A Gradient Analysis Of Urban Green Space Ecosystem Services And Human Well-being

For the first time in human history-more than50per cent of the world’s population now lives in towns and cities. Urban green space can provide ecosystem services such as carbon sequestration, temperature regulation, water conservation, biodiversity conservation, social cohesion and stress recovery. The human demand of urban green space gets explored along with the acceleration of urbanization. Therefore, studying the change of urban green space and analyzing the relationship between ecosystem service and human welfare on green space is important to guarantee the sustainable development of human society.This study assesses the value of ecosystem services of urban green space in Hangzhou, and discusses the change of ecosystem services’value across a gradient from city center to suburban district. In the world,286Asian cities,301European cities and1422North American cities are selected to explore the relationship between ecosystem service and human welfare. The main content and results are as follows:(1) The green space coverage is positively related to the distance from city center to suburban district. The highest and lowest green space coverage is90.6%and0.6%, respectively. Among tree, shrub and grass of green space, tree has largest proportion in all districts, such as63%in city center,53%in suburban district and46%in outer suburban district. Three primary tree species are Cinnamomum camphora, Platanus, Osmanthus fragrans in city center; Cinnamomum camphora, Osmanthus fragrans, Magnolia grandiflora in suburban district and Cinnamomum camphora, Ginkgo biloba, Elaeocarpussylvestris in outer suburban district.(2) The correlation analysis indicates that the green space coverage has a negative correlation with the distance from city center to suburban district. We also find that the value of green space in city center is124051.79yuan/ha, and it is44209.3yuan/ha and27486.49yuan/ha higher than suburban district and outer suburban district. The cultural value of green space accounts for74%,54%and41%in three districts green spaces’ecosystem service value, respectively. Comprehensive analysis shows that reasonable design vegetation structure of green space can effectively improve the value of ecosystem services in urban green space.(3) Different city has different green space coverage. The85%of Asian cities’(242) green space coverage gathered at the range of30-50%. The European cities’ green coverage is a left normal distribution, and the mode is10-20%. The North American cities’green coverage distribution is uniform, and22%cities’(315) green coverage is less than10%and18%of cities’(259) green coverage is10-20%. The economic development of the cities in the world has great disparity.(4) In this study, we select population, city area and per capital GDP as the indicator of human well-being. The77%of Asian cities’(217) per capita GDP is less than10thousand dollars, and61%of North American cities’(869) per capita GDP is in the range of20-30thousand dollars, but the European cities’per capita GDP distribution is uniform. The world sampled cities’area is mainly within300square kilometers. Different cities’population has huge difference. The Asian cities’ population distribution is uniform. The European and North American cities’ population concentrates in1million, and the proportion of cities in this range is92.5%and96.2%, respectively. Through the analysis, we found that urban green space coverage has close relationship with human well-being. The green space coverage has a liner positive correlation with per capital GDP, and has no significant relationship with city area. The correlation between green space coverage and population is also a positive correlation, but this correlation in Asian cities and North America cities is weak, and no correlation in European cities.