How far beyond cities do urban climates affect vegetation?

Details

Human activity, including changes in land use, is described as the most fundamental source of environmental change on Earth. The researchers used urbanization and the resulting urban heat islands as a way to evaluate the effect of climate warming on vegetation phenology—the timing of seasonal changes in vegetation.

Using data from the Moderate Resolution Imaging Spectroradiometer, they analyzed urban–rural differences in vegetation phenological transition dates and land surface temperatures for urban areas larger than 10 km² in eastern North America.

The effect of urban climates on vegetation phenology decayed exponentially with distance from urban areas, with substantial influence extending up to 10 km beyond the edge of urban land cover. The ecological footprint of urban climates was about 2.4 times that of urban land use in eastern North America. The net effect was a growing season about 15 days longer in urban areas than in adjacent unaffected rural areas.