Recommendation: RECEIVE and APPROVE staff report RPM-1-10, regarding the Emerald Ash Borer Management Strategy; and

Transcription

1 Page 1 of Report Roads and Parks Maintenance Department TO: Budget and Corporate Services Committee SUBJECT: Emerald Ash Borer Management Strategy Report Number: RPM File Number(s): Report Date: January 22, 2010 Ward(s) Affected: All Date to Committee: February 9, 2010 Date to Council: February 22, 2010 Recommendation: RECEIVE and APPROVE staff report RPM-1-10, regarding the Emerald Ash Borer Management Strategy; and REFER the multi-year financial implications of the recommended Emerald Ash Borer Management Strategy, Option 2 to 2010 budget deliberations; and DIRECT the Director of Roads & Parks Maintenance to prepare and report back with a 2010 Emerald Ash Borer Action Plan in the spring 2010; and FORWARD a copy of report RPM-1-10 to the Canadian Food Inspection Agency, Federal Minister of Natural Resources, Federal Ministry of Environment, Provincial Ministry of Natural Resources, the Association of Municipalities of Ontario and the Federation of Canadian Municipalities urging them to advocate for increased Emerald Ash Borer research funding and for the provision of financial assistance to affected municipalities. Purpose: Address goal, action or initiative in strategic plan Establish new or revised policy or service standard Respond to legislation Respond to staff direction Address other area of responsibility The purpose of this report is to update Council on the approaching Emerald Ash Borer (EAB) infestation and to

2 Page 2 of Report recommend an initial management strategy. Reference to Strategic Plan: N/A Executive Summary: The Emerald Ash Borer is probably already within Burlington and the impact of this infestation during the next ten years will be significant. Virtually all publicly and privately owned ash trees in the city will likely die. This is estimated to represent over ten per cent of the entire urban forest. Ash has been a very popular street and park tree for many decades due to its rapid growth and tolerance of urban environments. The city and homeowners will have to manage the risk presented by dying ash trees and consider their replacement. The city retained consultant Kenneth R. Marchant to develop EAB management options and strategic plans. Any management plan should be re-evaluated regularly against the latest information. The only available treatment product in Canada at this time comes with several reservations. Four Options were developed and considered: 1. Minimal Management; 2. Active Management; 3. Pre-Emptive Management; and 4. Aggressive Management Option 2: Active Management is recommended as the option that best balances various management concerns. It is further recommended that staff develop and report back with a detailed 2010 EAB Action Plan based on Option 2 in the spring The estimated cost of Option 2 is $11.5 million over the next ten years. There are sufficient funds proposed in the 2010 Capital Budget for year 1 of Option 2; however, the 10-year budget forecast does not provide full funding for the estimated costs of the recommended option. Future budgets will be refined as information regarding the infestation, management alternatives, timelines and related costs become clearer. Background: EAB was first identified in the Windsor area in Staff reports in February 2004 and December 2008 informed Council on the

3 Page 3 of Report expanding infestation of EAB in Southern Ontario. Council, at its regular meeting held on December 15, 2008, approved the following recommendation: THAT the Director of Roads and Parks Maintenance report back to the Community & Corporate Services Committee in the summer 2009 on an Emerald Ash Borer response plan (RPM 19/08). This report has been prepared in response to this direction. EAB has been positively identified in the Town of Oakville and the City of Hamilton, and has likely also reached Burlington. The impact on Burlington will be significant. Virtually all publicly and privately owned ash trees in the city, estimated to represent more than ten per cent of the entire urban forest, will likely die within the next ten years. Discussion: Ash in Burlington Street Trees Ash has been a very popular street tree for many decades due to its rapid growth and tolerance of urban environments. Appendix A shows the distribution of public ash trees on Burlington streets. The recently completed street tree inventory found that ash represents over 7,200 of the city s 53,000 street trees, or about 13 per cent. This is typical of many municipalities in Southern Ontario. The city has not planted ash on streets since 2004 and no longer approves ash for planting in new subdivisions. Monoculture Planting Park Trees Private Trees Ash is particularly well represented in areas of Burlington built after Its success as a street tree led to it being the dominant species planted in several neighbourhoods. Since 1980, the City has followed conventional urban forestry practices by limiting continuous monoculture (one species) planting. As with street trees, the hardiness of ash also made it a popular choice for trees in Burlington parks. Staff estimate there are over 6,000 trees in active park areas that will need to be managed. Ash has not been planted in Burlington parks since There are typically three private residential trees for every city street tree. This implies that there are over 20,000 ash trees on private residences, in addition to private woodlots and ravines.

