BACKGROUND / DISCUSSION
Council at its meeting of February 24th, 2014 received a presentation from Mr Philip van Wassenaer from Urban Forest Innovations concerning four distinct management plans recommended for the infestation of Emerald Ash Borer within public trees in the City of Cornwall. Council was provided with the completed document prepared by Urban Forest Innovations providing detailed information on the Emerald Ash Borer, its effect on the ash tree population throughout North America, the early stages in Cornwall and various management plans with their budget implications over the next fifteen years.
Each of the plans will require extensive communication with the residents as they will be encouraged to deal with their own ash trees in order to slow the spread and avoid personal liability.
The report will summarise each of the management plans provided for Council's consideration:
This plan is better described as a "do nothing" plan as it simply removes ash trees as they begin to die. The Emerald Ash Borer is permitted to run its course and the City is simply reacting by removing trees as they die from the infestation. The City would loose its complete canopy of ash trees with no re-planting initiative. The cost of $3.6 million over 15 years is to remove the trees as they die off for liability and safety reasons. The major disadvantage to this model is that the City will be faced with trees dying very quickly and having to remove them within a short time period therefore risking not having enough crews or tree removal companies reacting quickly enough to avoid the liability. As well the City incurs a significant loss to its urban tree inventory. The cost for a ten year approach is slightly lower at $3.2 million.
This plan provides for the removal of every dead ash tree and the replacement of that tree with a native non-ash tree species. The total 1:1 removal/replacement cost over 15 years will be $5.6 million and $9.2 million if the ratio is increased to 1:3 removal/replacement. This approach requires minimal intervention by the City other than removing the trees as they die and replanting with a different specie. Similar to the Reactive Management strategy, the City will loose a significant amount of mature ash trees that will be replaced with smaller trees. The benefits derived by the more mature trees lost will take time to regain with new plantings. And again, the City will have to mobilise many crews or tree removal companies in a short period of time in response to wide spread tree mortality. The costs of replacement are spread out equally over the 15 year planning exercise to avoid cost spikes. The cost for a ten year approach on a 1:1 ratio is $4.6 million.
Under this management strategy the City chooses a more active approach to the EAB infestation by removing dead ash trees, re-planting on a 1:1 ratio with a different specie and adding the pre-emptive removal of ash trees in order to spread the cost of removal over 15 years. This management plan also introduces the biannual treatment of existing mature ash trees that are in good condition and are greater or equal to 30 cm DBH in order to maintain some of the City's tree canopy until the new plantings are large enough to provide all of the benefits that mature trees provide to the environment. The selected trees are injected with TreeAzin ( azadirachtin) every two years. Good condition refers to the following criteria:
"Good condition, safe useful life expectancy in excess of 20 years, visual importance, forming component part of significant ash species cluster/group/avenue/feature, few adjacent trees, pruning intervention unlikely, few or no above/below ground conflicts, 'heritage' candidate tree, providing significant environmental and other benefits and/or high cost to remove if tree dies."
The cost of implementing this approach if the City decides to treat 100% of the ash trees that meet the "Good Condition" criteria is $5.9 million over 15 years. The cost decreases as the percentage of trees selected for treatment decreases. The same cost over 10 years is $4.5 million.
This is the approach that both the City's Municipal Environmental Advisory Committee and the Recreation Advisory Committee recommends to Council.
Under this management strategy the City agrees to a more proactive and vigorous approach in dealing with Emerald Ash Borer. Ash trees greater or equal to 20 cm DBH and in good or moderate condition are considered for treatment with TreeAzin. The City would also remove and re-plant on a 1:1 ratio, complete the plantable space inventory, continue the public education program and include an administration component for a total cost of $5.7 million over 15 years. This management option would have the City treating more ash trees with the hope that all of the treated trees would survive the 15 year mark allowing the City to maintain its mature ash tree canopy. The cost is slightly lower than the Active Management approach as it includes the treatment of more trees (75%) therefore the removal of less trees over the 15 year period. It is a risk as the treatment option is not 100% guaranteed. The cost over 10 years is $4.2 million.
It is anticipated that the continuing spread of the Emerald Ash Borer throughout the City will require a coordination and supervision task that is beyond what the current Parks Staff can provide. EAB demands an active management approach. The program chosen by Council will have to be reviewed, changed, updated as new approaches are found and the research is advanced. The planning process of which trees to be removed moving forward and where and when new plantings occur must be coordinated in an orderly fashion given the capital budget every year and the anticipated changes to how quickly the disease is spreading and in what regions of the City. The trajectory of EAB cannot be predicted therefore it is imperative that the City remain flexible and must be monitored very closely and reviewed on an annual basis for unanticipated events or changes
A further report will follow detailing our recommendation concerning requirements for a coordinator to deal with this infestation. Staff will continue to discuss potential partnerships with the Raisin Region Conservation Authority in order to maximise government working grants available and training and equipment opportunities.
