Introduction
A substantial portion of Stanley Park's once proud and famous forest of mature conifers is dying or dead. Many of the visitors to Stanley Park in the last several years have noticed the mounting number of defoliated and dead mature (80 years to 150 years of age) and old growth (150 years +) conifers in the park forest. The park itself was dedicated by Lord Stanley in 1888, 135 years ago, and two years after the founding of Vancouver. Many of the trees Lord Stanley saw then were quite possibly included in the attack by the Western Hemlock Looper moth in their larval stage (a caterpillar that arches its back when crawling). It was fully expected when it first arrived in 2019 or 2020 to die out in 1 to 2 years. Uncontrolled, it is attacking the forest again this year (year 3) with even greater vengeance. By all appearances, 2023 attack was light, and likely the final year of this cycle.
Ministry of Forests Recommendation Spring 2021
The Vancouver Board of Parks and Recreation had discussions in the Spring of 2021 with the Ministry of Forests, Lands and Natural Resource Operations Coast Region's Forest Health Officer Stefan Zeglan according to my discussions with him about controlling the looper moth. His recommendation was to aerial spray that year with Bacillus thuringiensis (Btk) a commonly biological treatment against defoliator moths.
August 17, 2021 Vancouver Sun Interview with J. McLeod
According to the August 17, 2021 interview by the Vancouver Sun with Joe McLeod, then Supervisor of Urban Forestry for the City of Vancouver, it was indicated that the Board had probably already decided as early as 2019 or 2020 that they would not attempt any procedure to control the then known invasion by the looper moth, and have said all along that "nothing could be done - it is a natural occurrence". It is clear that, if the Ministry of Forest's 2021 recommendation was followed, aerial spraying could have effectively commenced in the spring/summer of 2021 when the moths were in the larval stage (looper caterpillar) and were feeding voraciously and wastefully on the fresh tree-top needles. It was not until a year and one-half later (August of 2022 according to the Blackwell 2024 report) that the Board documented significant mortality in the forest, triggering the need for assessment, too late for treatment with BtK once again that year.
Four long years were foregone for preventative treatment. Now there's the public's realization of a much greater disaster from the looper moth than Typhoon Freda in 1962 and from the recent windstorm together, and causing incalculable costs, beyond the astronomical five million good tax-payers dollars for clearing and restoration costs that wouldn't have had to be spent. There now will be many decades - close to a full human lifetime - of mature forest qualities foregone - waiting for ecological and aesthetic restoration of the mature forest canopy and all it provides - provided, of course, the next major invasion isn't again allowed unchecked.
By 2023, the results of the damage were widespread, expanding greatly from north-east to south-west in the park. Although the moth population was already collapsing after 4 years, but newly attacked areas still could have benefited from aerial spraying. Bacillus thuringiensis (or Bt) is a gram-positive, soil-dwelling bacterium, the most commonly used biological pesticide worldwide. B. thuringiensis also occurs naturally in the gut of caterpillars of various types of moths and butterflies, as well on leaf surfaces, aquatic environments, animal feces, insect-rich environments, and flour mills and grain-storage facilities (source: Wikipedia). Btk was used successfully and without controversy recently to cover 300 hectares in Surrey and in other areas of the Lower Mainland being attacked by another defoliator, the Lymantria moth, (see link below).
Parks and Recreation General Manager's Response 2022
The General Manager's Office (GM Donni Rosa at the time, since replaced), responded to my e-mail with the following:
"Thank you for reaching out regarding the trees in Stanley Park. The trees located on the North end of Stanley Park that appear dead have suffered from the elevated population of Hemlock Looper Moths that have surged during the past summer seasons. Though the Looper Moth are native to this area they put additional stresses on Hemlock trees and other species (Douglas for and Grand fir) within the forested areas as evident from the Lions gate bridge. Dramatic shifts in elevated temperatures, including the heat dome in 2021 and prolonged periods of drought, have further exacerbated tree mortality since over mature trees are susceptible to the moths feeding on them [KF comment: the moth larvae actually prefer the abundant luscious needles at the tips of the branches of thrifty mature growth around 80 years of age, not "over mature" trees according to my literature research and on-the-ground indication: US Forest Service ]. The GM's note continued: The moths population boom typically occurs in an 11 to 15 year cycle. Effects of the Moth have been seen across the entirety of the North Shore with many trees dying in the process across various municipalities. Hazard mitigation efforts will be undertaken to remove the trees once determined to be hazardous to ensure public safety along both the Seawall and other high use areas of the Park. The majority of mortality has occurred within the short term. The response plan will be a multi-year effort engaging First Nation partners as well as several stakeholders. Fire fuel loading will also be reviewed in the course of an RFP to develop a holistic plan to cover the emerging issue." (e-mail dated August 29, 2022).