4 Page 4 of Report Managing EAB Development of an EAB Management Strategy Homeowners will have to manage the risk presented by dead and dying ash trees and consider their replacement. In 2007, Burlington forestry staff led the establishment of a local Invasive Insect Working Group comprised of local agencies, to share information and strategies for current and pending insect infestations. These meetings led Burlington, Halton Region and the City of Hamilton to partner in retaining consultant Kenneth R. Marchant to develop EAB management options and strategic plans with each municipality. The Executive Summary of the consultant s report, A Strategic Plan to Manage the Emerald Ash Borer in Burlington, is attached as Appendix B. EAB Management Factors In developing various general EAB management options, the consultant s report considers the latest information on a number of factors: the biology of the insect and progress of the infestation; insect detection and monitoring techniques; roles and actions of other levels of government, including potential for financial assistance; biological control potential and insecticide control options; impact on the urban forest and on communities; knowledge from other North American communities, which are either preparing for or experiencing EAB; and estimated financial impact over a ten-year period. Adaptive Strategy There is uncertainty involved in several key infestation factors, including: infestation spread rate; potential arrival of natural biological controls; and availability and efficacy of insecticides. With this uncertainly, any strategic approach to manage EAB should be adaptive and re-evaluated regularly against the latest information. Insecticides Fighting EAB effectively with insecticides is difficult since the insect is inside the tree during its destructive stage. As discussed in the consultant s Executive Summary, Canadians

5 Page 5 of Report have only one available treatment product at this time, namely the pesticide TreeAzin. This product has received emergency registration for 2010 by Health Canada s Pest Management Regulatory Agency. Other promising products are available in the United States; however, their future registration in Canada is uncertain. While all indications to date are that TreeAzin is promising, staff and the city s consultant are of the opinion that its use should be modest because: its long-term efficacy has not been established; the continuance of emergency registration or future granting of full registration is likely, but not certain; repeated injection of any pesticide compromises tree health; it is not known how long bi-annual treatments will need to continue; there can be complications with the administration and/or uptake of any injected pesticide; and for trees under about 30 centimetres in diameter, it becomes more cost effective to replace rather than treat a tree. Strategic Plan Options Defining Options The consultant s report defines several strategic options to manage EAB. Each option was developed based on different general approaches and then further refined and costed to Burlington s specific situation. These options are summarized below with associated staff comments. More detailed commentary on each option can be found in the consultant s Executive Summary in Appendix B. Replanting Considerations All options assume the replanting of an estimated 95% of street trees and 15% of park trees. Many affected park trees will be adjacent to woodlots and not warrant replacement. Replanting cost estimates are based on the city s current planting standards that have been found to provide the greatest potential for tree survivability. Option 1: Minimal Management With Option 1: Minimal Management, the city would manage dead and dying ash trees as they become a hazard. This option provides time to further monitor the infestation and how other municipalities are responding.

6 Page 6 of Report This option does not provide the ability to minimize the EAB population, manage costs or protect trees.

7 Page 7 of Report Option 2: Active Management (Recommended) With Option 2: Active Management, the city would perform measured proactive surveying for EAB and removal of infested public trees, and limited use of TreeAzin in an effort to protect about 250 street trees. This is the option recommended by staff and the city s consultant. Staff are of the opinion that this option best balances: the unknowns of the future of the infestation; the unknowns of a TreeAzin treatment program; the desire to save valued trees; accelerated canopy replacement through some proactive survey and replacement; and the total estimated cost. Option 3: Pre-Emptive Management With Option 3: Pre-emptive Management, the city would begin a pro-active program to systematically remove smaller street and park ash trees regardless of infestation status, in addition to a limited use of TreeAzin as in Option 2. While this option would serve to minimize costs through efficiencies, the removal of healthy trees would likely be poorly received by residents. Option 4: Aggressive Management With Option 4: Aggressive Management, the city would perform rigorous proactive surveying for and removal of infested and surrounding trees, and broader use of TreeAzin in an effort to protect about 730 trees. While this option offers the greatest potential to save ash trees, it is also the most costly, invests significantly in a treatment program with many unknowns, and is limited in effect as it would only address the minority percentage of trees in public ownership. Recommendation 2010 EAB Action Plan It is recommended that staff prepare a detailed 2010 EAB Action Plan based on the strategy in Option 2. This plan will provide details regarding: survey for EAB; criteria for determining which street trees will be selected for treatment; and communications strategy to inform residents about EAB and the city s activities.

