funding – Center for Invasive Species Prevention

Funding of tree pest programs through §7721

spotted lanternfly – target of many projects funded by USDA’s Plant Pest & Disease Management & Disaster Prevention Program; photo by Holly Raguza of Pennsylvania Department of Agriculture

I am belatedly reporting on the forest-pest projects funded by annual grants under the Plant Pest & Disease Management & Disaster Prevention Program ( of the Plant Protection Act). As usual, APHIS funded projects totaling $62.975 million in FY24. In total, 353 projects were funded. These projects represented 70% of the 504 project proposals submitted (the total funding sought was $106 M).

APHIS reserved $11 million for responding to P&P emergencies. I applaud this choice since the agency’s annual appropriation provides only a completely inadequate $1 million (or less) to cover emergencies.

APHIS notes that since initiation of the Plant Pest & Disease Management & Disaster Prevention Program in 2009, it has funded more than 5,500 projects with a total of nearly $870 million.

In FY24 the program funded 30 more projects than the 322 projects funded in FY23. blog 320 The FY24 allocation provides more than $1 million more for goal area 1S — Enhance Plant Pest/Disease Survey (from $14.4 million to $15.7 million). This was balanced by small decreases for the other goal areas: enhancing mitigation capabilities received $13.6 million; inspections at domestic sites important in invasive species’ spread received $6.3 million; pest identification and detection received $5.3 million; and outreach and education received $4.1 million. Projects safeguarding nursery production and those improving pest and disease analysis each received about $2 million.

By my calculation – subject to error! – about $7.5 million went to projects clearly dealing with forest pests [12% of total funding]. This is a welcome increase from FY23 – when funding of such projects reached about $6.5 million (a little over 10%). blog 320 Funding for tree pest projects might be higher. Some $1.9 million is allocated to surveys of grapevines and orchards — hosts of the spotted lanternfly (SLF). However, it is not clear whether these projects are focused on detecting and managing SLF; they might have a much broader goal. If we do include these projects, the total for tree-killing pests rises to $9.4 million — nearly 15% of the total.

Over both FY23 and FY24, the majority of funds went to similar topics: survey and management of sudden oak death in nurseries; surveys for bark beetles, Asian defoliators, and forest pests generally; and outreach programs targetting the spotted lanternfly. In FY24, just under $100,000 paid for efforts to develop tools for rapid detection of laurel wilt link to DMF in avocados – that is, in a crop rather than the natural environment.

No projects addressing tree or forest pests were funded in seven states or territories: Guam, Idaho, Nebraska, New Mexico, Rhode Island, South Dakota, and Utah. This was three fewer states than in FY23. In neither year do I know whether these states submitted proposals in this category that ended up not being funded.

In FY24, spotted lanternfly is by far the pest addressed by the most projects. As noted above, I can’t be precise about the number because of the lack of information about the 23 projects that fund pest surveys of grapes and/or tree crops that are SLF hosts. Eleven projects named SLF specifically. A final project (not included in above) is one funding registration of Verticillium nonalfalfae as a biocontrol for Ailanthus altissima – an invasive tree that is the preferred host of SLF.

The District of Columbia, Kansas, Missouri, and Oklahoma each had one tree pest project funded. In the cases of Kansas and Missouri, the single project was surveys for thousand cankers disease of walnut. Three other states — Iowa, Maryland, and Pennsylvania — also obtained funding to survey for TCD.

The single Oklahoma project concerned efforts to ensure that the sudden oak death pathogen(Phytopthora ramorum) is not present in nurseries. (An Oklahoma wholesaler was one of the hubs of this pathogen’s spread to 18 states in 2019). Eleven other states were also funded to survey their nurseries for P. ramorum: Alabama, Kentucky, Louisiana, Nevada, North Carolina, Ohio, Pennsylvania, South Carolina, Virginia, and West Virginia. P. ramorum is a “program pest” in 2024. That is, APHIS had designated it as a regulated pest for which the agency wished to fill knowledge gaps about its distribution. I note that last year APHIS published a risk assessment that downplayed the likelihood that P. ramorum would establish in the eastern states. Is APHIS seeking more information to test this conclusion?

In a separate case, Oregon received $76,000 to evaluating the threat to nurseries and forests arising from the presence in the state’s forests of two strains or lineages of P. ramorum that previously had not been extant in the environment of North America.

Another approximately 53 projects fund surveys for tree pests other than spotted lanternfly; these are often fairly general surveys, such as for woodborers or “Asian defoliators”. About ten projects fund management efforts – including evaluation of the efficacy of emerald ash borer biocontrol programs.

Last year I noted that two states – Mississippi and Nevada — had projects to survey the “palm commodity”. Hawai`i joined this group in FY24. The project descriptions don’t specify which pests are the targets. The South American palm weevil (Rhynchophorus palmarum) seems most probable; it is established in far southern California and neighboring Mexico. APHIS prepared a risk assessment on the species in 2012. link? In Hawa`ii, concern probably focuses on the coconut rhinoceros beetle (Oryctes rhinoceros). link? There are other threats to palms, e.g., the red palm weevil (Rhynochophorus ferrugineus), link? and a deadly Fusarium wilt. link?

native palms in the desert at Anza-Borrego, California; photo by F.T. Campbell

California has native palms (Washingtonia filifera); southern states from Texas to at least South Carolina have native palmettos. Of course, many species of palms are important ornamental plants in these states, and dates are raised commercially.

Another “program pest” that I have blogged about in the past is box tree moth. link to blog 287 In FY24 five projects addressed this pest, including surveys and efforts to develop better control tools.

beavertail cactus (*Opuntia basilaris*) in Anza-Borrego, California; photo by F.T. Campbell

I am pleased by continued funding of projects trying to utilize biocontrol agents to protect two groups of cactus severely threatened by non-native insects: lepidoptera that attack flat-padded prickly pear cacti (Opuntia spp.) link to DMF and the mealybug that attacks columnar cacti of Puerto Rico and the Virgin Islands. link to DMF

vulnerable cactus on St. John, US Virgin Islands; photo by F.T. Campbell

I applaud the decision to fund projects focused on determining the efficacy of biocontrol projects. As noted above, three projects are asking these questions in the case of the emerald ash borer. link to DMF Another project funds production, release, and efficacy evaluation of biocontrol agents targetting Brazilian peppertree in Florida & Texas.

I am also pleased that three projects assist Washington State in its efforts to eradicate the invasion by giant hornets from Asia. link to blogs & Hornet Herald – no detections in 2023 … A company in California also received funding to developing hornet detection tools.

Nineteen projects funded outreach efforts, including continued funding for the “Don’t Move Firewood” program. In addition to those focused on spotted lanternfly, such projects also included other firewood programs, Asian longhorned beetle awareness, and the nursery industry.

I note that while California received funding for 27 projects, none dealt with any of several deadly tree pests extant in the state – goldspotted oak borer, polyphagous and Kuroshio shot hole borers, Mediterranean oak borer, and the palm weevils. Nor did Hawai`i obtain funding to address rapid ohia death. Did no one submit proposals to address any of the many issues impeding management of these killers?

South American palm weevil; photo by Allan Hopkins via Flickr

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

www.fadingforests.org

Planting Trees to Sequester Carbon – Beware the Wrong Places!

Greater prairie chicken – denizen of the Tallgrass Prairie; NPS photo

In August 2022 I blogged about unwise planting of trees in New Zealand as a warning about rushing to ramp up tree planting as one solution to climate change.

New Zealand has adopted a major afforestation initiative (“One Billion Trees”). This program is ostensibly governed by a policy of “right tree, right place, right purpose”. However, Bellingham et al. (2022) [full citation at end of blog] say the program will probably increase the already extensive area of radiata pine plantations and thus the likelihood of exacerbated invasion. They say the species’ potential invasiveness and its effects in natural ecosystems need more thorough consideration given that the pines

have already invaded several grasslands and shrublands;
are altering primary succession;
are climatically suitable to three-quarters of New Zealand’s land

North American Tallgrass Prairie; photo by National Park Service

A new study by Moyano et al. [full citation at the end of the blog] tackles head-on the question of whether widespread planting of trees to counter climate change makes sense. They focus on plantings in naturally treeless ecosystems, i.e., grasslands, shrublands and wetlands. They find that:

relying on tree planting to significantly counter carbon change in the absence of reducing carbon emissions would require converting more than a third of Earth’s of global grasslands into tree plantations.
Reforestation of areas previously forested has the potential to produce a net increase in carbon sequestration more than twice as great as can be done by afforesting unforested areas.

Moyano et al. conclude that conservation and restoration of degraded forests should be prioritized over afforestation projects. This recommendation confirms points made in an earlier blog. Then I reported that Calders et al. (2022) said temperate forests account for ~14% of global forest carbon stocks in their biomass and soil. They worried that ash dieback link will kill enough large trees that European temperate deciduous forests will become a substantial carbon source, rather than sink, in the next decades. In my blog I pointed out that other tree taxa that also formerly grew large – elms, plane trees, and pines – have either already been decimated by non-native insects and pathogens, or face severe threats now.

Moyano et al. also point out that naturally treeless ecosystems are often at risk to a variety of threats, they provide numerous ecosystem services, and they should be conserved.

Loss of Biodiversity

Tree planting in naturally treeless areas changes ecosystems at the landscape scale. Moyano et al. say these changes inevitably degrade the natural biodiversity of the affected area. For example, grasslands provide habitats for numerous plant and animal species and deliver a wide range of ecosystem services, including provisioning of forage for livestock, wild food and medicinal herbs, + recreation and aesthetic value. Already 49% of Earth’s grassland area is degraded. Restoration of herbaceous plant diversity in old growth grasslands requires at least 100 years.

These obvious impacts are not the only losses caused by conversion of treeless areas to planted forests.

Ambiguous Carbon Sequestration Benefits

Grasslands store 34% of the terrestrial carbon stock primarily in the soil. Tree planting in grasslands can result in so much loss of carbon stocks in the soil that it completely offsets the increment in carbon sequestration in tree biomass. The underlying science is complicated so scientists cannot yet predict where afforestation will increase soil carbon and where it will reduce it. Important factors appear to be

Humid sites tend to lose less soil carbon loss than drier sites;
Soil carbon increases as the plantation ages;
Tree species: conifers either reduce soil carbon or have no effect; broadleaf species either increase soil carbon or have no effect.
Sites with higher initial soil carbon tend to lose more carbon during afforestation.
Afforestation has greater impacts on upper soil layers.

Moyano et al. assert that appropriate management of grasslands can provide low cost, high carbon gains: a potential net carbon sequestration of 0.35 Gt C/ year at a global level, which is comparable to the potential for carbon sequestration of afforestation in all suitable dryland regions (0.40 Gt C/year).

Changes in Albedo

Trees absorb more solar energy than snow, bare soil or other life forms (such as grasses) because they reflect less solar radiation (reduced albedo). Moyano et al. say the resulting warmer air above the trees might initially offset the cooling brought about by increased carbon sequestration in the growing trees’ wood. Only after decades does the increase in carbon sequestration compensate for the reduction in albedo and produce a cooling effect. Furthermore, they say, the eventual cooling effect that afforestation could create is slight, reducing the global temperature only 0.45°C by 2100 if afforestation was carried out across the total area actually covered by crops. As they note, replacing all crops by trees maintained to sequester carbon is highly unlikely.

Eucalyptus-pine plantation burned in Portugal; photo by Paolo Fernandez via Flickr

Increased fire severity

Planting trees in many treeless habitats – deserts, xeric shrublands, and temperate and tropical grasslands – increases fire intensity. This risk is exacerbated when managers choose to plant highly flammable taxa, e.g., Eucalyptus.Already the fire risk is expected to increase due to climate change. These fires not only threaten nearby people’s well-being and infrastructure; they also release large portions of the carbon previously sequestered, thus undermining the purpose of the project. Moyano et al. note that the carbon stored in the soil of grasslands is better protected from fire.

Water supplies reduced

Afforestation changes the hydrological cycle because an increase in carbon assimilation requires an increase in evapotranspiration. The result at the local scale is decreased water yield and increased soil salinization and acidification. Water yield losses are greater when plantations are composed of broadleaf species. Moyano et al. point out that these water losses are more worrying in areas where water is naturally scarce, e.g., the American southwest, including southern California. On the other hand, increased evapotranspiration can enhance rain in neighboring areas through a redistribution of water at the regional scale and increased albedo through the formation of clouds.

Moyano et al. say planting trees also alters nutrient cycles. To my frustration, they don’t discuss this impact further.

