上海3种用地类型的自生植物分布格局及其影响因素

生物多样性保护是城市生态建设的重要内容,除了对人工绿地物种组成和外来入侵种的关注外,自生植物作为特殊的类群应该得到重视。以上海多个城乡废弃地、道路绿化带和立交桥下为典型生境类型,调查探析自生植物多样性的分布格局特征。研究表明,3种用地类型都是以乡土植物为主（＞70%）,废弃地以一二年生草本占比最大（46.09%）,道路绿化带和立交桥以多年生草本占比最大（分别为38.70%和42.25%）。木本自生植物以道路绿化带占比最大,废弃地最低。自生植物的分布受到植物的生物学特性、生境历史、立地条件和人为干扰等因素的影响,其中废弃地植被受到初始基底和形成时长的影响,从农田废弃、旧住区废弃、垃圾场废弃和绿地废弃都能看到其初始基底的植被痕迹。人为重度干扰降低丰富度,而城市垃圾增加丰富度。研究结果可为今后城市自生植物的保护和利用提供理论依据。

Distribution Pattern of Spontaneous Species and Influencing Factors in Three Landuse Types of Shanghai

Biodiversity conservation is an important component of urban ecological construction.More attention should be paid on the spontaneous species,a special vegetation group,other than the artificial green space and invasion species.This study took examples of three typical habitats of abandon land,road greenbelt and overpass beneath in the urban-suburb gradient of Shanghai megacity.The spatial patterns of spontaneous species were analyzed.It was found that native species were dominant (>70%) in all of the three land use types.Annual species accounted for the highest ratio in abandon land (46.09%),while perennial species were dominant in road greenbelt and overpass beneath (38.70% and 42.25%,respectively).The highest ratio of wood species was in road greenbelt and the least were in abandon land.The distribution of spontaneous species were influenced by biological characteristics,habitat history,site condition and human disturbance.For example,the initial base and length of formation influenced abandon-land vegetation from farmland abandon,neighborhood abandon,dump abandon and greenspace abandon with specified vegetation signs.Heavy human disturbances decreased the species richness while urban wastes increased species richness.The results provide theoretical basement for the protection and application of spontaneous species.