8 Page 8 of Report Staff will report back regarding the 2010 EAB Action Plan in the spring Financial Matters: Option Cost Estimates The 10-year cost estimates (in 000 s) of each EAB Option are as follows: Street Trees Removal ($500 - $775/tree) Replacement ($400/tree) Treatment ($250/tree, every two years) Park Trees (and trails) Removal ($ /tree) Replacement ($400/tree) Dropped Only ($75/tree) General Costs Option 1 Option 2 Option 3 Option 4 5,050 4,870 4,760 4,540 2,730 2,640 2,640 2, ,410 2,410 2,130 2, Surveying Project Coordination Communications TOTAL $11,320 $11,460 $11,210 $11,830 These costs are based on the following estimated numbers of trees: Option 1 Option 2 Option 3 Option 4 Street Trees Removal 7,210 6,960 6,960 6,490 Replacement 6,850 6,610 6,610 6,170 Treatment Park Trees (and trails) Removal 4,400 4,400 4,400 4,400 Replacement Dropped Only 1,880 1,880 1,880 1,880 Budget Implications Limited funding for managing EAB has been identified in the city s 2010 Capital Budget. The 10 year projected preliminary cost estimates for Option 2 are shown below along with the funding

9 Page 9 of Report proposed for 2010 in Capital Budget Project, Urban Forestry, including Management Plan and Pest Management (ST-MP- 1225). Proposed Capital Project Funding, ST- MP-1225 (in 000 s) Preliminary Cost Estimate for Option 2 (in 000 s) to 2019 Total ,450 $11, ,550 8,640 $11,460 In 2009, $50,000 was approved in project ST-MP-1225 for pest management, of which approximately $43,000 remains available. Therefore, with the proposed budgeted amount for 2010, there are sufficient funds for Option 2 in As can be seen however, the budget forecast does not fully match the estimated costs of the recommended option for the remainder of the 10 year forecast. Future budget submissions will be adjusted as information on the infestation, management alternatives, timelines and related costs become more defined. There are no Federal or Provincial funding programs to assist municipalities or other property owners in managing EAB. It is recommended that a copy of this report be forwarded to relevant agencies and municipal associations urging them to advocate for increased EAB research funding and for the provision of financial assistance to affected municipalities. Environmental Matters: Canopy Loss EAB will result in the loss of an estimated 10-15% of the entire urban forest within Burlington. This represents a significant loss in canopy cover and the many associated benefits of trees. All options assume that the vast majority of street ash will be replaced. Only 15% replacement is considered in parks, chiefly in active park areas, since ash loss in naturalized areas will be less of an overall impact to the area and increased replacement rates would be cost prohibitive.

10 Page 10 of Report TreeAzin Several options consider use of the insecticide TreeAzin. TreeAzin is based on the natural compound azadirachtin, derived from the Neem tree. While staff are not aware of any particular or significant environmental concerns, the product has not yet received full registration by Canada s Pest Management Regulatory Agency. Communication Matters: Any EAB management plan will need appropriate communications strategies based on both the city s plans for managing public ash trees, as well as, current information for dissemination to the public for management of private ash trees. As noted above, the 2010 EAB Action Plan will include a detailed communications plan. The Plan will also include an opinion from the Halton Region Health Department on TreeAzin and any potential role the Health Department may play. Conclusion: While not yet positively identified, EAB has likely reached Burlington and the impact will be significant. Several options to manage the resulting mortality of thousands of public trees on streets and in parks were considered. It is recommended that the city implement Option 2: Active Management as an initial strategy, with an ongoing commitment to regular re-evaluation during the infestation. A 2010 EAB Action Plan will be developed by staff to detail initiatives based on Option 2. Related financial requirements are identified in the city s 2010 Capital Budget documents. Respectfully submitted, Mark Covert Manager of Program Development , ext Rick Lipsitt City Forester , ext Appendices: A. Public Ash Tree Distribution on Burlington Streets B. Executive Summary, A Strategic Plan to Manage the Emerald Ash Borer in Burlington

