Scott Schlarbaum collecting butternuts; photo by F.T. Campbell
I have blogged several times about the need to enhance efforts to breed trees resistant to the most damaging of the hundreds of introduced insects and pathogens. Others concur – see reports by the National Academy of Sciences in 2018; several publications by USFS scientists Richard Sniezko and Jennifer Koch; a workshop hosted by Purdue w/ USFS support, the creation and efforts of several consortia – Whitebark Pine Ecosystem Foundation, Great Lakes Basin Forest Health Collaborative, Forest Restoration Alliance …
Also, Richard J. A. Buggs, of the Royal Botanic Gardens, Kew, recently summarized barriers to tree breeding. It was published as an especially thoughtful editorial in Plants People Planet in anticipation of the International Year of Plant Health in 2020 (see reference at the end of this blog). That issue included several related articles, also noted below.
R.J.A. Buggs’ Perspective on Tree Breeding
Buggs says the need for tree resistance research is greater than ever before. First, damage caused by introduced insects and pathogen is rising. Plus, we now recognize trees’ importance in capturing atmospheric carbon. He sees encouraging signs of growing public awareness of both factors. Also, he thinks citizen science might reduce the cost of some activities … although he doesn’t name which they are.
Dr. Buggs lists six major hindrances to breeding programs, including some aspects that I, at least, have not considered:
1) Trees’ size and long generation times mean research is necessarily slow. One result is it is hard to formulate research proposals that match funding cycles. This in turn means a dependence on long-term institutional commitment from well-funded organizations, and such institutions are rare.
I point out that the U.S. government – especially the USFS – is one such institution. Unfortunately, it has so far been reluctant to take commit major resources to breeding pest-resistant trees. Every year I urge you to lobby Congress on appropriations for the agency. In this context, do you understand that while the USFS Research budget receives approximately $300 million each year, less than $5 million of that total is allocated to researching invasive species (of all taxa)? Some gaps are filled by projects funded by the Forest Health Program. You will have a new opportunity to lobby Congress for Fiscal Year 2023 in the spring!
2) On the other hand, reliance on long-term institutional funding shelters projects from multidisciplinary peer-review that could introduce improved technology or methods. This lack of peer review also contributes to a perception among other scientists that tree resistance research is a scientific backwater.
3) Similarly, studies requiring a long time horizon don’t fit publication schedules. Again, the result is that the findings often appear only in institutional reports or conference proceedings. This means they are hard to find and often lack external peer review at not only the proposal stage but also before publication.
4) The long decades without clear success in dealing with Dutch elm disease (but see recent encouraging developments here) and chestnut blight (see The American Chestnut Foundation here) gave the impression that resistance breeding of forest trees is impossible. Buggs says pest resistance problems are easier to tackle for other trees.
TACF American chestnut; photo by F.T. Campbell
5) Those considering what efforts to fund might demand complete resistance to the pest. This goal is not only unrealistic – it is often unnecessary. Often lower levels of resistance or tolerance can result in trees that can be self-sustaining. Dr. Sneizko concurs; see his article appearing in this issue.
6) Forest stakeholders differ over the goal of developing resistant trees. Some think any human intervention is unwarranted in wilderness areas. Some want a tree as similar as possible to pre-epidemic trees. Others want a tree that produces more timber.
Other Significant Articles
A second article in the same issue of Plants People Planet (Federman and Zankowski) discusses the USDA’s commitment to new approaches in tree resistance research.
I found a third article that discusses British approaches to mitigating tree pests to be more informative than Federman and Zankowski – although somewhat worrying. Spence, Hill and Morris praise the U.K.’s Plant Health Risk Register, which they say has enhanced vigilance on possible new pest introductions. However, the authors describe resistance breeding as a strategy to be considered “when a pest has established such that a tree population is unable to recover, and where a genetic basis for resistance is demonstrable in a proportion of the tree population.” Dr. Sneizko, and others – and I! – call for initiating exploration of the potential for resistance breeding much earlier in an invasion.
A fourth article – by Richard Sniezko and colleagues — describes encouraging levels of partial resistance to white pine blister rust in two western white pines and evidence for both qualitative and quantitative resistance to Phytophtohora lateralis in Port-Orford Cedar.
Port-Orford test seedlings; photo courtesy of Richard Sniezko
A fifth – by Showalter et al. — reports encouraging levels of resistance to both emerald ash borer DMF and ash dieback in European ash. The authors conclude that a breeding program might be a viable solution to both pests.
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
sassafras – vulnerable to the rapidly spreading laurel wilt disease; photo by F.T. Campbell
In summer 2019 I posted several blogs summarizing my analysis of forest pest issues after 30 years’ engagement. I reported the continuing introductions of tree-killing insects and pathogens; their relentless spread and exacerbated impacts. I noted the continued low priority given these issues in agencies tasked with preventing and solving these problems. Also, Congress provides not only insufficiently protective policies but also way too little funding. I decried the impediments created by several Administrations; anti-regulatory ideology and USDA’s emphasis on “collaborating” with “clients” rather than imposing requirements.
In my blogs, I called for renewed effort to find more effective strategies – as I had earlier advocated in my “Fading Forests” reports (link provided at the end of this blog), previous blogs, and Lovett et al. 2016
Areas of Progress
Now two years have passed. I see five areas of progress – which give me some hope.
1) Important Activities Are Better Funded than I had realized
a) The US Forest Service is putting significant effort into breeding trees resistant to the relevant pests, more than I had realized. Examples include elms and several conifer species in the West – here and here.
b) USDA has provided at least $110 million since FY2009 to fund forest pest research, control, and outreach under the auspices of the Plant Pest and Disease Disaster Prevention Program (§10201 of the Farm Bill). This total does not include additional funding for the spotted lanternfly. Funded projects, inter alia: explored biocontrol agents for Asian longhorned beetle and emerald ash borer; supported research at NORS-DUC on sudden oak death; monitored and managed red palm weevil and coconut rhinoceros beetle; and detected Asian defoliators. Clearly, many of these projects have increased scientific understanding and promoted public compliance and assistance in pest detection and management.
This section of the Farm Bill also provided $3.9 million to counter cactus pests – $2.7 million over 10 years targetting the Cactoblastismoth & here and $1.2 million over four years targetting the Harissia cactus mealybug and here.
flat-padded Opuntia cactus – vulnerable to the Cactoblastis moth; National Park Service photo
2) Additional publications have documented pests’ impacts – although I remain doubtful that they have increased decision-makers’ willingness to prioritize forest pests. Among these publications are the huge overview of invasive species published last spring (Polandet al.) and the regional overview of pests and invasive plants in the West (Barrettet al.).
3) There have been new efforts to improve prediction of various pests’ probable virulence (see recent blogs and here.
4) Attention is growing to the importance of protecting forest health as a vital tool in combatting climate change — see Feiet al., Quirionet al., and IUCN. We will have to wait to see whether this approach will succeed in raising the priority given to non-native pests by decision-makers and influential stakeholders.
Rep. Peter Welch
5) Some politicians are responding to forest pest crises – In the US House, Peter Welch (D-VT) is the lead sponsor of H.R. 1389. He has been joined – so far – by eight cosponsors — Rep. Kuster (D-NH), Pappas (D-NH), Stefanik (R-NY), Fitzpatrick (R-PA), Thompson (D-CA), Ross (D-NC), Pingree (D-ME), and Delgado (D-NY). This bill would fund research into, and application of, host resistance! Also, it would make APHIS’ access to emergency funds easier. Furthermore, it calls for a study of ways to raise forest pests’ priority – thus partially responding to the proposal by me and others (Bonello et al. 2020; full reference at end of blog) to create federal Centers for Forest Pest Control and Prevention.
This year the Congress will begin work on the next Farm Bill – might these ideas be incorporated into that legislation?
What Else Must Be Done
My work is guided by three premises:
1) Robust federal leadership is crucial:
The Constitution gives primacy to federal agencies in managing imports and interstate trade.
Only a consistent approach can protect trees (and other plants) from non-native pests that spread across state lines.
Federal agencies have more resources than state agencies individually or in likely collective efforts – even after decades of budget and staffing cuts.
2) Success depends on a continuing, long-term effort founded on institutional and financial commitments commensurate with the scale of the threat. This requires stable funding; guidance by research and expert staff; and engagement by non-governmental players and stakeholders. Unfortunately, as I discuss below, funding has been neither adequate nor stable.
3) Programs’ effectiveness needs to be measured. Measurement must focus on outcomes, not just effort (see National Environmental Coalition on Invasive Species’ vision document).
Preventing New Introductions – Challenges and Solutions
We cannot prevent damaging new introductions without addressing two specific challenges.
1) Wood packaging continues to pose a threat despite past international and national efforts. As documented in my recent blogs, the numbers of shipping containers – presumably with wood packaging – are rising. Since 2010, CBP has detected nearly 33,000 shipments in violation of ISPM#15. The numbers of violations are down in the most recent years. However, a high proportion of pest-infested wood continues to bear the ISPM#15 mark. So, ISPM#15 is not as effective as it needs to be.
We at CISP hope that by mid-2022, a new analysis of the current proportion of wood packaging harboring pests will be available. Plus there are at least two collaborative efforts aimed at increasing industry efforts to find solutions – The Nature Conservancy with the National Wooden Pallet and Container Association; and the Cary Institute with an informal consortium of importers using wooden dunnage.
2) Imports of living plants (“plants for planting”) are less well studied so the situation is difficult to assess. However, we know this is a pathway that has often spread pests into and within the US. There have been significant declines in overall numbers of incoming shipments, but available information doesn’t tell us which types of plants – woody vs. herbaceous, plant vs. tissue culture, etc. – have decreased.
APHIS said, in a report to Congress (reference at end of blog), that introductions have been curbed – but neither that report nor other data shows me that is true.
Scientists are making efforts to improve risk assessments by reducing the number of organisms for which no information is available on their probable impacts (the “unknown unknowns”).
Solving Issues of Prevention
While I have repeatedly proposed radical revisions to the international phytosanitary agreements (WTO SPS & IPPC) that preclude prevention of unknown unknowns (see Fading Forests II and blog), I have also endorsed measures aimed at achieving incremental improvements in preventing introductions, curtailing spread, and promoting recovery of the affected host species.
