FAQ EAB woodlot owners

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Q: Should I be harvesting ash trees from my woodlot, even if there is no sign yet of EAB?

A: If you are considering a harvest, it should be done as part of your woodlot management plan and with consideration of your long-term silviculture goals. If it is economically feasible to do so, there is no reason not to harvest ash trees for market in areas not under quarantine. However, landowners should not feel pressured to sell their merchantable ash. It might make sense to cull healthy ash trees before EAB restrictions are put in place, as they would require treatment before ash wood can be transported out of a regulated zone. However, it is not a good idea to remove all the ash from the woodlot immediately, especially if there are a significant number of ash trees. Removing large amounts of ash could negatively impact adjacent trees by the sudden alteration of growing conditions. Removal of all ash in stands where it makes up 50-percent or more of the dominant trees may result in damage from wind. An increase in the amount of sunlight by opening up the canopy could benefit invasive species, which could rapidly colonize large areas and out-compete regenerating tree species in the undergrowth.

Q: Should I be clearing my woodlot of ash trees as soon as EAB is discovered?

A: Research shows that about 98-percent of ash trees in a woodlot are likely to die within six years of an initial EAB attack. There is no urgent need to cut ash trees in your woodlot, since EAB damage is only a few centimetres deep under the bark. The trees will retain their timber value after the initial attach for about 3-5 years. It is not a good idea to remove all the ash from the woodlot immediately, especially if there are a significant number of ash trees. Removing large amounts of ash could negatively impact adjacent trees by the sudden alteration of growing conditions. An increase in the amount of sunlight by opening up the canopy could benefit invasive species, which could rapidly colonize large areas and out-compete regenerating tree species in the undergrowth.

Q: I’ve only got a couple of ash trees in my woodlot. What should I do?

A: If you have only a few ash trees, you may not need to do anything. The trees will die if/when they are infested. If it is not economically feasible to harvest the trees, you can leave them where they are and let nature take its course. One benefit of this approach is that it might reveal ash trees that have a natural resistance to EAB, which could prove valuable to scientific research and the potential generation of breeding stock immune or resistant to EAB.

Q: Is there any benefit to my woodlot in just letting the ash trees die off?

A: Yes, there are the typical benefits of woodland regeneration, from hosting beneficial insects and decay fungi to break down forest material and provide nutrients to other trees and forest plants. If some ash trees demonstrate a natural resistance to EAB, they will provide seed for the next generation of ash trees. Trees with partial resistance to EAB would likely die more slowly and also provide next-generation seeds.

Q: What is happening in Manitoba to the ash trees being culled because of EAB?

A: The EAB outbreak in Winnipeg was discovered only in late fall of 2017, and it is early days in planning what to do with the infested ash wood.  In Manitoba, the current plan seems focussed on chipping ash tree branches and trunks for wood chips that are disposed of at the Brady landfill site on the Perimeter Highway. Ash is a high-value hardwood, but it is not clear yet if there is a viable market for logs after they have been properly treated, either by debarking or being run through a sawmill to remove the bark and sapwood. Written permission from CFIA is required to move any ash material from the regulated zone.

Q: How do I contact CFIA for information and for written permission for moving regulated articles?

A: The local CFIA office in Winnipeg is in charge of the regulated area in Manitoba. For written permission or to inquire about the rules, contact:

Q: Is there any timber value to standing ash trees if they have EAB damage?

A: Ash is an excellent hardwood for use in flooring, furniture and cabinetry, as well as equipment such as baseball bats and hockey sticks. An infested tree still has timber value because the insect only damages the outer few centimetres of sapwood. However, moving untreated ash wood from a regulated area to a market or sawmill outside the regulated area is banned by CFIA. Treated ash lumber can be moved with written permission from CFIA.

Q: Will running ash logs through a debarker make them safe to transport to a sawmill outside the regulated zone?

A: Yes, debarking an ash log and removing at least one centimetre of the sapwood is effective in removing all EAB larvae. The larvae and pupae are in the bark and sapwood in logs large enough to be saw logs, and the larvae and pupae are removed in the debarking process. Be careful because crooked logs will sometimes have patches of bark on curved areas that could still be infested. You will need written permission from CFIA to move all ash logs out of the regulated area, regardless of whether they have been debarked.

Q: Black ash (hoop ash, basket ash) splits easily and has long been as source of basket-making material for Indigenous basket weavers. Will the practice of submerging ash logs in water over the winter kill off EAB?

A: The problem with submerging logs for the winter is that EAB larvae are dormant during that time. Research shows that logs examined after 8 weeks in water showed little die-off of the larvae. However, when logs remained submerged for 14 weeks, they showed a complete die-off of EAB larvae. The longer the log is in the water, the better the results. After 18 months of submergence, the outer rings of sapwood begin to decay and crumble off the log, removing the “home” of EAB larvae, but the interior rings of the sapwood remain intact and pliable, and still suitable for basket-making.

Q: Where are ash trees mostly likely to be found in southern Manitoba?

A: Green and black ash grow naturally in southern Manitoba, particularly in riverbottom (riparian) forests. The map below shows the Manitoba Sustainable Development’s inventory of ash trees outside the City of Winnipeg. You can see how clearly the red dots indicating natural ash mark the path of rivers and streams. Riverbottom forests are ideal vectors for the spread of the Emerald Ash Borer. Ash has also long been planted in cities, towns and villages, and in shelterbelts surrounding farmyards and along the edge of farm fields. The green dots indicating planted ash.

MB ash map

Q: My property is in southwestern Manitoba near Souris. If the EAB is in Winnipeg now (2018), how long will it take to reach my woodlot?

A: A fertile adult female can, on average, fly about two kilometres a season. They don’t tend to go far if there are healthy ash trees nearby where they can lay eggs. However, research has shown the females are capable of travelling up to 20 kilometres in a season. In theory, it would take more than 20 years for EAB to spread the 250-km distance from Winnipeg to Souris. However, it would take only three hours if the fertile female is hitchhiking on ash firewood being illegally transported from out of Winnipeg.