Bioinvasion risk

Moyano et al. cite several experts as documenting a higher risk of bioinvasion associated with planting trees in naturally treeless systems. These invasions expose the wider landscapes to the impacts arising from tree plantations, e.g., increased plant biomass carbon sequestration, reduced soil carbon, reduced surface albedo, increased fuel loads and fuel connectivity, reduced water yield, and altered nutrient cycles. Even native ecosystems that are legally protected can be threatened. Thickets of invading trees can exacerbate some of the impacts listed above since the invading trees usually grow at higher densities. On a more positive side, invading stands of trees often are more variable in age; in this case, they can be more like a natural forest than are even-aged stands in plantations. Because of these complexities, the effect of tree invasions on ecosystem carbon storage becomes highly context dependent. This is rarely evaluated by scientists. See Lugo below.

Moyano et al. say woody plant invasions can exacerbate human health issues by providing habitat for wildlife hosts of important disease vectors, including mosquitoes and ticks. I ask whether plantations using unwisely chosen tree species might raise the same risks. They decry the minimal research conducted on this issue.

Assessing the tradeoffs

The goal is to remove CO₂ from the atmosphere by fixing more carbon in plant biomass. Moyano et al. say careful consideration of projects’ potential impacts can minimize any negative consequences. An integrated strategy to address climate change should balance multiple ecological goals. Efforts to increase carbon storage should not compromise other key aspects of native ecosystems, such as biodiversity, nutrient and hydrological cycles, and fire regimes. First, they say, planners should avoid the obvious risks:

don’t plant fire-prone/flammable tree species; do adopt fuel- and fire-management plans.
don’t plant potentially invasive species.
don’t plant forests in vulnerable environments where negative impacts are likely.

In order to both minimize that certain risks will arise and ensure counter measures are implemented if they do, Moyano et al. suggest incorporating into carbon certification standards two requirements:

that soil carbon be measured throughout the whole soil depth.
that plantation owners be legally responsible for managing potential tree invasions.

The authors praise a new law in Chile, which prohibits planting monospecific tree plantations as a natural climate solution.

Furthermore, they advocate for regulators conducting risk analyses rather than accepting groundless assumptions about carbon storage and climate cooling effects.

Recognizing the uncertainty about some effects of introducing trees into naturally treeless areas, and interactions between these effects and the key role of the ecological context, Moyano et al. call for increased study of plant ecology. They specify research on the above-mentioned highly variable impacts on soil carbon as well as albedo.

Role of NIS trees in sequestering /storing carbon in U.S.

According to Lugo et al. (2022; full citation at the end of this blog), in the Continental United States, non-indigenous tree species contribute a tiny fraction of the forests’ carbon storage at the current time: about 0.05%. This is because non-native trees are widely scattered; while individuals can be found in more than 61% of forested ecosections on the continent, they actually occupy only 2.8% of the forested area.

However, non-native tree species are slowly increasing in both their area and their proportion of species in specific stands. Consequently, they are increasingly important in the forest’s carbon sink – that is, the amount of additional carbon sequestered between two points in time. In fact, non-native trees represent 0.5% of new carbon sequestered each year. This is ten times higher than their overall role in carbon storage. In other words, the invasive species play increasingly important ecosystem roles in the stands in which they occur.

neem tree – considered invasive in the Virgin Islands; photo by Miekks via Wikimedia

On the United States’ Caribbean and Pacific islands, non-native tree species are already much more common, so they are more important in carbon sequestration. On Puerto Rico, 22% of the tree species are non-native; link to blog 340 they accounted for 38% of the live aboveground tree carbon in forests. On the Hawaiian Islands, an estimated 29% of large trees and 63% of saplings or small trees are non-native. link to blog 339 Consequently, they store 39% of the mean plot area-weighted live aboveground tree carbon.

SOURCES

Bellingham, P.J., E.A. Arnst, B.D. Clarkson, T.R. Etherington, L.J. Forester, W.B. Shaw, R. Sprague, S.K. Wiser, and D.A. Peltzer. 2022. The right tree in the right place? A major economic tree species poses major ecological threats. Biol Invasions Vol.: (0123456789) https://doi.org/10.1007/s10530-022-02892-6

Calders, K., H. Verbeeck, A. Burt, N. Origo, J. Nightingale, Y. Malhi, P. Wilkes, P. Raumonen, R.G.H. Bunce, M. Disney. Laser scanning reveals potential underestimation of biomass carbon in temperate forest. Ecol Solut Evid. 2022;3:e12197. wileyonlinelibrary.com/journal/eso3

Lugo, A.E., J.E. Smith, K.M. Potter, H. Marcano Vega, and C.M. Kurtz. 2022. The Contribution of NIS Tree Species to the Structure and Composition of Forests in the Conterminous US in Comparison with Tropical Islands in the Pacific and Caribbean. USFS International Institute of Tropical Forestr. January 2022. General Technical Report IITF-54 https://doi.org/10.2737/IITF-GTR-54

Moyano, J., R.D. Dimarco, J. Paritsis, T. Peterson, D.A. Peltzer, K.M. Crawford, M.A. McCary,| K.T. Davis, A. Pauchard, and M.A. Nuñez. 2024. Unintended consequences of planting native and NIS trees in treeless ecosystems to mitigate climate change. Journal of Ecology. 2024;00:1-12

Posted by Faith Campbell

www.fadingforests.org

California bill – model for other states?

invasion of wild/black mustard *Brassica nigra*; photo by carlbegge via Flickr

A California state legislator has proposed a bill to expand state efforts to counter invasive species. Should we support it – and others like it in other states?

The bill is Assembly Bill 2827 introduced by Assembly Member (and former Majority Leader) Eloise Reyes of the 50th Assembly District. She represents urban parts of southwestern San Bernardino County, including the cities of Rialto, Colton, and Fontana.

According to media reports, Reyes was prompted to act by the current outbreak of exotic fruit flies, which as of some months ago resulted in detections in 15 California counties.

The bill is much broader than agricultural pests, however. It would find and declare that it is a primary goal of the state to prevent the introduction, and suppress the spread, of invasive species within its borders. I applaud the language of the “findings” section:

(a) Invasive species have the potential to cause extensive damage to California’s natural and working landscapes, native species, agriculture, the public, and economy.

(b) Invasive species can threaten native flora and fauna, disrupt ecosystems, damage critical infrastructure, and result in further loss of biodiversity.

Paragraph (c) cites rising threats associated with increased movement of goods, international travel, and climate change — all said to create conditions that may enhance the survival, reproduction, and spread of these invasive species, posing additional threats to the state.

(d) It is in the best interest of the state to adopt a proactive and coordinated approach to prevent the introduction and spread of invasive species.

California sycamore attacked by invasive shot hole borer; photo by Beatriz Nobua-Behrmann

The bill calls for

The state agencies, in collaboration with relevant stakeholders, to develop and implement pertinent strategies to protect the state’s agriculture, environment, and natural resources.
The state to invest in research, outreach, and education programs to raise awareness and promote responsible practices among residents, industries, and visitors.
State agencies to coordinate efforts with federal, local, and tribal authorities.

However, the bill falls short when it comes to action. Having declared that countering bioinvasion is “a primary goal of the state”, and mandated the above efforts, the bill says only that the California Department of Food and Agriculture (which has responsibility for plant pests) is to allocate funds, if available, to implement and enforce this article. Under this provision, significant action is likely to depend on holding agencies accountable and providing increased funding.

removing coast live oak killed by goldspotted oak borer; photo by F.T. Campbell

Would this proposed legislation make a practical difference? I have often complained that CDFA has not taken action to protect the state’s wonderful flora. For example, CDFA does not regulate firewood to prevent movement of pests within the State. It has not regulated numerous invasive plants or several wood-boring insects. These include the goldspotted oak borer; the polyphagous and Kuroshio shothole borers; and the Mediterranean oak borer.

On the other hand, CDFA is quick to act against pests that might enter the state from elsewhere in the country, e.g., spongy moth (European or Asian), emerald ash borer and spotted lanternfly.

I hope Californians and the several non-governmental organizations focused on invasive species will lobby the legislature to adopt Assembly Bill 2827. I hope further that they will try to identify and secure a source of funds to support the mandated action by CDFA and other agencies responsible for managing the fauna, flora, and other taxa to which invasive species belong.

I applaud Ms. Reyes’ initiative. I hope legislators in other states will consider proposing similar bills.

Posted by Faith Campbell

www.fadingforests.org

Birds v. mosquitoes: hope in Hawai`i

‘i‘iwi (Drepanis coccinea) – formerly very common from low to high elevations; photo by James Petruzzii_U

The endangered honeycreepers (birds) of Hawaiian forests are receiving the attention they deserve – and desperately need. There is good news! Promising and significant efforts are under way, matched to a recent strategic plan. However, it is too early to know their results.

Nearly two and a half years ago, I blogged about efforts by a multi-agency consortium (“Birds, Not Mosquitoes” ). It was working to suppress populations of non-native mosquitoes, which vector two lethal diseases: avian malaria (Plasmodium relictum) and avian pox virus (Avipoxvirus). A single bite from an infected mosquito is enough to weaken and kill birds of some species, e.g., the ‘i‘iwi.

The threats from these diseases – and their spread to higher elevations as mosquitoes respond to climate change – pile on top of – other forms of habitat loss and inroads by other invasive species. All of the 17 species of honeycreeper that have persisted until now are listed as endangered or threatened under the federal Endangered Species Act. Four are in danger of extinction within as little as 1 – 2 years. These are ‘Akeke`e (Loxops caeruleirostris), ‘Akikiki (Oreomsytis bairdi)), Kiwikiu (Maui parrotbill, (Pseudonestor xanthophrys), and `Akohekohe (Palmeria dolei).

All these bird species are endemic to the Hawaiian archipelago — found nowhere else on Earth. They are already remnants. Nearly 80 bird species have gone extinct since people first colonized the Hawaiian Islands 1,500 years ago. Eight of these extinctions were recognized in October 2021. Extinction of the final cohort would compromise the integrity of unique ecosystems as well as the Islands’ natural and cultural heritage.

I rejoice to report that the federal government has responded to the crisis. In late 2022 several Interior Department agencies adopted a multiagency Strategy for Preventing the Extinction of Hawaiian Forest Birds. The strategy specifies responsibilities for the key components of the program. These include: a) planning and implementing landscape-level mosquito control using Incompatible Insect Technique (IIT); b) translocating birds to higher elevation sites on other Hawaiian islands; c) establishing captive populations of at-risk birds; and d) developing next-generation tools that increase the scope or efficacy of these actions. All these activities are being developed and conducted through intensive consultation with Native Hawaiians.

On August 8, 2023, the Secretary of Interior announced the allocation of $15,511,066 for conservation and recovery efforts for Hawaiian forest birds. About $14 million of the total was from the Bipartisan Infrastructure Law (Public Law 117-58). The funds are being channelled primarily through the U.S. Fish and Wildlife Service (FWS) ($7.5 million) and the National Park Service (NPS) ($6 million). Other sources of funding are the “State of the Birds” Program (FWS – $963,786); the national-level competitive Natural Resource grants program (NPS – $450,000); and the Biological Threats Program of the U.S. Geological Survey (USGS – $100,000).

What Is Under Way

I do worry continuing these efforts will be harder once their funding is subject to annual appropriations. However, they are a good start!

Steps have been taken on each of the four key component of the Strategy for Preventing the Extinction of Hawaiian Forest Birds:

a) Planning and implementing landscape-level mosquito control using Incompatible Insect Technique (IIT – see below) to reduce the mosquito vector of avian malaria.

The Consortium has obtained all necessary state permits, regulatory approval of the approach by the U.S. Environmental Protection Agency, and done required consultations under the Endangered Species Act.
The Department of the Interior has funded a public-private partnership between the National parks and The Nature Conservancy (TNC) to develop, test, and carry out the first deployments of IIT. These occurred in May 2023 at high-elevation sites on the island of Maui. The next releases are planned for Kaua`i.
Consortium participants are carrying out the consultations and scientific preparations need to support the next deployment on the Big Island.

b) Translocating birds to higher elevation sites on the one island where they exist – Hawai`i.

Initial planning has begun to guide translocation of the endangered Kiwikiu (Maui parrotbill) and Akohekohe to higher-elevation, mosquito-free, habitats on the Big Island.

c) Establishing captive populations of the most at-risk species

To facilitate captive breeding of the four most endangered species, the two existing aviaries in Hawai`i need to be expanded. Space must be provided for at least 80 more birds. A contract has been signed for construction of this new aviary space.

d) Developing next-generation tools that increase the scope or efficacy of these actions.

Lab capacity has been expanded to monitor the effectiveness of IIT, as well as for developing next-generation mosquito control tools.

those who decide funding work here … & they work for us!!!!

