I am alerting you to two publications about our “favorite” tree-killing pathogen, Phytopthora ramorum (sudden oak death).
The Role of Nurseries in Spreading SOD
The first article informs the general public and raises important questions: “The Diseased Rhododendrons That Triggered a Federal Plant Hunt” by Ellie Shechet in The New Republic.
Ellie reviews the 2019 episode in which P. ramorum-infected rhododendron plants were shipped to retailers in the East and Midwest. Her article is based on interviews with state plant health and APHIS officials, several scientists and advocates (including me), and the executive director of the Oregon Association of Nurseries (OAN). Ellie notes that infected plants were found at more than 100 locations across 16 states.
Ellie notes that despite the risk to native plants in the eastern deciduous forest and the financial cost of implementing control actions (14 million plants were inspected in Washington State alone), plants have a “green” reputation; they are not recognized as potentially causing environmental harm.
The politics of the situation also are reviewed. She writes that the OAN representative has testified that he helped write the more relaxed regulatory approach that APHIS adopted by “federal order” in 2014 and formalized in changes to the regulations in 2019. APHIS denies this. [The article does not include the information that during this period, state regulatory officials detected P. ramorum-infected plants in between four and ten Oregon nurseries each year.] Ellie notes that individual consumers buying plants have few tools to try to ensure that plants they buy are not infected by SOD or other pathogens.
The fact is that the climate in the coastal areas of California, Oregon, Washington, and British Columbia is conducive to SOD, so the risk of diseased plants being produced there and sold is constant. The current APHIS regulations do not adequately address this, in my view!
Science: High Risk of Phytophthora Introductions from Southeast Asia
The second article reports results of intense scientific effort: Thomas Jung, Joan Webber, Clive Brasier, and other European plant pathologists report more completely on searches for P. ramorum and other Phytophthora species in East Asia. See the full citation at the end of this blog. [I blogged about their preliminary report a little over a year ago.] Jung et al. conclude that P. ramorum probably originates from the laurosilva forests growing in an arc from eastern Myanmar, across northern Laos, Vietnam, and southwestern China (Yunnan) to Shikoku & Kyushu islands in southwest Japan. The article notes that two other Phytophtoras – P. lateralis (cause of fatal disease on Port-Orford cedar) and P. foliorum – appear to be from the same area. Field science by this team has found 38 previously unknown Phytophthora species in these same forests – and expect that more are present.
They warn that the lack of information about potential pathogens in many developing countries presents a high risk of introduction to naïve environments through burgeoning horticultural trade – especially since the World Trade Organization requires that a species be named and identified as posing a specific threat before phytosanitary regulations can be applied. [I addressed the issue of international phytosanitary rules in Fading Forests II; see the link at the end of the blog.]
Other Pathogen Risks from the Region
Phytophthoras transported on imported plants are not the only pathogens that could come from Asia. The vectors and associated pathogens causing laurel wilt disease across the Southeast and Fusariumdisease in California are believed also to originate in the same region of Asia. Unlike the Phytophthoras, which are transported primarily through the trade in plants for planting, these fungi travel with the vector beetles in wood packaging material. U.S. imports of goods from Asia – often packaged in wooden crates or pallets – have skyrocketed since July 2020. The ports of Los Angeles-Long Beach, which receive 50% of U.S. imports from Asia, handled 6.3 million TEU (twenty-foot equivalent containers) from Asia during the period July 2020 through February 2021. The average of close to 800,000 TEU per month for eight consecutive months is unprecedented. Other ports also saw increased import volumes from Asia during this period. [I discussed these shifts in my blog in January.] Imports from Asia in 2020 accounted for 67.4% of total US imports from the world. Imports from China specifically accounted for 42.1% of total US imports. [Data on import volumes is from several reports posted by the Journal of Commerce at its website: https://www.joc.com/maritime-news/]
SOURCE
Jung, T.; Horta Jung, M.; Webber, J.F.; Kageyama, K.; Hieno, A.; Masuya, H.; Uematsu, S.; Pérez-Sierra, A.; Harris, A.R.; Forster, J.; et al.. The Destructive Tree Pathogen Phytophthora ramorum Originates from the Laurosilva Forests of East Asia. J. Fungi 2021, 7, 226. https://doi.org/10.3390/ open access!