The more radical suggestions focus on: 1) revising the US Plant Protection Act to give higher priority to preventing pests introductions than to facilitating free trade (FF II Chapter 3); 2) APHIS explicitly stating that its goal is to achieve a specific, high level of protection (FF II Chapter 3); 3) APHIS using its authority under the NAPPRA program to prohibit imports of all plants belonging to the 150 genera of “woody” plants that North America shares with Europe or Asia; 4) APHIS prohibiting use of packaging made from solid wood by countries and exporters that have a record of frequent violations of ISPM#15 in the 16 years since its implementation.
Another action leading to stronger programs would be for APHIS to facilitate outside analysis of its programs and policies to ensure the agency is applying the most effective strategies (Lovett et al. 2016). The pending Haack report is an encouraging example.
I have also suggested that APHIS broaden its risk assessments so that they cover wider categories of risk, such as all pests that might be associated with bare-root woody plants from a particular region. Such an approach could speed up analyses of the many pathways of introduction and prompt their regulation.
Also, APHIS could use certain existing programs more aggressively. I have in mind pre-clearance partnerships and Critical Control Point integrated pest management programs. APHIS should also clarify the extent to which these programs are being applied to the shipments most likely to transport pests that threaten our mainland forests, i.e. imports of woody plants belonging to genera from temperate climates. APHIS should promote more sentinel plant programs. Regarding wood packaging, APHIS could follow the lead of CBP by penalizing importers for each shipment containing noncompliant SWPM.
Getting APHIS to prioritize pest prevention over free trade in general, or in current trade agreements, is a heavy lift. At the very least, the agency should ensure that the U.S. prioritize invasive species prevention in negotiations with trading partners and in developing international trade-related agreements. I borrow here from the recent report on Canadian invasive species efforts. (I complained about APHIS’ failure to even raise invasive species issues during negotiation of a recent agricultural trade agreement with China.)
Solving Issues of Spreading Pests
The absence of an effective system to prevent a pest’s spread within the U.S. is the most glaring gap in the so-called federal “safeguarding system”. Yet this gap is rarely discussed by anyone – officials or stakeholders. APHIS quarantines are the best answer – although they are not always as efficacious as needed – witness the spread of EAB and persistence of nursery outbreaks of the SOD pathogen.
areas at risk to goldspotted oak borer
APHIS and the states continue to avoid establishing official programs targetting bioinvaders expected to be difficult to control or that don’t affect agricultural interests. Example include laurel wilt, and two boring beetles in southern California – goldspotted oak borer, Kuroshio shot hole borer and polyphagous shot hole borer and their associated fungi.
One step toward limiting pests’ spread would come from strengthening APHIS’ mandate in legislation, as suggested above. A second, complementary action would be for states to adopt quarantines and regulations more aggressively. For this to happen, APHIS would need to revise its policies on the “special needs exemption” [7 U.S.C. 7756]. Then states could adopt more stringent regulations to prevent introduction of APHIS-designated quarantine pests (Fading Forests III Chapt 3).
Finally, APHIS should not drop regulating difficult-to-control species – e.g., EAB. There are repercussions.
APHIS’ dropping EAB has not only reduced efforts to prevent the beetle’s spread to vulnerable parts of the West. It has also left states to come up with a coherent approach to regulating firewood; they are struggling to do so.
Considering interstate movement of pests via the nursery trade, the Systems Approach to Nursery Certification (SANC) program) is voluntary and was never intended to include all nurseries. Twenty-five nurseries were listed on the program’s website as of March 2020. It is not clear how many nurseries are participating now. The program ended its “pilot” phase and “went live” in January 2021. Furthermore, the program has been more than 20 years in development, so it cannot be considered a rapid response to a pressing problem.
Solving Issues of Recovery and Restoration via Resistance Breeding
I endorse the findings of two USFS scientists, Sniezko and Koch citations. They have documented the success of breeding programs when they are supported by expert staff and reliable funding, and have access to appropriate facilities. The principle example of such a facility is the Dorena Genetic Resource Center in Oregon. Regional consortia, e.g., Great Lakes Basin Forest Health Collaborative and Whitebark Pine Ecosystem Foundation are trying to overcome gaps in the system. I applaud the growing engagement of stakeholders, academic experts, and consortia. Questions remain, though, about how to ensure that these programs’ approaches and results are integrated into government programs.
resistant and vulnerable ash seedlings; photo courtesy of Jennifer Koch, USFS
In Bonello et al., I and others call for initiating resistance breeding programs early in an invasion. Often other management approaches, e.g., targetting the damaging pest or manipulating the environment, will not succeed. Therefore the most promising point of intervention is often with by breeding new or better resistance in the host. This proposal differs slightly from my suggestion in the “30 years – solutions” blog, when I suggested that USFS convene a workshop to develop consensus on breeding program’s priorities and structure early after a pest’s introduction.
Funding Shortfalls
I have complained regularly in my publications (Fading Forests reports) and blogs about inadequate funding for APHIS Plant Protection program and USFS Forest Health Protection and Research programs. Clearly the USDA Plant Pest and Disease Management and Disaster Program has supported much useful work. However, its short-term grants cannot substitute for stable, long-term funding. In recent years, APHIS has held back $14 – $15 million each year from this program to respond to plant health emergencies. (See APHIS program reports for FYs 20 and 21.) This decision might be the best solution we are likely to get to resolve APHIS’ need for emergency funds. If we think it is, we might drop §2 of H.R. 1389.
Expanding Engagement of Stakeholders
Americans expect a broad set of actors to protect our forests. However, these groups have not pressed decision-makers to fix the widely acknowledged problems: inadequate resources – especially for long-term solutions — and weak and tardy phytosanitary measures. Employees of federal and state agencies understand these issues but are restricted from outright advocacy. Where are the professional and scientific associations, representatives of the wood products industry, forest landowners, environmental NGOs and their funders, plus urban tree advocates – who could each play an important role? The Entomological Society’s new “Challenge” is a welcome development and one that others could copy.
SOURCES
Bonello, P., Campbell, F.T., Cipollini, D., Conrad, A.O., Farinas, C., Gandhi, K.J.K., Hain, F.P., Parry, D., Showalter, D.N, Villari, C. and Wallin, K.F. (2020) Invasive Tree Pests Devastate Ecosystems—A Proposed New Response Framework. Front. For. Glob. Change 3:2. doi: 10.3389/ffgc.2020.00002
Green, S., D.E.L. Cooke, M. Dunn, L. Barwell, B. Purse, D.S. Chapman, G. Valatin, A. Schlenzig, J. Barbrook, T. Pettitt, C. Price, A. Pérez-Sierra, D. Frederickson-Matika, L. Pritchard, P. Thorpe, P.J.A. Cock, E. Randall, B. Keillor and M. Marzano. 2021. PHYTO-THREATS: Addressing Threats to UK Forests and Woodlands from Phytophthora; Identifying Risks of Spread in Trade and Methods for Mitigation. Forests 2021, 12, 1617 https://doi.org/10.3390/f12121617ý
Krishnankutty, S., H. Nadel, A.M. Taylor, M.C. Wiemann, Y. Wu, S.W. Lingafelter, S.W. Myers, and A.M. Ray. 2020. Identification of Tree Genera Used in the Construction of Solid Wood-Packaging Materials That Arrived at U.S. Ports Infested With Live Wood-Boring Insects. Journal of Economic Entomology 2020, 1 – 12
Liebhold, A.M., E.G. Brockerhoff, L.J. Garrett, J.L. Parke, and K.O. Britton. 2012. Live plant imports: the major pathway for forest insect and pathogen invasions of the US. Front. Ecol. Environ. 2012; 10(3):135-143
Lovett, G.M., M. Weiss, A.M. Liebhold, T.P. Holmes, B. Leung, K.F. Lambert, D.A. Orwig, F.T. Campbell, J. Rosenthal, D.G. McCullough, R. Wildova, M.P. Ayres, C.D. Canham, D.R. Foster, SL. Ladeau, and T. Weldy. 2016. NIS forest insects and pathogens in the US: Impacts and policy options. Ecological Applications, 26(5), 2016, pp. 1437–1455
Mech, A.M., K.A. Thomas, T.D. Marsico, D.A. Herms, C.R. Allen, M.P. Ayres, K.J. K. Gandhi, J. Gurevitch, N.P. Havill, R.A. Hufbauer, A.M. Liebhold, K.F. Raffa, A.N. Schulz, D.R. Uden, & P.C. Tobin. 2019. Evolutionary history predicts high-impact invasions by herbivorous insects. Ecol Evol. 2019 Nov; 9(21): 12216–12230.
Poland, T.M., Patel-Weynand, T., Finch, D., Miniat, C. F., and Lopez, V. (Eds) (2019), Invasive Spp in Forests and Grasslands of the US: A Comprehensive Science Synthesis for the US Forest Sector. Springer Verlag. (in press).
Roy, B.A., H.M Alexander, J. Davidson, F.T Campbell, J.J Burdon, R. Sniezko, and C. Brasier. 2014. Increasing forest loss worldwide from invasive pests requires new trade regulations. Front Ecol Environ 2014; 12(8): 457–465
Schulz, A.N., A.M. Mech, M.P. Ayres, K. J. K. Gandhi, N.P. Havill, D.A. Herms, A.M. Hoover, R.A. Hufbauer, A.M. Liebhold, T.D. Marsico, K.F. Raffa, P.C. Tobin, D.R. Uden, K.A. Thomas. 2021. Predicting non-native insect impact: focusing on the trees to see the forest. Biological Invasions.
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
Sean Connery as Hotspur, Shakespeare Henry IV Part I (BBC, “Age of Kings”)
[Starlings – one of the agricultural pests that prompted adoption of the Lacey Act – were introduced to the U.S. because they were mentioned by Shakespeare: Hotspur says “Nay, I’ll have a starling shall be taught to speak nothing but ‘Mortimer,’ and give it him, to keep his anger still in motion.”]
Americans are increasingly aware of the damage caused by invasive species. The law that ostensibly protects our environment from most potentially invasive animals is the Lacey Act – more specifically, the “injurious wildlife” sections of the law, now known as 18 U.S.C. 42 or title 18.
When it was adopted 120 years ago, the Lacey Act was not intended to protect the environment from the full range of possible animal bioinvaders. While Congress amended it several times in the first 60 years of its existence, the law still has many gaps that impede its usefulness for that purpose.
Rep. John F. Lacey via Wikimedia Commons
When first adopted in 1900, the injurious wildlife provisions of the Lacey Act prohibited importation only of wild mammals and birds that posed a threat to agriculture and horticulture. The statute was quite broad in that it prohibited importation of any wild bird or mammal without a permit; there was no requirement that a species be designated as “injurious” to be regulated. The Act was then administered by the U.S. Department of Agriculture. [For a detailed discussion of the Lacey Act’s changing provisions, see Jewell 2020; full reference at the end of this blog.]