The Incompatible Insect Technique (IIT) explained

The incompatible insect technique has been used successfully elsewhere to combat mosquitoes that transmit human diseases. Many insect taxa – including mosquitoes – harbor a naturally-occurring bacteria (Wolbachia). This bacterium has more than one strain or type. When a male mosquito with one type of Wolbachia mates with a female mosquito bearing a different, incompatible type, resulting eggs do not hatch. The IIT project releases male mosquitoes that have an incompatible strain of the bacterium than do local females. (Male mosquitoes do not bite animals seeking a blood meal, so releasing them does not increase the threat to either birds or people.) Implementation requires repeat treatment of sites at a cost of more than $1 million per site per year. It is hoped that this cost will fall with more experience.

Funding for the Strategy’s Four Components

As I noted above, much of the funding for these efforts has come from the Bipartisan Infrastructure Law (Public Law 117-58). Grants under this one-time statute are intended to cover project costs for perhaps five years. Other sources of funds are Congressional appropriations to Interior Department agencies under programs which presumably will continue to be funded in future years. These include the “State of the Birds” program; Endangered Species Act (ESA) implementation, especially its §6 Cooperative Endangered Species Conservation Fund; and State Wildlife Grants administered by the U.S. Fish and wildlife Service. However, funding under these programs is never guaranteed and competition is fierce. I hope participants – and the rest of us! – can be effective in lobbying for future funds required to save Hawaii’s birds from extinction.

a) Deploying IIT

Over Fiscal Years 2017 – 2021 (ending September 2021), Interior Department agencies supported the IIT program by:

Providing $948,000 to the State of Hawai`i from “State of the Birds”, State Wildlife Grants, and Endangered Species Act (ESA) §6;
The U.S. Fish and Wildlife Service provided $545,000 plus staff time’
National Park Service provided $1.2 million for IIT preparations at Haleakala National Park and surrounding state and Nature Conservancy lands
U.S. Geological Survey provided about $7.05 million in research on Hawaiian forest birds, invasive mosquitoes, and avian malaria.

The State of Hawai’i allocated $503,000 and employee staff time.

In addition,

the National Fish and Wildlife Fund provided a total of $627,000 in grants to TNC and American Bird Conservancy for Wolbachia IIT.
TNC committed to supporting some of the initial costs to deploy Wolbachia IIT for the first site in Hawai`i through a contractor (see below)
American Bird Conservancy provided funding for coordination and public outreach.

In FY2022 (which ended in September 2022),

NPS provided $6 million for on-the-ground work on Maui, also development and initial production of Wolbachia IIT.
Interior Department Office of Native Hawaiian Relations provided in-kind services to engage with Native communities’ members

b) Moving endangered birds to mosquito-free areas at high elevations on the Big Island

This is planned to begin by 2030. Interior committed unspecified funds to planning and consultation with Native Hawaiians.

c) Rearing captive birds

FWS supports operation of the two existing aviaries through two funding channels: $700,000 annually provided directly to the aviaries, plus another $500,000 per year through ESA §6through the State of Hawai`i. The San Diego Zoo – which operates the aviaries — provides $600,000 – $800,000 per year in the form of in-kind services, staffing, veterinarians, and administrative support. Interior’s Office of Native Hawaiian Relations provided in-kind services to support to engagement with Native Hawaiian community members

d) Regarding exploration of “next-generation” mosquito control tools

The FWS provided $60,000 to a scientific laboratory to study precision-guided Sterile Insect Technique (pgSIT) tools to protect bird species threatened by avian malaria.

Funding for the portions of these programs dependent upon annual appropriations is uncertain. Current signs are promising: House and Senate bills to fund for the current year (Fiscal Year 2024) – which began in October 2023! – both support at least some aspects of the program. According to American Bird Conservancy, the Senate appropriations bill has allocated $2.5 million to parts of the program. According to the Committee report, the House appropriations bill allots $4.7 million to the State of the Birds program to respond to urgent needs of critically endangered birds. The report goes on to direct the FWS to “incorporate adaptation actions into new and revised recovery plans and recovery implementation strategies, such as with the mosquito vector of avian pox & malaria in the revised Hawaiian Forest Birds recovery plan. …” Per the report, the Appropriations Committee “continues to encourage the [NPS] to respond to the urgent landscape-scale needs of critically endangered forest birds with habitats in national parks.” The report then specifies species threatened by non-native mosquitoes carrying avian malaria and other pathogens. Finally, the report allocates $500,000 to the U.S. Geological Survey for research on the Hawaiian forest birds.

Meanwhile, the American Bird Conservancy is preparing to advocate for $20 million for FY25 through “State of the Birds” Activities and associated NPS and USGS programs. The details of this amount have not yet been laid out.

CISP will support this request and urges you to do so also. We will suggests ways to help when we know more.

Posted by Faith Campbell

www.fadingforests.org

Resistance Breeding – Let’s Do It! (Instead of thinking about it)

TACF back-crossed American-Chinese chestnut; photo by F.T. Campbell

I have advocated for considerably expanding efforts to breed trees resistant to non-native pests (including pathogens) for a decade. Again and again, I and others have pointed out the dire consequences for our forests if we Americans do not rise to the challenge.

In 2014, Scott Schlarbaum – coauthor of Fading Forests III – American Forests: What Choice Will We Make? warned that without restoration becoming an integral part of a strategy addressing non-native plant pests, American ecosystems are doomed to continuing transformation. Once established, a non-native pest is never eliminated, but its impact can be reduced through a combination of measures – as long as support is made available. Scott advised initiating a germplasm conservation strategy when invasion is imminent or once the pest is likely to become a resident pest. (See Chapter 6).

I have posted seven blogs since August 2021 describing the current status of various efforts and urging the U.S. Government and conservation organizations to step up. [To view these blogs, go to www.nivemnic.us, scroll below Archives to “Categories” and click on “resistance breeding.”

More, and Recent, Voices: Implications of Not Acting

More recently, several USDA Forest Service (USFS) experts, including Richard Sniezko, C. Dana Nelson, and Jennifer Koch, have published articles making the same point. These scientists note that many of the decimated species were formerly among the most common trees in our forests. Therefore, the cumulative effect of their disappearance on forest species composition and function is multiplied.

One blog, posted in 2022, is particularly pertinent. It summarizes a special issue of the journal Plants, People, Planet devoted to resistance breeding. The opening essay, by R.J.A. Buggs, concisely reviews six major reasons why so many believe that resistance breeding is a failed strategy.

Port-Orford cedar – one of the trees for which resistance breeding has been successful; photo courtesy of Richard Sniezko, USFS

Others say there have been successes – all through application of classic tree improvement measures, not “genetic engineering.” Pike, Koch and Nelson (2021) list as successes Port-Orford-cedar (Chamaecyparis lawsoniana), the western five-needle pine species, koa (Acacia koa), and resistance to fusiform rust (Cronartium quercuum f. sp. fusiforme) in the commercially-important loblolly (Pinus taeda) and slash (P. elliottii) pines. They also cite encouraging progress by The American Chestnut Foundation (TACF) through backcross breeding of America and Asian chestnuts and a USFS/private foundation effort to expand the genetic base of American elms (Ulmus americana). I regret to say this, but some of these efforts seem to me to be still in experimental stages or — at best — early in widespread – ‘though still experimental — plantings.

Participants in a 2021 Purdue University workshop have again called for greatly expanding breeding. See the special issue of New Forests, Vol. 54 Issue 4. Once again, experts reiterate the urgency of acting, then outline the opportunities and challenges.

In one of the articles (Jacobs et al.) several people – including me! – note that several keystone tree species or genera in North America and Europe have been driven to functional extinction by non-native pests. By this we mean they are no longer sufficiently abundant and/or of adequate size to reproduce sexually or perform their ecological function. Examples include – on both continents – ashes (Fraxinus) and elms; and on North America – American chestnut (Castanea dentata), butternut (Juglans cinerea), and whitebark pine (Pinus albicaulis).If these threats are left unchecked, these at-risk tree species might develop truncated ranges, lose genetic diversity, and face becoming threatened, endangered, or extinct.

In another article, Nelson says the question that should be asked about applying genetic engineering (GE) techniques to tree breeding is whether we should let a species be reduced to a marginal role — or disappear — when GE provides a solution to saving and restoring the species. His case study is a detailed history of TACF’s development of a transgenic American chestnut (called “Darling 58”). He points out that decades of breeding efforts were based on the hope of developing blight resistance within the native gene pool or to obtain resistance from related species through hybridization. However, those efforts have not yet provided trees suitable for restoring the “king of the Appalachian forest” to native landscapes. Nelson wrote his description before TACF discovered flaws in the GE trees they had been working with and decided to pursue different GE “lines” (see below).

Barriers

The overall strategy is clear. Schlarbaum, Sniezko, and Dana Nelson all describe essentially the same steps, built on the same kinds of expertise and facilities.

Of course, each species will require years of input by a range of experts. These challenges are not trivial. However, the experts named above agree that the principal barrier is the absence of sustained, long-term commitment of resources and facilities. With sufficient resources, many of the scientific challenge can be overcome for at least some of the species at risk.

So, what are the scientific challenges? First, scientists must assess whether the tree species contains sufficient genetic variation in resistance. This involves locating candidate resistant trees; developing and applying short-term assay(s) to screen hundreds or thousands of candidate trees; and determining the levels of resistance present. Second, scientists must develop resistant planting stock for use in restoration. This stage includes scaling up the screening protocol; selecting the resistant candidates or progeny to be used; breeding to increase resistance; establishing seed orchards or other methods to deliver large numbers of resistant stock for planting; and additional field trials to further validate and delineate resistance. Sniezko and Koch (2017) and Sniezko and Nelson (2022) discuss the challenges and describe successes.

facilities at Dorena Genetic Resource Center; photos courtesy of Richard Sniezko, USFS

Complicating the restoration phase is the fact that the resistant tree must be able to thrive and compete in an ecosystem that has changed greatly from that in which it formerly resided. Causes of these changes include repercussions from the absence of the tree species – and possibly associated species; the possible presence of other biotic stresses (pests); and climate change. This is discussed by Nelson (2022). See also my blog.

Successfully completing these steps requires a long-term commitment, which includes significant funding and strong supportive infrastructure. Schlarbaum pointed out that the public and politicians don’t understand the complexity of the restoration challenge and the resources required. He documented the shrinking tree improvement infrastructure as of 2014. At that time, funding for all USFS regional breeding programs was just $6 million. State and land grant university breeding programs were fragmented and seriously underfunded. Only 28 states still had some type of tree improvement activity – and some of these programs were only seed orchards, not active breeding and testing programs. Members of university-industrial cooperatives focus on a small number of commercial species – which are not the species threatened by non-native pests. I believe these resources have shrunk even farther in the decade since 2014.

A separate source of funds for resistance breeding is the Forest Health Protection program, which is under the Deputy Chief for State, Private, and Tribal Forestry rather than the Deputy Chief for Research and Development. While nation-wide data on seed or scion collection or screening to identify and evaluate genetic resistance are poorly reported, Coleman et al. indicate that the USFS Dorena Genetic Resource Center screens unspecified “hundreds” of seed lots for resistance to pathogens annually. The Center also participates in seed, cone, and scion collections, especially of white pines vulnerable to white pine blister rust (WPBR). Supplemental Table S3 lists projects funded over the two decades analyzed by Coleman et al. (2011 – 2020). These included efforts to identify and evaluate possible genetic bases for resistance to, e.g., hemlock woolly adelgid, balsam woolly adelgid, laurel wilt, emerald ash borer, butternut canker, rapid ʻōhiʻa death; and gene conservation for eastern hemlock, ashes, chestnut, in addition to the five-needle pines. Currently, FHP allocates $1.2 million annually to support the group of activities called Genetic Conservation, Resistance and Restoration (R. Cooksey, pers. comm.).

American beech grafts to be tested for resistance to beech bark disease; at USFS center in Delaware, Ohio; photo courtesy of Jennifer Koch, USFS

USFS scientists involved in these projects describe challenges arising from efforts to cobble together funding from these many sources to support coherent programs. Overall funding levels still fall short of the need, and failure to obtain funding for one component of a program stymies the entire endeavor.

However, some developments are encouraging. The number of private foundations devoted to tree breeding has increased in the last decade. The American Chestnut Foundation (TACF) and American Chestnut Cooperators Foundation (ACCF) have been joined by the White Pine Ecosystem Foundation, the Great Lakes Basin Forest Health Collaborative, Forest Restoration Alliance, ‘Ohi‘a Disease Resistance Program … These organizations raise awareness, coordinate efforts by multiple parties, and provide opportunities for individuals to contribute funds and volunteer work.

In Hawai`i, disease resistance programs with both koa (Dudley et al.) and ʻōhiʻa ((Metrosideros polymorpha) (Luiz et al.) are active. Work with ash species to find and develop resistance to emerald ash borer is under way but limited due to lack of funds.