Posted by Faith Campbell
We welcome comments that supplement or correct factual information, suggest new approaches, or promote thoughtful consideration. We post comments that disagree with us — but not those we judge to be not civil or inflammatory.
For a detailed discussion of the policies and practices that have allowed these pests to enter and spread – and that do not promote effective restoration strategies – review the Fading Forests report at http://treeimprovement.utk.edu/FadingForests.htm
The emerald ash borer (EAB) was first detected in European Russia in 2003, in Moscow. By 2020, EAB was recorded in 16 provinces [=‘oblast’] of European Russia, especially to the West of Moscow towards the borders with Belarus and Ukraine.
Russian scientists have documented that the emerald ash borer is spreading faster in the southwest of the country and in neighboring Ukraine than in the northwest (near St. Petersburg and the Baltic countries).
Despite an abundance of ash [both green ash (Fraxinus pennsylvanica) – native to North America – and European ash F. excelsior], EAB population density in the northwest remains low and damage is in scattered clusters.
However, in September 2020 officials detected an isolated outbreak in a St. Petersburg suburb, 520 km away from the apparent edge of the principal Russian population. The authors believe this outbreak has been present since 2015. They think it is the result of transport of EAB either by “insect-hitchhiking” on vehicles or by movement of plants for planting or other commodities.
The Petersburg population is only 130 km from Estonia and Finland – the border with the European Union.
A thousand kilometers to the south, in southwest Russian eastern Ukraine, an outbreak was reported in June 2019. By the next summer, EAB were detected more than 100 km to the West. While this outbreak is still 800 km from Ukraine’s border with eastern Europe (Poland, Slovakia, Hungary, Romania), the authors note that rapid spread is likely since F. excelsior and F. pennsylvanica have been extensively planted along roads, railways, field shelter belts, and urban greenings.
The slower spread in the North is attributed to colder temperatures, the local abundance of food, and possibly pressure by the native parasitoid Spathius polonicus Niezabitowski (note that USDA APHIS has approved two Spathius species as biocontrol agents in the U.S.). On the other hand, the climate is milder in Saint Petersburg (along the coast) than it is inland; and ash woodlands are common along the Baltic coast.
Noting that ash dieback (Hymenoscyphus fraxineus) has devastated more than 95% of European ash populations, the authors express concern about the future of ash.
SOURCE
Musolin, D.L.; Selikhovkin, A.V.; Peregudova, E.Y.; Popovichev, B.G.; Mandelshtam, M.Y.; Baranchikov, Y.N.; Vasaitis, R. North-Westward Expansion of the Invasive Range of Emerald Ash Borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae) towards the EU: From Moscow to Saint Petersburg. Forests 2021, 12, 502. https://doi.org/10.3390/f12040502
Posted by Faith Campbell
We welcome comments that supplement or correct factual information, suggest new approaches, or promote thoughtful consideration. We post comments that disagree with us — but not those we judge to be not civil or inflammatory.
For a detailed discussion of the policies and practices that have allowed these pests to enter and spread – and that do not promote effective restoration strategies – review the Fading Forests report at http://treeimprovement.utk.edu/FadingForests.htm
The North American Plant Protection Organization (NAPPO) has released a scientific study, Risks Associated with the Introduction of Exotic Tussock Moth Species (Lepidoptera: Erebidae: Lymantriinae) of Potential Concern to the NAPPO Region.
The report identifies 13 species of tussock moths — other than several Asian gypsy moths – that pose a serious risk to Canada, Mexico, and the United States and that should be addressed as quarantine pests. However, vital information was missing in key areas, on one variable for more than 84% of the 79 species screened. Thus many additional species were not fully evaluated; some of these might also pose serious risks. Study findings
North American countries already regulate several species of Lymantria native to east Asia: Lymantria dispar asiatica, L. dispar japonica, L. albescens (includes L. postalba), and L. umbrosa. NAPPO’s Regional Standard for Phytosanitary Measure (RSPM) No. 33urlsets up a system requiring inspection and cleaning of marine vessels travelling from China, Korea, and Russia to the NAPPO region during the specified risk periods (SRP) of moth flight and egg mass deposition by these species.
However, the U.S. and Canada have been intercepting egg masses belonging to other lymantriid species, especially Lymantria lucescens, Leucoma salicis, Lymantria mathura, and Lymantria xylina. In response, the NAPPO countries initiated this study. All life stages — egg masses, larvae, pupae, and adults — have been intercepted in the NAPPO region primarily during maritime port inspections of vessels and shipping containers originating in Asia (Russia, Japan, China, Philippines, and Korea) and Europe.
