Influence of urbanisation on the phenology of evergreen coniferous and deciduous broadleaf trees in Madrid (Spain)

Abstract

Plant phenology plays a crucial role in terrestrial ecosystems and is a key indicator of ecological changes. It is influenced by alterations in meteorological conditions at micro- and mesoscale in cities as a result of urbanisation and the intensification of anthropogenic activities. One example is the urban heat island (UHI), i.e. the increase in temperature in city cores compared to their surroundings. In this study, we used plant phenological data from the High-Resolution Vegetation Phenology and Productivity dataset of the Copernicus Land Monitoring Service to explore the relationship between urbanisation intensity (i.e., proportion of built-up area) and the phenology and productivity of broadleaf deciduous and evergreen coniferous trees in the city of Madrid and its surroundings, one of the largest metropolitan areas in Europe. We found the average start of season date advanced by 0.79–11.79 days in broadleaf deciduous trees in highly urbanised areas, and was delayed by 5.77–9.16 days in evergreen coniferous trees. Although differences were also observed for the end and length of the growing season, these patterns showed great interannual variability. Both broadleaf deciduous and evergreen coniferous trees were most productive in highly urbanised areas. Although previous studies have explored the response of different land-cover types to urbanisation, to our knowledge, none have looked at this relationship at a fine spatial scale in a Mediterranean city with different vegetation functional groups. The analysis of more specific classes of vegetation enables a better understanding of the phenological response of vegetation to urbanisation intensity.