Finally, we can persuade Congress to incorporate the provisions of two bills, H.R. 3174 and S. 1238, into the next Farm Bill. The bills would, inter alia, create two grant program. One would fund research addressing specific questions impeding the recovery of native tree species that have suffered severe levels of mortality caused by non-native plant pests. The second would fund implementation of projects to restore these pest-decimated tree species to the forest.

Funded projects would be required to be part of a forest restoration strategy that incorporates a majority of the following components:

(1) Collection and conservation of native tree genetic material;

(2) Production of propagules of the target tree species in numbers sufficient for landscape-scale restoration;

(3) Preparation of planting sites in the target tree species’ former habitats;

(4) Planting of native tree seedlings; and

(5) Post-planting maintenance of native trees.

For a detailed description, see this blog.

Details:

Facilities needed to support successful breeding programs

Sniezko and Nelson identified these needs as follows:

(a) growing space (e.g., greenhouses);

(b) seed handling and cold storage capacity;

(d) field sites for testing;

(e) database capability for collecting, maintaining, and analyzing data;

(f) areas for seed orchard development;

(g) skilled personnel (tree breeders, data managers, technicians, administrative support personnel, and access to expertise in pathology and entomology).

There are very few facilities dedicated primarily to development of populations of trees with resistance to non-native pests; the most notable is the Dorena Genetic Resource Center. Even the existing programs require significant funding increases to accelerate current programs or expand to address additional species. Sniezko and Nelson stress further that a resistance breeding program has different objectives, magnitude and focus than most research projects. It is applied science, that is, an action-oriented effort that is solution-minded—countering the impact of a major disturbance caused by a pest (in our case, a non-native pest).

Schlarbaum provides a shorter but similar list of facilities needed:

production of propagules (seed or clones);
mass propagation in growing facilities, e.g., bare-root seedling nursery or greenhouses;
site preparation of former habitat and planting; and
post-planting maintenance.

Schlarbaum emphasized that each of these activities requires different skill sets, equipment, facilities, and infrastructure.

Genetic Engineering as a Specific Tool

There is considerable interest in the potential role of genetic engineering in pest resistance breeding. None of the successful programs world-wide has yet used genetic engineering (Sniezko and Koch 2017). While incorporating it into holistic breeding programs might result in greater efficiency for certain processes, it raises legal and social acceptability issues. Jacobs et al. discuss the type of education and outreach program needed to generate widespread public support this approach to tree species “rescues.” They call for USDA Forest Service to lead this education effort.

The focus of the 2021 workshop hosted by Purdue University was to explore the pros and cons of using biotechnology in restoring pest-threatened forest tree species. The special issue of New Forests contains several participants’ analyses.

The overall conclusions are that:

“Genetic engineering” – defined as “any technique that uses recombinant, synthesized, or amplified nucleic acids to modify a genome” – is only one type of biotechnology applicable to tree breeding. Other biotechnologies include tissue culture-based propagation, molecular-based genetic markers, gene cloning and sequencing, and genome mapping and sequencing.
These new technologies can increase the efficiency of more traditional breeding techniques, However, biotechnologies cannot substitute for holistic programs that incorporate all helpful methods. Careful consideration goes into selecting which techniques are appropriate for a particular host-pest system.
Each tree species has unique needs regarding seed or scion collection; seedling propagation in nurseries; site preparation and planting techniques; and management of regeneration after its re-introduction into forests. Scientists don’t yet understand these various needs of many threatened species.
In the eastern U.S., the tree-breeding infrastructure is based in the Southeast and focused on a few pine species grown commercially. The facilities do not match the greatest need. That is, many of the at-risk species are hardwoods native to the Northeast.
Current resources are inadequate to support the sustained, long-term commitment of resources and facilities necessary to be successful.

Dana Nelson addressed the role of genetic engineering (GE) in detail. He emphasized repeatedly that GE is not a short-cut to tree improvement. Incorporating a GE component does not avoid the other steps. It can, though, provide new possibilities to address problems. Nelson says the crucial, initial question is – can GE solve the specific forest conservation or management problem more effectively and efficiently than existing methods? There are some important subtleties to consider. First, success does not require achieving immunity (100% resistance); the level of resistance needs to be only sufficient to allow the tree species to survive, reproduce and co-evolve with the pest. Second, “efficiency” is an important consideration. We cannot afford delay because during those years or decades the wild tree loses genetic variability as more trees die. Also, changes in the environment continues to change, and the decimated tree species is not adapting.

If genetic engineering promises to contribute meaningfully, then the breeders must answer several follow-up questions before proceeding to develop a specific plan. Nelson also stresses that the planned activities must be integrated with an ongoing tree breeding program to ensure project success.

Nelson provides a lengthy description of the process of integrating genetic engineering into tree breeding programs.

GE in Chestnut Breeding – Setback

The most prominent breeding effort incorporating genetic engineering in the U.S. has been The American Chestnut Foundation’s (TACF) program to restore American chestnut (Castanea dentata). For decades, TACF has pursued development of trees resistant to the fungus which causes chestnut blight (Cryphonectria parasitica). Over the past decade, hopes have centered on a genetically engineered line into which was inserted a gene from wheat (oxalate oxidase; OxO). The OxO gene detoxifies the oxalic acid produced by the chestnut blight fungus and thus prevents the cankers from killing the tree.

Years of tests have shown the gene to be effective and to cause no environmental harm. In 2023, when trees in outside test plots grew larger, scientists observed disappointing results. Trees’ blight tolerance varied greatly. Worse, resistant trees grew more slowly and exhibited lower overall fitness. [For a full discussion of the issues, visit TACF’s website] Prompted by these disappointments, scientists carried out further molecular analyses. They found that the OxO gene was on a different chromosome than expected.

TACF researchers now suspect that the trees’ variable performance stems primarily from the placement of the OxO gene and the fact that the gene is always “switched on”. That constant expression appears to result in high metabolic costs for the trees. Since all the genetic lines developed to date have this defect, TACF is no longer pursuing research efforts with any of the GE trees developed to date. The Foundation believes it would be irresponsible to continue efforts – by itself and by partners – focused on a genetic line that looks unable to compete successfully when introduced to the forest.

Instead, TACF has begun investigating other transgenic lines that use a “wound inducible” promoter that switches on the OxO gene only in cells where the plant is wounded. Researchers at both the State University of New York College of Environmental Science and Forestry (SUNY-ESF) and the University of Georgia are working with a variety of inducible promoters. TACF is also testing whether inducible OxO expression can be “stacked”onto genes for blight resistance present in the backcross hybrids. Finally, TACF and Virginia Tech are also exploring whether resistance can be enhanced by insertion of genes from Chinese chestnut directly into American chestnut using methods similar to OxO insertion.

It will be years before we know if these approaches provide sufficient levels of resistance. TACF will undertake more extensive testing for efficacy through the tree’s full life cycle – in the lab, greenhouse, and field – before submitting a new GE organism to regulators for review. Meanwhile, it will continue rigorous testing for plant health and environmental risks and will strengthen the cooperative structure to facilitate sharing of intellectual property and provide full transparency.

The Darling GE line was the most important transgenic hybrid chestnut line TACF had invested in. So this is a major setback – and comes when regulatory approval seemed near.

Let’s keep this in perspective, however. As a colleague has said, based on his years of teaching science to middle school students, “There are no failures in science, just reductions in the unknown; Edison failed a thousand times before getting the light bulb right, etc….” The technology is ready when it is ready. In addition, he praised TACF for choosing to explain its decision frankly: “nothing builds credibility like early failures openly admitted.”

Meanwhile, TACF continues to make gains in blight resistance with its traditional American chestnut backcross hybrid breeding program. They have established a genetically diverse, reproducing population of thousands of trees representing hundreds of breeding lines. These trees are planted in TACF’s expansive network of germplasm conservation orchards and regional breeding and backcross orchards. They have substantially increased resistance to both the blight and Phytophthora cinnanomi in these populations. The future inclusion of transgenic and/or gene-edited trees will further increase those gains.

Another Approach

Meantime, the American Chestnut Cooperators Foundation (ACCF), which breeds from persistent pure American chestnut, now has some trees that are nearly 50 years old. The program has bred five generations of pure American chestnuts that show durable blight resistance. Many trees are 60 feet tall or higher; they produce nuts. Vice President Jenny Abla (pers. comm.) reports that they show excellent canker response (swollen and superficial). The picture shows one of their most notable stands, which is in the Jefferson National Forest. Dr. Sniezko is exploring whether this program shows sufficient promise to justify increased support from the USFS.

ACCF chestnut trees; photo courtesy of Jenna Abla

Improving Coordination – will funds follow?

In July 2023, representatives from essentially all the forest tree resistance breeding programs in the U.S. met at Dorena Genetic Resource Center in Oregon to discuss their current successes and how to fast-track all programs. This is the first such meeting since 1982 (Richard Sniezko, pers. comm.). I encourage us all to study the report when it emerges and encourage USFS leadership to support the more unified enterprise.

Status of Efforts to Conserve Other Tree Species

The special issue of New Forests (Vol. 54 Issue 4) included several articles exploring the specifics of breeding elms, ashes, and ʻōhiʻa. These describe difficult challenges … and scientists determined to make progress on overcoming them.

“survival” American elm at Longwood Gardens; photo by F.T. Campbell

Elms (Ulmus spp.) (see article by Martin et al.)

Let’s not forget that elms were keystone species in Europe and North America until attacked by two epidemics of “Dutch” elm disease during the 20^th Century. While hybrid elms are available for urban plantings, many consider them not appropriate for planting in natural forests because these genotypes are not native.

Martin et al. describe a bewildering conglomeration of complexities and possibilities arising from biotic and abiotic factors. Initiation and especially intensity of the disease in a particular tree depend on

the species or strain of the tree, vectoring beetle, and pathogen;
timing of the attack; and
adequacy of water supplies at that time.

Possible targets for manipulation include the pathogen, its beetle vector, and the tree’s response — either in its bark or xylem. Martin et al. suggest that a combination of resistance to the pathogen within the xylem, resistance to beetles’ feeding wounds, and lowering tree clues that attract the beetles could considerably enhance longer-term overall resistance in the field.

However, verifying which approaches produce the best result will be complicated by the trees’ sensitivity to environmental factors such as season and water supply. Apparent resistance might actually be tied to, for example, low water supplies during the spring when the attack occurred.

Restoration strategies, including resistance to pests, must accommodate the diverse ecological conditions in the species’ large range, the rapid evolution of the Ophiostoma pathogens; and other pests and pathogens that attack elms. Nor do scientists know appropriate planting strategies.

Martin et al. believe Dutch elm disease is unlikely to be spread by movement of living elm plants, although other pests could be (and have been).

ash trees to be tested for resistance to emerald ash borer; photo courtesy of Jennifer Koch, USFS

Ashes (Fraxinus spp.)

While a USFS team led by Jennifer Koch link are conducting much of the on-the-ground efforts to breed ash trees resistant to the emerald ash borer (EAB; Agrilus plannipennis), Stanley et al. note that scientists cannot simply cross most North American ash species with the Asian ash, F. mandshurica, because the two groups are sexually incompatible. Scientists have instead focused on trying to enhance the resistance to EAB that is apparently present in a small proportion of ash trees, called “lingering ash.” Scientists funded by USDA Forest Service have already devoted over 14 years to finding such lingering ash to be tested for resistance.

Testing these trees is not simple (see Stanley et al.). But scientists are overcoming some of the obstacles. They have shown that the capability of a few green ash (Fraxinus pennsylvanica) (less than 1%) to defend themselves from EAB attack is genetic. Genes determine the relative abundance of specific metabolites manufactured by the tree; high levels kill more beetle larvae. These trees’ tolerance is not immunity but it might be sufficient to allow the tree to survive and grow. The level of metabolites synthesized by succeeding generations of the tree can probably also be enhanced by breeding.

To restore ash it is necessary to propagate large numbers of clones and to root the resulting embryos. This has been challenging. Merkle et al. describe five years of efforts to develop techniques that allow in vitro propagation to speed up selection and breeding. These techniques will facilitate establishment of numerous groups of propagules with the genetic differences needed to accommodate the large geographic range of several ash trees. For example, the green ash range covers more than half the continental U.S. plus multiple Canadian provinces.

ʻōhiʻa on lava field, Hawaii Volcanoes National Park

‘Ōhi‘a (Metrosideros polymorpha)

‘Ohi‘a is the most widespread tree species on the Hawaiian Islands. It provides vitally important habitat for conservation of countless taxa of endemic birds, insects, and plants. It is also of great cultural importance for Native Hawaiians.

Luiz et al. review the tree species’ importance, the many threats to native Hawaiian forests, and a coalition’s efforts to counter the most recent – and alarming – threat, rapid ʻōhiʻa death (ROD).

