Natural Resources staff working to keep tree-killing disease in check
A conservation officer with the provincial Department of Natural Resources examines a red pine tree with symptoms of damage from scleroderris canker, notably reddening of needles and “candles” where needles have dropped off shoots. Through aerial surveys and a detailed investigation in 2012, provincial staff tracked movement of the disease in Newfoundland. A plan has been set out to keep the disease in check. — Submitted photo
The disease is a killer — a tree killer. Government quarantine contained it for decades and then, like in a Holywood film, two new cases were confirmed, then a few more.
Over the last two years, the provincial Department of Natural Resources has investigated the spread of the European strain of scleroderris canker outside of the Avalon Peninsula, where it had
been kept and managed since being discovered in the St. John’s area in 1979.
The disease is not native to the province.
“It was suspected that it came in from nursery stock that was brought in from Europe,” said Dan Lavigne, current supervisor of the forest insect and disease section of the province’s Department of Natural Resources.
It is spread tree to tree through spores and affects hard pines. It is particularly fatal to red pine.
The province of Newfoundland and Labrador has rare, indigenous red pine stands that would be threatened if the disease was left to spread unchecked, Lavigne said.
As well, the province had spent about $3.1 million on red pine plantings, prior to the discovery of European scleroderris canker on the island.
When it was first found here, the federal government became in-volved with the efforts to protect against the spread of the disease, under the Plant Protection Act. A quarantine zone was brought in by the Canadian Food Inspection Agency, preventing movement of living pine outside the Avalon Peninsula.
“It was quite effective for about 28 years,” Lavigne said of the efforts to keep the tree killer contained.
Then, in 2007, there was a confirmed case in an area of red pine about 400 kilometres from the quarantine zone. The following year, 13 hectares of pine trees in that area were cut and burned as a precaution.
In 2011, new cases appeared further afield — discoloured trees with missing needles.
In 2012, forestry staff decided to conduct a survey of red pine sites, in search of infected trees. They trekked into the Newfoundland interior, inspecting 182 of 463 known red pine sites for signs of the disease.
Trees showing apparent symptoms were sampled and lab-tested. There were few positive results, but there were a scattered few.
“Right now we’ve got about seven sites on the island that are outside of the existing quarantine,” Lavigne said.
“We’re not exactly sure how this is moving around,” he added, noting a working group has been tasked with getting the canker back under wraps.
What is known is the disease spreads in the spring and early summer, carried in clouds of mist and fog, or splashed about in early summer rains. Birds and other wildlife may play a role and at least one forestry scientist has theorized hunters taking infected trees for firewood may have helped the outbreak.
It would not be the first time an invasive species was helped along by human beings. In parts of Ontario and Quebec, the Canadian Food Inspection Agency has warned against the spread of emerald ash borer — a species of insect that kills ash trees — in infected firewood.
The federal government has stepped in with regulations prohibiting the movement of firewood there.
Theories on the movement of European scleroderris canker here have yet to be confirmed.
Investigation around the activity of the disease is continuing, while a plan has been developed to re-establish containment.
“Before the spores have a chance to spread to other sites, we want to go in and we want to try to get rid of the disease at those sites,” Lavigne said.
Hollywood would call for the stealing of a military jet to shoot missiles at infected areas, but the working group has called for prescribed, controlled burns.
The plan has been filed with the provincial Department of Environment and Conservation and will affect management plans for forestry districts 2, 5, 7, 9 and 14.
“For infected red pine sites having a merchantable component, wood with cankers absent will be harvested and removed from the site, while cut tops and branches will be left on site and burned,” states the filing.
The sites will be replanted with a tree species other than pine.
“All harvesting equipment will be steam-cleaned on site following operations to prevent any movement of spores on equipment to other parts of the province,” notes the provincial Department of Environment and Conservation.
The documents state burns may come close to cabins in the Berry Hill Pond area, though officials assure cabin owners will be notified with respect to planned burning. Public comments are due in to Environment and Conservation by Sept. 20.
Lavigne said he is optimistic, with the success of the eradication efforts all those years ago, the current plan of action will be enough to contain the disease once more. He encourages anyone spending time in the woods to report strange or sickly-looking trees, to provide an extra set of eyes for the province’s disease prevention efforts.