Category: national parks

Sudden Oak Death – Bad News All Around

SOD in California;
photo by Joseph O’Brien. courtesy of Bugwood

We know that the international trade in living plants is a major pathway by which tree-killing pathogens are being spread – some of them again and again. According to Grünwald et al. (2019), Phytophthora ramorum, the pathogen that causes Sudden Oak Death (SOD), has been introduced to North America and Europe – probably from Asia – at least five times. One lineage or genetic strain – EU1 – has been established on both continents (strains explained here). There is strong evidence of two separate introductions to Oregon, at least 12 to California.

Jung et al. 2015 state definitively that the international movement of infested nursery stock and planting of reforestation stock from infested nurseries have been the main pathway of introduction and establishment of Phytophthora species in European forests.  

Clive Btasier in Vietnam
photo from UK Forest Research

Jung et al. 2020 have demonstrated that P. ramorum probably originated in Vietnam.  This region appears to be a center of diversity for Phytophtoras and other Oomycetes: baiting of soil and streams resulted in the detection of 13 described species, five informally designated taxa, and 21 previously unknown taxa of Phytophthoras plus at least 15 species in other genera. Noting the risk associated with any trade in plants from this region, the authors re-iterated past appeals that the international phytosanitary system replace the “outdated and scientifically flawed species-by-species regulation approach based on random visual inspections for symptoms of described pests and pathogens” by instituting “a sophisticated pathway regulation approach using pathway risk analyses, risk-based inspection regimes and molecular high-throughput detection tools.”

Pathogen’s Spread Proves U.S. Domestic Regulations Governing Nursery Trade Are Inadequate

Last year I blogged about the most recent spread of Phytophthora ramorum through the nursery trade.  As of now, we know that shipments of potentially infected plants had been sent to 18 states. Infected stock had been detected in nurseries in seven of these (Iowa, Illinois, Indiana, Kansas, Missouri, Nebraska, Oklahoma) plus the source state, Washington [COMTF Newsletter August 2019].

Since then, I learned [COMTF newsletter for December 2019]   that these plants were infected by the NA2 strain of the pathogen. This is the first time that this strain has been shipped to states outside the West Coast. It is unclear what the impact will be if – as is likely – infested plants are still extant in purchasers’ yards. Both the NA1 strain (the strain established in most infested forests of California and Oregon) and the NA2 strain belong primarily to the A2 mating type, so the potential spread of NA2 lineages might not exacerbate the probability of sexual reproduction of the pathogen.

I applaud agencies’ funding of genetic studies to determine the lineage of the pathogen involved. It not only helps narrow the possible sources of infected plants, but also could be important in determining risk and management options.

I have long criticized USDA’s P. ramorum regulatory program – see Fading Forests III and my blogs discussing the most recent revisions to the regulations here and here. I believe that both the earlier regulations and the revisions finalized last May provide inadequate protection for America’s forests. 

The updated regulations do take a couple of important positive steps. First, APHIS is now authorized to sample water, soil, pots, etc. – and to act when it finds evidence of the pathogen’s presence. APHIS also now mandated nurseries found to be infested to carry out a “critical control point analysis” to determine practices which facilitated establishment and persistence of P. ramorum.

However, these improvements are severely undermined by continuing the five-year-old practice of limiting close scrutiny to only those nurseries that tested positive for the pathogen in the recent past. The flaw in this approach was starkly demonstrated by the pathogen’s spread in 2019. The Washington State nursery that was the source of the infected plants had not previously been positive, so it was under routine nursery regulation, not the more stringent federal P. ramorum program.

Too often various iterations of the regulations have allowed infected plants to be shipped. Between 2003 and 2011, a total of 464 nurseries located in 27 states tested positive for the pathogen, the majority as a result of shipments traced from infested wholesalers (Campbell). The number of nurseries found to have infected plants has since declined, but not dropped to zero. These include 34 nurseries in 2010 (COMTF February 2011 newsletter), 21 in 2012, and 17 in 2013 (Pfister). During 2014, state inspectors detected the SOD pathogen in 19 nurseries – 11 in the three west-coast states and eight in other parts of the country (Maine-1, New York-2, Texas-1, and Virginia-4) COMTF newsletter December 2014). Despite the continuing presence of the pathogen in the nursery trade, APHIS formalized existing practices that narrowed the regulators’ focus to only those nurseries with a history of pathogen presence. This approach has been shown to fail – we need APHIS and the states to find a way to broaden their scrutiny.

The most immediate impact of the continuing presence of P. ramorum in the nursery trade is the burden borne by eastern states’ departments of agriculture. They are obligated to seek out in-state nurseries that might have received infected plants; inspect those plants; and destroy the infected plants, test nearby plants, and try to find and retrieve plants that had been sold. The heaviest, and most direct, burden is borne by the receiving nurseries. Anger about bearing this burden for 15 years doubtless prompted the National Plant Board to adopt a tart resolution calling on APHIS to carry out a review of its communications to the states during the 2019 incident. The NPB also questioned whether current program processes and guidance are effective in preventing spread of this pathogen. 

Unfortunately, the NPB had not commented formally on the rule change when it was proposed.

The states’ frustration is exacerbated by the fact that under the Plant Protection Act, when APHIS takes a regulatory action it prevents states from adopting more stringent regulations. While the law allows for exceptions if the state can demonstrate a special need, none of the five applications for an exemption pertaining to P. ramorum was approved (Porter and Robertson 2011). I have been unable to find evidence of petitions submitted in the nine years since 2011.

In Case You Needed A Reminder: P. ramorum is a Dangerous Pathogen – as Proved by the Situation in the West states and Abroad

Continuing Intensification of the Already Bad Infestations in the West

tanoak mortality in Big Sur
photo courtesy of Matteo Garbelotto, UC Berkeley

As of 2014 (see COMTF November 2018 newsletter available here), perhaps 50 million trees had been killed by P. ramorum in California and Oregon. The vast majority were tanoaks (Notholithocarpus densiflorus)  – an ecologically important tree. 

Since 2014, the disease has intensified and spread in response to recent wet winters. In 2016 (see COMTF

November 2016 newsletter here) disease was detected for the first time in a fifteenth California county and new outbreaks or more severe infestations were recorded in seven other counties.  In 2019, SOD was detected in the sixteenth county. Tanoak mortality in California increased by more than 1.6 million trees across 106,000 acres in 2018.

Perhaps more disturbing, the disease has also intensified on the eastern side of San Francisco Bay – an area thought to be less vulnerable because it is drier and where there are fewer of the principal sporulation host, California bay laurel (see COMTF March 2017 newsletter here).

A second disturbing event is the detection in Oregon forests of the EU1 strain of Phytophthora ramorum. The August 2015 detection was the first instance of this strain being detected in a forest in North America. Oregon authorities prioritized removing EU1-infected trees and treating (burning) the immediate area, which had expanded to more than 355 acres – all within the quarantine area in Curry County. The legislature provided $2.3 million for SOD treatments for 2017-2019 (Presentation by Chris Benemann of Oregon Department of Agriculture to the Continental Dialogue on Non-Native Forest Insects and Diseases; reported here).

The EU1 lineage is a different mating type than the NA1 lineage already established in Oregon. Scientists should study P. ramorum populations in Vietnam and Japan, where both mating types are present, to determine whether they are reproducing sexually. There is also the risk that the EU1 lineage might be more aggressive on conifers – as it has been in the United Kingdom (Grünwald et al. 2019).

The EU1 infestation was introduced to the forest from a nursery. The nursery had carried out the APHIS-mandated Confirmed Nursery Protocol, then closed.  I ask, what does this apparent transmission from nursery to forest say about the risk of transmission? Does it raise questions about the efficacy of the confirmed nursery protocol to clean up the area? Remember that a pond at the botanical garden in Kitsap, Washington has repeatedly tested positive, despite several applications of the clean-up protocols.

(For a discussion of the implications of mixing the various strains of P. ramorum, visit here)

These disasters remind us how sad it is that California and federal officials did not adopt aggressive management efforts aimed at slowing the pathogen’s spread at an early stage of  the epidemic. Experts on modeling the epidemiology of plant disease concluded three years ago that the sudden oak death epidemic in California could have been slowed considerably if aggressive and well-funded management actions had started in 2002 (Cunniffe, Cobb, Meentemeyer, Rizzo, and Gilligan 2016).

The Oregon Department of Forestry commissioned a study of the economic impact of the P. ramorum infestation that found few economic impacts to date, but potentially significant impacts in the future. It also noted potential harms to tribal cultural values and the “existence value” of tanoak-dominated forests and associated obligate species.

Situation Abroad

The situation in Europe is even worse than in North America. Two strains of P. ramorum are widespread in European nurseries and in tree plantations and wild heathlands of western the United Kingdom and Ireland. and here and here.  Jung et al. 2015 found 56 Phytophthora taxa in 66% of 2,525 forest and landscape planting sites across Europe that were probably introduced to those sites via nursery plantings.

larch plantation in UK killed by P. ramorum
photo from UK Forest Research

In Australia, Phytophthora dieback has infected more than one million hectares in Western Australia. More than 40% of the native plant species of the region are vulnerable to the causal agent, P. cinnamomi

 and here.  

Barber et al. 2013 reported 9 species of Phytophthora associated with a wide variety of host species in urban streetscapes, parks, gardens, and remnant native vegetation in urban settings in Western Australia. Phytophthora species were recovered from 30% of sampled sites.

In New Zealand, the endemic – and huge, long-lived – kauri tree (Agathis australis) is also suffering severe impacts from Phytophtoras and other pathogens (Bradshaw et al. 2020)

See the IUFRO Working Party 7.02.09 ‘Phytophthora Diseases of Forest Trees’ global overview (Jung et al. 2018), which covers 13 outbreaks of Phytophthora-caused disease in forests and natural ecosystems of Europe, Australia and the Americas.

The situation in the Eastern United States is Unclear

After 15 years of the nursery trade carrying P. ramorum to nurseries – and possibly yards and other plantings – in states east of the 100th Meridian, what is the risk that these forests will become infested? No one knows. We do known that the pathogen has been detected from 11 streams in six eastern states – four in Alabama; one in Florida; two in Georgia; one in Mississippi; one in North Carolina; and two in Texas. P. ramorum has been found multiple times in eight of these streams – two steams in Alabama, one each in Mississippi and North Carolina (see COMTF April 2019 newsletter available here). While established vegetative infections have not been detected, the question remains: how is the pathogen persisting? Scientists agree that P. ramorum cannot persist in the water; it must be established on some plant parts (roots?) or in the soil. Still, Grünwald et al. (2019) report that there is little evidence of plant infections resulting from stream splash in Oregon.

Unfortunately, fewer states are participating in the stream surveys – which are operated by the USDA Forest Service. In 2010, 14 states participated; in 2018, only seven (Alabama, Georgia, Mississippi, North Carolina, Pennsylvania, South Carolina, and Texas). Florida and Tennessee recently dropped out. The number of streams surveyed annually also has dropped – from 95 at the highest to only 47 in 2018 (see COMTF April 2019 newsletter available here). This reduced scrutiny makes it less likely that any infestation on plants will be detected. Risk maps (reproduced in Chapter 5 of Fading Forests III here) developed over more than a decade indicate that forests in the southern Appalachians and Ozarks are vulnerable to SOD.

Risks to other plants

The risk from Phytophthoras is not just P. ramorum and trees! Swiecki et al. 2018 report a large and increasingly diverse suite of introduced Phytophthora species pose an ever greater threat to both urban and non-urban plant communities in California. These threats are linked to planting of nursery stock. See also the information posted here.