In 1960 the Act was amended to expand the list of taxa eligible for designation as “injurious” to include fishes, mollusks, crustaceans, reptiles, and amphibians. Congress also expanded the justifications for listing a species as injurious. It added harm to people, to forestry, or to wildlife or US wildlife resources to the law’s original concerns for agriculture and horticulture. This second change brought the purposes of the Lacey Act closer to the mandate of the U.S. Fish and Wildlife Service (USFWS) – which had assumed responsibility for implementing the Act in 1939.
Unfortunately, Congress simultaneously took other action that greatly weakened USFWS’ ability to use the Act to protect the environment from introduced animals. First, it dropped the requirement that the Secretary approve, with a permit, any importation of a wild bird or mammal.
Second, the 1960 amendment clouded the originally clear prohibition of movement of listed species across state lines. The new language prohibits “any shipment between the continental United States, the District of Columbia, Hawaii, the Commonwealth of Puerto Rico, or any possession of the United States …”
For the next 57 years, the USFWS and Congress sometimes interpreted that language as continuing to prohibit transport between the states within the continental United States. However, this situation could not last. In 2017, acting in a case that had challenged the 2012 listing of several nonnative constrictor snakes as “injurious,” the D.C. Circuit court found that the plain language of §18 U.S.C. 42(a)(1) does not prohibit the transportation of injurious wildlife between states within the continental United States. So now, transportation of injurious wildlife among the continental states is not prohibited by the statute in most circumstances.
Burmese python; photo by R. Cammauf, Everglades National Park via Flickr
The Law’s Strengths
Some aspects of the law have been strengths. Since the term “injurious” has never been defined, the USFWS has been able to use its discretion to list species that are not necessarily invasive themselves but that might cause harm in some other way. For example, the salmon family and 20 genera of salamanders have been listed because they are vectors of harmful wildlife pathogens.
In addition, USFWS has listed entire genera or families of organisms – as long as each species within the taxon has been shown to possess the “injurious” trait(s). This flexibility has probably helped listings aimed at precluding importers from switching from the species that initially raised concerns to related species.
The Law’s Inherent Weaknesses
1) Legal shortfalls
Due to the confusion created by the 1960 amendment, the USFWS now lacks authority to prohibit interstate transport of species listed as “injurious”. This gap undermines the law’s efficacy in controlling spread of listed species once they are established within the U.S.
Also, the law does not prohibit other human actions that pertain to the presence and spread of species listed as “injurious,” e.g., sale, possession, or intra-state transport. Addressing these other aspects of invasive species policy was left to other players, such as states or resource managers.
2) Funding shortfall
Neither the Executive Branch nor Congress has ever provided specific funding for implementation of the Lacey Act. Only one USFWS staffer has the job of listing species under the Act. This situation might change now, since the American Rescue Plan Act adopted in spring 2021 does provide funding over the next five years for listing species that can vector pathogens harmful to people.
Staff’s Evaluation of Its Implementation of the Lacey Act
Since USFWS took over implementation of the Lacey Act in 1939, 36 taxonomic groups have been added to the “injurious wildlife” list. Seven of these listings comprise multiple species – either as genera or families.
Two mammals have been listed since the late 1960s – brushtail possum in 2002 and raccoon dog in 1983. Recent listings have strongly focused on aquatic organisms. This is because the staff is housed in the Fish and Aquatic Conservation program and their expertise is in these species.
silver carp; photo by University of Illinois
Listing activity appeared to be building in the second decade of the 21st Century, with multi-species listings of fish, snakes, and salamanders between 2012 and 2016. However, there has been only one listing action since 2016 – and that was by an act of Congress (listing of the quagga mussel).
In two peer reviewed papers, the USFWS’ Jewell and Fuller provide a history of the Lacey Act’s injurious wildlife title and analyze the effects of listing of 307 species (those listed since 1952). They conclude that 98% of the species listings were “effective” because the listed species either had not been introduced subsequent to listing [288 species; 94% of the total number of listed species] or had not spread to additional states [12 species, 4% of the total]. Another way to calculate the latter figure is to say that 63% of all established species have remained within the state(s) where they were established at the time of listing. Only three species have been spread to additional states by human actions. In these cases, Jewell and Fuller considered the Lacey Act measures to be “ineffective”. For further details on the Jewell and Fuller evaluations of listing efficacy, see their article – full citation given at the end of this blog.
Jewell and Fuller do not evaluate the impacts of animal species introduced to the U.S. after 1960 that have never been listed under the Lacey Act, or speculate about whether listing those species might have minimized the risk of their introduction.
Jewell and Fuller consider listing of species not yet established in the U.S. to be most effective for two reasons. First, listing minimizes the probability that the species will be imported intentionally or unintentionally. Second, listing provides states with risk analyses and other information on which to rely in adopting their own restrictions, including possible prohibitions on sale or possession.
Jewell and Fuller also argue that even in the absence of legal authority to regulate interstate transport of listed species among the continental states, it is still worthwhile to list species that are already established in the U.S. They give six reasons. I summarize those reasons (placing them in my order, not Jewell and Fuller’s):
1) Listing can protect the islands of Hawai`i, Puerto Rico, and the Caribbean and Pacific territories. All are extremely vulnerable to invasive species.
2) If a species shares the traits of injuriousness with other species, particularly those in the same genus or family, then including the already-invasive species demonstrates why the related species should also be listed.
3) Many imported animals carry parasites and pathogens harmful to native species, and stopping the continued importation can reduce those threats that cause disease.
4) Prohibiting further importation of the invasive species can prevent individuals from being introduced to new areas where the species would not otherwise have arrived and can reduce propagule pressure that could introduce hardier individuals.
5) Listing can provide states and other jurisdictions with the technical information they need to pursue additional restrictions not federally authorized under 18 U.S.C. 42, such as transport into a state, possession, and sale.
6) Listing reduces propagule pressure and might enhance the efficacy of any eradication or control measures.
How to Improve the Lacey Act
1) Amend the Lacey Act to restore authority to regulate interstate movement of listed species – including among the continental states and emergency listing authority. Also establish a more streamlined listing process.
2) Strengthen implementation of the law by providing a specific, adequate appropriation to hire additional staff. Utilize the enhanced resources to assess species proactively using risk assessment tools.
It is not yet clear whether the Biden Administration will initiate a more active listing process, especially beyond the zoonotic disease vectors that are the subject of the American Rescue Plan Act.
Note: The “injurious wildlife” section of the Lacey Act (18 U.S.C. 42, or title 18) is separate from another part of the Lacey Act (16 U.S.C. 3371-3378) that is has always been more widely known. This provision regulates wildlife trafficking across State lines. It was later broadened to include plants and trafficking of wildlife and plants from foreign countries.
SOURCES
Jewell S.D. (2020) A century of injurious wildlife listing under the Lacey Act: a history. Management of Biological Invasions. Volume 11, Issue 3: 356–371, https://doi.org/10. 3391/mbi.2020.11.3.01 https://www.reabic.net/journals/mbi/2020/3/MBI_2020_Jewell.pdf
Alternative view – that Lacey Act implementation has failed to protect the U.S. – presented by the following authors:
Fowler, A.J., D.M. Lodge and J. Hsia. 2007. Failure of the Lacey Act to protect US ecosystems against animal invasions. Frontiers in Ecology and the Environment.
Springborn, M. C.M. Romagosa and R.P. Keller. 2011. The value of nonindigenous species risk assessment in international trade. Ecological Economics
Jenkins, P.T. 2012. Invasive animals and wildlife pathogens in the United States: the economic case for more risk assessments and regulation. Biological Invasions
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.
lodgepole pines killed by mountain pine beetle in British Columbia; photo courtesy of Wikipedia
Natural systems, especially forests, could provide as much as 37% of the near-term mitigation necessary to meet Paris global climate goals. In the US, conservation, restoration, and improved land management could provide carbon sequestration equivalent to an estimated 21% of current net annual emissions.
However, the current U.S. forest carbon sink, which includes soils and standing and downed wood as well as live trees, might be in jeopardy due to increasing levels of disturbance, conversion, and/or declining sequestration rates in old growth stands.
Insects and plant diseases are one such disturbance agent. Acting alone or in combination with other forest stressors, they can damage or kill large numbers of trees in short periods of time, thereby reducing carbon sequestration and increasing emissions of stored carbon through decomposition of wood in dead or injured trees.
Historically, native and introduced insects and diseases have impacted an estimated 15% of the total U.S. forest cover annually. This impact is likely to increase. One study (Feiet al., 2019) found that an estimated 41% of the live forest biomass in the contiguous U.S. could be impacted by the 15 most damaging introduced pests already established in the U.S. Continuing introductions of new pests and exacerbated effects of native pests associated with climate change portend worsening losses of live trees. These rising impact of pests, combined with more frequent and severe fires and other forest disturbances, are likely to negate efforts to improve forests’ carbon sequestration capacity.
Sources of information about introduced pests’ impacts is available from, inter alia Campbell and Schlarbaum Fading Forests II and III, Lovett et al 2016, Poland et al. 2021, many blogs on this site, and pests’ profiles posed here under “invasive species” tab. Chapter 4 of Poland et al. (2021) provides a summary of what is known about interactions between invasive species and climate change – both climate impacts on bioinvaders and bioinvaders’ effect on carbon sequestration.
The United States and other major polluting countries have certain advantages. Their strong economies have the scientific and financial resources needed to implement effective invasive species prevention and forest management strategies. At the same time, many of them receive the most new forest pests – because they are major importers. These introduced pests pose the most serious and urgent near-term ecological threat to their forests and all the ecosystem services forests provide.
So, reducing insect and disease impacts to forests can simultaneously serve several goals—carbon sequestration, biodiversity conservation, and protecting the myriad economic and societal benefits of forests. See the recent IUCN report on threatened tree species.
A Major New Study
A new study by Quirion et al. (2021) takes another step in quantifying the threat to U.S. forests’ ability to sequester carbon by analyzing data from National Forest Inventory plots. Unfortunately, the re-measurement data for the period 2001 – 2019 are not available in the NFI for the Rocky Mountain states, which represents a critical data gap in the NFI program. This gap might not have had a significant impact on the national findings, however, because while the insect damage level (measured by an earlier inventory round) was quite severe in the Rocky Mountain States, the relatively slow growth of trees in that region means carbon sequestration rates are low.