Rapid ʻōhiʻa death is caused by two introduced species of in the genus Ceratocystis. C. lukuohia colonizes the tree’s sapwood and kills the tree quickly. This disease is present on two islands, Hawai`i and Kaua‘i. It has the potential to devastate ‘ohi‘a forests across the state. The other pathogen, C. huliohia, invades the phloem, cambium, and outer xylem, resulting in a well-defined area of necrotic tissue and slower mortality. This disease is on Hawai`i and Kaua‘i, plus Maui and O‘ahu. The two pathogens have different origins. C. lukuohia belongs to a genetic line that is based in Latin America, C. huliohia to a genetic line based in Asia and Australia.

Conservationists formed a coalition and developed a strategy to guide the process of identifying and developing disease resistance in M. polymorpha and, if possible, other Metrosideros species on the Islands. Luiz et al. describe the coalition’s many activities. The challenges are familiar ones:

obtaining sufficient facilities to screen large numbers of seedlings;
developing techniques for inoculation, propagation, and speeding up growth of seedlings;
improving techniques for detecting individual infected and healthy trees across difficult terrain;
testing trees native to all parts of the tree’s range, which is not large in area, but covers a great variety of elevations and climates); and
needing to develop trees resistant to both C. lukuohia and C. huliohia.

Luiz et al. reiterate the necessity to manage all threats to healthy ʻōhiʻa stands, for example, by

curtailing human spead of infected wood, using both quarantines and supportive public education;
testing repellants to reduce beetle attack.
reducing injuries to trees by fencing forests and removing feral ungulates. link to website?

SOURCES

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

Coleman, T.W., A.D. Graves, B.W. Oblinger, R.W. Flowers, J.J. Jacobs, B.D. Moltzan, S.S. Stephens, R.J. Rabaglia. 2023. Evaluating a decade (2011–2020) of integrated forest pest management in the United States. Journal of Integrated Pest Management. (2023) 14(1): 23; 1–17

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 https://doi.org/10.3390/f11121276

Jacobs, D.F., R. Kasten Dumroese, A.N. Brennan, F.T. Campbell, A.O. Conrad, J.A. Delborne, et al. 2023. Reintroduction of at-risk forest tree species using biotech depends on regulatory policy, informed

by science and with public support. New Forests (2023) 54:587–604

https://doi.org/10.1007/s11056-023-09980-y

Luiz, B.C., C.P. Giardina, L.M. Keith, D.F. Jacobs, R.A. Sniezko, M.A. Hughes, J.B. Friday, P. Cannon, R. Hauff, K. Francisco, M.M. Chau, N. Dudley, A. Yeh, G. Asner, R.E. Martin, R. Perroy, B.J. Tucker, A. Evangelista, V. Fernandez, C. Martins-Keli.iho.omalu, K. Santos, R. Ohara. 2023. A framework for establishing a rapid ‘Ohi‘a death resistance program. New Forests https://doi.org/10.1007/s11056-021-09896-5

Martín, J.A., J. Domínguez, A. Solla, C.M. Brasier, J.F. Webber, A. Santini, C. Martínez-Arias, L. Bernier, L. Gil1. 2023. Complexities underlying the breeding and deployment of Dutch elm disease resistant elms. New Forests https://doi.org/10.1007/s11056-021-09865-y

Merkle, S.A., J.L. Koch, A.R. Tull, J.E. Dassow, D.W. Carey, B.F. Barnes, M.W.M. Richins, P.M. Montello, K.R. Eidle, L.T. House, D.A. Herms and K.J.K. Gandhi. 2023. Application of somatic embryogenesis for development of emerald ash borer-resistant white ash and green ash varietals. New Forests https://doi.org/10.1007/s11056-022-09903-2

Nelson, C.D. 2023. Tree breeding, a necessary complement to genetic engineering. New Forests

https://doi.org/10.1007/s11056-022-09931-z

Pike, C.C., J. Koch, C.D. Nelson. 2021. Breeding for Resistance to Tree Pests: Successes, Challenges, and a Guide to the Future. Journal of Forestry, Volume 119, Issue 1, January 2021, Pages 96–105, https://doi.org/10.1093/jofore/fvaa049

Sniezko, R.A., J. Koch, J-J. Liu and J. Romero-Severson. 2023. Will Genomic Info Facilitate Forest Tree Breeding for Disease and Pest Resistance? Forests 2023, 14, 2382.

https://doi.org/10.3390/f14122382

Sniezko, R.A. and C.D. Nelson. 2022. Chapter 10, Resistance breeding against tree pathogens. In Asiegbu and Kovalchuk, editors. Forest Microbiology Volume 2: Forest Tree Health; 1^st Edition. Elsevier

Stanley, R.K., Carey, D.W., Mason, M.E., Doran, A., Wolf, J., Otoo, K.O., Poland, T.M., Koch, J.L., Jones, A.D. and Romero-Severson, J. 2023. Emerald ash borer (Agrilus planipennis) infestation bioassays and metabolic profiles of green ash (Fraxinus pennsylvanica) provide evidence for an induced host defensive response to larval infestation. Front. For. Glob. Change 6:1166421. doi: 10.3389/ffgc.2023.1166421

Posted by Faith Campbell

www.fadingforests.org

Eastern National Parks: Forest Regeneration Failing in 69%

Gettysburg battlefield; now under attack by emerald ash borer (see below)

Kathryn Miller and colleagues (full citation at end of blog) have published a study that examined the status and trends of forest regeneration in 39 National parks from Virginia to Maine. Four-fifths of the forest plots in the study are classified as mature or late successional – so at first glance the forests look healthy. However, the researchers made an alarming finding: in 27 of 39 parks, forest regeneration is failing – either imminently or probably. Acadia National Park is an exception; it is the only park in the study experiencing healthy regeneration. They warn that without intense, sustained – and expensive! – intervention, these forests are likely to be converted to other types of ecosystems. [I blogged recently about findings regarding regeneration in eastern forests: here and here and here and here.

The forests’ understories have too few seedlings and – especially – saplings to maintain themselves. Worse, in many cases the seedlings and saplings are not the same species as the mature trees that form the canopy. The saplings are shorter species that never reach the canopy. That is, species like pawpaw (Asimina triloba), American holly (Ilex opaca), American hornbeam (Carpinus caroliniana), and eastern redbud (Cercis canadensis) are regenerating, rather than the oaks (Quercus spp.), hickories (Carya spp.), maples (Acer spp.), and pines (Pinus spp.) that constitute the canopies of mature forests in these parks.

Miller and colleagues call these “regeneration mismatches.” In about half of the parks, these native canopy tree species make up less than half of current saplings and seedlings. This situation suggests the forests’ species composition will shift substantially, thereby undermining resilience in the face of other challenges, such as invasive plants and pests and climate change.

In many of these National parks, Miller and colleagues found abundant ash regeneration. For example, ash (Fraxinus spp.) constitute more than half of all seedlings in four parks (Johnstown Flood and Friendship Hill in Pennsylvania; Catoctin Mountain in Maryland; Manassas Battlefield in Virginia). Miller and colleagues consigned ash species to the “subcanopy class” because the emerald ash borer (EAB) has caused such high mortality of mature trees. They think regard it unlikely that current and future seedlings will ever reach full size. The devastating impact is most starkly illustrated in Gettysburg National Battlefield Park. Consistent deer management since 1996 has been rewarded: the Park ranks at the top for regeneration among the 39 parks. However, more than half of the seedlings and a quarter of the saplings are ashes. EAB has shifted the Park’s otherwise secure regeneration status into probable failure.

When regeneration fails: too many deer

Throughout the study region, the overwhelming reason regeneration fails is browsing by overabundant deer. The level of deer browse is considered “acceptable” in only four parks. Deer suppress the number of seedlings and saplings. They also skew species composition of native subcanopy species toward those less palatable. Miller and colleagues found that canopy tree density and cover and past human land use had minimal impacts on seedling and sapling numbers or species composition.

Overabundant deer also promote invasion and spread of non-native plants, which are the second most important factor impeding regeneration. Together, invasive plants and non-native earthworms are ecosystem engineers that negatively impact soil and cause cascades of biotic and abiotic impacts throughout forest ecosystems.

Many of the parks experiencing the most severe impacts of chronic deer browse also have the highest invasions by non-native plants. A natural process of regeneration occurs when the death or collapse of mature trees create gaps in the forest canopy. Where deer and invasive shrubs overlap, this process is often hijacked. Instead of nearby native tree species accelerating their growth toward the canopy, thickets of invasive shrubs crowd the space.

For this reason, Miller and colleagues recommend that park management prioritize treating invasive plants in canopy gaps of disturbed stands to avoid forest loss. They recommend deliberate creation of canopy gaps to promote resilience only for parks, or stands within parks, that have low deer and invasive plant abundance or the capacity to intensively manage invasive plants in gaps.

In most parks, non-native tree species are rare, less than 2% of total regeneration. In seven parks, though, non-native trees exceed ten percent of seedlings and/or saplings. In three parks, saplings of non-native trees are increasing. These are primarily tree-of-heaven (Ailanthus altissima) and Norway maple (Acer platanoides). In Saratoga National Historical Park, seedlings of common buckthorn (Rhamnus cathartica) are increasing.

Beech regeneration in Prince William Forest Park

Role of other pests

Miller and colleagues express fear that beech bark disease and beech leaf disease might have effects similar to those of EAB, leading to a greater “regeneration debt” in parks where American beech (Fagus grandifolia) is the dominant regeneration component. They cite specifically Prince William Forest Park in northern Virginia, [25 mi²] Rock Creek Park in the District of Columbia, [2.7mi²] and Saratoga National Historical Park. [5.3 mi²] The authors also suggest that thickets of beech root sprouts formed in response to BBD can suppress regeneration of other native canopy species and so might need to be managed.

Miller and colleagues mention hemlock woolly adelgid (HWA), but provide very little information. They report that Saint-Gaudens National Historical Park in New Hampshire (the home and studio of sculptor Augustus Saint-Gaudens) is at particular risk because of growth of both beech and eastern hemlock (Tsuga canadensis). I know that Delaware Water Gap National Recreation Area [109m²] has experienced major losses of mature hemlocks. [Shenandoah National Park has also, but it was not included in the study.]

Hemlock Ravine, Delaware Water Gap National Recreation Area; photo by Nicholas T via Flickr

Miller and colleagues report that Acadia National Park is seeing recovery of red spruce (Picea rubens) from a major fire in 1947 and possibly also from acid rain. They do not mention the longer-term threat from the brown spruce longhorned beetle. Their focus is on forest dynamics largely unaffected by deer.

In the same way, the authors make no mention of the absence of dogwood trees, presumably because they had been eliminated by dogwood anthracnose decades ago. Nor do they mention vascular streak dieback of redbud; the causal agent still uncertain. [See Annie Self’s presentation to National Plant Board, August 2023.]

dead ash tree in Shenandoah National Park

One omission is large enough that it might affect the study’s findings. At mi² Shenandoah is the largest National Park in the region. It was not included in the study because the Park’s forest monitoring process is not compatible with those in other NPS units. All the other parks – including Acadia (56² mi) – are much smaller, protecting historic sites like Civil War battlefields.

RECOMMENDATIONS

Miller and colleagues recommend that deer management be initiated in parks classified as at imminent or probable regeneration failure, if such programs are not already under way. They warn that effective deer management requires sustained commitment. Studies of deer exclosures show that full forest recovery from chronic deer overabundance can take as long as 40–70 years.

The authors also recommend actions to open the subcanopy to facilitate growth of saplings belonging to desired species. They caution that deer predation must be controlled. Furthermore, either invasive plant cover must be low, or management must ensure that that the park has sufficient resources to sustain an invasive plant control program – especially if invasive plants are combined with abundant deer.

Parks experiencing compositional mismatches and that are dominated by oak–hickory forest types might also benefit from prescribed burning. Again, deer browse pressure must be minimized. In addition, regeneration of oaks and hickories must already be present.

In park forests dominated by species vulnerable to lethal pests, e.g., beech-, ash-, or hemlock-dominated forest stands, Miller and colleagues recommend considering planting alternative native canopy species and protecting those plantings from deer. Park managers should also consider thinning beech thickets formed after beech bark disease kills canopy trees.

Media coverage

The Washington, D.C., public radio station, WAMU, reported on this research on the air (broadcast December 20) and on its website. It is written by Jacob Fenston, with great photographs by Tyrone Turner. The story emphasized the link between deer and invasive plants – since regeneration in eastern deciduous forest happens by saplings taking advantage of gaps formed when mature trees die. The story quotes DC-area people on their efforts to contain vines. The Natural Resource Manager at Catoctin Mountain Park [8 mi²] describes that park’s longstanding deer control program. The story also mentions impacts of EAB and threat of BLD.

News – Funding for these parks to counter the threats!

Lead author Kathryn Miller has informed me that the Bipartisan Infrastructure Law and Inflation Reduction Act has provided the 39 parks involved in this study over $10 million to improve forest resilience largely through reduction of invasive plants and overabundant deer.