There are more than 2,400 species of Lymantriids found on all continents except Antarctica. The group is also missing from Pacific islands, including New Zealand and Hawai`i. The greatest diversity occurs in the tropical areas of Africa, India, and Southeast Asia.
Lymantriid moths can have high fecundity, which can result in large population increases in a single generation. Some undergo cyclical outbreaks resulting in large-scale defoliation of their host plants.
The larvae are highly polyphagous. Some species feed on more than 150 hosts, especially trees – both deciduous and coniferous. The host plants are better known in temperate regions of the Northern Hemisphere; little is known about hosts of tropical moth species.
The study concluded that there is a high likelihood of introduction of lymantriid species into the NAPPO region due to the high volume of trade coming from Asia, the large number of probable lymantriid host species in North America, and the apparently suitable climatic conditions. While there are several possible pathways for transporting the moths from Asia to North America, the most important is the presence of masses of resilient eggs on surfaces of ships and hard-sided cargo (containers, motor vehicles, etc.). Once in North American ports, mated female moths can disperse either by flight (some species) or by “ballooning” on wind currents.
The authors initially collected data on 189 species. The report does not indicate whether they focused on Asia, but the results seem to be limited largely to that region. The authors winnowed the initial list down to 79 species for further analysis due largely to lack of resources and information. The Risk Assessment Model and Data Sheet are available here.
The study concluded that 13 species pose a high and that the NAPPO countries should designate them as “actionable pests” and take other actions to prevent their introduction. The high-risk species are Lymantria monacha, L. mathura, L. lunata and L. xylina, Euproctis kargalika, Euproctis subflava, Euproctis chrysorrhoea, Leucoma candida, Orgyia thyellina, Euproctis lunata, Leucom wltshirei, Lymantria fumida, and Sarsina violascens.
Evaluation Process
The 79 species were evaluated based on eight questions:
1) Are adult females attracted to light? (The authors thought such behavior would make them more likely to be flying during risk periods and attracted to ports and vessels).
2) Has the species been reported as a contaminant pest of commodities in trade in its
overwintering stage? (This presence was thought to result in species that are likely to move via trade and have the highest risk of survival and introduction).
3) Is the species reported to cause economic or environmental damage in its native range?
4) Does the species have larvae capable of ballooning?
5) Does the species have adult females capable of flight?
6) Does the species’ life history include a dormant stage able to withstand harsh environmental conditions? (Such species were thought to be more likely to survive transit to the NAPPO region and to persist once introduced).
7) Is the species capable of natural dispersal farther than 1 km/year?
8) Is the species reported to have allergenic properties?
Questions 2 & 3 were given more weight because they were considered to have a greater effect on the likelihood of the species being introduced and causing unacceptable impacts.
Weaknesses
Both the apparent focus on Asia and the emphasis on question 3 result in a process that was unlikely to uncover any potential pests that are currently “unknown unknowns”.
Vitally important information was missing for many of the species. For six of the eight questions, the evaluation found no information for more than 50 percent of the species evaluated. Information was lacking for Question 2 – one of the questions assigned greater weight – on 84 percent of the species! Ability to disperse more than 1 km per year had an even higher percentage of answers as “unknown”. Regarding “ballooning” of larvae, 80 percent of the species could not be classified.
These data gaps created a high level of uncertainty regarding the risk rankings of those species ranked as “low” risk. See Figure 2 from the report.
One of the reasons cited for the information gaps was the inability to access literature in foreign languages, specifically Russian. Surely both the U.S. and Canada have access to native Russian speakers!
The authors admit that the lack of information “affected the risk scores and possibly the risk categories for certain species.” They call for additional research and periodic reviews of the report’s findings.
They note that the report is a quick screening tool, not a rigorous pest risk assessment. They suggested additional research and sharing of interception data to address the information gaps. The research should focus on species’ flight periods and biological information relevant to regulatory actions; and detection tools (e.g., traps, lures, predictive phenology models, and molecular identification tools).
They note that the three countries currently limit surveillance and management programs to a few taxa.
I concur with the authors’ recommendation that a moth species be considered to pose a serious threat if it feeds on a host included in a tree or shrub genus that has economic value in the NAPPO region. (Under the terms of the International Plant Protection Organization, ISPM#5, environmental damage is included in the term “economic value”.)
