Vegetation productivity trends in response to urban dynamics

PAOLINI, LEONARDO; ARÁOZ, EZEQUIEL; GIOA, ANTONELA; POWELL, PRISCILA ANA

URBAN FORESTRY & URBAN GREENING

ELSEVIER GMBH

Año: 2016 p. 211 - 216

1618-8667

Urbanization is a global phenomenon with still unknown consequences for vegetation dynamics of urban ecosystems, especiallyin subtropical areas of developing countries. In this paper we analyze the vegetation productivity trend associatedto urban densification and urban expansion during the last decade, in twelve cities of northern Argentina. We used timeseries analysis of MODIS-NDVI images to reconstruct the phenological patterns to retrieve a productivity trend underthree spatial classes of urban dynamics: (1) urban, (2) expansion and (3) periphery. Our results show that trends in vegetationproductivity are more associated to the environmental characteristics (basal productivity and climate) than to theland cover class. The average trend in productivity in urban areas ranged between −2.54% year−1 (Metán) and −0.22%year−1 (Concepción). In contrast, the range was much tighter between classes; it was −1.37% year−1 in urban areas and−1.21% in the periphery. In this sense we found significant differences between cities, but no significant differences wereobserved between classes. Urban growth and urban expansion patterns found in our study suggest the system dynamicsis dominated by sprawl patterns rather than by a homogeneous densification. Related to this phenomenon, our resultsdismissed the idea of urban expansion as the main factor affecting vegetation phenology and supported the hypothesisof regional warming as an explanation for the decrease in vegetation productivity, probably due to the decrease of waterbalance in arid regions.