Jung et al. 2018 cite numerous other authors’ findings of multiple Phytophthoras in Oregon and. California nurseries as well as in nurseries in various eastern states.

Nor is Phytophthoras the only pathogenic genus to pose a serious risk to America’s trees. I remind you of the fungus Fusarium euwallacea associated with the Kuroshio and polyphagous shot hole borers, which is known to kill at least 18 species of native plants in California and additional species in South Africa.   The laurel wilt fungus kills many trees and shrubs in the Lauraceae family. ‘Ohi‘a or myrtle rust kills several shrubs native to Hawai`i and threatens a wide range of plants in the Myrtaceae family in Australia and New Zealand; rapid ‘ohi‘a death fungi (Ceratocystis huliohia and Ceratocystis lukuohia)  [All described here] are killing the most widespread tree on the Hawaiian Islands.

Solutions – complete & implement modernized international and domestic phytosanitary regulations

Clearly, standard phytosanitary practice of regulating pests known to pose a threat does not work when many – if not most – of the damaging pests are unknown to science until introduced to a naïve ecosystem where they start causing noticeable levels of damage. We need a more proactive approach – as has long been advocated by forest pathologists, including Clive Brasier 2008 and later, Santini et al. 2013, Jung et al. 2016, Eschen et al. 2017.

National and international phytosanitary agencies have taken some steps toward adopting policies and programs that all hope will be more effective in preventing the continued spread of these highly damaging tree-killing pests. First, APHIS has had authority since 2011 – through the Not Authorized for Importation Pending Pest Risk Assessment (NAPPRA) program — to prohibit temporarily imports of plants suspected of transporting known damaging pathogens until the agency has conducted a pest risk analysis. However, utilization has lagged: only three sets of species have been proposed for listing in NAPPRA in the eight and a half years since the program was instituted in 2011. The third list of proposed species is currently open for public comment.

Another weakness is that the program still focuses on organisms known to pose a risk.

Second, in 2018 APHIS completed a decades-long effort to revise its plant import regulations (the “Q-37” regulations). APHIS now has authority to require foreign suppliers of living plants to carry out “hazard analysis and critical control point” programs and adopt integrated pest management strategies to ensure that the plants are pest-free during production and transport.

However, implementation of this new authority depends on APHIS negotiating agreements with individual countries that would govern specific types of plants exported to the U.S. APHIS has not yet announced completion of any programs under this authority. Nor is it clear which taxa or countries APHIS will prioritize.

APHIS’ action was anticipated by the international plant health community. In 2012, member states in the International Plant Protection Convention adopted International Standard for Phytosanitary Measure 36 (ISPM#36)  The standard sets up a two-level system of integrated measures, which are to be applied depending on the pest risk identified through pest risk analysis or a similar process. The “general” integrated measures are widely applicable to all imported plants for planting. The second level includes additional elements designed to address higher pest-risk situations that have been identified through pest risk analysis or other similar processes. 

However, the preponderance of international efforts to protect plant health continues to rely on visual inspections that look for species on a list of those known to be harmful. Yet we know that most damaging Phytophthoras were unknown before their introduction to naïve ecosystems.

Furthermore, use of fungicides and fungistatic chemicals – that mask infections but do not kill that pathogen – is still allowed before shipment.

(For more complete analyses of the Q-37 revision and ISPM#36, see chapters five and four, respectively, of Fading Forests III.)

The nursery industry is working with state regulators and APHIS to develop a voluntary program utilizing  integrated measures – the Systems Approach to Nursery Certification (SANC) program. https://sanc.nationalplantboard.org/

SOURCES

Bradshaw et al. 2020. Phytophthora agathidicida: research progress, cultural perspectives and knowledge gaps in the control and management of kauri dieback in New Zealand. Plant Pathology (2020) 69, 3–16 Doi: 10.1111/ppa.13104

Brasier CM. 2008. The biosecurity threat to the UK and global environment from international trade in plants. Plant Pathology 57: 792–808.

Brasier, C.M, S. Franceschini, A.M. Vettraino, E.M. Hansen, S. Green, C. Robin, J.F. Webber, and A.Vannini. 2012. Four phenotypically and phylogenetically distinct lineages in Phytophthora lateralis

Fungal Biology. Volume 116, Issue 12, December 2012, Pages 1232–1249

Campbell, F.T. Calculation by F.T. Campbell from tables in U.S. Department of Agriculture, Animal and Plant Health Inspection Service – National Plant Board.  2011.  Phytophthora ramorum Regulatory Working Group Reports.  January 2011.

Cunniffe, N.J., R.C. Cobb, R.K. Meentemeyer, D.M. Rizzo, and C.A. Gilligan. Modeling when, where, and how to manage a forest epidemic, motivated by SOD in Calif. PNAS, May 2016 DOI: 10.1073/pnas.1602153113

Grünwald, N.J., J.M. LeBoldus, and R.C. Hamelin. 2019. Ecology and Evolution of the Sudden Oak Death Pathogen Phytophthora ramorum. Annual Review of Phytopathology date? #?

Jung T, Orlikowski  L, Henricot B, et al. 2016. Widespread Phytophthora infestations in European nurseries put forest, semi-natural and horticultural ecosystems at high risk of Phytophthora diseases. Forest Pathology 46: 134–163.

Jung, T., A. Pérez-Sierra, A. Durán, M. Horta Jung, Y. Balci, B. Scanu. 2018. Canker and decline diseases caused by soil- and airborne Phytophthora species in forests and woodlands. Persoonia 40, 2018: 182–220   Open Access!

Jung, T. et al. 2015. Widespread Phytophthora infestations in European nurseries put forest, semi-natural and horticultural ecosystems at high risk of Phytophthora disease. Forest Pathology. November 2015; available from Resource Gate

Jung, T., B. Scanu, C.M. Brasier, J. Webber, I. Milenkovic, T. Corcobado, M. Tomšovský, M. Pánek, J. Bakonyi, C. Maia, A. Baccová, M. Raco, H. Rees, A. Pérez-Sierra & M. Horta Jung. 2020. A Survey in Natural Forest Ecosystems of Vietnam Reveals High Diversity of both New and Described Phytophthora Taxa including P. ramorum. Forests, 2020, 11, 93 https://gcc02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fwww.mdpi.com%2F1999-4907%2F11%2F1%2F93%2Fpdf&data=02%7C01%7C%7Cfcd843919a3348a4a56108d7974039ab%7Ced5b36e701ee4ebc867ee03cfa0d4697%7C0%7C1%7C637144174418121741&sdata=WayrZsxp3P9Kj0h1aDPZnzu4yjDGA2ZEuH9NZITFQF4%3D&reserved=

Knaus, B.J., V.J. Fieland, N.J. Grunwald. 2015. Diversity of Foliar Phytophthora  Species on Rhododendron in Oregon Nurseries. Plant Disease Vol 99, No. 10 326 – 1332

Pfister, S. USDA APHIS. Presentation to the National Plant Board, August 2013

Porter, R.D. and N.C. Robertson. 2011. Tracking Implementation of the Special Need Request Process Under the Plant Protection Act. Environmental Law Reporter. 41.

Santini A, Ghelardini L, De Pace C, et al. 2013. Biogeographic patterns and determinants of invasion by alien forest pathogens in Europe. New Phytologist 197: 238–250.

Swiecki, T.J., E.A. Bernhardt, and S.J. Frankel. 2018. Phytophthora root disease and the need for clean nursery stock in urban forests: Part 1 Phytophthora invasions in the urban forest & beyond. Western Arborist Fall 2018

Tsao PH. 1990. Why many Phytophthora root rots and crown rots of tree and horticultural crops remain undetected

Hawaiian Dry Forests – Glimmer of Hope for one tree, Alarm for a shrub

wiliwili flower
photo by Forrest and Kim Starr, courtesy of creative commons

Hawaii’s dryland forest is a highly endangered ecosystem. More than 90% of dry forests are already lost due to habitat destruction and the spread of invasive plant and animal species. However, a new publication documents some recovery of wiliwili trees from one major pest. At the same time, a new pest is spreading and killing naio, a critical dryland shrub.  Both pests originated in countries that have rarely if ever been a source of U.S. pests. This is worrying because phytosanitary agencies have their hands full with imports from the usual sources. The role of California as a source of invasive species in Hawai`i has long deserved federal attention – but as far as I know has not received it.

Hope for Wiliwili Trees

The Hawaiian endemic wiliwili tree, Erythrina sandwicensis, occurs in lowland dry forests on all the major islands from sea level to 600 m. Wililwili is a dominant overstory tree in these habitats. (Unless otherwise noted, the principal source is Kaufman et al. in press – full citation at end of blog.)

The tree has been severely affected by the introduced Erythrina gall wasp, Quadrastichus erythrinae (EGW). The gall wasp was detected on Oahu in 2005 and quickly spread to the other Hawaiian islands.  

Arrival of the EGW on Oahu was part of the insect’s rapid global range expansion.  Originally from East Africa, it was first detected in the Mascarene Islands and Singapore in 2003. At the time, it was unknown to science. Within a few years it had spread across Asia, many Pacific islands (including Hawai`i), and to the Americas, including Florida in 2006, Brazil in 2014 (Culik 2014), and Mexico in 2017 (Palacios-Torres 2017). Although apparently restricted to the Erythrina genus as host, it has lots of opportunities. This genus has 116 species distributed across tropical and subtropical regions: 72 species in the Americas, 31 in Africa, and 12 in Asia.

The severe damage to wiliwili (and to non-native Erythrina trees planted in urban areas and as windbreaks) prompted Hawaiian officials to immediately initiate efforts to find a classical biological control agent. The process moved rapidly. A candidate – a parasitic wasp species new to science, Eurytoma erythrinae – was found in East Africa in 2006. Host specificity testing was carried out. Scientists quickly learned to rear the parasitic wasp in laboratories. Release of the biocontrol agent was approved in November 2008 – only three and a half years after the EGW was detected on Oahu.

The biocontrol agent’s impact was quickly apparent. Establishment was confirmed within 1–4 months at all release locations throughout Hawai`i. Reduced pest impacts to trees were detected within two years. By 2018, only 33% of the foliage was damaged on the majority of wiliwili trees. Damage to non-native Erythrina had also declined.

Results of Biocontrol Agent’s Release

The biocontrol agent’s efficacy in reducing EGW’s impacts on trees has been evaluated for 10 years after the agent’s release. Monitoring was conducted at sites on four of the six main islands. (The monitoring program and its findings are described in Kaufman et al. in press).

I wonder how many other biocontrol agents have been monitored so closely for such a long time? Shouldn’t they all be?

Given the uniqueness and importance of such long-term assessment, it is worth looking at the data in detail.

1) Foliar Damage and Tree Health

In 2008, before release of the biocontrol agent, more than 70% of young shoots in wiliwili trees that were inspected were severely infested. The damage rating of “severe” fell from about 80% of trees in 2008 to about 40% in 2011. About 20% of trees surveyed – at sites on all islands – had no gall damage.

By three years after release of the biocontrol agent (2011), mortality rates attributed to stress from the EGW infestation for trees in natural areas fell to 21%. Mortality rates for trees in botanical gardens was somewhat higher – 34%. Kaufman et al. proposed several possible reasons: a) lingering presence of systemic insecticides that might have harmed the biocontrol agents early in the releases; b) year-round sustenance for the EGW as a result of the i) presence of alternative hosts and ii) supplemental irrigation which maintained fresh foliage on the trees.

Less intensive monitoring occurred during 2013 – 2018. It showed continuing substantial suppression of EGW damage on Erythrina foliage, although levels varied among locations. Sites with the lowest precipitation and higher temperatures throughout the year had the slowest recovery of wiliwili. Still, trees are now producing vegetative flushes and healthier canopies during non-dormant periods.