The Metro Vancouver Watershed
The Metro Vancouver watershed was hit hard in 2020 with 300 hectares of forest affected of the 20,000 hectares in the Capilano watershed alone. At its closest proximity to Stanley Park, it is just 6km away and possibly the source of the looper infestation in the park. No spraying was carried out. The Stanley Park forest is about 300 hectares or 75% of the total area of the park in total. What may be argued for improving forest resilience by leaving it to nature in a large, closed-access, though scenically significant, watershed is not appropriate for Stanley Park and its millions of visitors where forest aesthetics and recreation values are intertwined with ecological values and health values (large trees are the fresh air lungs of Vancouver).
Contacts: City Arborist, Invasive Species Council and Stanley Park Ecological Society 2022
On August 31, 2022, I had a detailed conversation with Joe McLeod, City Arborist - now the Manager of Urban Forestry for the Parks Board, about how the city is going forward with the issue of the dying and dead trees in the park. The City obtained LiDAR and multi-spectral aerial photography that past month and are awaiting the data to be processed. There would also be a call for proposals on how to manage the risks going forward of the now changed forest, including visual landscape aesthetics (see below). While talking with the City Arborist, I learned they felt they should not act at the early stages of looper development each year, and also wished to avoid public criticism [KF: a systematic predictive moth egg count in the autumn would have provided the proper indication of the likely intensity of spring attack and need for action. See this link: BC Government].
I also heard from the Executive Director, Invasive Species Council of Metro Vancouver on the same day whose comments were similar, but were requested to be withheld here pending further joint communication from the organization and the Stanley Park Ecology Society. No word was ever received back from them. Also, no word is mentioned about the devastation caused by the looper moth on the SPES website as at February 3, 2024. A search for "hemlock looper moth" on that website on that date resulted in "Nothing Found".
Stanley Park Forest Management Plan 2009
The Stanley Park Forest Management Plan 2009 plan was produced under a consultative agreement with the University of British Columbia Faculty of Forestry.
The plan cites the Ministry of Forests' Hemlock Looper treatment:
B.C. Ministry of Forests and Range: Hemlock Looper Management Guide p. 26 of the management report (link is dead).
The current similar coverage is found at:
and at:
References cited in the 2009 Management Plan lead back as far as 1980:
B.A. Blackwell & Associates Ltd., Planting Summary for Stanley Park (North Vancouver: B.A. Blackwell & Associates Ltd., 2008).
B.A. Blackwell & Associates Ltd., Stanley Park Fire Preparedness Plan for 2007 (North Vancouver: B.A. Blackwell & Associates Ltd., 2007).
Beese, W. J. and G. J. Paris, Stanley Park Regeneration Program Forest Management Plan Folio I & II (Nanaimo: MacMillan Bloedel Limited, 1989).
Belyea, Sorensen and Marc St. Louis, The Stanley Park Technical Report (Vancouver: Belyea, Sorensen & Associates, 1992).
Blakewell, David R. Forest Maintenance Program for Stanley Park, 1980.
Bufo Incorporated/Cortex Consultants, Margaret Holm and Associates, Pavelek and Associates and The Portico Group, Stanley Park Interpretive and Wildlife Plan (Vancouver: The Vancouver Board of Parks and Recreation, 1992).
McLean, John A. 2007 Survey of Insect Biodiversity in Stanley Park – Setup and Progress Report to October 31st , 2007 (Vancouver: University of British Columbia, 2007).
Mitchell, Stephen. Follow-up to Visit of February 26, 2007 to Stanley Park to Discuss Windthrow Mapping and Pruning Treatments (Vancouver: University of British Columbia, Faculty of Forestry, 2007).
Mitchell, Stephen. Forest Health: Preliminary Interpretations for Wind Damage (Victoria: Ministry of Forests, 2000).
Mitchell, Stephen. Draft Preliminary Recommendations for Windthrow Management in Stanley Park – January 18, 2007 (Vancouver: University of British Columbia, Department of Forest Sciences) Mitchell, Stephen and Naa Lanquaye-Opoku, Windthrow Modelling for Stanley Park (Vancouver: University of British Columbia, Department of Forest Sciences, 2007).
Natural Resources Canada, Canadian Forest Service, Final Technical Report – Part C Monitoring Western Hemlock Looper Populations in British Columbia (Victoria: Ministry of Forests and Range, 2004).
Robertson, Ian and Timothy J. Bekhuys, Draft Lions Gate Crossing Project Stanley Park and First Narrows Environmental Assessment Study – Wildlife (Langley: Environmental Management and Emergency Planning, 1994).