Forest stand productivity – and carbon sequestration — will typically decline immediately after pest outbreaks, then recover or even increase beyond pre-outbreak levels depending on the productivity and maximum achieved biomass of replacement plant species and related soil characteristics. However, when prevalence of the disturbance increases, by, for example, more frequent pest outbreaks, carbon stocks in standing trees and sequestration rates can be reduced for extended periods.
Findings
Nationally, insects and diseases have decreased carbon sequestration by live trees on forest land by 12.83 teragrams carbon per year. This equals ~ 9% of the contiguous states’ total annual forest carbon sequestration and equivalent to the CO2 emissions from over 10 million passenger vehicles driven for one year.
This estimate includes the impacts of both native and introduced insects and diseases, because the NFI database does not distinguish between them.
Insect-caused mortality had a larger impact than disease-caused mortality (see below). Forest plots recently impacted by insect disturbance sequestered on average 69% less carbon in live trees than plots with no recent disturbance. Plots recently impacted by disease disturbance sequestered on average 28% less carbon in live trees than plots with no recent disturbance.
Ecoprovinces in which the greatest annual reductions in live tree carbon sequestration due to pests were the Southern Rocky Mountain Steppe, Cascade Mixed Forest, Midwest Broadleaf Forest, and Laurentian Mixed Forest. (Ecoprovinces are outlined – but not named – in Quirion et al. 2021; more complete information is provided in the supplementary material.)
If this study had been carried out in the 1920’s, when chestnut blight and white pine blister rust were spreading across vast areas and killing large trees, the impact of diseases would have been much higher. Today, the most widespread impacts of diseases are on either small trees (e.g., redbay succumbing to laurel wilt) or slow-growing, high-elevation trees (e.g., whitebark and limber pine to white pine blister rust). As long as no equivalents of those earlier diseases are introduced, insects will probably continue to have the larger impacts.
western white pine killed by blister rust; photo from National Archives
Quirion et al. 2021 note that their estimates should be considered conservative. The USFS’s inventory records only major disturbances. That is, when mortality or damage is equal to or exceeds 25% of trees or 50% of an individual tree species’ count on an area of at least 0.4 ha. This criterion largely excludes less severe pest disturbances, including those from which trees recover but which might have temporary negative effects on carbon sequestration.
The study’s authors note that their work has important limitations. The dearth of data from the Rocky Mountain states is one. Other factors not considered include transfers of carbon from live biomass to dead organic matter, soils, and salvaged or preemptively harvested wood products. As trees die from pests or diseases, their carbon becomes dead wood and decays slowly, producing a lag in the carbon emissions to the atmosphere. A small fraction of the carbon in dead wood might be incorporated into soil organic matter, further delaying the emissions. A full accounting of the carbon consequences of pests and diseases would require assessment of these lags, probably through a modeling study.
affects of mountan pine beetle on lodgepole pine in Rocky Mountain National Park, Colorado photo from Wikimedia
Actions to Maintain Carbon Sequestration
Quirion et al. (2021) outline several actions that would help protect the ability of America’s forests to sequester carbon. These suggestions address both native and introduced pests, since both contribute to the threatened reduction in capacity.
Concerning native pests, the authors call for improved forest management, but warn that measures must be tailored to species and environmental context.
Concerning introduced insects and pathogens, Quirion et al. (2021) call for strengthening international trade policies and phytosanitary standards, as well as their enforcement. The focus should be on the principal pathways: wood packaging (click on “wood packaging” category for on this blog site) and imported plants (click on “plants as vectors” category for on this blog site). Specific steps to reduce the rate of introduction of wood-boring insects include enforcement to increase compliance with the international treatment standard (ISPM#15), requiring trade partners – especially those which have repeatedly shipped infested packaging – to switch to packaging made from alternative materials. Introductions via the plant trade could be reduced by requiring foreign shippers to employ integrated management and critical control point systems (per criteria set by the U.S.) and using emergency powers (e.g., NAPPRA) to further restrict imports of the plants associated with the highest pest risk, especially plant species that are congeneric with native woody plants in North America. See Lovett et al 2016; Fading Forests II & III
As backup, since even the most stringent prevention and enforcement will not eliminate all risk, the authors urge increased funding for and research into improved inspection, early detection of new outbreaks, and strategic rapid response to newly detected incursions.
To reduce impacts of pests established on the continent – both recently and years ago – they recommend increasing and stabilizing dedicated funding for classical biocontrol, research into technologies such as sterile-insect release and gene drive, and host resistance breeding.
Thinning is useful in reducing damage by native bark beetles to conifers. However, it has not been successful in controlling introduced pests for which trees do not have an evolved resistance. Indeed, preemptive harvesting of susceptible species can harm forest ecosystems directly through impacts of the harvesting operation and indirectly as individual trees that may exhibit resistance are removed, reducing the species’ ability to develop resistance over time.
Further research is needed to clarify several more issues, including whether introduced pests’ impacts are additive to, or interact with, those of native species and/or other forest stressors.
SOURCE
Quirion BR, Domke GM, Walters BF, Lovett GM, Fargione JE, Greenwood L, Serbesoff-King K, Randall JM & Fei S (2021) P&P Disturbances Correlate With Reduced Carbon Sequestration in Forests of the Contiguous US. Front. For. Glob. Change 4:716582. [Volume 4 | Article 716582] doi: 10.3389/ffgc.2021.716582
SOURCES of additional information
Campbell, F.T. and S.E. Schlarbaum. Fading Forest reports at http://treeimprovement.utk.edu/FadingForests.htm
Lovett, G.M., M. Weiss, A.M. Liebhold, T.P. Holmes, B. Leung, K.F. Lambert, D.A. Orwig, F.T. Campbell, J. Rosenthal, D.G. McCullough, R. Wildova, M.P. Ayres, C.D. Canham, D.R. Foster, S.L. Ladeau, and T. Weldy. 2016. Nonnative forest insects and pathogens in the United States: Impacts and policy options. Ecological Applications, 26(5), 2016, pp. 1437-1455
Poland, T.M., Patel-Weynand, T., Finch, D., Miniat, C. F., and Lopez, V. (Eds) (2019), Invasive Species in Forests and Grasslands of the United States: A Comprehensive Science Synthesis for the United States Forest Sector. Springer Verlag. Available for download at no cost at https://www.fs.usda.gov/treesearch/pubs/61982
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
Port-Orford cedar resistance trials at Dorena Center; photo courtesy of Richard Sniezko, USFS
I have written several times about the importance of the United States adopting a comprehensive program to address all aspects of introduced forest pests including breeding of trees resistant to the introduced pests. See Fading Forests III from seven years ago; an earlier blog; and Bonello et al. 2020 (full citation at end of blog), in which we proposed the creation of a federal Center for Forest Pest Control and Prevention to implement end-to-end integrated responses to forest pest invasions. A similar view is being voiced internationally; see, e.g., Buggs et al. 2020.
I have seen efforts to restore pest-decimated tree species to the forest lagging. I complained in a recent blog link that the recent USDA Forest Service report on invasive species (Poland et al. 2021) gave a misleading impression that significant effort was being made on resistance breeding to address several pests.
The USFS does support breeding trees resistant to pests, but in my view this support has been inadequate – including in the USFS report. Others think so, too — see Sniezko and Koch 2017. This insufficiency only grows, despite USDA claims to recognize that promoting resistance to introduced forest pests is an essential component of achieving its strategic goals of maintaining or enhancing productivity while ensuring responsible stewardship of resilient natural resources (Federman and Zankowski 2019).
Work at the Dorena Genetic Research Center
The principal and most notable and successful resistance breeding effort has been the Dorena Genetic Resource Center. The Center was established by, and is funded through the USFS Region 6 Genetic Resource (part of the National Forest System) and Forest Health Management programs. The Center has a solid foundation in the expertise and facilities needed to carry out breeding efforts. Also, it has a 50-plus-year track record.
Dorena has supported breeding of white (five-needle) pines and Port-Orford cedar. Dorena also now provides expertise and some facilities to partners exploring a) breeding Oregon ash to resist the emerald ash borer and b) two Hawaiian trees (koa and ‘ōhi‘a) to resist introduced pathogens (see below). Dorena staff is assisting low-budget, shoe-leather efforts to explore breeding of other trees at risk to non-native pests. These programs are described briefly in Box 8 of Poland et al. 2021. Despite this valuable effort with proven success funding to continue Dorena’s work is tenuous.
White Pine Blister Rust — Efforts to develop resistance to white pine blister rust (WPBR) DMF in five-needle pine species (nine grow across the country) began more than 50 years ago. Currently Dorena focuses on whitebark pine (Pinus albicaulis), denizen of high elevations in the West, along with western white pine (P. monticola), sugar pine (P. lambertiana) , limber pine (P. flexilis), southwestern white pine (P. strobiformis), and foxtail pine (P. balfouriana). Testing whitebark for resistance to WPBR began in 2002. Seedling families from >1,300 parent trees are in various stages of testing. The discovery that some whitebark populations have much higher levels and frequency of partial resistance has allowed rapid distribution of seed. The first restoration plantings in the Pacific Northwest were in 2009.
3-year old seedlings of whitebark pine at Crater Lake National Park; photo by Richard Sniezko, USFS
There are many collaborators – especially the National Park Service, Washington State’s Department of Natural Resources, several Tribes, the Whitebark Pine Ecosystem Foundation, and American Forests. However, planting has been hampered by the high cost of restoration in these high elevation ecosystems, lack of frequent good seed crops on the resistant parent trees, and lack of approval to plant in designated wilderness areas. In the areas with the highest levels of resistant parents, management activities that encourage natural regeneration might be successful. In late 2020 the U.S. Fish and Wildlife Service proposed to list whitebark pine as a Threatened species
Oregon ash (F. latifolia) has not yet been attacked by the emerald ash borer, but all expect EAB to spread to the West coast. Dorena and cooperators have already collected seed from ash trees in Oregon and obtained funding for additional collections, to include Washington and California. The seeds are being stored at both Dorena and the USDA Agriculture Research Service facility at Ft. Collins, Colorado. Seedlings from two dozen families have also been planted at Dorena and a center operated by Washington State University, plus at a USFS Northern Research Station research center in Ohio, where EAB is established and they can be tested for resistance to the insect’s attack.
Koa and ‘ōhi‘a in Hawaii — Regeneration of the koa tree (Acacia koa) has been undercut by the koa wilt pathogen, Fusarium oxysporum f. sp. koae. Dorena initiated efforts with the Hawaii Agricultural Research Center (HARC) to respond in 2003. There has been rapid progress screening seedlings to identify resistant parent trees establishing seed orchards, delineating seed zones, and releasing seed with confirmed levels of resistance for reforestation and restoration (Sniezko and Koch 2017; see also Dudley et al. 2020).