2) Flower and Seed Damage

Successful reduction of infestations in flowers and seedpods was less immediate. Still, by 2011, seed-set had increased from less than 3% of trees setting and maturing seed, to almost 30% with mature seed. The proportion of trees bearing inflorescences also increased, with more than 60% of trees blooming three years after introduction of the biocontrol agent. There was also a slow but steady increase in seed production.

However, in 2019, it remains unclear how infestation of seedpods will affect germination and therefore future plant recruitment.

More worrying, little recruitment was observed over the 10 years. Hawaiian authorities have completed tests on, and are preparing a petition for release of, a second biocontrol agent, Aprostocitus nites. It is hoped that it will further suppress EGW in flowers and seedpods.  

Still, poor recruitment is likely due to the combined impacts of multiple invasive species in native environments. A significant factor is a second insect pest – a bruchid, Specularius impressithorax – which can cause loss of more than 75% of the seed crop. I hope authorities are seeking methods to reduce this insect’s impacts.

The Hawaiian species group of the IUCN has given the wiliwili tree the Reed Book designation of “vulnerable”.

Worries for Naio

naio in bloom
photo by Forrest and Kim Starr, courtesy of creative commons

Naio (Myoporum sandwicense)is an integral component of native Hawaiian ecosystems, especially in dry forests, lowlands, and upland shrublands. However, it is also found in mesic and wet forest habitats. Naio is found on all of the main Hawaiian Islands at elevations ranging from sea level to 3000 m. The loss of this species would be not only a significant loss of native biological diversity but also a structural loss to native forest habitats.

The invasive non-native Myoporum thrips, Klambothrips myopori, was detected on the Big Island (Hawai‘i Island) in 2009 – four years after it was first detected on ornamental Myoporum species in California. At the time of the California detection, the species was unknown to science. It is now known that this species is native to Tasmania.

The thrips feeds on and causes galls on plants’ terminal growth and can eventually lead to death of the plant.

For close to a decade, the Myoporum thrips was restricted to the Big Island.  It has now been found on Oahu (Wright pers. comm.) Alarmed by the high mortality of plants in California, in September 2010, the Hawaii Department of Lands and Natural Resources Division of Forestry and Wildlife and the University of Hawai‘i initiated efforts to determine spatial distribution, infestation rates, and overall tree health of naio populations on the Big Island. Monitoring took place at nine protected natural habitats for four years. This monitoring program was supported by the USFS Forest Health Protection program. (See also the chapter on naio by Kaufman et al. 2019 in Potter et al. 2019 – full citation at the end of this blog.)

naio damaged by thrips
photo by Leyla Kaufman, University of Hawaii

The monitoring confirmed that the myoporum thrips has spread and colonized natural habitats on the leeward side of Hawai`i Island. Infestation rates increased considerably at all sites over the duration of the four-year sampling period. Trees experiencing high infestation levels also showed branch dieback.

Medium-elevation sites (between 500–999 m) had the highest infestations and dieback: over 70% of the shoots  had the worst damage.. At two sites, over 70% of the monitored trees have died.

Even though flowers and fruits were still seen at all sites, little to no plant recruitment was observed at these sites. Thus another plant species important in this endangered plant community is in decline.

Few management strategies are available for this pest. They include preventing spread to other islands and early detection followed by rapid application of pesticides.

 Implications and Conclusions

The Erythrina gall wasp and myoporum thrips are only two of the thousands of invasive species established in Hawai`i. Island ecosystems, especially Hawai`i,  are well recognized as especially vulnerable to invasive species. It has been estimated that on average 20 new arthropod species become established in Hawai`i every year.

East Africa and Tasmania are new sources for invasive species. Phytosanitary agencies need to adjust their targetting of high-risk imports to recognize this reality. Regarding the Hawaiian introduction of the thrips, there was probably made an intermediary stop in California – which is not unusual. (See also ohia rust.)

I applaud Hawaiian officials’ quick action to counter these pests. I wish their counterparts in other states did the same.

There are multiple threats to Hawaii’s dry forests, including habitat modification and fragmentation; wild fires; seed predation by rodents; predation on seeds, seedling, and saplings by introduced ungulates (e.g. feral goats, pigs and deer); competition with invasive weeds; and damage by invasive insect pests and diseases.

With so much of Hawaii’s dry forests already lost, the release of biocontrol agents targetting specific pests is only one element of a much-needed effort. Long-term protection of wiliwili and naio depends on greater efforts to reduce all threats and to stimulate natural regeneration of this ecosystem. These programs could include predator-proof fencing to keep out ungulates; baiting rodents and snails; and active collection. Breeding, and planting of threatened plant species in an effort to protect both the individual species and the habitat.

SOURCES

Culik, M.P., D. dos Santos Martins, J. Aires Ventura & V. Antonio Costa. The invasive gall wasp Quadrastichus erythrinae (Hymenoptera: Eulophidae) in South America: is classical biological control needed?

Kaufman, L.V.,  J. Yalemar, M.G. Wright. In press. Classical biological control of the erythrina gall wasp, Quadrastichus erythrinae, in Hawaii.: Conserving an endangered habitat. Biological Control. Vol. 142, March 2020

Palacios-Torres, R.E., J. Malpica-Pita, A.G. Bustamante-Ortiz, J. Valdez-Carrasco, A. Santos-Chávez, R. Vega-Muñoz and H. Vibrans-Lindemann. 2017. The Invasive Gall Wasp Quadrastichus erythrinae Kim in Mexico. Southwestern Entomologist.

Potter, K.M. B.L. Conkling. 2019. Forest Health Monitoring: National Status, Trends, and Analysis 2018. Forest Service Research & Development Southern Research Station General Technical Report SRS-239

Kaufman, L.V, E. Parsons, D. Zarders, C. King, and R. Hauff. 2019. CHAPTER 9. Monitoring Myoporum thrips, Klambothrips myopori (Thysanoptera: Phlaeothripidae), in Hawaii

Wright, Mark. 2005. Assistant Professor and Extension Specialist, University of Hawaii. Personal communication.

 

NPS Report Published in Journal – Has it Been Implemented? Can it Be?

invasive lake trout in Yellowstone National Park

The National Park Service has a legal mandate to manage lands and waters under its jurisdiction so as to “preserve unimpaired” their natural and cultural resources (NPS Organic Act 54 U.S.C. § 100101, et seq.) Invasive species undermine efforts to achieve that mission. In 2000, the NPS adopted a program to coordinate management of invasive plants. It’s not as effective as needed – see the strategic plan.  

However, only recently has NPS begun trying to prioritize and coordinate programs targetting the many animals and animal diseases which threaten Park resources. These organisms range from emerald ash borer and quagga mussels; to pythons, goats, and pigs; to diseases such as white nose syndrome of bats and avian malaria in Hawai`i.

In 2017, NPS released an internal study of the pervasive threat to Park resources posed by invasive animals and discussed steps to overcome barriers to more effective responses (Redford et al., 2017; full citation at end of this blog). The Chief of the Biological Resources Division initiated this report by asking a Science Panel to evaluate the extent of the invasive animal problem, assess management needs, review best practices, and assess potential models that could serve as a service-wide organizational framework. The report was to pay particular attention to innovative and creative approaches including, but not limited to, new genomic tools. I summarized the Panel’s  findings and conclusions in a blog when its report appeared in 2017.

Significantly, the Panel’s final report states that “a general record of failure to control invasive species across the system” was caused principally by a lack of support for invasive species programs from NPS leadership.

This report has now appeared in the form of a peer-reviewed article in the journal Biological Invasions by Dayer et al. 2019 (full citation at end of this blog). Although nine of the ten authors are the same on both reports there are substantive differences in content. For example, the journal article reiterates the principal findings and conclusions of the Panel’s final report, but in less blunt language.

What’s Been Watered Down

The toning down is seen clearly in the statements some of the panel’s six key findings.

Finding #1

            The panel’s report says:  invasive animals pose a significant threat to the cultural and natural values and the infrastructure of U.S. national parks. To date, the NPS has not effectively addressed the threat they pose.

            Dayer et al. says: the ubiquitous presence of invasive animals in parks undermines the NPS mission.

Finding #2

            The panel’s report says: managing invasive animals will require action starting at the highest levels, engaging all levels of NPS management, and will require changes in NPS culture and capacity.

            Dayer et al. says: coordinated action is required to meet the challenge.

Finding #4

            The panel’s report states: effective management of invasive animals will require stakeholder engagement, education, and behavior change.

            Dayer et al. says: public engagement, cooperation and support is [sic] critical.

Wording of the other three “key findings” was also changed, but these changes are less substantive.

Drayer et al. also avoid the word “failure” in describing the current status of NPS” efforts to manage invasive animal species. Instead, these authors conclude that the invasive species threat “is of sufficient magnitude and urgency that it would be appropriate for the NPS to formally declare invasive animals as a service-wide priority.”

Where the Documents Agree – Sort of

Both the Panel’s report and Dayer et al. state that invasive animal threats are under-prioritized and under-funded. They say that addressing this challenge must begin at the highest levels within the NPS, engage all levels of management, and will require investments from the NPS leadership.  Even within individual parks, they acknowledge that staffs struggle to communicate the importance of invasive animal control efforts to their park leadership, especially given competition with other concerns that appear to be more urgent. And they admit that parks also lack staff capacity in both numbers and expertise.

Also, both the Panel’s report and Dayer et al. urge the NPS to acknowledge formally that invasive animals represent a crisis on par with each of the three major crises that drove Service-wide change in the past: over-abundance of ungulates due to predator control; Yellowstone fire crisis (which led to new wildfire awareness in the country); and recognition of the importance of climate change.

The Panel suggested ways to update NPS’ culture and capacity: providing incentives for staff to (1) address long-term threats (not just “urgent” ones) and (2) put time and effort into coordinating with potential partners, including other park units, agencies at all levels of government, non-governmental organizations, private landowners, and economic entities. Dayer et al. mention these barriers but does not directly mention changing incentives as one way to overcome them.

Both the Panel’s report and Dayer et al. suggest integrating invasive animal threats and management into long-range planning goals for natural and cultural landscapes and day-to-day operations of parks and relevant technical programs (e.g., Biological Resources Division, Water Resources Division, and Inventory and Monitoring Division).

What is Missing from the Journal Publication

The Panel’s final report noted the need for increased funding. It said that such funding would need to be both consistent and sufficiently flexible to allow parks to respond to time-sensitive management issues. It proposes several approaches. These include incorporating some invasive species control programs (e.g., for weeds and wood borers) into infrastructure maintenance budgets; adopting invasive species as fundraising challenges for non-governmental partners (e.g., “Friends of Park” and the National Park Foundation); and adopting invasive species as a priority threat. Dayer et al. do not discuss funding issues.

The final internal report envisioned the NPS becoming a leader on the invasive species issue by 1) testing emerging best management practices, and 2) educating visitors on the serious threat that invasive species pose to parks’ biodiversity. As part of this process, the authors suggest that the NPS also take the lead in countering invasive species denialism.  Dayer et al. do not mention the issue of invasive species deniers.