Additional research studies and conference presentations covering the hemlock looper in Stanley Park and elsewhere can be found at UBC's TREERINGLAB website.
In the news July 4, 2023:
https://dailyhive.com/vancouver/stanley-park-board-fire-prevention-strategy
KBF Observation - July 20, 2023
The 2023 season looks like there are much fewer looper moths around to munch at the remaining forest greenery. However, my new photo (to be posted soon) shows many looper caterpillars hanging down from overhead branches on silk threads and cavorting on the "Lovers Trail" signpost on Squirrel Trail again this year like it is a "Cirque de Looper". Logging is slowly getting underway, clearing the high-risk dead trees along roadsides. It appears the large trees were initially being bucked into short chunks without consideration of potential milling value. Full length logging trucks have been seen arriving in the park since late October 2023, indicating major salvage is well underway (see the City News articles in the November update (above)).
Hindsight
Hindsight is 20:20, as the saying goes, but had the Parks people acted on recommendations by FLNRO to control the pest with Btk, made known to them in 2021, we would likely still have most of our famous mature conifer forest in Stanley Park. Now we'll have to wait many generations [about a human lifetime] before the forest reaches that age, character, crown closure, ecological complexity, and important contribution to the healthy atmosphere of the City. Large trees contribute significantly as the "green lungs of the city" for their production of oxygen, and a carbon sink for carbon dioxide). An Australian study showed that a 100 year old tree can contribute 6.600 kg of O2 over its lifetime. Our big trees are too important to lose. Each tree takes a human lifetime to achieve its mature glory.
Forest Management Plan 2024
The City of Vancouver had a Request for Proposals out regarding forest management in Stanley Park going forward over the next several years. The "Consulting Services for Stanley Park Forestry Initiatives" (PS20220119-ACCS-RFA) can be accessed on the City of Vancouver portal. As stated in the RFP, "The City of Vancouver (“City”), as represented by its Board of Parks and Recreation (the “Park Board”) is seeking proposals from multi-disciplinary consultant teams (“Consultant”) led by an urban forestry or environmental management/consulting firm with expertise in urban forest assessment and management planning. The project team must include staff or sub-consultants with experience in forestry, arboriculture, planning, urban ecology, integrated pest management, silviculture, planning, and wildfire risk assessment. The successful Consultant will have prior experience leading similar projects of scope and complexity and will work closely with Park Board staff to: 1) Provide an assessment of Hemlock Looper impacts to trees and forest areas in Stanley Park and an associated mitigation response plan in combination with hazard mitigation efforts that are of high importance related to target values; 2) Provide an assessment and mitigation plan for wildfire risks in Stanley Park; and, 3) Create an inventory of Hemlock Looper and wildfire risk areas as polygons in Stanley Park." Closing date was November 1, 2022.
Comment of the RFP
Unlike in my discussion with the City Arborist (above), there is no mention in the RFP of forest aesthetics, or visual impact assessment / mitigation / rehabilitation in the internationally important, extensively used, Stanley Park. Following extensive salvage logging, the restoration and rehabilitation of the forest will require a gigantic effort, and several human generations to reach its recent glory again. Many of its trees now being lost were around when the park was first opened in 1888 by Lord Stanley, dedicated ‘to the use and enjoyment of peoples of all colours, creeds, and customs, for all time’.
Update November 30, 2023
A shocking article City News November 29, 2023 https://vancouver.citynews.ca/2023/11/29/stanley-park-tree-removal-moths/ reported that 160,000 trees covering 25% of the Stanley Park forest are now dead and being harvested in major logging operations. Many of these trees could likely have been seen by Lord Stanley when he dedicated the park 135 years ago. A follow-up article in December 2, 2023 from the same news source: https://vancouver.citynews.ca/2023/12/02/thousands-of-trees-will-be-felled-in-vancouvers-stanley-park-due-to-moth-infestation/ suggested that 140,000 trees to be cut are under 20cm in diameter "as the preferred food source". When requested under the Freedom of Information Act for the full report by Vancouverisawasome.com, the formal FOI request was refused by the Vancouver Board of Parks and Recreation. That article by Bob Mackin on December 6, 2023 follows:
Vancouver Park Board mum on science behind decision to cut one-quarter of the trees in the city’s largest park - Vancouverisawesome.com by Bob Mackin:
The Vancouver Park Board is removing 160,000 trees due to pest infestation and wildfire fears.
"For the time being, the Vancouver Board of Parks and Recreation is refusing to release the expert report behind the operation to cut down almost a quarter of the trees in Stanley Park.
At the end of November, the Vancouver Park Board announced scheduled closures of the Lions Gate Bridge, Stanley Park Causeway, and other roads and trails over the next two months while it removes 160,000 trees due to pest infestation and wildfire fears.