Posted by Faith Campbell
We welcome comments that supplement or correct factual information, suggest new approaches, or promote thoughtful consideration. We post comments that disagree with us — but not those we judge to be not civil or inflammatory.
For a detailed discussion of the policies and practices that have allowed these pests to enter and spread – and that do not promote effective restoration strategies – review the Fading Forests report at http://treeimprovement.utk.edu/FadingForests.htm
Two USDA agencies lead efforts to protect U.S. wildland, rural, and urban forests from non-native insects and disease-causing pathogens:
USDA Animal and Plant Health Inspection Service (APHIS) has legal responsibility for preventing introduction of tree-killing pests, detecting newly introduced pests, and initiating eradication and containment programs intended to minimize the damage they cause.
USDA Forest Service (USFS)
Forest Health Management (FHM) program assists partner agencies to counter pests where they are first found – usually near cities – and when they spread. This work falls primarily to the Cooperative component of Forest Health Management program. The Federal lands component helps the USFS, National Park Service, and other federal agencies counter pests that have spread to more rural/wildland areas.
Research and Development (R&D) program supports research into pest-host relationships, introduction & spread pathways, management strategies (including biocontrol) and host resistance breeding
Since 2010, several new tree-killing pests have been detected in the US, including polyphagous and Kuroshio shot hole borers, spotted lanternfly, two rapid ʻōhiʻa death pathogens, and Mediterranean oak beetle. Over the same period. the Asian longhorned beetle has been detected in two new states – Ohio and South Carolina; the emerald ash borer expanded its range from 14 to 35 states; laurel wilt disease spread from five states to 11; a second strain of the sudden oak death fungus appeared in Oregon and California forests; and whitebark pine has been proposed by the US Fish and Wildlife Service for listing as Threatened under the Endangered Species Act. (I have blogged often about policy failures that have contributed to these introductions; today I am focused on agencies’ ability to respond.)
Funding agencies’ essential programs has fallen behind these calamities. APHIS funding has been steady or has risen slowly – at least not dropping – but not enough to deal with the growing threat.
Meanwhile, the key USFS programs have been cut by half or more. In 2010, USFS FHP and Research, together, allocated $32 million to efforts to understand and manage a dozen introduced pests: Asian longhorned beetle, emerald ash borer, sudden oak death, hemlock woolly adelgid, goldspotted oak borer, laurel wilt, thousand cankers disease, European gypsy moth, Port-Orford cedar root disease, Sirex woodwasp, and white pine blister rust (especially on whitebark pine). By 2021, this total had fallen to about $10 million. There was no indication that any USFS R&D funding has been allocated to recently detected, highly damaging pests, i.e., rapid ʻōhiʻa death, the polyphagous and Kuroshio shot hole borers, Mediterranean oak beetle, or beech leaf disease. USFS FHP has funded work on some of these pests through its “emerging pest” fund – but that fund is limited to $500,000 for the entire country.
At present, more than 228 tree species growing in the “lower 48” states are infested by an exotic pest. The 15 most damaging of the introduced species threaten 41.1% of the total live forest biomass in the 48 conterminous states. Additional trees on the Hawaiian and other Pacific islands are also being killed by non-native insects and pathogens. Non-native forest pests have caused a 5% increase in total mortality by tree volume nation-wide. The greatest increases in mortality rates have been a four-fold increase for redbay; and a three-fold increase each for ash, beech, and hemlock.
Introductions of tree-killing pests occur because we import things! The highly damaging wood-borers can arrive in crates, pallets, and other forms of packaging made of wood. Other pests – especially plant diseases – come here on imported plants. Gypsy moth and spotted lanternfly egg masses can be attached to virtually any hard surface, e.g., steel slabs, vehicles, stone, containers, or ship superstructures.
Imports from Asia pose a particularly high risk – illustrated by the Asian longhorned beetle, emerald ash borer, polyphagous and Kuroshio shot hole borers, sudden oak death, and spotted lanternfly.
U.S. imports from Asia rose almost a third between 2019 and 2020. No part of the country is safe. While nearly half of imports from Asia enter via Los Angeles/Long Beach, California, another 21% entered via New York – New Jersey and Savannah. Other ports in the “Top 10” were the Northwest Seaport Alliance of Seattle and Tacoma, Oakland, Norfolk, Houston, Charleston, Baltimore, and Mobile.