Common Ground: Status of Invasive Animals in the Parks

The Panel’s report and Dayer et al. describe the current situation similarly:

  • More than half of the National parks that responded to the internal survey (245 of the 326 parks) reported problems associated with one or more invasive animal species.
  • The total number of species recorded was 331. This is considered to be an underestimate since  staffs often lack the ability to thoroughly survey their parks – especially for invertebrates.
  • Invasive species threats to Parks’ resources have been recognized for nearly 100 years. The original report notes that 155 parks reported the presence of one or more exotic vertebrate species in 1977. At that time, exotic animals were the fourth most commonly reported source of threats. In 1991, parks identified 200 unfunded projects to address exotic species, costing almost $30 million.
  • Only a small percentage of non-native animal invasions are under active management. Dayer et al. stated that 23% have management plans at the park unit level, and only 11% are reported as being ‘‘under control”.
  • Individual parks have effective programs targetting specific bioinvaders (examples are described in Redford et al;  a brief summary of these efforts is provided in my previous blog.    

Common Ground on Some Solutions

The report and Dayer et al. promote the same steps to improve invasive animal management across the Service. Both note that the NPS is adopting formal decision support tactics to update and strengthen natural resource management across the board. More specific steps include

  • establishing a coordination mechanism that enables ongoing and timely information sharing.
  • mainstreaming invasive species issue across the NPS branches or creating a cross-cutting IAS initiative among the Biological Resources Division, Water Resources Division, Inventory and Monitoring Division, Climate Change Response Program, and the regional offices.

While both documents call on the NPS to develop and test emerging technologies, the Panel’s final  report is more detailed, providing, in Table 5, a list of several areas of special interest, including remotely triggered traps, species-specific toxicants, toxicant delivery systems, drones, environmental DNA, and sterile-male releases. Dayer et al. mention eDNA and metabarcoding for ED/RR, biocontrol, and gene drives to control invasive pathogens. (Neither document discusses possible concerns regarding use of CRISPR and other gene-altering technologies, other than to say there would be public concerns that would need to be addressed.)

Both documents note the necessity of working with resource managers beyond park boundaries to detect and manage species before they arrive in parks. They note that developing and operationalizing such partnerships requires time and resources. Furthermore, invasive species prevention, eradication, and containment programs can be effective only with public support. They suggest strengthening NPS’ highly regarded public outreach and interpretation program to build such support, including through the use of citizen scientists.

The Panel’s final report said that the NPS should recognize that the condition of the ecosystem is the objective of efforts.  Its authors recognized that achieving this goal might require reconsidering how ecosystem management is organized within NPS so interacting stressors (e.g.,  fire) and management levers (e.g., pest eradication/suppression, prescribed fire) would be addressed. For this, the NPS would need to create a focused capacity to address the pressing issue of invasive animals in such a way that fosters integrated resource management within parks, focusing on fundamental values of ecosystem states, and not eradication targets. Dayer et al. called for the same changes without specifically labelling “condition of the ecosystem” as the goal.

Publication of Dayer et al. prompted me to find out what progress the NPS has made in responding to the “key findings” in the Panel’s final report (neither publication calls them “recommendations”). 

The National Park Service has acted on the recommendation to appoint an “invasive animal coordinator” within the Biological Resources Division. That person is Jennifer Sieracki. However, I wonder whether a person located in BRD is of sufficient stature to influence agency policy across all divisions. It is not clear whether there is active coordination with the national-level invasive plant coordinator.

Dr. Sieriaki responded to my query by noting the following new efforts 1) to improve outreach to partners and the public, and 2) to expand formal and informal partnerships with local, state, federal and tribal entities and local communities near parks.

  • NPS should soon finalize two formal partnerships with other agencies and organizations for outreach and management of invasive animal species.
  • NPS is working with researchers at the US Geological Survey to expand an existing modeling tool for identifying potential suitable habitat for invasive plant species to include invasive insects. This will help staff focus on the most likely locations for introductions and thus assist with early detection and control.
  • NPS has created a Community of Practice so NPS employees can seek each other’s advice on addressing invasive animal issues. A workshop of regional invasive species coordinators is planned for the coming months to guide direction of the service-wide program and identify other top priorities. (Seriacki pers. comm.)

I also wonder whether the NPS can achieve the top-level coordination and outreach to the public called for by both reports while complying with the terms of Public Law 116-9 – the John N. Dingle Jr. Conservation, Management, and Recreation Act, which was enacted a year ago. Title VII, Section 10(i)  of this law limits spending to carry out invasive species program management and oversight to 10% of appropriated funds. Less than 15% may be spent on investigations (research), development activities, and outreach and public awareness efforts (Section 10(h)). The law does allow spending for investigations regarding methods for early detection and rapid response, prevention, control, or management; as well as inspections and interception or confiscation of invasive species to prevent in-park introductions.

For more information, see my previous criticism of NPS failure to address invasive species issues here.

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.

See also my earlier discussion of the new legislation here.

SOURCES

Dayer, A.A., K.H. Redford, K.J. Campbell, C.R. Dickman, R.S. Epanchin-Niell, E.D. Grosholz, D.E. Hallac, E.F. Leslie, L.A. Richardson, M.W. Schwartz. 2019. The unaddressed threat of invasive animals in U.S. National Parks.  Biol Invasions

https://doi.org/10.1007/s10530-019-02128-0

Redford, K.H., K. Campbell, A. Dayer, C. Dickman, R. Epanchin-Niell, T. Grosholz, D. Hallac, L. Richardson, M. Schwartz. 2017. Invasive animals in U. S. National Parks: By a science panel. Natural Resource Report NPS/NRSS/BRD/NRR—2017/1564. NPS, Fort Collins, Colorado. Commissioned by the NPS Chief of Biological Resources Division. https://irma.nps.gov/DataStore/DownloadFile/594922

Jennifer Sieracki, Invasive Animal Coordinator, Biological Resources Division, National Park Service

30 years of Analyzing Forest Pest Issues

dead whitebark pine in Crater Lake National Park
photo by F.T. Campbell

I began studying and writing about the threat to North America’s forests from non-native insects and pathogens in the early 1990s – nearly 30 years ago. I reported my analyses of the evolving threat in the three “Fading Forests” reports – coauthored by Scott Schlarbaum – in 1994, 2003, and 2014. These reports are available here.

So what has changed over those 30 years? What remains the same? Why have both the changes and the stasis occurred? What can we do to fix the gaps, close unaddressed pathways, strengthen flabby policies? I will address these issues in this and following blogs.

experimental American chestnut planted in Fairfax County, VA
photo by F.T. Campbell

What has changed since the early 1990s:

  • Adoption and implementation of significant new international and national regulations and programs aimed at preventing introductions of non-native invasive species.
  • Despite the welter of new regulations, an alarming increase in numbers of highly damaging forest pests established in the country.  (By my count, about 50 new species have established on the continent, six on Pacific islands; see details below.)
  • Alarming spread of established pests to new geographic regions and new hosts (e.g., emerald ash borer in 35 states and 5 provinces; laurel wilt disease across the range of redbay and swamp bay; rapid ‘ōhi‘a death on three of the main Hawaiian islands).
  • Introductions via unexpected pathways and vectors far removed from phytosanitary agencies’ usual targets, e.g., ship superstructures, imported steel and stone …

What has remained the same since the early 1990s:

  • Inadequate resources provided to response and recovery efforts.
  • Available funding focused on only a few of the more than 90 species causing damage.
  • Adoption of insufficiently protective regulations that have failed to prevent introduction and spread of tree-killing pests.
  • Lengthy delays in implementing programs that tighten controls – another factor in continuing introductions and spread.
  • Continued importance of expected pathways – nursery stock and raw wood, especially crates, pallets, and other forms of wood packaging.
  • Federal and state agencies still choose not to take action on pests e.g., goldspotted oak borer, polyphagous and Kuroshio shothole borers, beech leaf disease.
  • Inadequate coordination despite several efforts to set priorities.
  • Spurts of attention by media and political decision-makers, contrasted by lengthy periods of inattention.
  • Failure of most stakeholders to support efforts to prevent and respond to introductions of tree-killing pests. 

Details: The Situations Then and Now

(Many of the individual species mentioned here are described more fully here.  Full citations of sources are at the end of blog.)

American elm on the National Mall, Washington, D.C.

photo by USDA Agricultural Research Service

In 1993:

  • The number of non-native forest pest species established in the U.S. was estimated at between 300 (Millers et al. 1993) and 380 (Mattson et al., 1994; Liebhold et al., 1995) .
  • The area suffering the greatest numbers and impacts was the Northeast.
  • Several highly damaging pests that had been established for decades, including chestnut blight, white pine blister rust, Port-Orford-cedar root disease, Dutch elm disease, hemlock woolly adelgid, butternut canker, and dogwood anthracnose were receiving some attention but continued to spread.
  • USDA Forest Service funding for management of exotic pest infestations was crisis-oriented, with “… priorities … set under political pressures for immediate answers, with too much regard for short-term problems and too little consideration for broader management objectives.” (NAS 1975)
  • Since few high-profile pests had been introduced in recent years, APHIS was not actively engaged. In FY92, APHIS spent $20 million on efforts to eradicate the Asian gypsy moth. The narrow focus is illustrated by the fact that in FY93, more than two-thirds of all USDA tree pest control funds were devoted to efforts to suppress or eradicate the European gypsy moth (See FFI).
  • Concern about possible new introductions had grown; it focused on proposals to import unprocessed wood from Siberia, New Zealand, and Chile. The USDA Forest Service, academic scientists, and therefore APHIS emphasized the risks of known Asian pests, e.g., Asian gypsy moth, to western coniferous forests (See FFI). While individual scientists had expressed concern about wood packaging material, there was little public discussion of this threat.
  • We would learn later that several of the most damaging pests were already present in the country but not yet recognized – Asian longhorned beetle, sudden oak death pathogen, probably emerald ash borer.

beech leaf disease

photo by John Pogacnik

In 2019:

  • Numbers of non-native insects and pathogens attacking trees in North America approach 500 species.  (In Fading Forests III, I calculated that by the first decade of the 21st Century, the number had risen to at least 475. Several more have been detected since 2014. More than 181 exotic insects that feed on woody plants had established in Canada. (Source: USDA APHIS. 2000. Wood packaging risk assessment.)
  • Of these, 91 are considered “serious” threats (Guo et al. 2019). This estimate excludes pests native to portions of North America that are causing severe damage in naïve hosts – e.g., goldspotted oak borer; pests of palms; and pests attacking trees on U.S. Pacific and Caribbean islands.
  • Introductions had continued.
    • Between 1980 and 2016, at least 30 non-native species of wood- or bark-boring insects (Scolytinae / Scolytidae) were newly detected in the U.S. (Haack and Rabaglia 2013; Rabaglia et al.  2019). A few of these are highly damaging, e.g. redbay ambrosia beetle, polyphagous and Kuroshio shothole borers.
    • In addition to these 30 new pests, other highly damaging tree-killing pests probably introduced since the 1980s include (on the continent):
      • Eight Cerambycids such as Asian longhorned beetle (Wu et al. 2017)
      • 7 Agrilus, including emerald ash borer and soapberry borer; plus goldspotted oak borer transported from Arizona to California (Digirolomo et al. 2019; R. Haack, pers. comm.)
      • Sirex woodwasp
      • Pests of palm trees, e.g., red palm mite, red palm weevil, South American palm weevil
      • Spotted lanternfly
      • Beech leaf disease
    • Also not included in the above estimate and lists are tree-killing pests on America’s Pacific Islands :
      • ‘ōhi‘a rust
      • Cycad scale
      • Cycad blue betterfly
      • Erythrina gall wasp
      • two Ceratocystis pathogens that cause rapid ‘ōhi‘a death
      • Coconut rhinoceros beetle
    • Authorities also carried out approximately 25 eradication programs targetting introductions of the Asian gypsy moth (USDA Pest Alert Asian Gypsy Moth plus additional outbreaks since 2014).
  • Impacts of exacerbated tree mortality rates linked to these introduced pests are seen across wide swaths of the country, and affect widespread species, genera, and families. 
dead redbay in Claxton, Georgia
photo by Scott Cameron

I will discuss the risk of continuing new introductions in a separate blog.