The board previously announced periodic closures on Oct. 19 for a two-week period, but did not peg the number of trees marked for removal at that time. [KF: Closures of the Stanley Park Causeway for logging nearby trees are happening in February, 2024].
“The primary focus is to prioritize the removal of trees affected by the hemlock looper moth infestation in heavily visited areas of Stanley Park, in alignment with preparations for winter storms, wildfires and bird nesting season,” said Vancouver Park Board spokeswoman Eva Cook.
Cook said B.A. Blackwell & Associates Ltd. is the forestry consultant working with the board, but she refused to say how much the contract is worth. The website for North Vancouver-based consultancy includes a long list of clients, such as the Canadian Forest Service, Parks Canada, B.C. Parks, Ministry of Environment, Metro Vancouver, Resort Municipality of Whistler and Union of B.C. Municipalities.
“Additional information regarding the long-term management of Stanley Park, and associated financial details, will be disclosed in due course,” Cook said.
B.C.’s freedom of information law contains a clause under the heading “public interest paramount” that requires disclosure, without delay, of any information that is about the imminent risk of significant harm to the environment or to the health or safety of the public or a group of people.
It also requires the same disclosure without delay if it is, for any other reason, clearly in the public interest.
While the Vancouver Park Board did announce basic details of the tree removal program and how it affects routes for motorists, cyclists and pedestrians, it has not provided details about the science behind the program.
On Monday, it rejected a reporter’s request to make the expert report available without delay.
“After reviewing the subject matter and seeking advice, I have determined the requested subject matter does not require disclosure in the public interest, under section 25 of [the Freedom of Information and Protection of Privacy Act],” said Cobi Falconer, the city’s director of access to information and privacy.
The executive director of a transparency watchdog organization said the Vancouver Park Board is falling short of its obligations to the public. [KF: the report might provide insight into the presumed absence of prediction of the intensity build-up of the looper destruction year-after-year and of the tolerance for such build-up].
“It’s a trust, but … it is a dynamic where there is trust in transparency for public bodies, and they need to be appropriately transparent for people to trust the decision that they are making,” said Jason Woywada of the B.C. Freedom of Information and Privacy Association. “Particularly when you're dealing with a park as prominent as Stanley Park, it's important for the public to be able to understand why 160,000 trees are being cut down in that area.”
In 2016, then Information and Privacy commissioner Elizabeth Denham concluded that the public interest override section of the law may not require disclosure of a record, but sometimes disclosure of a record must happen.
In her analysis of a 2014 drinking water advisory in Spallumcheen, B.C., Denham said it was necessary to require the Ministry of Environment release a soil test data analysis report in order to “assist with public understanding of the science, and to assist with evaluation of the Ministry‘s interpretation of that information and its actions based on that interpretation.”
“This objective could not be accomplished by the disclosure of the mere summary of information contained in those records,” Denham wrote.
Woywada said the province has provided public bodies thorough instructions on how to make decisions under Gender-Based Analysis Plus or the Declaration of the Rights of Indigenous Peoples. But it has not done the same when it comes to deciding when to release information in the public interest.
“That is why, I think fundamentally, we've got so many failings in the access to information system in Canada right now, is it's just defaulting to secrecy and risk management,” Woywada said."
Looper's Preferred Food - Older Trees
According to data from the US Forest Service, the actual preferred food source is Western hemlock is trees 80 years and over. Younger growth trees are usually only attacked as the large trees are defoliated as the looper progresses. The literature is in strong disagreement with the finding that 87.5% of the affected trees in the park are under 20cm diameter. Close observation by this writer last year showed most dead and dying trees were hemlocks 60cm and greater and were by far the greatest proportion of biomass and forest canopy in the vicinity of 90% or greater in the affected areas which a few years earlier were in thrifty mature condition. Those big trees provide much of the oxygen produced in the Stanley Park forest - known popularly as the "green lungs of the city"). Clear-cut operations are now underway in the Prospect Point area (see recent Google Earth image at the top of this page clearly displaying the predominantly large dead and dying trees occupying most of the forest canopy that are the focus of the operations). Regardless of the disparity between counts and estimates, even 20,000 large trees are an overwhelming, once-avoidable loss (approximately one 30" tree has the same basal area of eight 8" trees) . Reforestation will take decades to resume the extent of oxygen production that the older trees have been providing. A study in Australia found that a 100 year old tree could produce 6,600kg of oxygen over its lifetime, while also providing carbon capture.
