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Seventy-five percent of the human population will live in urban areas by 2050, and urban vegetation will be the main source of ecosystem services. Unequal access to urban vegetation might exacerbate existing socioeconomic differences. Studies performed in cities of developed countries show that the population with higher socioeconomic status has more access to ecosystem services provided by vegetation. In urban areas, with small internal climatic variation, plant productivity measured through satellite imagery is a good indicator of vegetation availability that can be mapped. In this study, we characterized the distribution of plant productivity in 40 Argentine urban centers and we identified socio-environmental variables that control its spatial patterns within and among urban centers. We used socioeconomic indicators obtained from the 2010 National Population and Households Census and a 4-year mean plant productivity measured through the integration of NDVI values derived from MODIS satellite images. In most of the analyzed cities, plant productivity increased as socioeconomic status decreased; and only in 25% of the cities, we found a positive relationship between socioeconomic status and plant productivity. In the latter case, most of the cities were placed in arid environments, where both the cost of watering and the effect of subsidized water on plant productivity are proportionally higher. Buenos Aires and Bariloche, which also showed positive associations between socioeconomic status and plant productivity, are located in humid environments, but Buenos Aires is the most densely populated city of Argentina and Bariloche is a touristic city; in these cities, the relative cost of keeping green spaces instead of building housing infrastructure is also high. These results show that vegetation distribution among socioeconomic status is more diverse than suggested by the literature and that the appropriation of vegetation productivity by groups with higher socioeconomic status only occurs when vegetation cost increases to the point of becoming a luxury good. [ABSTRACT FROM AUTHOR]

Urbanization is causing profound alterations of ecosystem functions at local and regional scales. The need to maximize ecosystem services to improve the livability of cities is resulting in intensive management of urban vegetation, which is likely generating new conditions for the ecosystem functioning. In this paper, we address the association between vegetation functioning (i.e., primary productivity) and climate in urban and adjacent non-urban areas in Auckland, New Zealand. We used time series analysis of integrated vegetation indices derived from satellite images (MODIS) to estimate a proxy of primary productivity of urban and non-urban vegetation. We analyzed the interannual variability of vegetation productivity in relation to climate fluctuations. In Auckland's urban area the variability of primary productivity was not associated with any of the climatic variables considered, while in the non-urban area (i.e. reference area) vegetation productivity was strongly associated with cumulative rainfall during the growing season. Our results suggest that the productivity of urban vegetation may be undergoing a decoupling from the regional climate. If a decoupling of ecosystem functions from climate becomes a general pattern in urban areas it could have significant effects on urban vegetation planning and management. In a context of increased variability, urban ecosystems could constitute stable habitats and they will probably contribute to the viability of vulnerable populations. [ABSTRACT FROM AUTHOR]