Trying to Develop the Big Picture and Set Priorities

In recent years, USDA Forest Service scientists have made several attempts to provide nation-wide assessments of the impact of these pests and criteria for establishing priorities.

The National Insect and Disease Forest Risk Assessment predicted the loss of basal area to various pests over the 15-year time period 2012 – 2027. The assessment predicted the following losses for specific species: 90% for redbay; 60% for whitebark pine; more than 40% for limber pine; 24% for tanoak; 11% for coast live oak; 6% for eastern and Carolina hemlock; 27% for eight species of ash; 20% for American elm; 19% for red oak; 18% for American beech (Krist et al. 2014).

A separate group of scientists found that, nation-wide, non-native forest pests are causing an approximate 5% increase in total mortality by tree volume (Randy Morin at NEFPC). For details on Dr. Morin’s findings, see my blog here.

A third approach to developing a nation-wide picture, Project CAPTURE, (and my blog here) utilized FIA data to develop priorities for conservation action. Fifteen species were placed in the highest priority category, including Florida torreya (Torreya taxifolia), American chestnut and Allegheny and Ozark chinquapins, redbay, five species of ash, two species of hemlock, Port-Orford cedar, tanoak, and butternut (Potter et al. 2019(b).

According to Project CAPTURE, the non-native pests affecting the largest number of hosts are the European gypsy moth, which attacks 65 hosts; and oak wilt (Bretziella fagacearum), which infects 61 hosts. The Asian longhorned beetle attacks 43 hosts (Potter et al. 2019(b).

I note that several other non-native pests also have high numbers of host species. In the Project CAPTURE study, these pests are ranked lower because the project limited its evaluation to the five agents with the greatest effect on any particular host. Thus, of the 18 native tree species that host one or both of the invasive shothole borers and associated Fusarium disease complex (PSHB website), the project included only six. Of the 22 tree species listed by APHIS as hosts of Phytophtora ramorum, the project included 12 (K. Potter, pers. comm. April 17, 2019).

SOD-killed tanoak on the Big Sur peninsula, California
photo by Matteo Garbelotto, University of California Berkeley

More extensive discussions of non-native pests’ impacts are provided in Lovett et al. 2006, Lovett et al. 2016, and Potter et al. 2019. A book-length discussion of invasive species impacts – ranging from feral hogs to invasive plants, is expected in December; look for Poland et al. (in press).

SOURCES

Aukema, J.E., D.G. McCullough, B. Von Holle, A.M. Liebhold, K. Britton, & S.J. Frankel. 2010. Historical Accumulation of Nonindigenous Forest Pests in the Continental United States. Bioscience. December 2010 / Vol. 60 No. 11

Digirolomo, M.F., E. Jendek, V.V. Grebennikov, O. Nakladal. 2019. First North American record of an unnamed West Palaearctic Agrilus (Coleoptera: Buprestidae) infesting European beech (Fagus sylvatica) in New York City, USA. European Journal of Entomology. Eur. J. Entomol. 116: 244-252, 2019

Guo, Q., S. Fei, K.M. Potter, A.M. Liebhold, and J. Wenf. 2019. Tree diversity regulates forest pest invasion. Proceedings of the National Academy of Sciences of the United States of America. www.pnas.org/cgi/doi/10.1073/pnas.1821039116

Haack, R.A. and R.J. Rabaglia. 2013. Exotic Bark and Ambrosia Beetles in the USA: Potential and Current Invaders. CAB International 2013. Potential Invasive Pests of Agricultural Crops (ed. J. Peña) 

Krist, F.J. Jr., J.R. Ellenwood, M.E. Woods, A. J. McMahan, J.P. Cowardin, D.E. Ryerson, F.J. Sapio, M.O. Zweifler, S.A. Romero 2014. National Insect and Disease Forest Risk Assessment. United States Department of Agriculture Forest Service Forest Health Technology Enterprise Team FHTET-14-01

Leung, B., M.R. Springborn, J.A. Turner, E.G. Brockerhoff. 2014. Pathway-level risk analysis: the net present value of an invasive species policy in the US. The Ecological Society of America. Frontiers of Ecology.org

Liebhold, A. M., W. L. MacDonald, D. Bergdahl, and V. C. Mastro.  1995.  Invasion by exotic forest pests:  a threat to forest ecosystems.  Forest Sci., Monograph 30. 49 pp.

Lovett, G.M., C.D. Canham, M.A. Arthur, K.C. Weathers, and R.D. Fitzhugh. Forest Ecosystem Responses to Exotic Pests and Pathogens in Eastern North America. BioScience Vol. 56 No. 5 (May 2006)

Lovett, G.M., M. Weiss, A.M. Liebhold, T.P. Holmes,  B. Leung, K.F. Lambert, D.A. Orwig, F.T. Campbell, J. Rosenthal, D.G. McCullough, R. Wildova, M.P. Ayres, C.D. Canham, D.R. Foster, SL. Ladeau, and T. Weldy. 2016. NIS forest insects and pathogens in the US: Impacts and policy options. Ecological Applications, 26(5), 2016, pp. 1437–1455

Mattson, W. J., P. Niemela, I. Millers, and Y. Ingauazo.  1994. Immigrant phytophagous insects on woody plants in the United States and Canada: an annotated list.  USDA For. Ser. Gen. Tech. Rep. NC-169, 27 pp.

Millers, I. United States Department of Agriculture, Forest Service Entomologist, Forest Health Protection Northeastern Area State and Private Forestry. Durham, NH. Personal communication to F.T. Campbell, 1993.

Morin, R. presentation at Northeastern Forest Pest Council 81st Annual Meeting, March 12 – 14, 2019,  West Chester, Pennsylvania

National Academy of Sciences. 1975. Forest Pest Control. Washington, D.C.

Poland, T.M., Patel-Weynand, T., Finch, D., Miniat, C. F., and Lopez, V. (Eds) (2019), Invasive Species in Forests and Grasslands of the United States: A Comprehensive Science Synthesis for the United States Forest Sector.  Springer Verlag. (in press).

Polyphagous shothole borer website https://ucanr.edu/sites/pshb/overview/About_PSHB/

Potter, K.M., M.E. Escanferla, R.M. Jetton, and G. Man. 2019. Important Insect and Disease Threats to US Tree Species and Geographic Patterns of Their Potential Impacts. Forests 2019, 10, 304.

Potter, K.M., Escanferla, M.E., Jetton, R.M., Man, G., Crane, B.S. 2019. Prioritizing the conservation needs of US tree spp: Evaluating vulnerability to forest insect and disease threats, Global Ecology and Conservation (2019), doi: https://doi.org/10.1016/

Rabaglia, R.J., A.I. Cognato, E. R. Hoebeke, C.W. Johnson, J.R. LaBonte, M.E. Carter, and J.J. Vlach. 2019. Early Detection and Rapid Response. A Ten-Year Summary of the USDA Forest Service Program of Surveillance for Non-Native Bark and Ambrosia Beetles. American Entomologist Volume 65, Number 1 

USDA, Animal and Plant Health Inspection Service. 2014. Asian gypsy moth pest alert https://www.aphis.usda.gov/publications/plant_health/content/printable_version/fs_phasiangm.pdf and pers. comm.

U.S. Department of Agriculture, Animal and Plant Health Inspection Service.  2009.  Risk analysis for the movement of wood packaging material (WPM) from Canada into the US.

Wu,Y., N.F. Trepanowski, J.J. Molongoski, P.F. Reagel, S.W. Lingafelter, H. Nadel1, S.W. Myers & A.M. Ray. 2017. Identification of wood-boring beetles (Cerambycidae and Buprestidae) intercepted in trade-associated solid wood packaging material using DNA barcoding and morphology  Scientific Reports 7:40316

Collapse of Biodiversity – Causes and What We Can Do

frogs in California killed by chytrid fungus
photo by Rick Kyper, US Fish and Wildlife Service

I expect you have heard about the report issued on May 6 by the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. The executive summary is available here

Based on thousands of scientific studies, the report concludes that the biosphere, upon which humanity as a whole depends, is being altered to an unparalleled degree across all spatial scales. The trends of decline are accelerating. As many as 1 million species (75% of which are insects) are threatened with extinction, many within decades.

Humans dominate Earth: natural ecosystems have declined by 47% on average. Especially hard-hit are inland waters and freshwater ecosystems: only 13% of the wetland present in 1700 remained by 2000. Losses have continued rapidly since then.

The report lists the most important direct drivers of biodiversity decline – in descending order – as habitat loss due to changes in land and sea use; direct exploitation of organisms; climate change; pollution; and invasive species. The relative importance of each driver varies across regions.

If you have been paying attention, these conclusions are not “news”.

However, the report serves two valuable purposes. First, it provides a global overview, a compilation of all the data and trends. Second, the report ties the direct drivers to underlying causes which are in turn underpinned by societal values and behaviors. Specifically mentioned are production and consumption patterns, human population dynamics and trends, trade, technological innovations, and governance (decision making at all levels, from local to global).

The report goes to great lengths to demonstrate that biological diversity and associated ecosystem services are vital for human existence and good quality of life – especially for supporting humanity’s ability to choose alternative approaches in the face of an uncertain future. The report concludes that while more food, energy and materials than ever before are now being supplied to people, future supplies are undermined by the impact of this production and consumption on Nature’s ability to provide.   

The report also emphasizes that both the benefits and burdens associated with the use of biodiversity and ecosystem services are distributed and experienced inequitably among social groups, countries and regions. Furthermore, benefits provided to some people often come at the expense of other people, particularly the most vulnerable.  However, there are also synergies – e.g., sustainable agricultural practices enhance soil quality, thereby improving productivity and other ecosystem functions and services such as carbon sequestration and water quality regulation.

The report contains vast amounts of data on the recent explosion of human numbers and – especially – consumption – of agricultural production, fish harvests, forest products, bioenergy production … and on the associated declines in “regulating” and “non-material contributions” ecosystem services. In consequence, the report concludes, these recent gains in material contributions are often not sustainable.

While invasive species rank fifth as a causal agent of biodiversity decline globally, alien species have increased by 40% since 1980, associated with increased trade and human population dynamics and trends. The authors report that nearly 20% of Earth’s surface is at risk of bioinvasion. The rate of invasive species introduction seems higher than ever and shows no signs of slowing.

The report notes that the extinction threat is especially severe in areas of high endemism. Invasive species play a more important role as an extinction agent in many such areas, especially islands. However, some bioinvaders also have devastating effects on mainlands; the report cites the threat of the pathogen Batrachochytrium dendrobatidis to nearly 400 amphibian species worldwide.

The report also mentions that the combination of species extinctions and transport of species to new ecosystems is resulting in biological communities – both managed and unmanaged — becoming more similar to each other — biotic homogenization.

The report notes that human-induced changes are creating conditions for fast biological evolution of species in all taxonomic groups. The authors recommend adopting conservation strategies designed to influence evolutionary trajectories so as to protect vulnerable species and reduce the impact of unwanted species (e.g., weeds, pests or pathogens).

The report says conservation efforts have yielded positive outcomes – but they have not been sufficient to stem the direct and indirect drivers of environmental deterioration. Since 1970, nations have adopted six treaties aimed at protection of nature and the environmental, but few of the strategic objectives and goals adopted by the treaties’ parties are being realized. One objective that is on track to partial achievement is the Aichi Biological Diversity Target that calls for identification and prioritization of invasive species. 