‘ōhi‘a trees killed by rapid ‘ōhi‘a death; photo courtesy of J.R. Friday
When the threat to Hawaii`s most widespread tree ‘ōhi‘a (Metrosideros polymorpha) from rapid ‘ōhi‘a death (ROD) pathogens became apparent, the Dorena staff provided advice on breeding strategies. Its Center Geneticist is part of an ad hoc resistance team. Scientists have identified surviving trees in stands affected by ROD on the Big Island using a variety of methods. These include aerial surveys by drones and fixed-wing aircraft. They then began collecting seeds and cuttings. As of spring 2021, they have collected cuttings or seeds from more than 300 ‘ōhi‘a trees belonging to five varieties. The effort is low-cost, using Americorps volunteers coordinated by a single full-time person, a USFS employee. The program is still in its infancy. It will have to find funding to expand its scope to an operational resistance program once more information on resistance is has been obtained.
Other Efforts
Most other breeding programs are small and poorly funded. In fact, they have been described by one USFS scientist as “hobby projects” of a few scientists determined to try this strategy. Not only are efforts minimal; but also retirement of those few scientists can bring an end to the individual project.
There were greater efforts in the past. I have a document (of unknown origin) from 2011 that describes breeding efforts funded by both the National Forest System and USFS Research and Development. Table 1 listed 16 projects for western conifers; Table 2 listed 32 projects funded by R&D. During this period, the USFS provided start-up funds for the Healthy Forests Initiative, a consortium that sought to prove the concept that genetic engineering could quickly produce an American chestnut able to live and reproduce in its native range. This support was in addition to support for The American Chestnut Foundation backcross hybridization program link.
Part of the problem is the longstanding decline in funding and staffing of USFS research program. A graph in Chapter 6 of FFIII shows the decline in numbers of forest entomologists and pathologists over the 20-year period 1985–2007. Wheeler et al. 2015 discuss the parallel decline in tree breeders and geneticists (citation at end of this blog).
Cuts continue. Funding for research conducted by the USFS Research stations on ten non-native pests decreased from $10 million in Fiscal Year 2010 to just $2.5 million in Fiscal Year 2020 – a cut of more than 70%. I have lobbied for increased appropriations for decades.
The need for new approaches and increased effort is more widely asserted. One example is the group I am working with that promotes a new Center for Forest Pest Control and Prevention. Link A second example is the University of Florida’s recent conference of forest health researchers, representatives of the forest products industry, non-governmental organizations, and leaders of universities with forest-resource programs. This group suggested forming a united organization to increase capacity to improve forest health research. An article outlining the proposal is available here.
The Role of Biotechnology in Breeding Resistant Trees
what happened? same tree a few years apart — a TACF hybrid chestnut
Part of the discussion on forest research explores the proper role of biotechnology in tree species’ restoration. Purdue University hosted a related workshop in April 2021, in which I took part. (“Society and Policy Influences on Biotechnology Risk Assessment for Restoration of Threatened Forest Tree Species”). I hope participants will soon publish a paper based on our discussions.
Meanwhile, Revive & Restore, a wildlife conservation organization promoting the incorporation of biotechnologies into standard conservation practice, sponsored a workshop in June 2020. The 57 conservationists, wildlife biologists, restoration specialists, conservation geneticists, ethicists, and social scientists who participated agreed on an appropriate structure for using biotechnology. These included:
A broader definition of risk and application of new risk assessment tools;
Consideration of the risks of not taking action, as well as going ahead with a proposal;
Transparency about social and cultural values and engaging stakeholders
Monitoring results to ensure actions have been successful, manage uncertainty, and codify lessons learned.
In the literature I read, the workshops I participate in (e.g., National Academy of Sciences 2019; Purdue’s), biotechnology is seen as a potentially helpful set of tools that must be integrated into broader programs, all having research, tree improvement, restoration, and reforestation components. Such programs must have sustained management and resources stemming from public support. (For more complete descriptions of components of a resistance breeding program, see Sniezko and Koch 2017 (full reference below); or Chapter 6 of FFIII). Activities that must be incorporated include:
Germplasm collection and storage (applying the varied strategies that are appropriate);
Research to detect and test potential resistance or tolerance;
Research to identify techniques for producing propagules;
Planting sites that will be secure for decades;
Site preparation & planting;
Post-planting maintenance; and
Monitoring to determine success or problems
During the Purdue workshop, and in my writing, I have emphasized the principal hindrance to progress is the lack of resources being allocated to resistance breeding. USFS and academic scientists determined to pursue breeding approach must scrounge for funds. I describe some of their efforts below.
Collaborations on Breeding for Specific Species
(still) healthy hemlocks in Cook Forest State Park, Pennsylania; photo by F.T. Campbell
USFS Hemlock Woolly Adelgid (HWA) Initiative [apparently no website]
This initiative was developed under the leadership and direction of FHP staff. The list of cooperators includes dozens of state, federal, university and private organizations. The annual budget has averaged between $2.5 and $3.5 million. Most resources are apparently allocated to biocontrol, but some funding has been provided for breeding activities, including:
Seed collection and storage for both Carolina and eastern hemlocks. Two seed orchards have been established in western North Carolina. I believe they are protected from the hemlock woolly adelgid (HWA) by application of pesticides.
Research on these tree species’ silviculture and ecology, including manipulation of sunlight levels to protect seedlings from the adelgid and promote growth
The 2021-2025 Program – currently under review – foresees more integrated pest management applying biocontrol, chemical control, and silviculture. It aims to maintain the health of hemlocks being used in breeding programs and “explore” hemlock replacement options, such as hybrids or HWA-tolerant hemlocks (Mayfield et al. 2021). This effort is encouraging, but I have heard complaints from academics that they can’t get funding to pursue what they regard as promising breeding strategies.
Other small programs to breed resistant hemlocks are under way. The Forest Restoration Alliance (formerly the Alliance to Save Threatened Forests) asks citizens to identify surviving hemlocks and balsam firs. The Alliance has collected and propagated both cuttings and seeds and is testing their resistance.
Ash and Other Trees of the Upper Midwest
To date, few resources have been allocated to resistance breeding of ash. Between 2003 and 2017, only about 7% of research funds allocated to ash and emerald ash borer DMF have been devoted to host resistance. Of the host resistance research, 61% applied to identifying mechanisms, 14% to use of transgenics to develop resistance, only 7% (0.5% of the total research) has supported actual breeding for resistance (Sniezko and Koch 2017).
In May 2021 the USFS announced it was seeking funds from the water-focused Great Lakes Restoration Initiative. The USFS expects to receive up to $5.4 million for reforestation, ecosystem restoration. and forest health improvements on non-federal lands in the Great Lakes basin. (This includes parts of the states of Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania and Wisconsin). The announcement doesn’t mention resistance breeding for ash, beech, hemlock, or other trees in the region. I hope some of the new funds will be allocated to this strategy.
“lingering” ash; photos courtesy of Jennifer Koch, USFS
In an encouraging show of entrepreneurship, USFS scientists and others have formed the Great Lakes Basin Forest Health Collaborative – a partnership with Holden Forests and Gardens, American Forests, and USFS (Kappler et al. 2021). The purpose of the Collaborative is to advance resistance breeding for these important tree species. The initial focus is on the five ash species in the region, especially black ash (Fraxinus nigra) link to blog The Collaborative is recruiting a network of partners, and will provide training and technology transfer. The partners will provide volunteers and other resources. Partners do not have to be within the region if their work helps the Great Lakes Basin, but plantings have to be there.
Partners will help identify survivor trees with potential resistance (e.g., “lingering” ash); establish clone banks and/or seed orchards; and manage seed collections. Each partner will operate independently, but in collaboration with the others. The initial focus is on obtaining representative seed collections of ash and hemlock. Then cloning, testing resistance, and crosses can begin. Eventually select lines will be chosen for bulking up and reintroduction.
In future the Collaboration hopes to engage in breeding hemlocks and identifying beech trees that remain healthy in areas heavily impacted by beech leaf disease (BLD).
Other efforts under way include the Monitoring and Managing Ash (MaMA) Program, based in the Ecological Research Institute in New York State.
Beech trees with resistance to beech bark disease (BBD) were identified as early as the 1980s, but a breeding program was begun only in 2002. A collaborative, multi-agency effort has resulted in the establishment of five regional American beech seed orchards with four others in progress as of 2017. Partners provide a cost-effective process for identifying resistant parent trees. State and National Forest personnel surveyed natural forests for candidate trees and then tested each tree and identified markers associated with resistance (Sniezko and Koch 2017).
Challenges Beyond Breeding
Large-scale restoration of tree species across much of their ranges will require significant inputs of funds, over long time periods, as well as resolving daunting logistical issues.
Some think the most likely scenario will be to plant focal areas, or islands, that can aid future natural regeneration (Sniezko and Koch 2017). The American Chestnut Foundation (TACF) anticipates it will take 1,000 years to re-establish American chestnut DMF across its range through a process of three phases: long-term research and demonstration plantings; a relatively small-scale public horticultural program using trees and/or pollen made available by TACF; and a larger-scale public restoration program using progeny from years of outcrossing and production. (This assumes APHIS approves release of the transgenic “Darling 58” tree, plus – I believe – progress in developing resistance to root disease caused by Phytophthora cinnamomi). Already good progress using focal areas has started with several white pine species, and a national plan is in the works for whitebark pine.
Such efforts will require access to land that can be protected from other uses, e.g., development for decades or centuries. Also it will require management of sites to protect propagules from browsing wildlife (deer, rabbits!), provide adequate water and light, and probably give plantings a competitive advantage in relation to other plants growing there …
non-resistant elms will grow anywhere! photo by F.T. Campbell
And there is the issue of how a relatively small number of resistant propagules will succeed in spreading their improved genetics in areas where non-improved elm, ash, beech and hemlock are reproducing naturally. Is reproduction of unimproved trees likely to continue in the face of new and old pests’ spread? If biocontrol agents succeed in reducing a pest’s impact on a host tree species, will that enhance the competitive ability of unimproved trees to the disadvantage of genetically improved conspecifics? What are realistic expectation for programs, and for their success?