11 Page 11 of Report Notifications: (after Council decision) Name Mailing or Address Approvals: *required Committee Disposition & Comments Council Disposition & Comments *Department City Treasurer General Manager City Manager To be completed by the Clerks Department 01-Approved 02-Not Approved 03-Amended 04-Referred 06-Received & Filed 07-Withdrawn 01-Approved 02-Not Approved 03-Amended 04-Referred 06-Received & Filed 07-Withdrawn

12 Page 12 of Report

13 Page 13 of Report APPENDIX B: EXECUTIVE SUMMARY, A STRATEGIC PLAN TO MANAGE THE EMERALD ASH BORER IN BURLINGTON Background EAB in North America The Emerald Ash Borer (EAB), Agrilus planipennis Fairemaire, is considered to be one of the worst invasive alien forest pests to ever be introduced to North America. EAB has killed or infested, by some reports as many as 70 million ash trees since it was first detected in Michigan, and south-western Ontario in 2002; an estimated 10 billion ash trees in Canada and the US are at risk of infestation and death. Both Canada and the US consider EAB to be a pest of quarantine significance and slowing its spread and protecting the North American ash resource is a top priority for both countries. Despite aggressive control, regulatory and communication measures aimed at slowing its spread, new populations continue to be found at numerous locations in both countries. These are often attributed to human activities such as the movement of infested nursery stock and firewood. EAB only attacks ash trees (genus Fraxinus). Notwithstanding, these comprise a significant percentage of street trees, parks and woodlands throughout southern Ontario, including the Burlington area and its economic and environmental impact can be expected to be very heavy once populations develop to damaging levels. EAB in Halton Region While EAB has yet to be found in Burlington, it is likely established there at subdetectable levels by virtue of it having been found in the neighbouring municipalities of Oakville in 2008, and early 2009 in Hamilton at numerous sites. In June, 2009, EAB was found in the Welland Area of Niagara Region and is now known to be well established at several locations there. Burlington is already included in an amalgamated regulated (quarantine) zone under a Federal Ministerial Order which prohibits the movement of potentially infested ash materials to non-infested areas. Assuming that EAB continues to infest and kill trees at its present rate, that biological control organisms do not emerge as a major control factor and that the current limitations on pesticide efficacy do not change, it can be expected that EAB will become pervasive throughout the City of Burlington over the next 10 years and kill most of its ash trees during this period. Managing EAB EAB is proving to be an extremely difficult pest to manage and there is no hope of eradicating it. Federal initiatives in both Canada and the US are geared towards K.R. Marchant: Abstract from A Strategic Plan To Manage the Emerald Ash Borer in Burlington. January 2010

14 Page 14 of Report protecting currently non-infested areas through the use of quarantines on known infested areas to lower the risk of long distance spread. In areas where EAB is already present, there is little that can be done to protect or save the majority of ash trees. While management initiatives may delay the onset of widespread mortality somewhat, most ash trees in infested areas will die within 10 years ; the best that can be hoped for is that some high value trees can be protected until such time as biological control organisms and other natural controls come into play and EAB s status as an invasive alien pest becomes normalized. Surveillance and Detection Despite considerable research being conducted on EAB since it was first discovered, the major obstacles to its effective management continue to be the extreme difficulty of reliably detecting it early in the infestation when populations are at low levels and treating trees in woodland or forest settings. Early detection and treatment are paramount to any effort to save at-risk trees. While some progress has been made by researchers, there are still no truly effective lures, traps or other survey tools that can reliably detect EAB early enough in the infestation cycle to be of use in managing infestations. Signs and symptoms of infestation such as crown die-back and emergence holes may not be present until EAB has been in the area four or five years, during which time it will have spread extensively. Furthermore, because EAB spends much of its life cycle within the tree and is usually not detectable until the tree is in decline; it is very difficult to control with pest control products. Pest Control Products At present, the natural pest control product TreeAzin TM is the only effective pesticide available in Canada. It currently has an emergency registration issued by the Pest Management Regulatory Agency (PMRA) of Health Canada to BioForest Inc. BioForest provides the product, specialized injection device (Ecoject ), and technical support to licensed subcontractors, who in turn can treat public and private ash trees. BioForest has successfully extended its emergency registration for 2010, and anticipates full registration of the product in 2010 or 2011 by PMRA. Even with bulk discount rates factored in, treatments are expensive, and range from $200 to $300 for an average sized tree. To be effective, trees must be in good health and treated on a continual basis for as long as EAB is present in the area; untreated trees would soon decline in the presence of high EAB populations. Additionally, because the injections are damaging to the tree s vascular system, trees are usually only treated every second year. While not conclusive, there is some data to suggest that this will be sufficient to protect the tree against EAB. TreeAzin has only been in use against EAB for a relatively short period and while preliminary results are encouraging, it is uncertain how well it will protect ash trees in the longer term, especially when EAB populations rise to their expected epidemic levels in a few years. Furthermore, it is not known what the long-term effects of the injections K.R. Marchant: Abstract from A Strategic Plan To Manage the Emerald Ash Borer in Burlington. January 2010

