Urban Beetle Battle
Skidders and forwarders are being used carefully in unfamiliar territory-a city park in Halifax-to control a beetle advance.
By Chris Lambie
The faint hum of chainsaws echoes through Point Pleasant Park as joggers and dog walkers make the rounds of this popular Halifax landmark whose forest has been infested. Workers from Asplundh Tree Services are toppling red spruce in the park in an effort to eradicate the brown spruce longhorn beetle. "The goal is to remove the trees that are infested without doing any damage to the surrounding trees," says Rick Williams, the site supervisor for Asplundh.
Infested trees are identified by forest technicians, then cut down with chainsaws after security guards close off the area to pedestrian traffic. A logging operation would usually entail moving heavy equipment into the woods in a big way, but on this job Williams and his crew are working especially hard not to disturb the 75hectare park. Scientists believe the pests came to Halifax from either Europe or Asia more than 10 years ago as stowaways in wooden packing crates.
The park is about 85 per cent forested, with 80 per cent of the forest made up of softwood. About 70 per cent of the softwood is red spruce-the beetle's favourite target, though it has also been found in some white and Norway spruce. The Asplundh loggers are using a Timberjack 230 skidder and the slightly larger 240 model to pull felled trees out of the woods on 100footlong cables using hydraulic winches. And they employ a Bombardier Muskeg, which is also equipped with a winch, to pull logs from deep in the park.
"Some of the trees are down over rocky slopes or they're far enough in where our cables from the skidders won't reach," Williams says. "So we can take the track machine, which is a very low impact piece of equipment, and we can go back further in the woods. It's not rutting up the soil, and it's not causing as much compaction to the root systems." That's important because human impact on the park's soil may have allowed the foreign beetles to take over in the first place.
The brown spruce longhorn beetle is probably attacking Point Pleasant Park trees because they're more stressed than their wild counterparts. Salt spray from the sea, little organic matter in the shallow soil, three years of drought and the 1.5 million people who tromp through the park every year all make life difficult for the red spruce. "The excessive use of ground space by people and machines, even on trails surrounding trees, is detrimental to root growth and development," says a park management plan written seven years before the beetle was even detected.
"Soils in these areas tend to have too much water, and not enough oxygen as a result." So with a complicated system of blocks, the Asplundh crews are guiding logs out of the woods without scraping the bark on healthy trees. Sometimes the beetle infested logs have to cut in sections to get them out. Once the logs are hauled to one of the many small gravel roads that run through the park, workers use two forwarders- either a C5 Tree Farmer, or a small British tractor style Same Drago-to move them to the portable mill set up in the centre of Point Pleasant.
At the mill-a laser guided Morbark portable model equipped with a circular saw-slabs of bark where the beetle larvae live are cut off the logs and then taken to the burner. "So everything that could be contaminated by the insect is disposed of, and anything that's saleable is left," explains Williams. All terrain vehicles with trailers and the forwarders are also being used to transport branches to the fenced off burner at the southwest tip of the park.
At the burner site, the beetle infested bark and branches are loaded into an incinerator using a Komatsu PC220LC excavator. The burner is a Litton Industries model with an open top that's specially designed to burn at 2,200 F, says Gregg Cunningham, a plant protection officer with the Canadian Food Inspection Agency. A manifold blows air across the top of the 27foot long box, and down into the flames. "Any particulate that wants to go up out of the box is going to be swirled down around again for a reburn," Cunningham says. "So you get very little ash coming out ." That's important for park users and the Halifax Regional Fire Department, which specified emission standards for the burn. "The emissions are much lower than conventional burning," Cunningham says.
None of this can be done quickly because the loggers must contend with the thousands of people who use Point Pleasant every day for everything from their morning stroll to cross-country skiing. "Obviously the park is still open and being used a lot by the public," Williams says. "You do have a lot of foot traffic and dogs going through there. So we have to be extra careful and just take our time. It's not a production atmosphere; it was never meant to be one."
The salvaged lumber is expected to be sold for about $20,000, which will go toward park restoration. That's a paltry sum compared to the estimated $3 million it will cost to identify and cut down 2,200 trees in the park and another 950 infested trees that lie within a 15kilometre radius of Point Pleasant. The beetle burrows into the tree, eventually killing it. In Europe and Asia, where the beetle is believed to have originated, it attacks sickly trees. Here, it has infested apparently healthy red spruce and has been called a threat to the forests of North America. "It could have wiped out the red spruce trees in Nova Scotia," says Steve Talbot, executive director of the Nova Scotia Forest Products Association.
Red spruce makes up about 60 per cent of the province's $1.4billion a year forest products industry. Talbot compares the potential threat to that of beech bark disease. Coincidentally, that plague also came to North America via a Halifax park, the Public Gardens, about a century ago on two imported beech trees. "Now there is virtually not a decent beech tree to be found in Nova Scotia, down the eastern seaboard, and as far west as central Canada," Talbot says. The beetle has the same potential for damage, he says. And the Point Pleasant trees it has infested were either dead or dying. "They were going to be lost anyway, so why not curb the infestation and get those insects out of there at the same time?" he says.
Efforts to wipe out the beetles in the park came to a halt last August-after 700 trees had been felled-when the anti-cutting group Friends of Point Pleasant Park won a temporary injunction to stop the chainsaws. But in December a Federal Court judge ruled against the Friends and the cutting started again as the snow began to fly. Scientists estimate there are as many as four million brown spruce longhorn beetles living in Point Pleasant. At up to two centimetres in length, the bugs-laid end to end-could stretch from the park to Mahone Bay, an hour's drive away. With many of the park's red spruce showing symptoms of beetle invasion-including the telltale bore holes with white sap running down the trunks-some bug experts compare the problem to a slow burning fuse.
If left alone, they fear the beetle population could grow so large inside the park that it could prompt a mass flight, spreading the insects beyond Nova Scotia's borders. Despite the large number of people using Point Pleasant, there have been few complaints about the loggers, says Stephen King, the city's senior parks advisor. "They seem to coexist quite well," says King, a landscape horticulturist by trade who helped stage public information sessions in the park to explain the cutting to city residents.
In Chicago and New York City, the Asian long horned beetle-a cousin to the brown spruce longhorn beetle-caused "absolute and total devastation", King says. "New York City spent $16 million this year on the problem and Chicago spent $11 million. It's pretty scary stuff when you're managing a major park system ." Specific species of trees would normally be planted to replace those taken down, King says. "But we're probably going to be looking at something that's a little more biodiverse." Instead of planting, park employees will let the forest regenerate itself after the cutting is done.
The province's 300 sawmill operators are now "fairly confident" that humans have won the brown spruce longhorn beetle battle, Talbot says. Any future logging to fight the beetle will probably be done on a much smaller scale than what's just taken place in Point Pleasant, he says. "Even that is not really a large cutting. I would suspect that anybody walking into Point Pleasant Park would probably not notice a radical difference in there ."
Now that about five per cent of the park's trees have been removed, it could take another two to three years to get rid of the beetle altogether in Point Pleasant, King says. "It looks like we've made one heck of a dent in the brown spruce longhorn beetle's spread," he says. "Hopefully, knocking on wood- excuse the pun-we've got the bulk of it behind us."
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