Trunks from dozens of ash trees taken down in Indian Gardens await removal last week.Bob Uphues/Staff

Combined with last summer’s drought, another sustained dry spell in 2013 and the continued spread of the emerald ash borer, it’s been a very tough year for trees in Riverside.

How tough?

“It’s horrible,” said Riverside Village Forester Michael Collins. “There are a lot of trees dying. I’ve been here 10 years and this is the most trees I’ve ever removed in the village.

“And next year it’s going to ramp up.”

Collins couldn’t give an exact count of the number of trees removed so far in 2013; he hasn’t had time to tally the ever-growing list back at his office in the Riverside Public Works building.

For two days last week — Sept. 10 and 11 — he spent much of his time in Indian Gardens, where a tree removal company cut down 35 dying green ash trees, all victims of the emerald ash borer, despite many of them receiving preventive chemical treatments for the past two years.

The number of trees removed last week represents about half of the ash trees in Indian Gardens proper — in addition to the 35 trees cut down, crews trimmed another 40, not all of them in Indian Gardens — although there are other ash trees in the heavily wooded areas bordering the park.

Next year, said Collins, he expects more green ash trees in Indian Gardens to succumb to the ash borer.

Twenty-two of the 35 trees removed had been part of a research study begun last year and headed by Dr. Frederic Miller from Morton Arboretum. The study involved dozens of trees, including the green ash trees in Indian Gardens and blue ash trees on public parkways scattered throughout Riverside.

The trees were treated with various chemical applications to gauge their effectiveness in combating the emerald ash borer. While the blue ash trees appeared to thrive, the green ash trees took a hit.

However, said Collins, there are no specific conclusions to draw until the trees that were cut down this week are analyzed by Miller’s study team. Collins said crews cut four branch samples from each fallen and trimmed tree. Those samples will be taken to Morton Arboretum and examined to see how the insect fared against each type of treatment.

“There’s no simple conclusions … until they start peeling these branches back and looking into them, which will likely happen over the winter,” said Collins.

While the loss of so many trees in one spot is a little jarring, Collins said their loss also creates potential opportunities.

Since the ash trees in Indian Gardens were concentrated in specific areas, there is the potential for more open space in the park to create either field or playground space, should the Parks and Recreation Board and village board choose to move in that direction.

From a forestry standpoint, the loss of the ash trees provides an opportunity to replace what Collins referred to as a “monoculture” with a diverse array of trees to create a multi-layered canopy.

“It depends on if you look at it as a half-empty or half-full situation,” said Collins. “At the end of the day, I see a tremendous positive in the way of being able to start underplanting and starting the reforestation process.

“It’s sad to remove mature trees, but plan it out and do it right. Get some diversity. That’s why this is such a sad impact. Plant a monoculture and this is what you get.”