The Impacts Of Urban Land Use/Land Cover On Plant Species Diversity In Shanghai,China

Plant diversity can enhance urban ecosystem services,improve the quality of urban life and facilitate the planning and management of urban green spaces.However,how urban plant diversity varies with landscape pattern and urbanization processes in cities,especially in China is still unclear.In this study,134 randomly selected sample points along two 18km-width transects run across urban center of Shanghai city in horizontal and vertical directions were investigated to explore how land use/cover and urbanization degree influence plant diversity using Split Modified-Whittaker sampling method and land use/cover data derived from high resolution aerial photos of Shanghai acquired in 2013.? and ? diversity index were calculated to indicate plant species diversity.My main findings are as following:1.The species richness,Shannon diversity and Heip evenness have significant differences between land use types each other.The richness of the total,woody and perennial herb species were highest in residential land.Shannon diversity index and Heip evenness index were lowest on residential land.Species richness of annual herbs and indices of Shannon diversity and Heip evenness were highest in agricultural land.The differences of native plant richness between different land use types were not significant.While the species richness of exotic plant in residential and agricultural land use types were significantly higher than the others.2.The ? diversity among land use types were different.Species accumulation rate of all plots was slowest,but the other land use type was the fastest,species accumulation rate of agricultural land just above the overall level.In general,there weren't much difference of species accumulation rate between each land use type.Transportation land and green land have the highest species similarity,and species composition of other land has the most dissimilarity with residential land.3.The percentage of urban land use type was significantly positively correlated with the richness of the total,woody and perennial herbaceous species,but negatively with annual herbs species richness,Shannon diversity index and Heip evenness index.The percentage of green land use type was significantly positively correlated with woody and perennial herbaceous richness,but negatively with annual herbs richness.The percentage of the agricultural land and water were significantly negatively correlated with woody and perennial herbaceous species richness,and positively with annual herbs richness,Shannon diversity and Heip evenness,respectively.4.The species richness of the total,woody and perennial herbs increased with urbanization index.The annual herbs' richness,Shannon diversity and Heip evenness decreased with urbanization index.5.The native plant species richness at different urbanization levels was not significantly different each other.Species richness of exotic plants in moderate and high urbanization areas were significantly higher than that in the area with lower urbanization degree.6.At the landscape level,species richness of woody and perennial herbs were higher in these patches with better connection,more shape irregularity and complexity.Annual herbs' richness,Shannon diversity and Heip evenness were higher with more fragmentation and heterogeneity of landscape.At the class level,the greater dominance and better connectivity of urban land type,the higher the richness of woody and perennial herbs species,however the lower the annual herb richness,Shannon diversity and evenness Heip.Total species richness increased with shape irregularity of green land use patches,while species richness of woody and perennial herbaceous plants increased with patch density of green land use type.The landscape indexes of agricultural land and waters were significantly negative correlated with woody plants and perennial herbaceous richness,and were significantly positively correlated with annuals richness.