That might well be true – but I would not consider global efforts to manage invasive species to be a success story in any way. I have blogged often about studies showing that introductions continue unabated … and management of established bioinvaders only rarely results in measurable improvements.   [For example, see here and here.]

The report gives considerable attention to problems caused by some people’s simultaneous lack of access to material goods and bearing heavier burden from pollution and other negative results of biodiversity collapse. Extraction of living biomass (e.g. crops, fisheries) to meet the global demand is highest in developing countries whereas material consumption per capita is highest in developed countries. The report says that conservation of biodiversity must be closely linked to sustainable approaches to more equal economic development. The authors say both conservation and economic goals can be achieved – but this will require transformative changes across economic, social, political and technological factors.

One key transformation is changing people’s conception of a good life to downplay consumption and waste. Other attitudinal changes include emphasizing social norms promoting sustainability and personal responsibility for the environmental impacts of one’s consumption. Economic measures and goals need to address inequalities and integrate impacts currently considered to be “economic externalities”. The report also calls for inclusive forms of decision-making and promoting education about the importance of biodiversity and ecosystem services.

Economic instruments that promote damaging, unsustainable exploitation of biological resources (or their damage by pollution) include subsidies, financial transfers, subsidized credit, tax abatements, and commodity and industrial goods prices that hide environmental and social costs. These need to be changed.

Finally, limiting global warming to well below 2oC would have multiple co-benefits for protecting biodiversity and ecosystem services. Care must be exercised to ensure that large-scale land-based climate mitigation measures, e.g., allocating conservation lands to bioenergy crops, planting of monocultures, hydroelectric dams) do not themselves cause serious damage to biodiversity or other ecosystem services.

The threats to biodiversity and ecosystem services are most urgent in South America, Africa and parts of Asia. North America and Europe are expected to have low conversion to crops and continued reforestation.

Table SPM.1 lays out a long set of approaches to achieve sustainability and possible actions and pathways for achieving them. The list is not exhaustive, but rather illustrative, using examples from the report.

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.

Promising Biocontrol to Protect Some Cacti

Photo of infested cactus at Cabo Rojo National Wildlife Refuge, Puerto Rico. Taken August 20, 2018 by Yorelyz Rodríguez-Reyes

Three and a half years ago, I blogged about the threat to columnar cacti in Puerto Rico from the Harrisia cactus mealybug. The mealybug clearly threatens the endemic cacti of the Caribbean islands, and possibly some of the hundreds of other columnar cacti growing across two million square miles of desert ecosystems that straddle the U.S.-Mexico border region.

I am pleased to report that scientists continue efforts to find biocontrol agents to reduce this insect’s damage on Caribbean islands. Much of this work is being done by the Center for Excellence in Quarantine and Invasive Species at University of Puerto Rico. The team consists of Michael West Ortiz, Yorelys Rodrígues Reyes, Ferdinand Correa and Jose Carlos Verle Rodrigues.

As of February 2019, the Center is conducting host specificity tests on a primary parasitoid of the Harrisia Cactus mealybug — Anagyrus cachamai. This wasp was found as a result of almost a decade of searching in South America and other locations. It is native to Argentina and Paraguay (Triapitsyn et al. 2018; sources listed at the end of the blog).The Center also continues surveys and studies of other primary and secondary parasitoids of the mealybug.

The work to develop a biocontrol agent for the mealybug continues despite continuing uncertainty about the true species of the mealybug. At the time of its discovery on Puerto Rico, the mealybug was believed to belong to a species used as a biocontrol agent for invasive cacti in Australia and South Africa, designated as Hypogeococcus pungens. However, H. pungens is now thought to be a species complex, and the species in Puerto Rico differs from the earlier designation (Triapitsyn et al. 2018). 

Apparently the mealybug was introduced in Puerto Rico around 2000   — probably on the ornamental common purslane (Portulaca olerácea), an annual succulent. (Note: the introduction was on a host different from the vulnerable cacti.) Within five years of the first detection in San Juan, the mealybug was sighted on cacti on the other side of the island in the Guánica State Forest and Biosphere Reserve. By 2010, the mealybug was widely distributed in most dry districts. Surveys found it in all 11 municipalities surveyed in southern Puerto Rico. At some locations, infestation levels were extremely high – e.g., 86% of stems surveyed were infested at Guánica. Infestation rates were lower in other municipalities. As of 2010, infestations were estimated to be present on about 1,400 km2 on the southern coast; the rate of new infestations suggests that the mealybug was spreading rapidly (Segarra-Carmona et al. 2010).  I have been unable to obtain more recent estimates.

The mealybug impacts seven of 14 native cactus species occurring in dry forests of the island, including three endemic and two endangered species in the subfamily Cactoideae. The two endangered species are Harrisia portoricensis and Leptocereus grantianus (USDA ARS). The tissue damage caused by the mealybug interferes with sexual reproduction and can cause direct mortality of the plant (Triapitsyn et al. 2018).  These cacti provide food or shelter for endemic bats, birds, moths and other pollinators (Segarra & Ramirez; USDA ARS). The mealybug is also now killing native cacti on the U.S. Virgin Islands (H. Diaz-Soltero pers. comm. August 2015).

 USDA Funds Conservation Efforts Despite Apparent Absence of a Constituency Calling for Such Action

Efforts to identify and test possible biocontrol agents targetting the Harrisia cactus mealybug received significant funds from the Plant Pest and Disease Management and Disaster Prevention Program. This is a competitive grant program managed by APHIS. It is permanently funded and thus not subject to the vagaries of annual appropriations. Until last year, this program operated under Section 10007 of the 2014 Farm Bill. With passage of a new Farm Bill, it is now designated as Section 7721 of the Plant Protection Act.

Since Fiscal Year 2018, APHIS has had authority to spend more than $60 million per year on this program.  In Fiscal Year 2017, , the program provided $120,000 to an unspecified federal agency, $70,000 to an academic institution in Puerto Rico (presumably the Center), $15,000 to another academic institution in California, and $3,000 divided among two APHIS facilities – for a total of $208,000. The next round of funds came in FY19, when the program provided $277,267 to an unspecified federal agency to continue work on biocontrol. In addition, the program provided $78,507 to an unspecified federal agency to “safeguard[e] genetic diversity of native and listed cacti threatened by Harrisia cactus mealybug in Puerto Rico”.

No Apparent Action on Threats to Opuntia Cacti

In my earlier blog, I also described the threat to flat-padded Opuntia (prickly pear) cacti from the cactus moth Cactoblastis cactorum. Various federal, state, and academic entities received $463,000 from the permanent fund in Fiscal Year 2016 and another $100,000 in FY2017. No cactus moth programs have received funds in more recent years.

SOURCES

Segarra-Carmona, A.E., A. Ramirez-Lluch. No date. Hypogeococcus pungens (Hemiptera: Pseudococcidae): A new threat to biodiversity in fragile dry tropical forests.

Segarra-Carmona, A.E., A. Ramírez-Lluch, I. Cabrera-Asencio and A.N. Jiménez-López. 2010.  FIRST REPORT OF A NEW INVASIVE MEALYBUG, THE HARRISIA CACTUS MEALYBUG HYPOGEOCOCCUS PUNGENS (HEMIPTERA: PSEUDOCOCCIDAE). J. Agrie. Univ. RR. 94(1-2):183-187 (2010)

Triapitsyn, Aguirre, Logarzo, Hight, Ciomperlik, Rugman-Jones, Rodriguez. 2018. Complex of primary and secondary parasitoids (Hymenoptera: Encyrtidae and Signiphoridae) of Hypogeococcus spp. mealybugs (Hemiptera: Pseudococcidae) in the New World. Florida Entomologist Volume 101, No. 3 411

USDA Agriculture Research Service, Research Project: Biological Control of the Harrisia Cactus Mealybug, Hypogeococcus pungens (Hemiptera:pseudococcidae) in Puerto Rico Project Number: 0211-22000-006-10 Project Type: Reimbursable

West Ortiz, M. pers. comm. February 2019

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.

Invasive Species Policy: Will New Law Empower Agencies? Or Hinder Strategic Planning, Research, and Engaging the Public through Outreach?

Much-Heralded Major Conservation Legislation — S. 47 – Mandates “On-the-Ground” Actions 

Senate bill S. 47 enjoyed strong support from the conservation community because it expanded protection for several National parks and wilderness areas, mandated easier access to public land for hunters and anglers, and provided permanent status for the most important program that funds purchase of lands and waters for recreation and other purposes – the Land and Water Conservation Fund. It passed the Senate on February 12, 2019 by a vote of 92 for, 8 against. The bill passed the House of Representatives on February 26, 2019 by a vote of 363 for, 62 against. Everyone expects President Trump to sign it into law.

The new language had previously been a stand-alone bill introduced in two previous sessions of Congress. The first version, S. 2240, was introduced in 2016; I blogged about a hearing on that legislation in May 2016, describing my reservations. The bill was not enacted in that Congress. It was reintroduced in 2017, when it was called the “WILD Act” (S. 826).

Title VII of the new legislation now expected to become law governs programs implemented by the Departments of Interior, Agriculture (specifically the Forest Service) and the U.S. Army Corps of Engineers. It also applies to the head of “any federal agency” having duties related to planning or treatment of invasive species “for the purpose of protecting water and wildlife on land and in water.”

Title VII takes the form of an amendment to the Fish and Wildlife Coordination Act (16 U.S.C. 661 et seq.)

As in the original 2016 bill (S. 2240), the new law – at Title VII, §10(c)(2)(C) – agencies are required to adopt strategic plans for their invasive species programs. The priorities in the federal agencies’ invasive species plans will be set by state governors – not the federal agency charged with managing that land unit and its resources.

  • Under§10(a)(4)(C), tribal, regional, State, or local authorities are authorized to weigh in on the determination of which terrestrial or aquatic species fit the definitions of ‘invasive’ and ‘alien’ species.
  • Under §10(c)(3).the Secretaries are required, in developing their strategic plans, to take into consideration the ecological as well as the economic costs of acting or not acting, I welcome this provision.

Like the original 2016 bill (S. 2240), the new law – at Title VII, §10(g) – (i)  – requires land-managing agencies to allocate their invasive species funds according to the following formula: 75% for on-the-ground activity; 15% for combined research and outreach; 10% or less for administrative costs.

  • Fortunately, “on-the-ground” activities have been expanded to include
    • detection and monitoring.
    • “the use of appropriate methods to remove invasive species from a vehicle or vessel capable of conveyance.” 
    • “investigations regarding methods for early detection and rapid response, prevention, control, or management of the invasive species.”
    • It is unclear whether “on-the-ground” activities include the salaries of staff who manage such programs from desks (as distinct from people who work in the field).
  • Unfortunately, the definition of “prevention” is unnecessarily limited by §10(a)(6) (B). This clause authorizes agencies ‘‘to impede the spread of the invasive species … by inspecting, intercepting, or confiscating invasive species threats prior to the establishment of the invasive species onto land or water of an eligible State.” This clause reflects too narrow an understanding of prevention actions. They are not limited to (inefficient) inspection and seizure programs at “borders”. It is much more efficient to apply measures intended to prevent the presence of a pest in the transported good in the place of production. One example is APHIS’ requirements governing nursery stock intended to be shipped interstate so as to prevent the spread of the sudden oak death pathogen.

Following the revised 2017 version of the bill (text here; see my blog here) the law requires the agencies to make “substantive annual net reduction of invasive species populations or infested acreage …”  (The original bill mandated an annual reduction of 5%.) It is unclear whether this mandate applies to all invasive species on the affected acreage, or only those designated by a flawed process (see below) and included in the agency’s strategic plan [Title VII, §10(c)(1)].

