要救樹還是重新種樹? Chicago has only 50,000 ash trees left. Should we spend millions to keep them alive? By Mariah Woelfel

Chicago has only 50,000 ash trees left. Should we spend millions to keep them alive?

By Mariah Woelfel

Chicago has tried for more than a decade to slow the declining health of ash trees, some of the city’s oldest and most mature trees that provide communities benefits like shade and flood mitigation, as the trees have been overcome by a small but mighty green pest.

Starting in 2008, the city began inoculating the ash trees, which numbered about 96,000 at the time, against the invasive emerald ash borer beetle.

But by 2018, with almost half of the ash population dead and removed, the city decided to stop inoculations and let the remaining 50,000 ash trees die off.

Now with a flush of federal money in the city’s coffers, some activists and aldermen are pushing for the city to bring that inoculation program back, arguing it could save Chicago’s second most populous tree, a key part of the overall tree canopy.

That’s in part because of the type of trees ash are — featuring larger, wider leaves.

“In terms of their leaf surface area, they are one of the larger leaves that we have,” said Daniella Pereira with the conservation and tree-planting group, Openlands. “So … we have to remember that if we lose an ash tree, we’re losing a significant amount of canopy.”

The years-long issue of whether to treat the trees or let them die to make way for new ones took center stage at a budget hearing this week for the Department of Streets and Sanitation, which oversees the city’s tree population.

Aldermen questioned whether this year’s budget should include a few million dollars to give the remaining trees another dose of chemicals so that they don’t all die off at once — causing a headache, potential safety hazards, and a hefty price tag for the cost of removing and replacing the trees.

Advocates say the cost of treating the city’s ash trees would be around $2.7 million. But the city’s Streets and Sanitation department officials say it would be more.

Commissioner Malcolm Whiteside, who leads the Bureau of Forestry within the department, says it would take at least $6 million, or about $120 per tree, to protect the remaining ash for just an additional three years.

“In terms of their leaf surface area, they are one of the larger leaves that we have,” said Daniella Pereira with the conservation and tree-planting group, Openlands. “So … we have to remember that if we lose an ash tree, we’re losing a significant amount of canopy.”

The years-long issue of whether to treat the trees or let them die to make way for new ones took center stage at a budget hearing this week for the Department of Streets and Sanitation, which oversees the city’s tree population.

Aldermen questioned whether this year’s budget should include a few million dollars to give the remaining trees another dose of chemicals so that they don’t all die off at once — causing a headache, potential safety hazards, and a hefty price tag for the cost of removing and replacing the trees.

Advocates say the cost of treating the city’s ash trees would be around $2.7 million. But the city’s Streets and Sanitation department officials say it would be more.

Commissioner Malcolm Whiteside, who leads the Bureau of Forestry within the department, says it would take at least $6 million, or about $120 per tree, to protect the remaining ash for just an additional three years.

“In terms of their leaf surface area, they are one of the larger leaves that we have,” said Daniella Pereira with the conservation and tree-planting group, Openlands. “So … we have to remember that if we lose an ash tree, we’re losing a significant amount of canopy.”

The years-long issue of whether to treat the trees or let them die to make way for new ones took center stage at a budget hearing this week for the Department of Streets and Sanitation, which oversees the city’s tree population.

Aldermen questioned whether this year’s budget should include a few million dollars to give the remaining trees another dose of chemicals so that they don’t all die off at once — causing a headache, potential safety hazards, and a hefty price tag for the cost of removing and replacing the trees.

Advocates say the cost of treating the city’s ash trees would be around $2.7 million. But the city’s Streets and Sanitation department officials say it would be more.

Commissioner Malcolm Whiteside, who leads the Bureau of Forestry within the department, says it would take at least $6 million, or about $120 per tree, to protect the remaining ash for just an additional three years.

These tags show the years the ash tree was treated to fight the invasive emerald ash borer. Angela Rozas O’Toole / WBEZ

資料來源:

https://www.wbez.org/stories/chicago-ash-trees-are-dying-should-we-pay-to-save-them/6fb028df-f70d-4014-a33d-39a1c5a73d94