Of course, invasive species threats to National parks are not limited to the Northeast – nor are they new. I have raised this problem from the beginning. To see these blogs, on the “nivemnic” website, scroll down below the archives to the “categories”, then click on “national parks”.

SOURCE

Miller, K.M., S.J. Perles, J.P. Schmit, E.R. Matthews, M.R. Marshall. 2023. Overabundant deer and invasive plants drive widespread regeneration debt in eastern United States national parks. Ecological Applications. 2023;33:e2837. https://onlinelibrary.wiley.com/r/eap Open Access

Posted by Faith Campbell

www.fadingforests.org

SOD – 3 strains spreading in the West …

locations of P. ramorum in forests of Oregon in 2023

In a recent blog I offered several critiques of APHIS’ new Phytophthora ramorum risk assessment regarding possible establishment of the causal agent of sudden oak death, in the eastern U.S. states. One of my objections was the brevity of its discussion of the likelihood of sexual combination of the recently introduced EU1 strain with the strain established in North America, NA1 and – more recently – NA2.

This blog provides updates on the status of the Phytophthora ramorum invasion in California and Oregon. My information comes primarily from the newsletter posted by the California Oak Mortality Task Force (COMTF), supplemented by presentations at the recent on-line meeting.

Research by several scientists, including Tyler Bourret, now with USDA Agricultural Research Service, [summarized in the November 2023 COMTF annual meeting] reported that 216 species are now recognized in the genus Phytophthora.

Establishment of Additional Strains of the Pathogen

Scientists now recognize 12 strains of P. ramorum (Sondreli et al., summarized in COMTF newsletter for August 2023). Three of these strains are established in western North American forests. All three – NA1, NA2, & EU1 – are established in southern Curry County, Oregon. Two of the three – EU1 & NA1– are established in neighboring Del Norte County, California. The genetic lineage of the EU1 population in Del Norte points to a link to the Oregon outbreak. [Robinson/Valachovic presentation to COMTF annual meeting November 2023] Given the poor record of efforts to prevent additional introductions of P. ramorum to the United States (the APHIS risk assessment notes that the pathogen has been introduced eight to14 times – or more! — in California), continued introductions of strains not yet established in the U.S. appear likely. Once a strain is established in a North American nursery, it is very likely to spread to nurseries – and possibly forests – in other parts of the country. Remember, the risk assessment reported that P. ramorum has probably been moved over a thousand times on nursery stock from West Coast nurseries across the U.S.

*P. ramorum*-infected *Rhododendron*; photo by Jennifer Parke, Oregon State University

Why this matters

Phytophthora ramorum can reproduce sexually only when gametes of the two different mating types (A1 & A2) combine. Most of the North American populations are A2 mating type and most European populations are A1. Establishment of the European EU1 in Oregon and California increases the likelihood that sexual reproduction will occur, which in turn increases the probability that the pathogen will evolve. Sexual combination between NA2 (mating type A2) & EU1 (mating type A1) has occurred at least once – in a nursery in British Columbia. Authorities believe this hybrid has been eradicated. However, the possibility of such matings remains.

The most widespread strain in North America is NA1. It was first detected in the forests north of San Francisco in the middle 1990s; and in Oregon in 2001. Infestations of NA1 are now found from central Curry County, Oregon to Monterey County, California.

The EU1 lineage was first detected in Oregon in 2015. How did it get there since it was previously known only in Europe? The outbreak in Del Norte County, California – detected in 2020 – apparently is associated with the Oregon infection. [Robinson/Valachovic presentation to COMTF annual meeting November 2023] Both states attempted eradication, but the strain is well established. By 2023, the Oregon infestation was detected spreading at sites where intensive surveys in previous years detected no symptomatic trees. In California, new centers of infection have been detected along additional tributary creeks in the area. Scientists expect these infections to spread downhill. Control efforts and even surveys have been hampered by a large fire in the area, which diverted needed personnel and funding. [COMTF newsletter for October 2023 & Robinson/Valachovic]

The NA2 lineage has been found in some nurseries in the Pacific Northwest since 2005. The first detection in forests occurred near Port Orford, Oregon in 2021. Port Orford is 30 miles north of Gold Beach – the hitherto northern extent of the SOD infestation. Oregon authorities believed this signaled a new introduction to the state. By 2023, three sites in the state are now infested with this strain. [Ritokova presentation to COMTF annual meeting November 2023] Oregon now focuses its control efforts on NA2 outbreaks near Port Orford.

In California’s Del Norte County, there are now infestations of two strains of opposite mating types ~ 6 miles apart.The forests between them are conducive to infection, so interactions are likely. Robinson & Valahovic [COMTF annual meeting November 2023] ask how land managers should deal with any interactions. I ask – given the likelihood of hybrids forming – shouldn’t the APHIS risk assessment have tried harder to analyze this risk to the East?

Meanwhile, the NA1 strain continues to spread

In Oregon, the NA1 strain has spread 18 miles to the north and eight miles to the east since 2001 [Ritakova COMTF newsletter October 2023]. In California, spread after the wet winter of 2022-2023 has so far been less than expected. The SOD Blitz [Garbelotto at COMTF annual meeting November 2023] found that the statewide rate of positive trees rose from 7.1% in 2022 to 8.8% in 2023. In the Big Sur region some canyons now test negative that once were positive. Scientists think the negative tests reflect the multi-year drought. Scientists expect the spread will be more visible next year – especially if there is a second wet winter.

As noted above, the exception is in Del Norte County – an area described by CAL FIRE forester Chris Lee as a very wet “pathology” site. SOD (NA1 strain) was first detected in the area north of Crescent City in 2019 [Robinson and Valachovic]. This outbreak could not be re-confirmed for three years, despite intensive surveys. But, in 2022, scientists detected a new concentration of dying tanoak. The infected area is near both rare plants associated with serpentine soils and Jedediah Smith State Park, a unit of Redwood National Park. [Robinson] Meanwhile, the infestation of EU1 strain was first detected in 2020; it has expanded in 2022 and 2023.

In addition to spread facilitated by weather, we also see a continuing role in pathogen transfer via movement of shrubs intended for planting. In fall 2022 Oregon authorities were alerted by a homeowner to an outbreak in Lincoln City, Oregon. This was alarming for four reasons:

it was 201 miles north of the generally infested area in southern in Curry County.
it was well established and had apparently been present for many years.
P. ramorum was not detected in any associated waterways, raising questions about the efficacy of this standard detection method for use in community detections.
one of the infected plants was a new host: western sword fern (Polystichum munitum).

Fortunately, the infection has not (yet) been detected in nearby natural forests. Perhaps this is because there are no tanoaks this far north.

Detection Difficulties

Forest pathologists report several examples of outbreaks involving dozens of trees or plants suddenly being detected in areas which had been surveyed intensively in preceding years with no detections. See Robinson/Valachovic presentation [COMTF annual meeting November 2023, re: both EU1 & NA1 strains in Del Norte County]. I noted above that streams near the Lincoln City, Oregon neighborhood outbreak did not test positive. Nor did water associated with a positive nursery in Oregon[description of Oregon Department of Agriculture nursery regulatory program in COMTF newsletter for August 2023]. Stream baiting is an important component of detection surveys, so I worry about the possible implications of these negative results.

Identification of Additional Hosts [all from COMTF newsletter for August 2023.]

silverleaf cotoneaster Cotoneaster pannosus (an invasive non-native plant species)
“Mountain Moon” dogwood Cornus capitata [host previously identified in the United Kingdom]
western swordfern (Polystichum munitum) (discussed above)

Oregon *P. ramorum* eradication attempt; photo by Oregon Department of Forestry

Management

Oregon has tried to manage SOD in the forest since its first detection, but the pathogen’s spread and the recent appearance of two additional strains have overwhelmed the program. One hope was to find a less expensive eradication or containment method. For 20 years, attempts to suppress the disease has focused on eradicating local populations of tanoaks (Notholithocarpus densiflorus) because they are the principal host supporting sporulation in Oregon. When an outbreak has been detected and delimited, they first kill the tanoaks with herbicides to prevent resprouting from the roots. The trees are then felled, piled, and burned. This treatment costs $3,000 – $5,000 / acre. Scientists tested whether they could greatly reduce the cost of the suppression programs by leaving tree boles standing after they have been killed by herbicide. Unfortunately, leaving dead, herbicide-killed trees standing increased sporulation, so this approach would probably exacerbate pathogen spread. [See Jared LeBoldus presentation to COMTF annual meeting November 2023]

Worrying Developments in Europe

In Ireland, sudden larch death – caused by the EU1 strain on Japanese larch (Larix kaempferi) – has spread to several counties. This strain is also causing disease on European beech (Fagus sylvatica) & Noble fir(Abies procera) in locations where these tree grow in association with nearby heavily infected Japanese larch. The EU2 lineage was found in late 2021, infecting L. kaempferi at one site.

Several other Phytophthora species are causing disease on trees, including P. lateralis on Lawson’s cypress, Port-Orford cedar (Chamaecyparis lawsoniana); P. pseudosyringae on Japanese larch; and P. austrocedri on trees in the Juniperus and Cupressus genera.

[information about Ireland from R. O’Hanlon, summarized in COMTF newsletter for August 2023]

Regulation

The European Union has relaxed phytosanitary regulation of Phytophthora ramorum. Previously the species – all strains – was considered a quarantine pest. Now its regulatory status depends on the origin of the infected material. “Non-EU isolates” of Phytopththora ramorum are still quarantine pests (presumably the two North American strains [NA1 & NA2] and the eight other strains identified in Asian forests). These pests are treated as the most serious pests in the Union; when they are detected, extensive control actions must be taken. “EU isolates” (presumably EU1 & EU2) are now treated as regulated non-quarantine pests. The focus is to limit the spread of these on plants for planting only.

The European Union and USDA APHIS regulatory emphases differ to some extent (APHIS does not regulate P. ramorum in natural settings, only interstate movement via, inter alia, the nursery trade). However, I am worried that both seem intent on minimizing their regulatory programs.

*Arbutus canariensis*; photo by Moreno José Antonio via Plantnet

Another region at risk

Macaronesia is a group of several North Atlantic islands,e.g., Madeira and the Azores, Canary, and Cape Verde islands. The islands have climates similar to areas affected by P. ramorum. The Macaronesian laurel forest is a remnant subtropical evergreen forest which shares some plant taxa with those that host the pathogen elsewhere. Moralejo et al. found that, overall, plant species showed considerable tolerance of the pathogen. However, P. ramorum was “rather aggressive” on Viburnum tinus, Arbutus canariensis and Ilex canariensis. Furthermore, mean sporangia production on five Macaronesian laurel forest species was similar to levels on Umbellularia californica, a key host driving the SOD epidemics in California.Moralejo et al. concluded that there is a moderate to high risk of establishment if Phytophthora ramorum were introduced in the Macaronesian laurel forest. [Study summarized in October 2023 COMTF newsletter.]

Important Research

The COMTF August newsletter reports exciting work developing improved detection tools for Phytophthora species, especially P. ramorum. Sondreli, Tabima, & LeBoldus have developed a method to quickly distinguish among the four most common clonal lineages (NA1, NA2, EU1 and EU2). These assays are sensitive to weak concentrations and effective in testing a variety of sample types including plant tissue and cultures. Oregon State University is already using in its diagnostic laboratory.

YuFang, Xia, Dai, Liu, Shamoun, and Wu have developed a simple, rapid, sensitive detection system for the molecular identification of P. ramorum that does not require technical expertise or expensive ancillary equipment. It can be used in laboratory or using samples collected from the field.

Quiroga et al. found that thinning – with or without burning of the slash – significantly reduced stand density and increased average tree size without significantly decreasing total basal area. This effect persisted for five years after treatments – especially when supported by follow-up basal sprout removal. Preventative treatments also significantly increased dominance of tree species not susceptible to Phytophthora ramorum.

In a study summarized in the October 2023 COMTF newsletter, Bourret et al. reported results of nearly 20 years of leaf baiting in watersheds covering an 800-mile section of the Pacific Coast in northern and central California. They found 22 Phytophthora & Nothophytophthora species. Several – including P. ramorum — were abundant and widespread. Some isolates in northern California differ from those found elsewhere. Mitochondrial sequences revealed multiple hybridization events between P. lacustris and P. riparia.

Bourret et al. also found that P. pluvialis is probably native to Western North America. The strain invasive on conifers in New Zealand probably originated in California rather than Oregon or Washington.