Pests don’t stay in the cities where they first arrive. Instead, they proliferate and spread to other vulnerable trees – often assisted by people moving firewood, plants or household goods. For example, less than 20 years after their first detections, the emerald ash borer has spread to 35 states, the redbay ambrosia beetle to 11.
[For more information, read my earlier blogs posted here or species-specific descriptions here.]
Please contact your Representative and Senators and urge them to push for increased funding for key programs managed by these two agencies. I describe funding needs below. I list members of the appropriate Congressional subcommittees at the end of this blog.
USDA APHIS programs (all included under “Plant Protection and Quarantine”)
APHIS Program
FY 2020 (millions)
FY 2021 (millions)
FY 2022 ask
Tree & Wood Pest
$60.000
$60.456
$70 million
Specialty Crops
$192.000
$196.553
$200 million
Pest Detection
$27.446
$27.733
$30 million
Methods Development
$20.686
$20.844
$25 million
APHIS’ “Tree & Wood Pests” account has traditionally supported eradication and control efforts targeting only three insects: the Asian longhorned beetle (ALB), emerald ash borer (EAB), and gypsy moth. The program to eradicate the ALB has received about two-thirds of the funds — $40 million. There is encouraging progress in Massachusetts, New York, and Ohio. Clearly, this program must be maintained until final success is achieved. Plus the program must now counter the Charleston, South Carolina, outbreak, where more than 4,000 infested trees have been detected in an area of 58 square miles. (See my blog here, which describes the difficult conditions arising from wetlands in South Carolina.)
APHIS has terminated its emerald ash borer regulatory program, which had previously been funded at about $7 million per year. (See my blog). APHIS has said it will now focus on production and release of biocontrol agents, although it has not indicated the funding level. It is probable that EAB will now spread more rapidly to the mountain and Pacific Coast states, threatening both riparian woodlands and urban forests.
APHIS’ “Specialty Crops” program funds APHIS’ regulation of nursery operations to prevent spread of the sudden oak death pathogen. APHIS must improve that program to avoid a repetition of the 2019 incident, in which plants infected by the SOD pathogen were shipped to 14 states.
This budget line also supports efforts to manage the spotted lanternfly, which has spread from Pennsylvania to seven other mid-Atlantic states.
The “Pest Detection” budget line supports the collaborative state –federal program that detects newly introduced pests. Successful eradication and containment programs depend on early detection.
The “Methods Development” program assists APHIS in developing detection and eradication tools essential for an effective response to new pests.
USDA Forest Service
USFS PROGRAM
FY20
FY21
FY 22 ask
FHP Coop Lands
$32 M
$30.747M
$51 million (to cover both program work & personnel costs)
FHP Federal lands
$19 M
$15.485M
$25 million (ditto)
Research & Develop
$305 million
$258.7 million; of which about $3.6 million allocated to invasive species
$320 million; seek report language specifying $5 million for invasive species
The Mission of the USDA Forest Service is “To sustain the health, diversity, and productivity of the Nation’s forests and grasslands to meet the needs of present and future generations.” To achieve this mission, the Forest Service needs adequate funding to address the difficult challenge of containing the spread of introduced pests, protecting host tree species from mortality caused by those pests, and restoring decimated tree species to the forest. Meeting this challenge requires gaining scientific understanding of the pest’s and host’s biology and what motivates people to avoid activities that facilitate pests’ spread (e.g., transporting firewood that might harbor wood-boring insects).
Given the hundreds of damaging non-native pests, the Forest Service must set priorities. One attempt to do so is “Project CAPTURE” (Conservation Assessment and Prioritization of Forest Trees Under Risk of Extirpation). Priority species for forests on the continent are listed below. A separate study is under way for forests in Hawai`i, Puerto Rico, and U.S. Virgin Islands.
Florida torreya (Torreya taxifolia)
American chestnut (Castanea dentata)
Allegheny chinquapin (C. pumila)
Ozark chinquapin (C. pumila var. ozarkensis)
redbay (Persea borbonia)
Carolina ash (Fraxinus caroliniana)
pumpkin ash (F. profunda)
Carolina hemlock (Tsuga caroliniana)
Port-Orford cedar (Chamaecyparis lawsoniana)
tanoak (Notholithocarpus densiflorus)
butternut (Juglans cinerea)
eastern hemlock (Tsuga canadensis)
white ash (Fraxinus americana)
black ash (F. nigra)
green ash (F. pennsylvanica).