City of Vancouver Mayor's Initiative to Disband Parks Board
In a somewhat expected move, the Mayor of Vancouver plans to remove the Vancouver Parks and Recreation Board announced December 6, 2023. In his press conference and in follow-up replies to questions, the Mayor twice appeared to suggest the allowed destruction of 25% of the Stanley Park forest contributed to his reasoning:
CBC News re: Mayor's Initiative
"Ken Sim made the announcement at a news conference Wednesday morning.
The mayor said his council motion asking the provincial government to amend the Vancouver Charter, which governs the city, "is long overdue" to address systemic issues of having two elected bodies governing in the city.
"The system is broken and no amount of tweaking will fix it,'' Sim said. "We have two groups. It just doesn't work. It's hard to see who has jurisdiction over what, that's why there's squabbling over a bunch of different things."
Vancouver is the only large city in Canada with a separately elected park board.
While council is in charge of setting the parks budget and approving a capital plan, oversight of the city's 240-plus parks and dozens of recreation facilities falls to seven elected park commissioners and separate park board management." Justin McElroy, Chad Pawson, CBC News, posted December 5, 2023.
City News December 18, 2023 (link) re: Logging Stanley Park:
https://vancouver.citynews.ca/2023/12/17/heavy-logging-stanley-park/
City New January 19, 2024
"Vancouver City Council being asked to approve $4.9M to fight looper moths"
report by Emma Crawford January 19, 2024
"Vancouver City Council is being asked to give the park board $4.9 million to take down trees damaged by looper moths across dozens of hectares of the park.
The report to council is also calling for extensive tree planting and vegetation management work over the next two years. The looper moth outbreak started on the north shore 2019, and it was found in Stanley Park in 2020 following warmer winter and spring conditions.
“There is no feasible treatment for the insect, and the use of pesticides would impact all other moths, butterflies, and other non-target insect species,” the report says.
“When the looper population did not naturally decrease after two years, significant tree mortality was observed, and a professional forestry consultant was engaged in 2022 to develop a risk
assessment and mitigation plan.”
As trees die and decay, they can fall, posing a safety risk to the public.
Council will decide whether to approve funding at a meeting next week."
KF note: see Ministry of Forests recommendation for safe biological treatment in 2021 above. A $5MM cost and decades of ecological and aesthetic losses while supposedly protecting unidentified and unmeasured butterfly populations doesn't make any sense, currently, and definitely won't the next time there in the face of such a costly and devastating invasion. A fire left unattended in the forest could have had equal consequences. We would never have allowed that to happen. If so, a formal public inquiry would likely have been launched. The slower but obviously equally as deadly "burn" from the looper moth should have been treated no differently.
Lungs of the City
As the "lungs of the city", a 25% loss of the forest of vigorous mature trees aged 80 to 100 years (the looper's main feeding target) is seriously akin to a major lobectomy of the human lungs. Recovery time for a human is relatively brief if the disease is not too pervasive, while the forest takes a human lifetime to restore to its full oxygenating and carbon capturing potential while scenic and aesthetic beauty qualities might return in starting in about 60 years. A new plantation has little of these qualities. Although Western hemlock is relatively short-lived (150 years), Douglas fir and Western redcedar will achieve old-growth status (150-250 years) and much beyond (600 years+).
A Bit of Stanley Park's History
In 1886, as its first order of business, Vancouver’s City Council voted to petition the Dominion of Canada Government to lease the military reserve for use as a park (Source: Wikipedia). To manage their new acquisition, city council appointed a six-person park committee, which in 1890 was replaced with an elected body, the Vancouver Park Board. In 1908, 20 years after the first lease, the federal government renewed the lease for 99 more years. In 2006, a letter from Parks Canada stated that “the Stanley Park lease is perpetually renewable and no action is required by the Park Board in relation to the renewal. The park was first opened in 1888 by the Governor General of Canada (1888-1893), Lord Frederick Arthur Stanley. Stanley Park was officially designated as Stanley Park National Historic Site of Canada by Parks Canada in 1988 and thus is infinitely worthy of our unwavering protection and investment, commanding the excellence of stewardship and fullest duty of care. Read the Historic Site description here and here.
Existing plaque: " Remarkable for its magnificent setting, the park displays a harmonious relationship between its natural environment and its cultural features. The dense and lofty treed landscape, essentially unaltered by human hand, typifies the British Columbian coastal forest."