15 Page 15 of Report will be on the trees and it has been speculated that continued use may predispose them to other mortality factors. The relatively high cost of TreeAzin at present would not make it cost effective to treat most trees on private or public properties. Additionally, there is no practical way of treating the tens of thousands of ash trees in natural or woodland areas in the Burlington area and these would quickly succumb during the anticipated epidemic and act as brood material for developing populations of beetles. The resulting epidemic level of EAB would place all untreated ash trees in the Burlington area at imminent risk of infestation and death. Notwithstanding, it is recommended that the City of Burlington treat some high value trees along roadways or in parks and that it develop criteria for determining which trees should be designated high priority. Financial Assistance EAB is a federally regulated pest of quarantine significance and the Canadian Food Inspection Agency (CFIA) has actively attempted to slow its spread since it was initially detected in Windsor in Despite requests from Canadian Municipalities to the CFIA and other levels of government for financial assistance there is no expectation that the federal government will provide assistance at the municipal level to assist affected municipalities in off-setting costs associated with managing EAB. It is recommended however, that affected municipalities such as Burlington continue their quest to obtain assistance. Summary of Possible Management Options: Four management options have been developed for consideration by the City of Burlington; all are feasible and each has associated risks and benefits with respect to short and long-term management of EAB. All options are based on current science and incorporate elements of the various strategies implemented or attempted in North America since A brief description of each with their associated Pros and Cons is included below. Regardless of the option selected, it is anticipated that close to 100% of Burlington s ash trees will be lost over the next decade. All options have the following elements in common: Flexibility/Adaptability: research is on-going and new technology with respect to detection or control could be incorporated into each option when available; for instance, should new and more effective pest control products be registered in Canada, this could have a major bearing on the relative effectiveness and costs of the various options and they would be amended accordingly Replacement of removed trees with non-host trees consistent with the City s current recommendations for size and species K.R. Marchant: Abstract from A Strategic Plan To Manage the Emerald Ash Borer in Burlington. January 2010

16 Page 16 of Report Communication strategies with strong public messaging to maximize public support Training staff on EAB recognition and symptomology A moratorium on planting ash on public lands in the City until further notice The Options are: 1. Minimal Management 2. Active Management 3. Pre-emptive Management, and 4. Aggressive Management Option 1: Minimal Management With Minimal Management, there is no intent to manage the pest or off-set costs associated with EAB infestations. No surveys specific to EAB would be conducted, and ash trees would be treated the same as any other genus of trees; they would only be removed if they die and/or become hazardous. No public trees would be treated with insecticides by the City. PROS EAB has yet to be detected in Burlington The initial financial impact to the Municipality would be minimal There is some data to suggest that biocontrols are playing an increasingly important role in controlling EAB and it may come under natural control in the future Minimal Management CONS EAB is likely present in Burlington This option is reactive rather than pro-active with respect to detection and removal of infested trees Biocontrol organisms, while present in some areas have not had a major impact in measurably reducing EAB populations to this point Allowing infested trees to stand will exacerbate the rate of population build-up to epidemic levels and dispersal to currently non-infested areas High EAB populations would compromise control measures by private property owners and others wishing to save their trees through pesticide treatments As EAB reaches epidemic levels the Municipality may be overwhelmed with the sheer volume of dead trees that must be removed resulting in sizable and non-discretionary budget pressures Standing dead ash trees rapidly decompose and will become hazardous with associated liabilities for the City K.R. Marchant: Abstract from A Strategic Plan To Manage the Emerald Ash Borer in Burlington. January 2010

