A new study, using high-resolution satellite images collected over 25 years, shows a longer, greener season, thanks to the heat from nearby big cities.
The study was headed by Dr. Andrew Elmore of the University of Maryland Center for Environmental Science:
“Cities have a strong impact on the timing of spring and autumn. We found that in cities, for example in Baltimore and Washington, which are in our study region, the timing of spring is up to five days earlier than it is out here in the forest outside the city.”
The reason is that urban landscapes trap heat in the hotter months and hold it through the cooler months, causing spring-like behavior to occur earlier in the year, and fall-like behavior to occur later. That means a longer growing season and more carbon-dioxide usage by plant life – a growing trend that could negatively affect forests’ growth cycles.
The solution, says Elmore, is to simply create greener, more open urban spaces, which should act as a counterweight to industrial urban developments, like roads, buildings and concrete structures.