Under Subsection (d), the plan is to prioritize the use of methods that are effective (as determined by the Secretary, based on sound scientific data); that minimize environmental impacts; and control and manage invasive species in the least costly manner. I worry that this requirement, combined with the mandate to achieve “annual net reductions” in invasive species numbers, will promote the use of chemical pesticides.

Under Section (f), agencies are to apply all available tools and flexibilities to expedite invasive species control projects and activities. Those projects are to be located in an area that is at high risk for invasive species introduction, establishment, or spread; and determined by the Secretary to require immediate action to address that risk. These actions are to be carried out in accordance with applicable agency procedures, including any applicable land or resource management plan. This language apparently replaces earlier efforts to exclude invasive species control projects from analysis under NEPA. How this mandate interacts with state governors’ setting priorities under §10(c)(2)(C) is unclear.

Remember that under the funding allocations specified in Title VII, §10(g) – (i), “… not more than 10% may be used for administrative costs incurred to carry out those programs, including costs relating to oversight and management of the programs, recordkeeping, and implementation of the strategic plan …”. At the same time, §§10(e), (j), and (l) require economic analyses and reports detailing compliance with requirements and results of projects. In other words, the new law restricts expenditure of funds for “administrative costs” but imposes significant additional administrative duties.

Fortunately, Title VII §10(k)(1) states that “Nothing in this section precludes the Secretary concerned from pursuing or supporting, pursuant to any other provision of law, any activity regarding [invasive species]  control, prevention, or management …, including investigations to improve the control, prevention, or management of the invasive species.

In all iterations, the bills called for the projects to be carried out through collaboration with wide range of partners, including private individuals and entities – apparently including non-governmental organizations such as state or local invasive plant coalitions.

Earlier in Congressional consideration of the new law’s provisions, the National Environmental Coalition on Invasive Species (NECIS) responded by adopting its own description of an effective, comprehensive invasive species program.  Under the title “Tackling the Challenge of Invasive Species,” the coalition makes the following major points:

  • Focus prevention efforts on pathways of introduction. Until they are closed, managing established infestations will be a never-ending burden.
  • Broader and more aggressive efforts to control existing invaders is a solid investment, but should not be at the expense of other aspects of a comprehensive national response.
  • Close loopholes in the “Injurious Wildlife” sections of the Lacey Act to provide agencies with more agile processes for regulating the importation and transport of harmful invasive species.
  • Enhance funding for invasive species control and management projects; prioritize efforts to reduce invasive species’ spread at landscape scales.
  • Ensure that federal actions do not inadvertently promote the introduction or spread of harmful invasive species; use caution when promoting nonnative species for biofuels, bioenergy, or other
  • purposes.
  • Adopt metrics to gauge the effectiveness of efforts to prevent the introduction and spread of new invasives and to achieve long-term control or removal of existing invaders.
  • Support robust research and outreach programs, which are essential to improving the efficacy of federal, state, and local invasive species prevention and control efforts.

Given the new legislation’s focus on land-managing agencies, I point to the importance the coalition gave to research on the invasion processes utilized by various species and education of land and water users  so as to gain their cooperation. These recommendations are directly counter to the new law’s stringent limitations on research and “outreach”.

I think particularly pertinent are the recommendations on metrics to measure programs’ efficacy. Proper metrics should metrics address outcomes and program effectiveness re:

  • efforts to prevent species introduction and spread
  • activities that target pathways or vectors
  • the effectiveness of treatments in eradicating or reducing the target invasives.

Potential additional metrics include, but are not limited to:

  • Rate of new invasions; possibly categorized by type of invader or geography
  • Acres infested and changes in infestations over time
  • Acres protected, based on projections of future spread avoided by eradication
  • Economic impact of invasive species
  • Number of species intercepted.

The full document is available here .

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.

2018 – More Bad News on Sudden Oak Death

Tanoak mortality at Big Sur photo by Matteo Garbelotto
  1. Outbreaks intensified in western North America and Western Europe (UK, France).
  2. Outbreaks are increasingly genetically diverse – raising the possibility of sexual reproduction and evolution.
  3. Evidence accumulated that eradicating Phytophthora ramorum from the environment once it is present is extremely difficult, if not impossible.

Meanwhile, APHIS proposed revisions that would weaken its regulation of nursery stock. See my earlier blog. Copies of all comments can be viewed here.

1) Intensifying Outbreaks

North America

According to the California Oak Mortality Task Force’s (COMTF) November 2018 newsletter, about 50 million trees have been killed by P. ramorum in California and Oregon. This breaks down to:

  • 29 – 44 million tanoaks (Notholithocarpus densiflorus) (1.6 – 2.5% of the species’ total population in California and Oregon);
  • 1.9 – 3.3 million coast live oaks (Quercus agrifolia) and Shreve oaks (Q. parvula var. shrevei), combined (0.4 – 0.7% of their populations); and
  • up to 1.1 million California black oaks (Q. kelloggii) (less than 0.17% of their population).

Of course, the oaks face additional threats from goldspotted oak borer and  polyphagous and Kuroshio shot hole borers hin more southern parts of California.

California bay laurel (Umbellularia californica) is not killed by P. ramorum but instead drives the spread of the outbreak in California. The state has an estimated 91.4 million infected California bay laurel trees.

These estimates are considered to be conservative. They are based only on trees that have been confirmed to be infected by direct, cultural isolation during the period up to 2014 — more than four years ago! And before a sharp intensification of infection (see below).

Data from a USDA Forest Service aerial detection survey – reported in COMTF’s September 2018 newsletter — detected a large increase in tanoak mortality in counties California counties reaching from Mendocino south to Monterey. This intensification in tree mortality was expected because the pattern is already well established: two seasons after a wet winter seasons, trees die. Such a wet and extended winter occurred in 2016-2017.

United Kingdom

Outbreaks of the EU1 strain of P. ramorum on larch (Larix kaempferi) in Scotland have also intensified. The infection is now found throughout much of Scotland, not just in the heavily infested zone in the the southwest part of the country. See updated map of outbreaks on Larch sites in woodland settings at https://scotland.forestry.gov.uk/supporting/forest-industries/tree-health/phytophthora- ramorum?highlight=WyJyYW1vcnVtIiwiJ3JhbW9ydW0iLCIncmFtb3J1bSciXQ

–

There is more on the status of P. ramorum in the the UK (England, Wales, Scotland and Northern Ireland) in a situation report posted by Forestry Commission England in 2018. Find it here: https://www.forestry.gov.uk/pdf/PRamorumSituationReport30June2018.pdf/$FILE/PRamorumSituationReport30June2018.pdfh

As in North America, the large number of outbreaks is attributed to favorable, wet conditions in the summer and fall of 2017. (This situation was summarized in COMTF’s September 2018 newsletter.

France

The outbreak on larch in France, first reported in 2015, is also spreading. This is particularly significant because, first, it is the first report of  P. ramorum outside of nurseries and ornamental settings in mainland Europe and, second, because it is a new genotype not tied to any other outbreak. By May 2018, about 80% of the trees in the Saint-Cadou larch plantations in Brittany (Northwest France) were symptomatic or dead in the more infected plots. A second outbreak has been detected a few kilometers away in a mixed forest stand of larch, oak, and sweet chestnut (Castanea sativa).  There, disease prevalence was much lower. Both stands have been removed.

(This was also  summarized in COMTF’s September newsletter.

2) Increasing Genetic Diversity

EU1 Strain in Oregon

As I have reported in the past, Oregon now has a second strain of Phytophthora ramorum – the “EU1” strain. This opens the possibility of sexual reproduction between it and the NA1 strain already established in forests in Oregon’s Curry County.

According to a presentation by Chris Benemann of the Oregon Department of Agriculture to the Continental Dialogue on Non-Native Forest Insects and Diseases, in 2018 – three years after the initial detection of one tree in 2015 – the number of trees infected by the EU1 strain has risen to 73. Oregon has prioritized removing these trees and treating (burning) the immediate area – now more than 355 acres. The legislature has provided $2.3 million for SOD treatments for 2017-2019. ODA believes that eradication of the EU1 outbreak is still possible.

3) But Is Eradication Possible?

According to the COMTF September newsletter, P. ramorum was detected by a water bait in a small pond downstream from a previously-infected botanical garden in Kitsap County, Washington. The garden undertook extensive mitigation efforts – including soil steaming –  and the pathogen had not been detected in this managed landscape for about 2 ½ years. Hundreds of samples of host plants were collected in September, with only one warranting further analysis to determine whether it was positive.  Surveys will continue in 2019.

In the East, USDA has baited streams to detect P. ramorum for several years. Seven states participated in the 2018 Spring National P. ramorum Early Detection Survey of Forests: Alabama, Georgia, Mississippi, North Carolina, Pennsylvania, South Carolina, and Texas. As reported in the COMTF’s September newsletter, h292 samples were collected from 48 sites. As in past years, positive samples were collected from streams associated with previously positive nurseries. These included three samples from two locations in Alabama; two samples from one location in Mississippi; and one sample from North Carolina. The Alabama and Mississippi sites have tested positive for approximately a decade.

So, the pathogen is persisting in water – but how? I have been told that P. ramorum requires plant material on which to survive – so how is it persisting without detectable infested plants? Also, does the presence of zoospores pose a threat of infesting streamside plant material? What studies are examining this issue?

Awareness through Art

Artists have transformed a SOD-infected tanoak tree into 7,000 pencils as part of their thoughtful “7,000 Marks” project. They  explore issues around global industrial trade, quarantine boundaries as a conservation tools, and the opposing concern that restricting trade can echo a rising tide of xenophobia. You can learn more (and buy pencils) here.

SOURCES

Cobb, R.; Ross, N.; Hayden, K.J.; Eyre, C.A.; Dodd, R.S.; Frankel, S.; Garbelotto, M. and Rizzo, D.M. 2018. Promise and pitfalls of endemic resistance for cultural resources threatened by Phytophthora ramorum . Phytopathology. Early view.

https://apsjournals.apsnet.org/doi/abs/10.1094/PHYTO-04-18-0142-R

Harris, A.R.; Mullett, M.S.; Webber, J.F. 2018. Changes in the population structure and sporulation behaviour of Phytophthora ramorum associated with the epidemic on Larix (larch) in Britain. Biological Invasions. 20(9): 2313–2328.

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.

New Study of Why People Move Firewood – and Its Relation to EAB Deregulation

We know that people moving firewood long distances is cause for great concern because of the likelihood that tree-killing pests will be transported to new and previously uninfested locations. This concern has been heightened by the USDA APHIS proposal to deregulate the emerald ash borer (EAB). As the principal federal “quarantine pest” transported by firewood, the EAB provides the legal foundation for most federal and state firewood regulations. (Of course, the EAB regulations also govern other articles that could transport wood-boring pests). (See earlier blogs here and here.)

Most forest pest professionals agree that the greatest risks are associated with individuals who transport firewood for recreational camping or summer homes. These people have proven to be the most difficult to regulate and the most likely to not see – or to ignore – messages intended to discourage them from moving firewood. The Nature Conservancy manages the “Don’t Move Firewood” program. It has done polling on messages and impact and concludes that the percentage of U.S. voters who have heard a “don’t move firewood” message remains steady and that those who have heard that message are less likely to transport firewood, especially over distances greater than 50 miles. More details are here

A recently published study by several academics and one forest service scientist reinforces The Conservancy’s earlier conclusion about the importance of outreach efforts as an essential component of programs intended to manage wood-boring pests. On the other hand, the new study points to additional nuances in crafting messages that will be effective in changing people’s behavior.