Criteria for Success
Woodcock, Marzano, and Quine (2019) analyzed five breeding programs to identify aspects that contribute to success. Four of the programs were in North America; they targetted chestnut, western white pines, and Sitka spruce & white pine weevil. They concluded that
Success is influenced by the level of resistance present in individual trees, the frequency of resistance in the population, and the heritability of resistance.
It is important to consider current and potential future risks to the species in addition to the target pest or pathogen— the benefits of trees resistant to a specific threat are negated if it is susceptible to other threats.
Demand [for a resistant tree to plant] should be evaluated, and the priorities of potential supporters and end users should inform the methods used to produce resistant trees.
Operational deployment should balance the urgency of the threat with the consequences if resistant material does not perform as hoped. Urgency might differ for an emerging pest or pathogen.
Deployment strategies should be informed by the risks of imposing a strong selection pressure on the pest or pathogen to evolve to overcome host resistance, and by potential impacts on partially resistant trees.
Continued monitoring of field performance is important for evaluation, and can help to identify and mitigate emerging threats (e.g. new pathogen strains).
SOURCES
Bonello, P., F.T. Campbell, D. Cipollini, A.O. Conrad, C. Farinas, K.J.K. Gandhi, F.P. Hain, D. Parry, D.N. Showalter, C. Villari, and K.F. Wallin. 2020. Invasive tree pests devastate ecosystems – A proposed new response framework. Frontiers in Forests and Global Change. January 2020. Volume 3, Article 2
Buggs, R.J.A. 2020 Changing perceptions of tree resistance research. Plants, People, Planet. 2020; 2: 2– 4. https://doi.org/10.1002/ppp3.10089
Dudley, N.; Jones, T.; Gerber, K.; Ross-Davis, A.L.; Sniezko, R.A.; Cannon, P.; Dobbs, J. 2020. Establishment of a Genetically Diverse, Disease-Resistant Acacia koa A. Gray Seed Orchard in Kokee, Kauai: Early Growth, Form, and Survival. Forests 2020, 11, 1276
Kappler, R., C. Blashka, D. burke, E. Hall, C. Pike, J. Koch. 2021. Great Lakes Basin Forest Health Collaborative: What it’s all about. North American Forest Insect Work Conference 28 May 2021
Mayfield, A.E. III, Salom, S., Jetton, R., Havill, N., Rhea, R., and Mausel, D. 2021. North American Forest Insect Work Conference 28 May 2021. Spread, impact and management of HWA in eastern North America
National Academies of Sciences, Engineering, and Medicine. 2019. Forest Health and Biotechnology: Possibilities and Considerations. Washington, DC: The National Academies Press. https://doi.org/10.17226/25221.
Poland, T.M., P. Patel-Weynand, D.M Finch, C.F. Miniat, D.C. Hayes, V.M Lopez, editors. 2021. Invasive Species in Forests and Rangelands of the United States. A Comprehensive Science Synthesis for the US Forest Sector. Springer
Sniezko, R.A. and J. Koch. 2017. Breeding trees resistant to insects & diseases: putting theory into application. Biol Invasions. 2017. 19:3377-3400. DOI 10.1007/s10530-017-1482-5
Wheeler, N.C., K.C. Steiner, S.E. Schlarbaum, D.B. Neale. 2015. The Evolution of Forest Genetics and Tree Improvement Research in the United States, Journal of Forestry, Volume 113, Issue 5, September 2015, Pages 500–510, https://doi.org/10.5849/jof.14-120
Woodcock, P., M. Marzano, C.P. Quine. 2019. Key lessons from resistant tree breeding programmes in the Northern Hemisphere. Annals of Forest Science (2019)76:51 https://doi.org/10.1007/s13595-019-0826-y
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
Ailanthus – one of the invasive species shared by South Africa and the U.S.
A few years ago, I posted a blog in which I pointed to a report on South Africa’s response to bioinvasion as a model for the U.S. and other countries. South Africa has published its second report. This report outlines the country’s status as of December 2019 and trends since the first report (i.e. since December 2016). (I describe the report’s findings on South Africa’s invasive species situation in a companion blog.) Again, I find it a good model of how a country should report its invasive species status, efforts, and challenges. In comparison, many U.S. efforts comes up short.
U.S. Reports Need to Be More Comprehensive
The South African report provides a national perspective on all taxa. Various United States agencies have attempted something similar a few times. The report issued by the Office of Technology Assessment in 1993 summarized knowledge of introduced species and evaluated then-current management programs.
The 2018 report by the U.S. Geological Service focused on data: the authors concluded that 11,344 species had been introduced and described the situation in three regions – the “lower 48” states, Alaska, and Hawai`i. However, the USGS did not evaluate programs and policies. The new USDA Forest Service report (Poland et al. 2021) describes taxa and impacts of invasive species in forest and grassland biomes, including associated aquatic systems. Again, it does not evaluate the efficacy of programs and policies.
The biennial national reports required by the Executive Order establishing the National Invasive Species Council (NISC) are most similar to the South African ones in intent. However, none has been comprehensive. For example, the most recent, issued in 2018, strives to raise concern by stating that invasive species effect a wide range of ecosystem services that underpin human well-being and economic growth. Some emphasis is given to damage to infrastructure. The report then sets out priority actions in six areas: leadership and prioritization, coordination, raising awareness, removing barriers, assessing federal capacities, and fostering innovation. NISC also issued a report in 2016 – this one focused on improving early detection and rapid response. NISC posted a useful innovation – a “report card” updating progress on priority actions — in October 2018. It listed whether actions had been completed, were in progress, or were no longer applicable. However, the “report card” gave no explanation of the status of various actions; the most notable omissions concerned the actions dismissed as “not applicable”. Worse, no report cards have been posted since 2018. I doubt if those or any more comprehensive reports will be forthcoming. This reflects the increasing marginalization of NISC. The Council has never had sufficient power to coordinate agencies’ actions, and now barely survives.
U.S. Reports Need to Be More Candid
The authors of the South African report made an impressive commitment to honest evaluation of the country’s gaps, continuing problems, progress, and strengths. As in the first report, they are willing to note shortcomings, even of programs that enjoy broad political support (e.g., the Working for Water program).
It is not clear whether decision-makers have acted — or will act — on the report’s findings. That is true in many countries, including the United States. However, that is separate whether decision-makers have an honest appraisal on which to base action.
Assessment of South Africa’s Invasive Species Programs
Here is a summary of what the authors say about South Africa’s invasive species program. I want to state clearly that my intention is not to criticize South Africa’s efforts. No country has a perfect program, and South Africa faces many challenges. These have been exacerbated by COVD-19.
The report identifies the areas listed below as needing change or improvement.
1) Absence of a comprehensive policy on bioinvasion. Such a policy would provide a vision for what South Africa aspires to achieve, clarify the government’s position, guide decision-makers, and provide a basis for coordinating programs by all affected parties (e.g., including conservation and phytosanitary agencies).
2) As in the first report, the authors call for monitoring program outcomes (results) rather than inputs (money, staffing, etc.) or outputs (e.g., acres treated). The authors also say data must be available for scrutiny. In those cases when data are adequate for assessing programs’ efficacy, they indicate that the control effort is largely ineffective.
3) Inadequate data in several areas. The report notes progress in developing and applying transparent and science-based criteria to species categorization as invasive (as distinct from relying on expert opinion). However, this change is taking time to implement, and sometimes results in species receiving a different rating. [I agree with the report that data gaps undermine understanding of the extent and impacts of bioinvasion, domestic pathways of spread, justification of expenditures, assessment of various programs’ efficacy (individually or overall), priority setting, and identifying changes needed to overcome programs’ weaknesses. However, I think filling these data gaps might demand time and resources that could better be utilized to respond to invasions – even when those invasions are not fully understood.]
4) Funding of bioinvasion programs by the National Department of Forestry, Fisheries, and the Environment has been fairly constant over 2012–2019, but this is a decline in real terms. The figure of 1 billion ZAR does not include spending by other government departments, national and provincial conservation bodies, municipalities, non-governmental organizations, and the private sector. Authors of the report expect funding to decrease in the future because of competing needs.
While at least 237 invasive species are under some management (see Table 5.1), funding is heavily skewed – 45% of funding goes to management of one invasive plant (black wattle); 72% to management of 10 species.
5) Need for policies to address the threat emerging from rising trade with other African countries, especially considering the probable adoption of the proposed African Continental Free Trade Area. Under this agreement, imported goods will only be inspected for alien species at the first port of entry, and most African countries have limited inspection capacity. [European pathologists Brasier, Jung, and others have noted the same issue arising in Europe, where imported plants move freely around the European Union once approved for entry by one member state.]
The authors of the South African report say programs’ efficacy would be considerably improved if species and sites were prioritized, and species-specific management plans developed. They warn that, in the absence of planning and prioritization, there is a risk that funding could be diluted by targeting too many species, leading to ineffective control and a concomitant increase in impacts.
In South Africa, regulations, permits, and other measures aimed at regulating legal imports of listed species are increasingly effective. However, there is still insufficient capacity to prevent accidental or intentional illegal introductions of alien species. There is also more enforcement of regulations requiring landowners to control invasive species. Six criminal cases have been filed and – as of December 2019, one conviction (guilty plea) obtained. However, the data do not allow an assessment of the overall level of compliance.
The report found little discernable progress on the proportion of pathways that have formally approved management plans. Management is either absent or ineffective for 61% of pathways. There has been no action to manage the ballast water pathway. On the other hand, in some cases, other laws focus explicitly on pathways, e.g., agricultural produce is regulated under the Agricultural Pests Act of 1983.
During the period December 2016 – December 2019, the Plant Inspection Services tested more than 12,000 plant import samples for quarantine pests and made 62 interceptions. The report calls for more detailed information from the various government departments responsible for managing particular pathways (e.g., the phytosanitary service), and for an assessments of the quality of their interventions.
The number of non-native taxa with some form of management has grown by 40% since December 2016 – although – as I have already noted — spending is highly skewed to a few plant species. The number and extent of site-specific management plans has also increased, apparently largely due to a few large-scale plans developed by private landowners. However, few of these plans have been formally approved by some unspecified overseer.
Citing the strengths and weaknesses described above, the current (second) report downgraded its assessment of governmental programs from “substantial” to “partial”.
Comparison to U.S.
How does the United States measure up on the elements that need change or improvement? I know of no U.S. government report that is as blunt in assessing the efficacy of our programs –individually or as a whole.
Nevertheless, each of the five weaknesses identified for South Africa also exist in the United States:
Re: lack of a comprehensive policy, I think the U.S. also suffers this absence. This is regrettable since the National Invasive Species Council (NISC) was set up in 1999.