17 Page 17 of Report Option 1: Preliminary Annual Costs Estimated Total: $11.3 million 2,500,000 2,000,000 1,500,000 1,000, , Option 2: Active Management With Active Management the Municipality would conduct annual detection surveys to find publicly owned infested trees which would then be removed prior to the emergence of EAB adults in the spring. A delimitation survey would also be conducted in the immediate vicinity of infested trees to detect any additional trees which may be infested. Early detection and removal may result in efficiencies associated with economy of scale with respect to removal operations. This option would also feature the treatment of approximately 250 high-value trees every second year with TreeAzin for as long as EAB remained a threat. Failure to continue these treatments during the anticipated epidemic phase of the EAB outbreak would result in their rapid decline and death. The success of TreeAzin treatments will be evaluated on an annual basis and additional resources may be diverted to treatment in future years. K.R. Marchant: Abstract from A Strategic Plan To Manage the Emerald Ash Borer in Burlington. January 2010

18 Page 18 of Report Option 2: Active Management PROS EAB has yet to be detected in Burlington Only known infested trees will be removed More proactive than Option 1 o Detection surveys would result in infested trees being found earlier o Distribution of removal costs over a longer period Treating some high-value trees with TreeAzin could preserve the canopy in some streets with high ash populations The sooner trees are removed, the sooner they can be replaced CONS EAB is likely present in Burlington EAB cannot be reliably detected at low population levels Tree removal and select pesticide applications as proposed will do little to suppress EAB population build-up, slow the spread of EAB or preserve ash trees Biocontrol organisms, while present in some areas have not had a major impact in measurably reducing EAB populations to this point As with option 1, the Municipality may be overwhelmed with the sheer volume of dead trees that must be removed in future years resulting in sizable and non-discretionary budget pressures Only a relatively small percentage of the canopy will be saved by using TreeAzin; the remainder of the trees will die within 10 years 2,500,000 2,000,000 1,500,000 1,000, ,000 Option 2: Preliminary Annual Costs Estimated Total: $11.5 million Option 3: Pre-emptive Management The objective of Pre-emptive Management is to manage and distribute the costs associated with EAB infestation over an extended period rather than manage (or react to) the pest per se. The basic assumption with this option is that all trees are going to become infested anyway, and removing them in a planned orderly fashion will reduce the overall costs associated with EAB in the long run. While the Municipality would conduct annual surveys to detect publicly owned infested trees and any EAB hot K.R. Marchant: Abstract from A Strategic Plan To Manage the Emerald Ash Borer in Burlington. January 2010

19 Page 19 of Report spots, the overall plan would call for the removal of all publicly owned ash trees as costefficiently as possible over a defined period (10 years irrespective of their infestation status. Priority would be given to the staged removal of smaller ash trees (<20cm) in areas where their numbers are high to gain efficiencies and accelerate canopy replacement. As with Active Management, the Municipality could elect, at its discretion, to treat highvalue publicly owned trees with TreeAzin. Irrespective of the pro-active nature of this option, it is likely that mass die-off would still occur a few years after initial EAB detection and the sheer number of dead or dying trees would overwhelm the system as with options 1 and 2. PROS This option maximizes the opportunity for a planned, staged canopy replacement with nonhost trees Staged removals would result in cost efficiencies Proactive (rather than reactive) removal of trees will distribute costs over a longer period The removal of ash trees before they die will limit the number of hazard trees and associated potential liabilities to the Municipality Option 3: Pre-emptive Management CONS This option is likely to be unpopular with residents: o There would be a severe impact on some streetscapes with high percentages of ash o Selective cutting of trees (especially those in apparent good health) could draw the ire of residents and activist groups and may be difficult to defend Because only public trees would be cut, there would be little impact on EAB population build-up and tree mortality on private property, woodlands or naturalized areas Irrespective of the proactive intent of Option 3, EAB is still likely to experience a mollified epidemic phase and require more than 10% of the ash canopy to be removed in peak years. There is an upfront funding requirement for this option While not a known factor to this point with EAB, potentially resistant trees could be culled (and their genetic makeup lost forever) K.R. Marchant: Abstract from A Strategic Plan To Manage the Emerald Ash Borer in Burlington. January 2010

