The Trees of Tree Town
The elms' dominance ended in the sixties when Dutch elm disease decimated that population--and forty years later the emerald ash borer killed thousands of white and green ashes. And last year's dry winter, an early spring followed by a late freeze, and summer drought were tough on all trees. The dry winter failed to replenish the ground water, an unseasonably warm March forced premature growth that was then killed by the freeze, and the drought stressed them into shedding bark and leaves. How well they'll recover won't be known till this summer.
Beyond natural causes like drought and disease, the town's trees have been affected by the reduction of the city forestry department's staff from twenty-five to eight over the last thirty years and the cuts in its budget from $2 million to $1.5 million over the last five. This sapped the department's resources and left jobs like pruning, planting, and regular maintenance undone or underdone, though a separate $2 million budget paid for removing dead ash and planting replacements. Since 2005, the city's planted 7,760 trees.
No one knows how many trees the city had before the epidemic of Dutch elm disease, but a recent survey estimated there are 1.45 million on public, private, and U-M property now. They create an overall leafy canopy that covers 33 percent of the city's land: 46 percent of residential areas, 24 percent in public rights-of-way, and 22 percent in recreational areas. That makes Ann Arbor just a bit above average for towns of its size.