Re: monitoring outcomes to assess programs’ efficacy, I think U.S. agencies do seem to be more focused on collecting data on programs’ results – see the Forest Service’ budget justification. However, I think too often the data collected focus on inputs and outputs.
Re: data gaps, I think all countries – including the U.S. — lack data on important aspects of bioinvasion. I differ from the South African report, however, in arguing for funding research aimed at developing responses rather than monitoring to clarify the extent of a specific invasive species. Information that does not lead to action seems to me to be a luxury given the low level of funding.
Re: funding, I find that, despite the existence of NISC, it remains difficult to get an overall picture of U.S federal funding of invasive species programs. Indeed, the cross-cut budget was dropped in 2018 at the Administration’s request. I expect all agencies are under-funded; I have often said so as regards key USDA programs. As in South Africa, funding is skewed to a few species that I think should be lower in priority (e.g., gypsy moth).
Re: upgrading invasive species programs to counter free-trade policies, I think U.S. trade policies place too high a priority on promoting agricultural exports to the detriment of efforts to prevent forest pest introductions. This imbalance might be present with regard to other taxa and pathways. See Fading Forests II here.
South African and U.S. agencies also face the same over-arching issues. For example, the U.S. priority-setting process seems to be a “black box.” Several USFS scientists (Potter et al. 2019) spent considerable effort to develop a set of criteria for ranking action on tree species that are hosts of damaging introduced pests. Yet there is no evidence that this laudable project influenced priorities for USFS funding.
SOURCES
Poland, T.M., P. Patel-Weynand, D.M Finch, C.F. Miniat, D.C. Hayes, V.M Lopez, editors. 2021. Invasive Species in Forests and Rangelands of the United States. A Comprehensive Science Synthesis for the US Forest Sector. Springer
Potter, K.M., Escanferla, M.E., Jetton, R.M., Man, G., Crane, B.S. 2019. Prioritizing the conservation needs of United States tree species: Evaluating vulnerability to forest P&P threats, Global Ecology and Conservation (2019), doi: https://doi.org/10.1016/j.gecco.2019.e00622.
SANBI and CIB 2020. The status of bioinvasions and their management in South Africa in 2019. pp.71. South African National BD Institute, Kirstenbosch and DSI-NRF Centre of Excellence for Invasion Biology, Stellenbosch. http://dx.doi.org/10.5281/zenodo.3947613
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
If you have not communicated to your Representative and senators your support for adequate funding of U.S. government programs to address non-native insects and pathogens threatening our forests, please do so now!
If political leaders do not hear from us that expanding these programs is important, these programs will continue to languish. It is easiest – and most direct – to inform your representative and Senators of your support. Please do so! If you do not agree that these programs should be expanded & strengthened, I ask that you send a comment outlining what approach you think would be more effective in curtailing introductions, minimizing impacts, and restoring affected tree species. I can then initiate a discussion to explore these suggestions. [I already have endorsed the suggestion to create a CDC-like body to oversee management of non-native forest pests.] You can find your member of Congress here. Your Senators here.
Last week the Biden Administration sent to Congress its proposed budget for the fiscal year beginning October 1, 2021. I find it falls short in key areas. Next, the House and Senate will pass a package of appropriations bills to set actual funding levels. This is the moment to press for boosted funding. In an earlier blog I explained my reasons for seeking specific funding levels.
Asian longhorned beetles – introduced in wood packaging (USDA photo)
Two USDA agencies lead efforts to protect U.S. wildland, rural, and urban forests from non-native insects and pathogens. Their funding is set by two separate – and critical — appropriations bills:
USDA’s 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 their damage. Funding for APHIS is contained in the Agriculture Appropriations bill.
USDA Forest Service (USFS)
The Forest Health Management (FHM) program provides funding and applied science to help partners manage pests. The program has two sides: the Cooperative component helps states and private forest managers, so it can address pests where they are first found – usually near cities – and when they spread. The federal lands component helps the USFS, National Park Service, and other federal agencies counter pests that have spread to the more rural/wildland areas that they manage.
The Research and Development (R&D) program supports research into pest-host relationships; pathways of introduction and spread;; management strategies (including biocontrol); and host resistance breeding
Forest Service funds are appropriated through the Interior Appropriations bill.
APHIS – the Administration’s official budget proposal, and justification, is here.
The Administration proposes a small increase for three of four APHIS programs that are particularly important for preventing introductions of forest pests or eradicating or containing those that do enter. The Administration proposed significant funding for a fourth program that plays a small but important role in managing two specific forest pests.
APHIS Program
Current (FY 2021)
FY22 Administration proposed
FY 2022 Campbell recommended
Tree & Wood Pest
$60.456 million
$61 million
$70 million
Specialty Crops
$196.553 million
209 million
$200 million
Pest Detection
$27.733 million
No change
$30 million
Methods Development
$20.844 million
No change
$25 million
Tree and Wood Pests: It will be a major challenge for APHIS to eradicate the current outbreak of Asian longhorned beetles (ALB) in the swamps of South Carolina. APHIS should also address other pests. Even after cutting spending on the emerald ash borer (EAB), I think APHIS needs significantly more money in this account.
The Specialty Crops program is supported by such traditional USDA constituencies as the nursery and orchard industries, which probably explains the proposed increase. APHIS’ program to curtail spread of the sudden oak death (SOD) pathogen through interstate nursery trade receives funding from this program – about $5 million. I believe this program also now funds the agency’s efforts to slow spread of the spotted lanternfly.
SOD-infected rhododendrons in Indiana nursery in 2019
I would like the Pest Detection program to receive a small increase so the agency and its cooperators can better deal with rising trade volumes and associated pest risk. Similarly, Methods Development should receive a boost because of the need for improved detection and management tools.
USDA Forest Service – the Administration’s official budget proposal is here.
While the Forest Health Management (FHM) and Research and Development (R&D) programs are the principal USFS programs that address introduced forest pests, neither has non-native pests as the principle focus. Non-native forest pests constitute only a portion of the programs’ activities. In the case of Research, this is a very small portion indeed.
President Biden’s budget proposes to spend $59.2 million on the Forest Health Management program and $313.5 million for Research. Both represent significant increases over spending during the current fiscal year. However, the FHM level is still below spending in recent years, although both the number of introduced pests and the geographic areas affected have been rising for decades.
In my earlier blog I suggested the funding levels:
USFS PROGRAM
Current (FY21)
FY22 Administration
FY22 my recommendation
FHP Coop Lands
$30.747 million
$36.747 million
$51 million (to cover both program work & personnel costs)
FHP Federal lands
$15.485 million
22.485 million
$25 million (ditto)
Research & Develop
$258.7 million; of which about $3.6 million allocated to invasive species
$313.560 million
$320 million; I seek report language instructing the USFS to spend more on invasive species
Under the FHM program, a table on pp. 46-47 of the budget justification lists existing and proposed spending on 14 pest taxa (plus invasive plants and subterranean termites). Spending on these 14 species is proposed to total $30.3 million. Of this amount, less than half – $14.9 million – is allocated to such high-profile invasive species of forests as the emerald ash borer (EAB), hemlock woolly adelgid (HWA), sudden oak death (SOD), and threats to whitebark pine (recently listed as a threatened species under the Endangered Species Act). (The USFS does not engage in efforts to eradicate Asian longhorned beetle (ALB) outbreaks; it leaves that task to APHIS.) And of the nearly $15 million allocated to invasive non-native pests, more than half – $8 million – is allocated to European gypsy moths. While I agree that the gypsy moth program has been highly successful, I decry this imbalance. Other non-native pests cause much higher levels of mortality among hosts than does the gypsy moth.
dead whitebark pine at Crater Lake National Park; photo by FT Campbell
I applaud the modest increases in the Administration’s budget for other non-native forest pests. These range from tens to a few hundred thousand dollars per pest. FHM also supports smaller programs targetting rapid ohia death, beech leaf disease, the invasive shot hole borers in southern California, Mediterranean oak beetle, etc. Budget documents don’t report on these efforts.
The imbalance of funding allocated to damaging non-native pests compared to other forest management concerns is even worse in the Research program. Of the $313.5 million proposed in the budget for the full research program, only $9.2 million is allocated to the 14 pest taxa (plus invasive plants and subterranean termites) specified in the table on pp. 46-47. Of this amount, less than half — $4.5 million – is allocated to the high-profile invasive species, e.g., ALB, EAB, HWA, SOD, and threats to whitebark pine. The budget does provide extremely modest increases for several of these species, ranging from $12,000 for ALB to $114,000 for EAB. Again, some smaller programs managed at the USFS regional level might address other pests. Still – the budget proposes that USFS R&D allocate only 1.4% of its total budget to addressing these threats to America’s forests! This despite plenty of documentation – including by USFS scientists – that non-native species “have caused, and will continue to cause, enormous ecological and economic damage.” (Poland et al. 2021; full citation at the end of the blog). Poland et al. go on to say:
Invasive insects and plant pathogens (or complexes involving both) cause tree mortality, resulting in canopy gaps, stand thinning, or overstory removals that, in turn, alter microenvironments and hydrologic or biogeochemical cycling regimes. These changes can shift the overall species composition and structure of the plant community, with associated effects on terrestrial and aquatic fauna. In the short term, invasive insects and diseases can generally reduce productivity of desired species in forests. Tree mortality or defoliation can affect leaf-level transpiration rates, affecting watershed hydrology. Tree mortality … also leads to enormously high costs for tree removal, other management responses, and reduced property values in urban and residential landscapes.
eastern hemlock in Shenandoah National Park; photo by FT Campbell
I seek report language specifying that at least 5% of research funding should be devoted to research in pathways of invasive species’ introduction and spread; their impacts; and management and restoration strategies, including breeding of resistant trees. Several coalitions of which the Center for Invasive Species is a member have agreed to less specific language, not the 5% goal.
Two other USFS programs contribute to invasive species management. The Urban and Community Forest program provided $2.5 million for a competitive grant program to help communities address threats to urban forest health and resilience. Of 23 projects funded in FY2020, 11 are helping communities recover from the loss of ash trees to EAB. (On average, each program received $109,000.)
The Forest Service’ International Program is helping academic and other partners establish “sentinel gardens” in China and Europe. North American trees are planted and monitored so researchers can identify insects or pathogens that attack them. This provides advance notice of organisms that could be damaging pests if introduced to the United States.
