Global warming hits Madison! - Isthmus The Daily Page:
Madison has been an officially designated Tree City, USA, for more than 20 years. How will climate change affect our urban forest?
Laura Whitmore, a spokeswoman for the Madison Parks Division, says the city is not sure what to expect. It is just completing an inventory of all city trees in coordination with Philip Townsend, a UW-Madison associate professor of forest and wildlife ecology.
Townsend surveyed Madison's tree canopy using imagery generated by NASA last July. In August he went out with the city bucket trucks to collect leaf samples from the top branches, which are now being analyzed and linked to the NASA images.
When the project is complete, Townsend says, 'we will see which parts of the city forest are already under stress and therefore most susceptible to climate change. In general, urban trees tend to live hard and die young because of the urban heat island effect.'
Townsend fears the longer growing season will do our urban trees more harm than good, by giving a boost to insect pests and tree diseases. Some trees, including bur oaks and maples, will do fine, while firs and spruces, which are native farther north, will not adapt well to our new climatic conditions.
The city's inventory, he says, is a good first step toward preparing the urban treescape for climate change.
'In a progressive city like Madison, urban foresters now know what they didn't know 50 years ago,' he says. 'You need diversity in your tree canopy.'