城市化背景下公园木本植物多样性的分布格局

The effect of urbanization on distribution of woody plant diversity in parks

为了揭示城市化背景下沿城郊梯度植物种类组成、多样性和分布格局的差异,以福州市为例,分别选取了市区、近郊区和远郊区各3个区域公园作为研究对象,对其进行植被调查。结果显示:(1)共记录61科110属139种植物。共9个优势科,主要是百合科(Liliaceae)、大戟科(Euphorbiaceae)和豆科(Leguminosae)等;市区公园优势种不明显,近郊和远郊公园以造林种台湾相思(Acacia confuse)和柳杉(Cryptomeria japonica var.sinensis)为主。(2)物种丰富度、生态优势度和物种多样性在水平空间尺度上均表现为市区公园>近郊公园>远郊公园,在垂直分布上表现为乔木层>灌木层。结果表明,在人为引进外来物种和土地利用类型改变等城市化因素影响下,亚热带城市公园木本植物多样性沿城郊梯度呈现出由市区向远郊区线性递减的分布格局。

The effect of urbanization on plant composition, diversity and distribution in parks along the urban-rural gradient area was investigated in nine parks in Fuzhou＇s three regions （including urban, suburban and rural areas）. Results were as follows： （1） a total of 139 species that belong to 61 families and110 genera were recorded. Meanwhile, 9 dominant families, mainly including Liliaceae, Euphorbiaceae, Leguminosae and so on, were identified in 9 parks. There were no obvious dominant species in urban parks, while the main species for afforestation were Acacia confuse and Cryptomeria japonica var. sinensis in suburban and rural parks; （2） the order of Margalef index, Simpson index and Shannon-Wiener index were urban, suburban parks, and rural parks from high to low on the horizontal spatial scale. Meanwhile, the three indices of the tree layer were higher than those of the shrub layer in vertical distribution. Our results indicated that woody plant diversity was influenced by the urbanization factors, such as introduction of exotic species and changes of land use types, the diversity of woody species showed the linear decreasing pattern from urban to rural areas along the urban-rural gradient in subtropical city parks.