteristics presented as the dominant leaf type was single leaf whose percentage was 71.8%,the percentage of entire leaf (65.9%) was higher than that of non-entire leaf,and sclerophyll had a higher percentage ( 52.9%) among the leaf quality.The proportion of microphyll (45.3%) in research area of Qi ao Island was significantly higher compared to that of its adjacent land regions,which tended to suggest the higher proportion of microphyll was one of the reasons to adapt to the dry habitats with the intensive lights in research area of Qi ao Island.(3) Microphanerophytes (33.72%) and nanophanerophytes (23.26%) were predominant in life form,which was presumably influenced by both the manual intervention (introduced exotic plants for community construction) and the stage of vegetation succession.(4) Due to the sea wind and barren soil in Qi ao Island,the species diversity of tree layer was lower than shrub layer and the Shannon-Wiener indexes in the study communities were low that was between 1.84 and 2.65,which indicate that the community was an immature one,and was in the intermediate phase of climax succession.