Staff will continue to provide up to date information to our residents through our City website, Facebook, twitter and will organise public workshops as was done in the past. The City will also continue to maintain a working relationship with the Canadian Food Inspection Agency and the Provincial Government in order to gain information on the development of new strategies to combat this disease for the future.
The following information was provided by Morris McCormick, Division Manager for Environmental Services:
Interim disposal will be provided at the City of Cornwall landfill site. Two locations away from the tipping face will be made available. One location will accept large tree sections in sizes no larger that can be accommodated by a portable grinder. The remainder of the tree that has been chipped on site prior to delivery to the landfill site will go to a second location.
This is interim storage only and there is no intention to use the landfill as a permanent disposal site.
The objective is to not have the material delivered to the landfill on site for more than one year. This material would be removed from the landfill for reuse in a manner that will be in compliance will all applicable regulations.
The existing practice is to receive chipped wood at the landfill free of charge. Tipping fees are assessed to larger unchipped material. The intention is to continue with this practice with EAB materials.
The following represents some information received recently by the Canadian Food Inspection Agency, responsible for the management and control of Emerald Ash Borer:
7.0 Risk Management Considerations
The presence of EAB has now been confirmed in 27 Ontario counties, and in seven areas in the province of Quebec. The CFIA does not have resources available to maintain individual regulations on numerous, discrete regulated areas.
As Canada’s National Plant Protection Organization, the CFIA has a domestic mandate to protect Canada’s forests in uninfested areas, as well as market access related aspects in demonstrating that its pest-mitigation programs are effective at producing pest-free wood products. In order to do so, pest management programs must be based on science, and regulated areas must include adequate buffers to protect uninfested parts of Canada, as well as providing effective risk mitigation options in support of a viable ash products industry.
Given the continued spread of EAB and limited resources to maintain the current regulatory approach, the CFIA must revise its overall resource utilisation for this pest by April 2014. Consequently, the CFIA is moving from an emergency response based programme towards a pest management approach aimed at protecting uninfested areas of Canada (i.e., surveillance, regulation, enforcement, research and communication efforts).
Activities for voluntary implementation by stakeholders must also be considered for the management of EAB.
The following activities are examples of activities that may be implemented irrespective of which regulatory option is implemented; these activities can be delivered by any stakeholder partner or collaborative group. It is important to note that the CFIA may not be involved with the points listed below.
Implement non regulatory recommendations such as Best Management Practices
Increase industry, stakeholder, and public awareness through communication materials and media campaigns, signs, pamphlets
Reducing the risks presented by the firewood pathway will be an important component. The CFIA will update its firewood policy to include import requirements and domestic guidelines to reduce risks.
- Manage stand health through silviculture & tree removal, etc.
- Maintain surveillance program to determine extent of spread
- Maintain trade negotiation efforts to ensure market access
- Support research and development of management tools
Given the current wide-spread distribution of EAB in parts of Ontario and Quebec, the use of biological control agents, in combination with the above measures, may offer the best method of managing the pest. This approach is being tested in parts of the U.S. and the CFIA will review petitions received for the release in Canada of these biological control agents.
Attached to this report is a more detailed Risk Management Document provided by the CFIA.
The impact of the loss of ash trees in the City of Cornwall as a result of the spread of Emerald Ash Borer will be significant. As quoted by the report prepared by Urban Forest Innovation: "It will result in the increase of storm water runoff, ultraviolet light exposure, urban heat island effects, reduced carbon sequestration, and air pollution filtration and the loss of aesthetic and property values"
It is critical for the City to commence a management plan in 2014 that will attempt to control the spread of the disease and continue to reduce the City's liability by removing trees that are in poor condition, treatment of trees that are in good condition and re-planting with other species thus spreading the cost over a 10 or 15 year period depending on aggressiveness of the spread.
The City must recognise the importance of mature trees in the urban environment thus the need to preserve some of those trees with the treatment option as recommended by Urban Forest Innovation. There is always a future possibility that researchers will find a natural predator or a treatment program that will eventually eradicate this disease for good. In the interim, the City needs to implement its own management plan in order to minimise the damage Emerald Ash Borer will inflict on the City's ash tree inventory.