KBF Statement February 3, 2024
With such history and significance of Stanley Park to Canada and the world, a much higher order of management and protection of the mature conifer forest was always commanded by its very significant Canadian Historic Site designation. The BC Ministry of Forests' Forest Health Officer's recommendation several years back to aerial spray when it would have made a profound difference (pers. comm., Stefan Zeglan, 2022) was inconceivably rejected to avoid potential public criticism and protect some butterflies and otherer moths. As a result, and exacerbated by drought, 160,000 magnificent thrifty conifer trees in Stanley Park covering 25% of the forest area, at Park Board estimates, have been lost for the dubious purpose of saving an undetermined number of butterflies or moths which might have been in the direct path of aerial application and who might have similarly been in the required vulnerable larval stage if BtK was applied within the recommended brief time-window to eradicate the looper invasion. The invasion will certainly return and the remaining mature forest may further be disastrously destroyed if the preference is not to intervene in natural processes over the now certain and devastating realities facing Stanley Park forest by the rampant defoliators. The Park Board or its successors will still be most likely to stubbornly to avoid spraying looper moths with BtK if/when the next infestation arrives in 11 to 15 years. Stanley Park is ideal for treatment, being uniquely isolated by the substantial waters of Coal Harbour, Burrard Inlet and English Bay bordering 90% of the 9km long edge of its peninsular landform. The Lepidoptera-hugging mentality can no longer be allowed to freely prevail over sound forest management practices and protection ever again in our world famous Stanley Park forest, given the outrageous, heart-breaking, five-million-dollar, a-human-lifetime-to-fully-restore, results of willfully not controlling the looper moth outbreak at the proper time.
KBF Update February 20, 2024
The Parks Board published an updated webpage this week on their website on the looper and the recovery plan. The new page is found under the "Nature, environment, and sustainability" entitled "Stanley Park forest management". The only information about the forest in crisis until now over the course of the multi-year invasion had been mainly provided by local citizen initiatives such as the Save Stanley Park Society's website and media such as
vancouverisawesome.ca, vancouver.citynews.ca, and cbc.ca/news/canada/british-columbia/local (see above links to articles from these sources earlier in this summary).
The Parks Board's detailed website covers the recovery operations, a link to the B. A. Blackwell & Assoc. report entitled Hemlock Looper Impact and Wildfire Risk Assessment. and a video featuring the Manager of Urban Forestry for the Parks Board focused solely on recovery, planting and raking, plus an earlier information video about the looper. Nothing is said to explain the several year's failure to control the current enormous loss of mature forest nor about plans to control future such outbreaks. The statement in the video about the "small amount of high-value trees" being removed appears to be easily contradicted by the number of large logs and stumps evident in the video, by simple on-the-ground visual assessment, and by the previously stated 20,000 number of large trees being removed. The large trees being removed would have to comprise the largest proportion when measured in volume in cubic metres of wood compared to the small trees. That the high proportion of forest canopy and crown closure once covered by mature forest comprising most of the intensive areas of attack is now open ground is also ignored in this "feel-good" video.
The Blackwell & Associates report reveals the astounding extent of death of 30% and damage of 36% requiring monitoring of large trees greater than 20cm dbh (p. 11). Page 12 of the report has an equally astounding impact severity map with high and moderate severity areas across vast areas of the park. The report concludes that "Ongoing monitoring should be a key component of addressing the hemlock looper outbreak in Stanley Park.... Adaptive management will be key to successfully mitigating hemlock looper and wildfire risk...within a context of healthy forest ecosystems and functional park assets." The report does not make specific recommendations for timely prescriptive interventions to avoid or control future attacks of such magnitude, including judicious application of BtK as was recommended by the Ministry of Forests in discussion with the Parks Board in 2021. If acted upon then and in the subsequent two years, the current enormous fire hazard and safety mitigation operations may have largely been unnecessary.
Going forward, hopefully the severe lessons have been learned, and the park won't be allowed to face another similar devastation to the remaining mature forest unchallenged. To ensure this as much as possible, not withstanding other factors, the 2024 Forest Management Plan would have to acknowledge the Ministry of Forests' guidance as did the 2009 Forest Management Plan with its 15 year old link on page 26 (link now broken) and to the current Ministry of Forests' advice on managing the hemlock looper. Given the manifold evidence of the Ministry's many successful and safe treatments against defoliators with BtK in many parts of British Columbia, the Management Plan should adopt specific Ministry guidance and procedures (as below) for the control of the Western hemlock looper and other significant forest defoliators when invasions potentially reaching epidemic proportions are predicted by autumn egg counts in the autumn of the year. This would trigger, if warranted, a spring/summer targeted aerial spraying program with the Ministry-recommended Bacillus thuringiensis biological insecticide (BtK) the following year or years when the larvae of the looper moth are voraciously and murderously ingesting the tender coniferous foliage in Stanley Park. Present resistance by the Parks Board to spraying unlikely to change.