REFERENCE:
Invasive Species in Forests and Rangelands of the United States. Editors T.M. Poland, T. Patel-Weynand, D.M. Finch, C.F. Miniat, D.C. Hayes, V.M. Lopez 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
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.
APHIS headquarters
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
arrows indicate red maples in the swamps of ALB regulated site in South Carolina photo by David Coyle
The Asian longhorned beetle (ALB) is one of the most threatening of the hundreds of non-native insects and pathogens introduced to American forests since European colonization began 400 years ago. The ALB attacks about 100 species of trees in 12 or 13 genera; it prefers maples, poplars, willows, and elms. Forests with substantial components of susceptible species constitute 10% of forests on the U.S. mainland and nearly all of Canada’s hardwoods. Host trees species also make up a significant proportion of trees in urban areas. A two-decade old estimate is that ALB could cause more than $1.2 billion in damage to urban trees [Coyle et al. 2021; full citation at the end of the blog]. The contemporary estimate would be higher.
The ALB began showing up in imports and in warehouses less than a dozen years after the U.S. opened trade with China [see Chapter 3 of Fading Forests II; url provided at the end of this blog]. Now there is a new infestation in South Carolina that threatens to be the most difficult to eradicate. Given the level of resources and extended commitment this will demand from APHIS and South Carolina, I worry that the agencies and Congress will give up. To find more money, will the agency take funds from other pests that also need to be addressed? Will it seek – and receive – emergency funding? Congress is currently considering funding for APHIS for the fiscal year that begins in October. Let’s inform them of the need to ensure adequate resources to carry forward necessary eradication efforts.
ALB in the U.S.: 25 Years of Repeated Infestations and Eradications
The first established ALB population to be detected was that in Brooklyn, New York, in 1996. Since then, seven more outbreaks have been detected in the United States [Poland et al. 2021; South Carolina press release] plus two in Canada. Several populations have been eradicated: a single population in Illinois, several populations in New Jersey, three populations in New York; a small outlying population in Ohio (APHIS newsletter Feb 2021); and two Canadian outbreaks.
Despite the U.S. and Canada having adopted regulations requiring treatment of wood packaging from China effective January 1999, ALB larvae continue to be detected in wood packaging from that country. Between 2012 and 2017, the ALB was intercepted six times in wood packaging made of Populus wood – each time originating from a single wood-treatment facility in China (Krishnankutty et al. 2020 – full citation at the end of the blog).
Port of Charleston; photo by Walter Lagrenne, South Carolina Port Authority
ALB Near Charleston, S.C.: Recently Detected; Must be Eradicated
The most recent detection is near Charleston, South Carolina. As usual, a beetle was found by a member of the public. Dendrological studies indicate that this infestation was seven years old at the time of its detection in May 2020, meaning it began about 2013 (Coyle et al. 2021). As the authors note, it has proved impossible to determine whether the South Carolina outbreak resulted from transport of infested wood from the Ohio outbreak or from China directly. Lots of visitors travel from the Midwest to South Carolina every winter. The center of the primary area of infestation includes a railway and an RV park which might be utilized by such travelers. On the other hand, two ports that receive high volumes of incoming shipping containers including wood packaging are nearby — Charleston, SC and Savannah, GA (Coyle et al. 2021). Charleston imported almost 666,000 containers (measured as 20-foot equivalents, or TEUs) in 2013.
Even under the best circumstances, eradicating an ALB infestation is difficult. Eradicating the Chicago outbreak took ten years [Poland et al. 2021]; eradicating the Brooklyn infestation took 23 years [APHIS ALB newsletter]. Massachusetts might be on the verge of eradicating the Worcester outbreak twelve years after it was detected because only one infested tree was found in 2020 [Felicia Hubacz at Northeast Forest Pest Council meeting, March 2021]
Eradication entails removing large numbers of trees – more than 171,000 in the Northeast and Midwest; and pesticide treatment of at least 800,000 [Poland et al. 2021]. Tens of thousands of trees must be inspected – especially in areas with significant woodland areas like the South Carolina site. In Clermont County, Ohio, 3,500,000 trees have been surveyed in the regulated area – which is 56 square miles [APHIS newsletter]
In South Carolina, APHIS and the state are already regulating 72.6 mi2 — and that is before the full extent of the infestation has been delimited. This regulated area is larger than the Ohio and New York regulated areas, although smaller than that in Massachusetts (110 mi2 Coyle et al.). As of February 2021, 4,425 infested trees have been identified (APHIS newsletter]. Ninety-eight percent are red maples; half of the others are willows (Coyle et al.) In May 2021, APHIS expanded the quarantine zone to 76.4 square miles (APHIS press release May 21, 2021).
So APHIS and South Carolina face a great deal of hard work. But acreage and numbers of trees affected don’t convey the real extent of the challenge.
The first challenge is anticipating the timing of events in the ALB life cycle. Scientists understand a great deal about the ALB life cycle. However, that knowledge all applies to areas with temperate climates such as the U.S. northeast, southern Canada, and Europe. South Carolina has a subtropical climate. How will the warmer climate affect the beetle’s speed of development, timing of emergence, etc. Already, dendrologial studies indicate that the ALB in South Carolina might complete development from egg to mature adult much faster – in less than a year rather than one to four years (Coyle et al.)
working conditions in the South Carolina swamps; photo by David Coyle
An even bigger challenge will be trying to carry out searches for infested trees and standard responses. Removing infested trees and removing or applying pesticides to at-risk host trees is standard practice. Much of the regulated area has standing water and/or saturated soil. These conditions – plus the presence of venomous snakes and alligators – make visual surveys from the ground or by tree climbers difficult. Use of lifts and bucket trucks will be impossible. When infested trees are found, felling trees in swampy conditions presents a heighted risk for felling crews. And it will be impossible to operate the equipment needed to remove or chip infested trees (Coyle et al.). I believe it is impossible to use soil injection to treat at-risk trees under such conditions.
SOURCES
Coyle, D.R., R.T. Trotter, M.S. Bean, and S.E. Pfister. 2021. First Recorded Asian Longhorned Beetle (Coleoptera: Cerambycidae) Infestation in the Southern United States. Journal of Integrated Pest Management, (2021) 12(1): 10; 1–6
Krishnankutty, S., H. Nadel, A.M. Taylor, M.C. Wiemann, Y. Wu, S.W. Lingafelter, S.W. Myers, and A.M. Ray. 2020b. Identification of Tree Genera Used in the Construction of Solid Wood-Packaging Materials That Arrived at U.S. Ports Infested With Live Wood-Boring Insects. Commodity Treatment and Quarantine Entomology
Poland, T.M., T. Patel-Weynand, D.M. Finch, C.F. Miniat, D.C. Hayes, V.M. Lopez. 2021. Invasive Species in Forests and Rangelands of the United States. Springer.
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
Rep. Peter Welch of Vermont has reintroduced his bill to improve programs intended to prevent introduction of non-native forest pests and enhance efforts to reduce their impacts. The latter provisions include support for breeding trees resistant (or tolerant) to the pest. I hope H.R. 1389 will be adopted – then spur new efforts to conserve and restore forest trees! Please follow my suggestion below.
The Invasive Species Prevention and Forest Restoration Act H.R. 1389 is co-sponsored by Reps. Brian Fitzpatrick (PA), Annie Kuster & Chris Pappas (NH), and Elise Stefanik (NY).
“Invasive species are devastating to forests which are a central part of Vermont’s economy and our way of life. This bill will fund efforts to revitalize damaged forests and highlight the need for making this a priority within the federal government.”
Major provisions of H.R. 1389:
Expands USDA APHIS’ access to emergency funding to combat invasive species when existing federal funds are insufficient and broadens the range of actives that these funds can support.
Establishes a grant program to support institutions focused on researching methods to restore native tree species that have been severely damaged by invasive pests.
Authorizes funding to implement promising research findings on how to protect native tree species.
Mandates a study to identify actions needed to overcome the lack of centralization and prioritization of non-native insect and pathogen research and response within the federal government, and develop national strategies for saving tree species.
As I have described in earlier blogs, the measures adopted by federal and state governments to prevent non-native pathogen and insect pest introductions – and the funding to support this work – have been insufficient to meet the growing challenges. In just the past decade, several new tree-killing pests have been detected: polyphagous and Kuroshio shot hole borers, spotted lanternfly, two rapid ʻōhiʻa death pathogens, Mediterranean oak beetle, velvet longhorned beetle. Over the same period, the Asian longhorned beetle has been detected in Ohio and South Carolina; the emerald ash borer expanded its range from 14 to 35 states; the redbay ambrosia beetle and its associated fungus spread from five states to 11; a second strain of the sudden oak death fungus appeared in Oregon forests; and whitebark pine has been proposed by the US Fish and Wildlife Service for listing as Threatened under the Endangered Species Act.
During this same period, funding for the USDA Forest Service Forest Health Protection program has been cut by about 50%; funding for USFS Research projects targetting 10 high-profile non-native pests has been cut by about 70%.
One reason for this disconnect between need and resources is that the non-native tree pest problem is largely out of sight and therefore does not lend itself to the long-term public attention needed to remediate the threats. It is up to us to raise the political profile of these issues.
On the positive side, the passage of time has brought forth new solutions, a deeper understanding of the genetics of plants and animals, new measures for igniting public awareness and invasive identification, new technologies and strategies for helping trees adapt, and a recognition of what resources and organization it will take to mount a proper solution to the problem.
“Project CAPTURE” (Conservation Assessment and Prioritization of Forest Trees Under Risk of Extirpation) has proposed priority species for enhanced conservation efforts. Top priorities in the continental states are listed below. A separate study is under way for forests in Hawai`i, Puerto Rico, and U.S. Virgin Islands.
dead redbay on Jekyll Island, Georgia
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).
For a brief explanation of Project CAPTURE, see my earlier blog here. For an in-depth description of the Project CAPTURE process and criteria for setting priorities, read Potter, K.M., M.E. Escanferla, R.M. Jetton, and G. Man. 2019. Important Insect and Disease Threats to United States Tree Species and Geographic Patterns of Their Potential Impacts. Forests 2019, 10. https://www.fs.usda.gov/treesearch/pubs/58290
Please ask your representative to co-sponsor H.R. 1389. Please ask your senators to sponsor a companion bill. For more information, contact Alex Piper at Alex.Piper@mail.house.gov or 202-306-6569 .
H.R. 1389 is endorsed by Vermont Woodlands Association, American Forest Foundation, Center for Invasive Species Prevention, the Reduce Risk from Invasive Species Coalition,, Entomological Society of America, and North American Invasive Species Management Association.
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