These 15 priority species should be the focus of both comprehensive gene conservation programs and tree breeding and restoration programs. Unfortunately, USFS programs do not reflect this recommendation.
Forest Health and Management Programs (FHM)
Despite severe cuts (see above), FHM has continued its commitment to projects addressing Port-Orford-cedar root disease, threats to whitebark pine, and thousand cankers disease; plus it is support for managing “lingering” ash which appear to survive EAB attack. However, I am concerned about past reductions in programs targetting laurel wilt and sudden oak death. And as I noted above, several highly-damaging pests lack a “program” at all. I applaud establishment of an “emerging pest” line. However, competition will be fierce for the $500,000 – pitting the invasive shot hole borers in California against the coconut rhinoceros beetle and rapid ‘ōhi‘a death in Hawai`i, against beech leaf disease in Ohio to Massachusetts.
And where is federal leadership on managing continued spread of the emerald ash borer, now that the USDA APHIS has terminated its regulatory program?
USDA Forest Service Forest and Rangeland Research Program
Effective programs to prevent, suppress, and eradicate non-native pests depend on understanding of the pest-host relationship gained through research. In recent years, about 1.5% of the USFS Research budget has been allocated to the non-native pests listed above. Past reductions have hit programs targetting hemlock woolly adelgid, white pine blister rust, sudden oak death, and the Sirex woodwasp. Programs targetting several other high-impact pests, including the Asian longhorned beetle, emerald ash borer, goldspotted oak borer, thousand cankers disease, and laurel wilt have been funded at a steady rate. I could find no documentation of USDA Forest Service research into beech leaf disease, rapid ʻōhiʻa death, or other pests currently killing trees.
Members of Key Congressional Committees
Note that some Representatives or Senators are members of subcommittees that fund both APHIS and the USFS. It is especially important that they hear from their constituents!
APHIS is funded through the Agriculture appropriations bill. Members of the House Subcommittee on Agriculture and Rural Development:
Sanford Bishop Jr., Chairman GA
Chellie Pingree ME
Mark Pocan WI
Lauren Underwood IL
Barbara Lee CA
Betty McCollum MN
Debbie Wasserman Schultz FL
Henry Cuellar TX
Grace Meng NY
Jeff Fortenberry, Ranking Member NE
Robert Aderholt AL
Andy Harris MD
David Valadao CA
John Moolenaar MI
Dan Newhouse WA
Members of the Senate Subcommittee on Agriculture and Rural Development:
Tammy Baldwin, Chair WI
John Merkley OR
Dianne Feinstein CA
Jon Tester MT
Patrick Leahy VT
Brian Schatz HI
Martin Heinrich NM
Ranking Republican John Hoeven ND
Mitch McConnell KY
Susan Collins ME
Roy Blunt MO
Jerry Moran KS
Cindy Hyde-Smith MS
Mike Braun IN
The USFS is funded through the Interior appropriations bill. Members of the House Subcommittee on Interior and Related Agencies: add states
Chellie Pingree, Chair ME
Betty McCollum MN
Derek Kilmer WA
Josh Harder CA
Susie Lee NV
Marcy Kaptur OH
Matt Cartwright PA
David Joyce, Ranking Member NC
Mike Simpson ID
Chris Stewart UT
Mark Amodei NV
Members of the Senate Subcommittee on Interior and Related Agencies:
Jeff Merkley, chair OR
Dianne Feinstein CA
Patrick Leahy VT
Jack Reed RI
Jon Tester MT
Chris van Hollen MD
Martin Heinrich NM
Ranking Rep. Lisa Murkowski AK
Roy Blunt MO
Mitch McConnell KY
Shelly Moore Capito WV
Cindy Hyde-Smith MS
Bill Hagerty TN
Marco Rubio FL
Posted by Faith Campbell
We welcome comments that supplement or correct factual information, suggest new approaches, or promote thoughtful consideration. We post comments that disagree with us — but not those we judge to be not civil or inflammatory.
For a detailed discussion of the policies and practices that have allowed these pests to enter and spread – and that do not promote effective restoration strategies – review the Fading Forests report at http://treeimprovement.utk.edu/FadingForests.htm