Any future control initiative for the hemlock looper and other forest defoliators would require consistent, co-ordinated buy-in by the Parks Board, the Manager of Urban Forestry for the Parks Board, the Stanley Park Ecological Society, the Invasive Species Council of Metro Vancouver (iscmv.ca), the Invasive Species Council of BC (bcinvasives.ca) and of course, following the BC Ministry of Forests lead. As well, since the outbreak appears to have originated in the Metro Vancouver Watershed, spreading to forests in West Vancouver and North Vancouver (all doing nothing to control the outbreak) before reaching Stanley Park, these bodies will have to also be on-board.
Advance public communication and education will be essential to engender public support for the looper control program. Co-ordinated information would most easily be disseminated on the website pages of all of these agencies. Except for the Ministry's website, there is a total absence on Stanley Park looper biological control information. The BC Government website covering invasive species does return search results for the hemlock looper, and has a section on biological control, focused largely on invasive plants.
The interested media must be kept informed such as CBC News (local), vancouverisawesome.com, vancouver.citynews.ca, dailyhive.com, and cbc.ca/news/canada/british-columbia/local. They have been largely the only sources of investigative reporting throughout the 4-year looper crisis.
Update March 27, 2024
Just talking numbers of trees removed by size alone, as they only do, leads to a gross under-representation of the contribution of big trees which create the closed forest canopy (and much of what we see and enjoy) vs. the small, often suppressed understory trees, and why the once thrifty-mature Stanley Park forest, is so rapidly being cleared out, visually and in reality.
The basal area of wood on the stump increases almost exponentially in the formula 3.14* square of radius, so an 8 inch diameter tree at breast height (dbh) which is where trees are measured, not stump diameter, but since all that’s left is stump height, so measuring the 8 inch stump diameter gives 50.24 sq. in. basal area, while the 30 inch diameter stump has 706.5 sq. in. basal area or 14 times greater basal area than the 8 inch tree in comparison to the tree diameters alone. So it would take fourteen 8” trees to match the cross-sectional area of a single 30” tree.
The cylindrical volume in a 10-ft trunk (tree taper is ignored for simplicity of this exercise) is also 14 times greater in a 10-ft trunk. In other words, one 8 inch diameter tree would have 3.49 cu. ft. volume, while the 30” diameter tree would have 49 cu. ft. in the first 10 ft. of trunk height, or 14 times that of the 8 inch tree – the same relationship as cross-sectional area, therefor it takes roughly fourteen 8 inch trees to have comparable volume (trunk size) as a single 30 inch tree in the first 10 feet of straight tree bole. That exponential contribution of big trees is what we were seeing as we walked through the forest, and have now largely lost for another 80 years. The 20,000 large trees represent an overwhelming proportion (14:1) of the volume being removed.
Some steps to control the looper published by the BC Government:
Predictive Sampling Techniques
Egg sampling happens in the fall when defoliation has been noticed, or when an outbreak is anticipated. The egg samples predict levels of defoliation the following summer.
Short-term Strategies
The recommended short-term strategy is:
· Identify high-hazard stands containing the highest frequency of infestations, and monitor those areas in years before the next outbreak is expected
In eastern Canada, Bacillus thuringiensis var. kurstaki (Btk) has been sprayed on outbreaks. In 1993 B.C. tested two formulations of Btk. The formulations were effective and the information was used to obtain registrations for use against the western hemlock looper. BtK was successfully applied to 300 hectares in Surrey BC in 2022.
Long-term Strategies
A stand that is well-spaced, even-aged and thrifty is less likely to be impacted by western hemlock looper defoliation.
Mixed-species stands with the following characteristics are less susceptible to damage:
· Less than 50% western hemlock
· Few cedar-hemlock mixes
· Non-host species
Stand-tending treatments such as spacing and fertilization will help maintain a healthy, resilient stand.
Conclusion
The Stanley Park Forest Management plan is being revised in 2024. It must provide hope and confidence that these procedures, including direct intervention, will be implemented, including BtK against the looper when posing a threat of such serious magnitude as it did this recent cycle, while maintaining the natural ecosystems as much as possible in the face of climate change. The plan must be made public. The forest cannot be allowed to bear such a disastrous outcome again. Stanley Park's managers now doubly-owe an over-riding duty of care and responsibility to protect the remaining mature forest for current and succeeding generations of Vancouverites and the 18 million of its visitors locally and from around the World. A December 13, 2023 brief video of logging in progress along Stanley Park Drive approaching Prospect Point is linked here. The clearings continue beyond Prospect Point down to the picnic grounds where log-sorting operations are taking place. The motion to amend the City Charter to dissolve the Parks Board was passed December 13 and will now go to the Provincial Government for approval.
- KBF December 14, 2023.
