Plant Diversity Along the Urban–Rural Gradient and Its Relationship with Urbanization Degree in Shanghai, China

Meng Wang,Conghe Song,Junxiang Li,Yujuan He,Shengjian Kuang,Damian Łowicki,Guojian Chen,Pippin Anderson,Yue Huang

doi:10.3390/f11020171

Abstract

Urbanization is one of the major causes for plant diversity loss at the local and regional scale. However, how plant species distribute along the urban–rural gradient and what the relationship between urbanization degree and plant diversity is, is not very clear. In this paper, 134 sample sites along two 18 km width transects that run across the urban center of Shanghai were investigated. We quantified the spatial patterns of plant diversity along the urban–rural gradient and measured the relationship between plant diversity and urbanization degree, which was calculated using a land use land cover map derived from high spatial resolution aerial photos. We recorded 526 vascular plant species in 134 plots, 57.8% of which are exotic plant species. Six spatial distribution patterns of species richness were identified for different plant taxa along the rural to urban gradient. The native plant species richness showed no significant relationship to urbanization degree. The richness of the all plants, woody plants and perennial herbs presented significant positive relationship with urbanization degree, while the richness of annual herbs, Shannon-Wiener diversity and Heip evenness all exhibited a negative relationship to urbanization degree. Urbanization could significantly influence plant diversity in Shanghai. Our findings can provide insights to understand the mechanism of urbanization effects on plant diversity, as well as plant diversity conservation in urban areas.

Highlights

Urbanization has been accelerating for several decades at an alarming rate around the world.The world’s population was nearly 7.6 billion as of mid-2017, and it was projected that 70% of the world’s population increase would be concentrated in urban areas [1]
We aim to address the following questions: (1) What is the distribution pattern of plant species richness along the urban–rural gradient? (2) What is the relationship between plant diversity and urbanization degree?
We recorded 526 vascular plant species that belong to 114 families and 364 genera in our 134 sample plots

Summary

Introduction

Urbanization has been accelerating for several decades at an alarming rate around the world. The world’s population was nearly 7.6 billion as of mid-2017, and it was projected that 70% of the world’s population increase would be concentrated in urban areas [1]. China exceeded population by 54% at the end of 2018 Cities have become increasingly important habitats for preserving biodiversity and homes for threatened and rare species [2,3]. Urbanization associated with the habitat degradation and fragmentation, intense human activities and disturbances has led to biodiversity loss even extinction [4]. The urbanization impact on plant diversity is bringing about more and more concerns and has become a hot topic in urban ecology [5,6,7,8]

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