Jared LeBoldus and colleagues are studying the ecological impact of tanoak mortality in Oregon forests. [Summarized in November 2023 COMTF newsletter.] They expect impacts at various trophic levels and functions. Preliminary findings regarding the plant community show increases in understory and herbacious species diversity; a shift away from tanoak to Douglas-fir; and increased coarse woody debris. These findings are similar to results from studies in central California by Dave Rizzo and colleagues at UC Davis. LeBoldus is now studying the microbiome of plant leaves; soil mycorrhizal diversity; invertebrates and pollinators (loss of the large annual flower crop of tanoaks presumably affects pollinators). They hope in the future to study small mammal communities (which they expect to be affected by the loss of acorns).

Jared LeBoldus and colleagues also reported early results of genomic studies exploring disease resistance in tanoaks. Various scientists started such studies in the past, but so far all efforts have petered out due to absence of sustained funding, support from agency management, and links to facilities with the necessary tree improvement/breeding resources. (See Richard Sneizko’s description of requirements for resistance breeding, here.) I hope this project proves more sustainable.

Posted by Faith Campbell

www.fadingforests.org

USFS Forest Health Protection program: what it funds

affects of mountan pine beetle on lodgepole pine in Rocky Mountain National Park, Colorado photo from Wikimedia; one of pests addressed by USFS FHP

Several USFS scientists have published an assessment of the agency’s program to enhance forest health across the country: the Forest Health (FHP) program. [see Coleman et al., full citation at end of this blog.] The program assists cooperators (including other federal agencies) to prevent, suppress, and eradicate insect and pathogen outbreaks affecting trees, regardless of land ownership.

Each year, I advocate for adequate funding for the FHP program — which comes from annual Congressional appropriations. Funding has remained static at about $100 million per year. I interpret the article as providing support for my call for increased appropriations. First, it reports that the number of projects and extent of area treated have declined from 2011 to 2020. This is because static funding levels are stretched increasingly thin as costs to implement the same activities rise. Second, the program does not address many damaging forest pests already in the country. The result is growth of established threats to forest health. Finally, new insects and pathogens continue to be introduced. Protecting forest health necessitates tackling these new pests – and that requires money and staff.

Coleman et al. analyzed data from the decade 2011- 2020 to determine the most frequently used project types, integrated pest management (IPM) strategies and tactics, dominant forest pests and associated hosts managed, and most comprehensive forest IPM programs in practice. While there is a wide range of possible projects, most of those funded consist of some form of treatment (more below). The databases relied on do not include funding through the National Forest System aimed at improving forest health through such management activities as stand thinning treatments and prescribed fire. Nor are all pest management activities recorded in the centralized databases. I regret especially the fact that “genetic control” (= resistance breeding) are left out.

Port-Orford cedar seedlings in trial for resistance to *Phytophthora lateralis* at Dorena center; photo courtesy of Richard Sniezko, USFS

Summary of Findings

The data are sorted in various categories, depending on whether one wishes to focus on the type of organism being managed or the management approach. All presentations make evident a dramatic imbalance in the projects funded. Again and again, spongy moth (Lymantria dispar dispar), southern pine beetle (SPB, Dendroctonus frontalis), and several bark beetles attacking conifers in the West (in particular mountain pine beetle, [MPB] Dendroctonus ponderosae) dominate, as measured by both funding and area treated.

oak trees in Shenandoah National Park killed by spongy moth; photo by F.T. Campbell

The bulk of the funding went to the above species, plus hemlock woolly adelgid (HWA; Adelges tsugae); emerald ash borer (EAB, Agrilus planipennis), oak wilt (caused by Bretziella fagacearum), and white pine blister rust (WPBR, Cronartium ribicola).
95% of the projects focused on only four taxa: oaks, Quercus spp. [spongy moth suppression and eradication]; loblolly and ponderosa pines [bark beetle prevention and suppression]; and eastern hemlock [HWA suppression].
Projects seeking to suppress an existing pest outbreak covered 87% of the total treatment area. However, 98% of the treated area was linked to only 20 taxa; again, spongy moth dominated.
Projects seeking to prevent introduction or spread of a pest constituted only 30% of all projects and covered only 11% of the total treatment area.
Eradication and restoration projects each equaled less than 5% of total projects and treatment areas.
Native forest pests were targetted by 79% of projects; non-native pests by 21%. However, non-native pests accounted for 84% of the total treatment area (again, the spongy moth).
While 67% of projects took place on USFS lands (focused on MPB and SPB), 89% of the total treatment area was on lands managed by others (state or other federal agencies, or private landowners). Again, the size of the non-USFS area treated was driven primarily by the spongy moth Slow the Spread program.
Insect pests received nearly all of the funding: 70% of funding targetted phloem-feeding insects, especially SPB and MPB; 10% targetted foliage feeders, especially spongy moth; 6% targetted sap feeders. 4% tackled rusts (e.g., WPBR); just 2% addressed wood borers (e.g., Asian longhorned beetle, emerald ash borer).
The ranking by size of area treated differs. In this case, 82% of areas treated face damage by foliage feeders (e.g., spongy moth); 15% of the treated areas are threatened by phloem feeders (e.g., MPB); only 1.4% of the area is damaged by sap feeders (e.g., HWA); 0.6% is threatened by rust; and 0.2% by wood borers.
Re: control strategies, 32% of projects relied on silvicultural strategies; 22% used semiochemical strategies; 21% exploited other chemical controls; and 18% used physical/mechanical control methods.

Coleman et al. regretted that few programs incorporated microbial/biopesticide control strategies; these were applied on only 10% of total treated area. Again, the vast majority of such projects were aerial applications of spongy moth controls, Bacillus thuringiensis var. kurstaki (Btk) and nucleopolyhedrosis viruses (NPV) (Gypchek). Coleman et al. called for more research to support this approach efforts to overcome other obstacles (see below).

Coleman et al. also called for better record-keeping to enable analysis of genetic control/ resistance breeding projects, treatment efficacy, and survey and technical assistance activities.

History

The article provides a brief summary of the history of the Forest Service’ pest management efforts. Before the 1960s, the USFS relied on labor-intensive physical control tactics, classical biocontrol, and widespread chemical applications. Examples include application of pesticides to suppress or eradicate spongy moth; decades of Ribes removal to curtail spread of white pine blister rust; salvage logging and chemical controls to counter phloem feeders / bark beetles in the South and West. These strategies were increasingly replaced by pest-specific management tactics during the 1970s.

Over the decade studied (2011-2020), tree defoliation attributed to various pests (including pathogens) affected an estimated 0.7% of the 333 million ha of U.S. forest land annually. Mortality attributed to pests impacted an estimated 0.8% of that forest annually. See Table 1. Two-thirds of the area affected by tree mortality is attributed to phloem feeders; a distant second agent is wood borers. These data are incomplete because many insects, diseases, and parasitic higher plants are not tracked by aerial surveys.

As I noted above, these data do not include projects that screen tree species to identify and evaluate genetic resistance to a pest; or efforts to collect cones, seed, and scion. I consider these gene conservation and resistance programs to be some of the most important pest-response efforts. I have blogged about the USFS’ Dorena Genetic Resource Center’ efforts to breed five-needle pines, Port-Orford cedar, and ash. link

41% of silvicultural control treatments targetted phloem feeders; 48% addressed cankers and rusts together. Restoration planting was done in response to invasions by ALB, EAB, and WPBR, as well as native bark beetles and mistletoes.

effort to eradicate SOD in southern Oregon; partially funded by USFS FHP. Photo courtesy of Oregon Department of Forestry

Physical/mechanical control projects were most widely applied in the Rocky Mountains in response particularly to diseases: vascular wilts, rusts, and cankers, including WPBR. This type of project was also used to deal with non-native diseases in other parts of the country, e.g., oak wilt, sudden oak death (SOD), Port-Orford cedar root rot, and rapid ʻōhiʻa death. Sanitation treatments (i.e., removal of infected/infested trees) was used for native mistletoes and root rots, and some non-native insects, e.g., EAB and coconut rhinoceros beetle (Oryctes rhinoceros). Pruning is a control strategy for WPBR. Trenching is applied solely to suppress oak wilt.

Chemical controls were limited to small areas. These projects targetted seed/cone/flower fruit feeders, foliage and shoot diseases, sap feeders [e.g., balsam woolly adelgid (BWA), HWA], wood borers (e.g., EAB) and phloem feeders (e.g., Dutch elm disease; DMF oak wilt vectors). Cover sprays have been used against goldspotted oak borer (GSOB); and many native insects. Fungicides are rarely used; some is applied against the oak wilt pathogen in areas inaccessible by heavy equipment.

treating hemlock trees in Conestee Falls, NC; photo courtesy of North Carolina Hemlock Restoration Initiative

Classical biocontrol projects funded by the program targetted almost exclusively HWA. Some 4.3 million predators have been released since the early 1990s; 820,057 in just the past 10 years.

Gene conservation and breeding projects were directed primary at commercially important hosts, e.g., loblolly Pinus taeda and slash pine P. elliottii; and several non-native pests, including chestnut blight, EAB, HWA, and WPBR.

Survey and technical assistance (i.e., indirectly funded activities) conducted by federal, state, and tribal personnel contributed to education/outreach, evaluating effectiveness, identification, monitoring, and record keeping strategies.

As should be evident from the data presented here, suppression treatments dominated by number of projects and treatment area. The poster child project is the national spongy moth Slow the Spread program. The authors say this program is the most advanced forest IPM program in the world. It has successfully slowed spongy moth’s rate of spread by more than 80% for more than 20 years.

A second widely-used subset of suppression programs consists of physical / mechanical control. This is often the principal suppression strategy in high-visitation sites (e.g., administration sites, campgrounds, picnic areas, and recreation areas). Sanitation harvests are one of the few viable management techniques for suppressing or slowing the spread of recently introduced non-native pests. Nevertheless, the largest number of suppression projects and use of sanitation treatments focused on a native pest, mountain pine beetle, at the height of its outbreak in early 2010s.

Silvicultural control, specifically tree thinning, represents the predominant forest pest prevention tactic, especially on lands managed by the USFS. Two programs dominate: the Southern Pine Beetle Prevention Program and the Western Bark Beetle Initiative. Again, Coleman et al. assess these treatments as very successful. Forest thinning treatments also address other management concerns, i.e., reduce threat of catastrophic wildfires and reduce adverse effects of climate change.

Chemical control tactics are applied to suppress most forest insect feeding guilds in high-value sites and seed orchards. Soil or tree injections of systemic pesticides are used to protect ash and hemlock trees. Topical sprays have been applied to protect whitebark pine (Pinus albicaulis) from mountain pine beetle. Whitebark pine was listed as threatened under the Endangered Species Act in December 2022.

dead whitebark pine at Crater Lake NP; photo by F.T. Campbell

Soil or tree injections target two non-native insects, EAB and HWA.

Genetic control via resistance breeding represents the primary strategy to combat several non-native diseases. (More options are typically available for insects than diseases.) Coleman et al. focus on the extensive effort to protect many of the five-needle pines from WPBR. As I have described in earlier blogs, the Dorena Genetic Resource Center in Oregon has engaged on numerous other species, too.

Coleman et al. describe pest-management associated monitoring efforts as consisting largely of coordinated annual aerial detection surveys, detection trapping, stream-baiting of Phytophthora ramorum, and ground surveys to address site-specific issues.

Coleman et al. call for improvement of record-keeping / databases to encompass all pests, management actions, and ownerships. They also advocate for additional decision-making tools, development of microbial/biopesticides, genetic research and breeding, and biocontrol strategies for several pest groups.

They consider the southern pine beetle and spongy moth programs to be models of comprehensive IPM programs that could be adapted to additional forest health threats. They note, however, that development and implementation of these programs require significant time, financial commitments, and collaborations from various supporting agencies. Not all programs enjoy such resources.

SOURCE

Coleman, T.W, A.D. Graves, B.W. Oblinger, R.W. Flowers, J.J. Jacobs, B.D. Moltzan, S.S. Stephens, R.J. Rabaglia. 2023. Evaluating a decade (2011–2020) of integrated forest pest management in the United States

Journal of Integrated Pest Management, (2023) 14(1): 23; 1–17

Posted by Faith Campbell

www.fadingforests.org

Hot off the presses: How beech leaf disease kills trees

beech leaf disease symptoms; photo courtesy of Jennifer Koch, USFS

As we know, beech leaf disease (BLD) has spread rapidly in the decade since its discovery in northeast Ohio. It has been detected as far east as the Maine coast, as far south as northern Virginia, as far north as southern Ontario, and as far west as eastern Michigan and northern Indiana. It has been found in 12 states.

BLD is associated with a nematode, Litylenchus crenatae subsp. mccannii (Lcm), although whether this is the sole causal agent is not yet clear.