In the news October 13, 2022:
Looper Description:
Looper and other Destructive Moth Control in BC and Elsewhere:
The looper moth isn't the only moth species that causes defoliation in BC's conifer forests. The list includes:
- Western spruce budworm
- Douglas fir tussock moth
- Lymantria "spongy" moth
- Western black-headed budworm
- Black army cutworm
The most common treatment used to eradicate spongy moths (formerly referred to as gypsy moth) [and looper moth - KF] in B.C. is to spray with the biological insecticide Btk.
Spraying can be:
Btk is a bacterium harmful only to moth and butterfly caterpillars. It must be applied by spraying.
Aerial spraying
The Ministry of Forests has a 2024 request for proposals out for aerial spraying of BtK for moth control in populated areas including Langley, Tsawwassen, Victoria, Saanich, Sooke-Metchosin, Esquimalt, Nanaimo, West Kelowna, Cranbrook, Salt Spring Island, Qualicum, and Cowichan Bay.
The most efficient way to eradicate and suppress widespread moth populations is to apply Btk from the air. This method has several important advantages over others.
Low Risk: Btk products pose a low risk to humans and other non-target organisms (other than moth and butterfly caterpillars). It can be applied over populated areas and water bodies with very little risk.
Effective: After several decades of use, aerial sprays have been proved to be highly effective for controlling the spongy moth.
Fast: Large areas can be treated in just a few hours. Most droplets will have reached the ground within 10 minutes of application.
Thorough: Aerial spraying can treat remote or difficult-to-access areas, providing even coverage throughout the target area. Also, and most important, the droplets can penetrate the crowns of even the tallest trees.
Cost effective: Aerial application has the lowest cost-per-hectare of any effective treatment.
Drawback: Aerial spraying has one technical disadvantage — weather limitations. Rain and wind are the most important limitations to aerial application of Btk. Spraying can be done in moderate winds but low-to-no-wind is preferred (treatments are not completed if wind speeds exceed 8 km per hour). A period of two hours without precipitation after spraying is required to allow Btk to stick properly to foliage.
General information about the aerial Btk spraying process
Date: Aerial spraying is usually carried out between April 1 and June 30. Exact dates depend both on spongy moth development and the weather.
Time: Spraying starts between dawn and is typically completed before 7:30 a.m. in populated areas.
Duration: Spraying usually takes about two hours per application and depends on the treatment area.
Number of applications: There are usually three applications of Btk, ideally spaced 7 - 10 days apart. The actual time between sprays will depend on insect development and weather.
Public awareness:
- A public notice is released at least 24 hours in advance of any aerial application, through media releases, updates on the spongy moth news web page, automated emails are sent to the spongy news web page subscribers, and updates to the toll-free, 24-hour information line.
- All schools and hospitals in the affected areas are notified in writing at least 24 hours before a spray is conducted
Safety: Highly trained spray specialists use a multi-engine aircraft, with all activities monitored by the project team. All necessary safety precautions are taken to ensure minimal risk to the public and the applicators.
Impact on the public: Aircraft flying as low as 150 feet above ground level apply the Btk. The public will hear aircraft noise during the early morning.
https://news.gov.bc.ca/releases/2024FOR0003-000029
The Ministry of Forests will conduct aerial-spray treatments on Vancouver Island and Salt Spring Island in spring 2024 to eradicate spongy moths and minimize the risk they pose to forests, farms, orchards and trees.
Under the direction of the B.C. Plant Protection Advisory Council’s Spongy Moth Technical Advisory Committee, the ministry plans to safely treat the following areas in the Vancouver Island and Southern Gulf Islands region:
- North Saanich: 170 hectares
- Greater Victoria: (Gorge-Tillicum: 120 hectares; Esquimalt: 31 hectares; and Belmont: 430 hectares)
- Cowichan Bay: 126 hectares
- Nanaimo: 130 hectares
- Qualicum Beach: 96 hectares
- Salt Spring Island: 48 hectares
Invasive spongy moths (also known as Lymantria moths and formerly known as gypsy moths) pose a risk to B.C.’s ecosystems and economy. Spongy moth caterpillars feed on tree leaves. In recent years, they have defoliated sections of forests and residential areas in Ontario and the eastern United States. Untreated spongy moths risk spreading to other areas of B.C. and are a threat to urban forests and farms.
The biological insecticide used for treatment is Foray 48B. It is used in organic farming, and the active ingredient, Bacillus thuringiensis var kurstaki (Btk), is naturally present in urban, agricultural and forest soils throughout the province. It only affects the stomachs of moth and butterfly caterpillars, and is specific to their digestive systems. The treatment has been approved for the control of spongy moth larvae in Canada since 1961.
https://www.healthlinkbc.ca/healthlinkbc-files/aerial-spraying-bcs-forests