20 Page 20 of Report 2,500,000 Option 3: Preliminary Annual Costs Estimated Total: $11.2 million 2,000,000 1,500,000 1,000, , Option 4 (Aggressive Management) The objective of Aggressive Management is to save as many trees as possible and slow the spread of EAB locally by detecting and removing or treating known infested trees as well as those within a prescribed buffer zone (the premise being that EAB spreads radially from its initial point of introduction to a new area). This would be the option of choice in generally uninfested areas with newly established outlier populations that could be traced to a single introduction event. Unfortunately, there is no evidence that this option has ever been effective. Larger scale versions of this option have been implemented in both Canada and the US in past years and for the most part these have failed to contain EAB or to even measurably slow it down. The Municipality would conduct intensive annual surveys of its street and park trees to detect those infested with EAB and increase the use of TreeAzin. Infested trees would either be removed or treated depending on their condition. Additionally, all ash trees within a defined radius of these (usually 500m) would either be treated with TreeAzin, or removed. In some areas, this would require large numbers of apparently symptomless trees to be removed or, treated every two years for as long as EAB was present in the area. Although this option could delay the onset of the epidemic phase of the outbreak somewhat by suppressing the numbers of emerging adult beetles, the potential for success in Burlington is very much limited by EAB populations in neighbouring municipalities such as Oakville and Hamilton, the absence of municipal bylaws compelling private property owners to treat or remove infested trees, and the absence of any federal or provincial government initiatives to slow the spread in infested areas such as Halton Region. Furthermore, EAB infestations generally pop up at numerous K.R. Marchant: Abstract from A Strategic Plan To Manage the Emerald Ash Borer in Burlington. January 2010

21 Page 21 of Report disparate locations and control actions around these often evolve into clear-cutting situations. Overall, this option is likely to have very little impact on the overall epidemiology of EAB in the area and has the potential to become a money sink. PROS Pro-active rather than reactive Limits number of hazard trees and potential liabilities to the Municipality Allows for the option of protecting highvalue ash in parks, cemeteries, golf courses etc. through treatment May reduce the overall infestation potential for EAB by reducing EAB populationscould be a factor in slowing the spread of EAB within the Municipality Could preserve the genetic diversity of ash within the area The best option for maintaining the percentage of ash in urban canopy Option 4: Aggressive Management CONS The overall potential for success with this option is very much compromised by: o The absence of bylaws compelling private property owners to treat or remove infested trees o The large number of ash in woodlands and naturalized areas which cannot be treated o The requirement to remove or treat symptomless trees in buffer zones o Perceived lack of public support for large scale tree removal or treatment o The prevalence of EAB in neighbouring communities EAB cannot be reliably detected at low population levels and is likely to be established in Burlington at numerous locations and to have already dispersed from these sites Once EAB enters its epidemic phase this option is likely to evolve into clear-cutting of Burlington s ash canopy which could greatly add to its costs in the long term Large scale tree removal could result in potentially resistant trees being culled (and their genetic makeup lost forever) Treatment with pest control products is not 100% reliable and results are variable; even treated trees die or decline This is a long-term commitment; pesticide treatments would have to continue indefinitely to protect the investment and even with an economy of scale factored in, costs are likely to be exorbitant in the long run As surveys or treatments on private property would be at the discretion of the homeowner, the failure to remove or otherwise treat infested or at-risk trees would compromise control actions on nearby street and park trees K.R. Marchant: Abstract from A Strategic Plan To Manage the Emerald Ash Borer in Burlington. January 2010

22 Page 22 of Report 2,500,000 Option 4: Preliminary Annual Costs Estimated Total: $11.8 million 2,000,000 1,500,000 1,000, , Recommendation In consultation with the City of Burlington, Option 2 (Active Management) is recommended for implementation. Further details on the history of EAB in North America, its biology, the options considered, and case studies from other communities are provided in the document from which this summary is abstracted: A Strategic Plan to Manage the Emerald Ash Borer in Burlington. K.R. Marchant: Abstract from A Strategic Plan To Manage the Emerald Ash Borer in Burlington. January 2010