Despite documented intra-urban heterogeneity in the urban heat island (UHI) effect, little is known about spatial or temporal variability in plant response to the UHI. Using an automated temperature sensor network in conjunction with Landsat-derived remotely sensed estimates of start/end of the growing season, we investigate the impacts of the UHI on plant phenology in the city of Madison WI (USA) for the 2012–2014 growing seasons. Median urban growing season length (GSL) estimated from temperature sensors is ~5 d longer than surrounding rural areas, and UHI impacts on GSL are relatively consistent from year-to-year. Parks within urban areas experience a subdued expression of GSL lengthening resulting from interactions between the UHI and a park cool island effect. Across all growing seasons, impervious cover in the area surrounding each temperature sensor explains >50% of observed variability in phenology. Comparisons between long-term estimates of annual mean phenological timing, derived from remote sensing, and temperature-based estimates of individual growing seasons show no relationship at the individual sensor level. The magnitude of disagreement between temperature-based and remotely sensed phenology is a function of impervious and grass cover surrounding the sensor, suggesting that realized GSL is controlled by both local land cover and micrometeorological conditions.
Freshwater & Marine Sciences Program, University of Wisconsin-Madison, Madison WI, USA;Department of Civil & Environmental Engineering, University of Wisconsin-Madison, Madison WI, USA;Department of Agronomy, University of Wisconsin-Madison, 1575 Linden Drive, Madison WI 53706, USA;Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, 1630 Linden Drive, Madison WI 53706, USA;Department of Agronomy, University of Wisconsin-Madison, 1575 Linden Drive, Madison WI 53706, USA;Center for Sustainability and the Global Environment, University of Wisconsin-Madison, Madison WI, USA;Department of Forest and Wildlife Ecology, University of Wisconsin-Madison, 1630 Linden Drive, Madison WI 53706, USA;Freshwater & Marine Sciences Program, University of Wisconsin-Madison, Madison WI, USA;Department of Civil & Environmental Engineering, University of Wisconsin-Madison, Madison WI, USA
Recommended Citation:
Samuel C Zipper,Jason Schatz,Aditya Singh,et al. Urban heat island impacts on plant phenology: intra-urban variability and response to land cover[J]. Environmental Research Letters,2016-01-01,11(5)