BLD’s North American host, American beech (Fagus grandifolia),is an important native deciduous hardwood species. It plays important roles in nutrient cycling, erosion control, and carbon storage and sequestration in forests. Wildlife species depend on the trees’ canopies and especially cavities blog for nesting sites, shelter, and nutritious nuts. American beech – with sugar maple (Acer saccharum) and yellow birch (Betula alleghaniensis) – dominate the northern hardwood ecosystem of northeastern United States and southeastern Canada. These forests occupy a huge area; in just New England and New York they occupy 20 million acres (Leak, Yamasaki and Holleran. 2014; full citation at end of blog).

Beech leaf disease also affects European beech, (F. sylvatica), Chinese beech (F. engleriana), and Oriental beech (F. orientalis) planted in North America. The disease has not yet been detected in Asia or Europe. Japanese beech (F. crenata) sporadically display symptomatic leaves, but the disease has not been reported there.

Scientists working to understand the disease, how it spreads, and its ecological impact confer every other month. The next time is in early December.

Paulo Vieira, of the USDA Agriculture Research Service, leads one group seeking to better understand how the disease infects its host. They published a new study (see full citation at end of blog) examining how the nematode provokes changes in the cells of the trees’ leaves. As they point out, leaves are plants’ primary organs for photosynthesis – hence providing energy for growth. The leaf is composed of a several cell types organized into different tissues with specific function related to photosynthesis, gas exchange, and/or the transportation of water and nutrients. Thus, changes in leaf morphology affect the normal functioning of the leaf and therefore the tree’s growth and survival.

Vieira et al. found that:

The BLD nematode enters the leaf bud as it forms in late summer. In early autumn, all nematode developmental stages were found in the buds, including eggs at various stages of embryonic development, juveniles, and adults. Adult males were found in fewer than 20% of the buds, suggesting that the nematode can reproduce asexually.
Feeding by the BLD nematode induces abnormal and extensive cell proliferation, resulting in a significant increase of the number of cell layers inside the leaf. These changes improve the nutrition that the leaves provide to the nematode. However, the BLD-induced distortions of the bud persist as the leaf grows. Symptomatic leaf “banding” results. These areas have a proliferation of abnormally large and irregularly shaped cells with more chloroplasts. Intercellular spaces are also larger; this is where the nematodes are found. in. (The publication has dramatic photographs.)
Sites damaged by nematodes are a major resource for metabolites needed for plant performance. So their damage imposes a considerable drain.
Colonization of roots by ectomycorrhizal fungal is also reduced in severely diseased trees.
Immature female nematodes are the principal winter survivors. However, many die, making it difficult to culture nematodes in the spring. The nematodes reproduce during the growing season. Buildup of nematode numbers makes culturing easier, so facilitating confirmation of the disease’s presence.
Nematodes can migrate along the stem to other leaves, thus spreading the infection.

Vieira et al. tell us fascinating facts about the nematode. The BLD nematode, Litylenchus crenatae subsp. mccannii (Lcm) is now considered one of the top ten most important plant-parasitic nematodes in the United States. To date, species of this genus have been found only in Japan and New Zealand. The species L. crenatae was first described from Japan. A second species — L. coprosma – was detected in 2012 in New Zealand in association with small chlorotic patches on leaves of two native plants in the Coprosma genus.

Litylenchus belongs to the family Anguinidae. Several species in the family are designated quarantine pests because they cause economically significant damage to food and ornamental corps, including grains (wheat, barley, rice) and potatoes. Anguinidae nematodes often parasitize aerial parts of the hosts (e.g., leaves, stems, inflorescences, seeds); less frequently they infest roots. They can migrate along the host tissue surfaces in water films. Their host ranges vary from broad to narrow. Other Anguinidae nematodes apparently share the ability to manipulate the host’s cellular machinery, which often results in the induction of cell hyperplasia [the enlargement of an organ or tissue caused by an increase in the reproduction rate of its cells], and hypertrophy [increase and growth of cells] of the tissues on which they feed.

Vieira et al. assert that the rapid spread of Litylenchus crenatae subsp. mccannii – combined with the apparent lack of resistance in native beech trees – suggests that this nematode was recently introduced to North America. Furthermore, the ability of this subspecies to change the host’s cell cycle machinery supports the link between the presence of the nematode and the disease.

The mechanisms by which nematodes change host-plant cells are unknown. I hope that scientists will pursue these questions. Perhaps the nematode family’s threat to grains and other food crops will prompt funding for such work. Unfortunately, I don’t think the threat to an ecologically-important native tree species will have the same power.

SOURCES

Leak, W.B, M. Yamasaki and R. Holleran. 2014 Silvicultural Guide for Northern Hardwoods in the Northeast. United States Department of Ariculture Forest Service Northern Research Station. General Technical Report NRS-132. April 2014.

Vieira P, M.R. Kantor MR, A. Jansen, Z.A. Handoo, J.D. Eisenback. (2023) Cellular insights of beech leaf disease reveal abnormal ectopic cell division of symptomatic interveinal leaf areas. PLoS ONE October 5, 2023. 18(10) https://doi.org/10.1371/pone.0292588

Posted by Faith Campbell

www.fadingforests.org

FY24 Appropriations for Key Programs: current status

In March I asked your help in asking Congress to fund USDA programs that protect forests from non-native insects and pathogens. The Congress has now taken major steps to specify funding for Fiscal Year 2024 – which begins on 1 October. Both the House and Senate Appropriations committees have adopted their bills. They differ substantially. When Congress returns from its August recess in September, it will face many difficulties in negotiating the final spending levels – not just the different funding levels but also attached “riders” dealing with social and political issues, most of which have nothing to do with invasive species. [Some of the riders to seek to restrict application of the Endangered Species Act to several species, e.g., sage grouse and grey wolf.]

USDA APHIS

As you know, USDA’s Animal and Plant Health Inspection Service (APHIS) is responsible for preventing introduction of pests that harm agriculture, including forests; and for immediate efforts to eradicate or contain those pests that do enter. While most port inspections are carried out by the Department of Homeland Security Bureau of Customs and Border Protection, APHIS sets the policy guidance. APHIS also inspects imports of living plants. In the table below, I provide information on funding for key APHIS programs in FY23, the Administration’s request for FY24, the funding level the Center for Invasive Species thought necessary, and the House and Senate funding levels.

The earlier blog link has additional information: the FY22 funding levels and a fairly long justification for funding these APHIS programs. I never posted a blog discussing USFS funding due to my trip to Europe.

Appropriations for APHIS programs (in $ millions)

Program	FY 2023	FY 2024 Pres.’ request	CISP ask	House bill	Senate bill
Tree & Wood Pest	$63	$64	$65	$55.6	$62.6
Specialty Crops	$216	$222	$222	$224.5	$217.9
Pest Detection	$29	$30	$30	?	?
Methods Development	$23	$23	$25	?	$21.8
Emerg. Preparedness	$44	$45.2	NA	$44.6	$48
Contingency fund	$514	$543		$514	$514

I have not seen a report from the House Committee so I don’t know whether that body prioritized any invasive species issues.

The Senate report included this statement re: Sudden oak death

“The European strain 1 [EU1] and the North American strain 1 [NA1] of the sudden oak death pathogen are major threats to western Douglas-fir/tanoak forests, resulting in quarantine restrictions that threaten U.S. forests and export markets for log shipments and lily bulbs. The Committee recommendation includes no less than the fiscal year 2023 funding level to improve understanding of EU1 and NA1 strains of the sudden oak death pathogen and treatment methods to inform control and management techniques in wildlands.”

Appropriations for USFS programs (in $ millions)

Program	FY 2023	FY 2024 Pres.’ request	CISP ask	House bill	Senate bill
Forest Health Protection
Federal Lands			$32		$17
Coop Lands			$51		$33
Research & Development		$349.1	$349.1	$275	$307.3
Forest Inventory		$30.2	$30.2	$32.2	$32.2
Work on 10 invasive spp	$.5	$4.4	$8.5*	0	0

* CISP ask was intended as first step to increasing funding for invasive species to 5% of R&D funds. See the March blog for an explanation.

SOD-killed tanoaks in southern Oregon; Oregon Department of Agriculture photo

Senate report = Sudden Oak Death. “Since 2001, USFS has been treating SOD infestations on public lands in Oregon and California, in cooperation with Bureau of Land Managemebt. The Committee expects USFS continue these efforts; it provides $3M for SOD treatments and partnerships with States and private landowners.”

Urban & Community Forestry.—”The bill provides $40 M for urban and community forestry. The Committee recognizes the critical need to restore and improve urban forests due to dominance of exotic invasive woody species. USFS should prioritize regional multi-organizational collaborations to support conservation efforts that help trees adapt to and offset climate change, which model best practices for effective urban and community forestry grants. The Committee also expects the program to prioritize tree-planting in socially disadvantaged and historically underserved communities with low canopy coverage, including Tribal communities.”

Summary of Justifications: The Costs of Introduced Pests

Introduced pests threaten many forest products and ecosystem services benefitting all Americans. Already, the 15 most damaging non-native pests threaten at least 41% of forest biomass in the “lower 48” states. In total, these 15 species have caused an additional annual conversion of live biomass to dead wood at a rate similar in magnitude to that attributed to fire (5.53 TgC per year for pests versus 5.4 to 14.2 TgC per year for fire). Fei et al.; full citation at end of blog.

These pests also impose significant costs that are borne principally by municipal governments and homeowners. As more pests have been accidentally introduced over time, these costs have risen.

Pathways of Introduction

The many tree-killing wood-boring pests arrive in inadequately treated crates, pallets, and other forms of packaging made of wood. The March blog presents 2023 data on import volumes and the findings of Haack et al. 2022. The point is, ISPM#15 has fallen short. [See blogs under “wood packaging” category on this site]

APHIS’ Tree and Wood Pests account supports eradication and control efforts targeting principally the Asian longhorned beetle and spongy (= gypsy) moth. Eradicating the ALB normally receives about two-thirds of the funds. The programs in Massachusetts, New York, Ohio, and South Carolina must continue until eradication succeeds. The emerald ash borer continues to spread since APHIS dropped regulations attempting to halt this. EAB was detected in Oregon in 2022; and on Colorado’s western slope in 2023.

Other pests—especially plant diseases like sudden oak death and sap sucking insects like hemlock woolly adelgid—come on imported plants. I noted that no studies have examined the risk of pests arriving on the ~5 billion plants we Americans now import annually (see March blog). The information gap is particularly alarming regarding pathogens. Evidence of failures:

the recent detection of two strains of Phytopthora ramorum that were formerly limited to Europe in forests of Oregon and California;
introduction of rapid ‘Ōhi‘a death in Hawai`i;
and the apparent introduction of the causal agent(s) of beech leaf disease.

APHIS manages damaging pests introduced on imported plants or other items through its Specialty Crops program. The principal example is its efforts to prevent spread of the SOD pathogen through the interstate trade in nursery plants. I am pleased that the Senate report calls on APHIS to focus on that pathogen’s growing genetic diversity.

Beech leaf disease has spread >700 miles since its first detection just 11 years ago

The Administration did not persuade the Congress to fund a $1 million emergency fund for APHIS – although they did fund both “emergency” and “contingency” programs. I am not certain about the difference.

Furthermore, both chambers of Congress included in their legislation – not in the report – language instructing the Secretary of Agriculture to use his authority to obtain emergency funds from other USDA agencies to address animal or plant health emergencies:

“Provided further, That in addition, in emergencies which threaten any segment of the agricultural production industry of the United States, the Secretary may transfer from other appropriations or funds available to the agencies or corporations of the Department such sums as may be deemed necessary, to be available only in such emergencies for the arrest and eradication of contagious or infectious disease or pests of animals, poultry, or plants, and for expenses in accordance with sections 10411 and 10417 of the Animal Health Protection Act (7 U.S.C. 8310 and 8316) and sections 431 and 442 of the Plant Protection 15 Act (7 U.S.C. 7751 and 7772), and any unexpended bal1ances of funds transferred for such emergency purposes in the preceding fiscal year shall be merged with such transferred amounts.”

The Congress has included this or similar language in appropriations reports for almost two decades, but it has not succeeded in freeing up many funds for countering plant pests. Perhaps placing the language in the legislation rather than the report will help … we will have to see.

In the meantime, I have been working with others to amend the Plant Protection Act to ensure that the emergencies so referenced include threats to forests. See §2 in H.R. 3174 link (Balint, Vermont) and S. 1238 (Welch, Vermont).

SOURCES CITED

Fei, S., R.S. Morin, C.M. Oswalt, and A.M. 2019. Biomass losses resulting from insect and disease invasions in United States forests. PNAS August 27, 2019. Vol. 116 No. 35 17371–17376

Haack R.A., J.A. Hardin, B.P. Caton and T.R. Petrice .2022. Wood borer detection rates on wood packaging materials entering the United States during different phases of ISPM#15 implementation and regulatory changes. Front. For. Glob. Change 5:1069117. doi: 10.3389/ffgc.2022.1069117

Posted by Faith Campbell