 

Findings

 

Daigle et al. 2018 (see full citation at the end of the blog) surveyed 272 people who were camping in public (state) or private campgrounds in three New England states in 2013 – four years after each of those states adopted regulations prohibiting out-of-state firewood and began their outreach efforts. Some campers apparently feel a strong connection to the place they are visiting, as shown by the fact that 84% of the 79 campers at private campgrounds had spent two or more nights camping in the same state in the previous year. That emotional connection might provide a motivation that could be activated to persuade those campers to stop transporting firewood (see below).

The authors found that slightly more than 25% of the 272 respondents reported that they often or always brought firewood from home for camping. More discouraging is that they found that people might not comply even when informed about the risks. Instead, compliance depended largely on the individual’s motivation and commitment level rather than knowledge. Worse yet, campers categorized as “highly involved” in the forest pest issue were just as likely to transport firewood from home as were others. Apparently, these non-compliant campers did not fully “connect the dots” between their concerns about forest health and their own actions. See below for Daigle et al.’s suggestions for ways to help people make those connections.

To understand the role of motivation, Daigle et al. tried to assess the strength of each camper’s beliefs about the relationship between tree-killing pests and the transport of firewood by recreational campers.

Overall, 25% of respondents were very highly involved with tree pest issues; another 22% were highly involved. Respondents’ perception of the relationship between damaging tree pests and transport of firewood differed significantly based on their levels of involvement. Respondents with a low level of involvement were less likely to agree with three statements (listed below) that firewood-associated pests pose a serious threat. Campers with very high levels of involvement strongly disagreed with three other statements that either downplayed the threat or portrayed the respondent’s compliance as “useless” as long as others continue to transport firewood.

Perception questions against which respondents’ agreement or disagreement was measured:

  • “There is not much one individual can do about invasive pests brought in by firewood”
  • “I don’t think invasive pests brought in by firewood are very important.”
  • “The threat of invasive pests brought in by firewood is serious.”
  • “As long as other people continue to bring firewood from home, my efforts to prevent invasive pests are useless.”
  • “The invasive forest pest risk from firewood is exaggerated.”
  • “In the long run, things will balance out with invasive pests.”

 

Rationale

Respondents’ most frequent explanations for why they take firewood from home when they go camping were cost, quality, and convenience. The most frequently cited reason for not transporting firewood was that the respondent knew that it was not allowed.

Level of pest awareness:

While nearly all respondents (92%) had heard something about non-native pests killing trees, but 57% could not recall the name of a specific pest in the absence of a prompt. When asked about the emerald ash borer and Asian longhorned beetle, more respondents had heard about the ALB (77% v. 52%). Most said the principal source of information was a state agency.

 

Suggested Actions

Daigle et al. conclude that authorities need to increase citizens’ exposure to outreach materials in order to activate concern and bring about desired actions to curtail risk of pests in firewood.

One clear need is to counter many campers’ belief that their wood is safe so it is okay to transport it regardless of the regulations. Often they based that belief on the fact that their home is not in a designated quarantine zone. Daigle et al. suggested that educational material should try to counter this belief by emphasizing the time lag between a pest’s establishment and its detection.

To help “connect the dots” between campers’ concerns about forest health and the implications of their actions (transporting firewood), survey respondents suggested using more visuals showing the destruction caused by the invasive forest pests, especially in areas they care about – close to home or favorite recreation areas. Daigle et al. thought such pictures would “help the campers with high involvement to trigger activation of attitudes with the association of forest pests and firewood transport.”

Other suggestions for strengthening outreach were to ensure that the message

  • Is novel – that it does not simply reiterate a camper’s initial belief system.
  • Produces agreement by the recipient without generating counterarguments.
  • Is relevant to the audience’s concerns.

They also suggested that campgrounds (public and private) help motivate campers to leave firewood at home by coordinating with local firewood vendors to provide competitively priced firewood at the campground or by including the cost of providing some firewood in the camping fee.

Daigle et al. made two other suggestions that call for stronger actions.

First, they suggested that outreach programs incorporate incentives or rewards to engage people who don’t have a high level of involvement in forest health issues.

Second, they suggested that authorities reinforce the educational message by using “more direct” actions, such as

  • confiscating illegally transported firewood at check stations,
  • issuing warnings about such actions, or
  • administering fines for moving non-compliant firewood.

The authors suggest that state agencies should consider taking these actions – but I see no reason why federal agencies should not also.

EAB; David Cappaert

Conclusions re APHIS’ Proposal to Deregulate EAB

Daigle et al. conclude that outreach efforts aimed at curtailing movement of firewood need to be continued. They are a critical component of overall management programs targetting non-native tree-killing pests – programs developed through decades of research and trials. The motive is clear: more effectively delaying these pests’ spread provides large benefits to municipalities and homeowners.

These are the same points made by many who opposed APHIS’ proposal to deregulate the emerald ash borer.

In its comments to APHIS, The Nature Conservancy noted that the domestic EAB quarantine had been effective in limiting spread of the pest through two of the most important pathways – firewood and nursery stock. The resulting slower spread had protected three-quarters of the ash range in the United States and bought time to develop mitigation measures.

Further, eliminating the federal quarantine would not only unleash this pathway for long-range movement of EAB but undermine the many federal, state, regional, tribal, private, and non-profit  partners’ efforts to curtail movement of all invasive forest pests in firewood.

Many other commenters, including several state agencies, the National Association of State Foresters and Southern Group of State Foresters called for APHIS to continue leading national efforts to curtail spread of EAB and other pests through careless movement of infested firewood. The Montana Department of Natural Resources and Conservation and NASF specifically urged that APHIS reinstate the National Firewood Task Force (which APHIS led in 2009-2010).

The Don’t Move Firewood program has a more informal blog on this topic, available here.

 

Source

Daigle, J.J., C.L. Straub, J.E. Leahy, S.M.De Urioste-Stone, D.J. Ranco, N.W. Siegert. How Campers’ Beliefs about Forest Pests Affect Firewood Transport Behavior An Application of Involvement Theory. Forest Science XX(XX):1-10  https://academic.oup.com/forestscience/advance-article/doi/10.1093/forsci/fxy056/5232804

 

National Park Service Experts Urge Improvements to Invasive Species Efforts

 

cats – reported to be the most widespread invasive animal in National parks

In two recent evaluations and resulting reports, National Park Service experts admit the agency has fallen short on managing the invasive species threat and suggest ways to improve. One report – that on invasive animals (see below) identifies the principal problem to be lack of support for invasive species programs from NPS leadership.

They’re not alone: I have previously criticized the NPS here and here

 

Invasive Animals

The bolder of the two reports addresses invasive animals – “Invasive Animals in U.S. National Parks – By a Science Panel” https://irma.nps.gov/DataStore/DownloadFile/594922 commissioned by the NPS Chief of Biological Resources Division. The report was released in December 2017.

The report is blunt – which I welcome.

 

Key Message

The NPS’ mission of preserving America’s natural and cultural resources unimpaired for future generations is “under a deep and immediate threat as a consequence of invasive animal species, yet the National Park Service does not have a comprehensive understanding of the costs and impacts of invasive animals or a coordinated strategy for their management.”  The result: “The consequence is a general record of failure to control invasive species across the system.”

The report says there are opportunities for the NPS to take a lead in addressing the threat – including to help counter invasive species denialism. It suggests ways to provide the needed capacity and to change the agency culture that hampers efforts to realize this ambition.

 

Current Picture

More than half of all National Park units reporting to the report’s authors (245 out of 326 parks) reported the presence of invasive animals – ranging from freshwater mussels to feral cats. In the process of compiling the report, the authors received reports of 1,409 invasive animal populations – comprising 331 species — probably an underestimate. Only a small percentage can be considered under some form of management. The most widely reported species:

Domestic cat                69 parks

Common starling         66 parks

Common pigeon          47 parks

House sparrow             40 parks

Red imported fire ant   40 parks

Feral hog                      39 parks

Rainbow trout              36 parks (often introduced deliberately)

 

The report mentions several tree-killing insects or pathogens among the damaging animal invaders in National parks: emerald ash borer, hemlock woolly adelgid, and rapid ohia death (a pathogen). (Background on all three is here.)

 

This new report acknowledges management efforts. They reviewed 80 NPS projects in the pipeline from 2000 through 2023. Most projects target a limited number of species: feral hogs, cats, and horses/burros; fire ants; hemlock woolly adelgid; and emerald ash borer.

EAB-killed ash tree in Shenandoah NP  (F.T. Campbell)

Eradication has reportedly been attempted for 21 invasive animal populations; 17 of those populations remained under some control efforts (e.g., monitoring to detect any re-invasion) in 2016. Nine of the eradicated populations were in the Pacific West region – especially Channel Islands National Park. Another eight were in the Southeast. Three other regions — Intermountain, Northeast, and National Capital regions — each reported one invasive animal population eradicated and under control. Another 150 invasive animal populations were reportedly “controlled”.

 

What’s the Problem?

The report’s authors note numerous (and well-known) difficulties in managing invasive animals. These include difficulty detecting invaders at early stages of invasion; paucity of effective management tools; and social constraints such as perceived benefits associated with some (e.g., trout and other sport fishes) and ethical and humane objections to killing vertebrates.

However, the report identifies the principal problem to be lack of support for invasive species programs from NPS leadership. Constraints that hamper park managers’ efforts within the agency include Service-wide coordination, lack of capacity, park culture, “social license” (i.e., public approval), and cross-boundary coordination.

The authors suggest that to correct these deficiencies, the Service should formally acknowledge that invasive animals represent a crisis on par with each of the three major crises that drove Service-wide change in the past:

1) over-abundance of ungulates due to predator control (leading to the “Leopold Report” in the 1960s);

2) Yellowstone fire crisis (which led to new wildfire awareness in the country); and

3) recognition of the importance of climate change (which resulted in the report “Leopold Revisited: Resource Stewardship in the National Parks”).

To achieve true success in such a major undertaking, all levels of NPS management must be engaged. Further NPS’ current culture and capacity must be changed. The report suggests providing incentives for (1) efforts to address long-term threats (not just “urgent” ones) and (2) putting time and effort into coordinating with potential partners, including other park units, agencies at all levels of government, non-governmental organizations, private landowners, and economic entities.

An additional step to realizing a comprehensive invasive animal program would be to integrate invasive animal threats and management into long-range planning goals for natural and cultural landscapes and day-to-day operations of parks and relevant technical programs (e.g., Biological Resources Division, Water Resources Division, and Inventory and Monitoring Division).

The report notes the need for increased funding. Such funding would need a flexible timeline (unlike existing Service-wide funding for more general purposes), allowing parks to be responsive to time-sensitive management issues. It would also have to be available consistently over the long term – since eradication can take a long time. Several approaches are proposed, including incorporating some invasive species control programs (e.g., weeds, wood borers) into infrastructure maintenance budgets; adopting invasive species as fundraising challenges for “Friends of Park” and the National Park Foundation; and adopting invasive species as a priority threat.

The authors would like NPS to become a leader on the invasive species issue – specifically by testing emerging best management practices and by better educating visitors on the ecological values of parks and the serious threat that invasive species pose to the their biodiversity. The authors suggest that the NPS also take the lead in countering invasive species denialism.

While officially-approved deliberate introductions of non-native species are probably unlikely to continue, the report expects that the numbers of invasive animals and species in national parks will increase due to continuing spread of invaders from neighboring areas. Therefore, NPS’ current piecemeal approach needs to be replaced with a much stronger, strategic approach in which parks engage in collaboration with conservation partners on adjacent lands or waters and across the greater landscape.

 

Invasive Plants

The NPS launched a coordinated effort targetting invasive plants years ago — in 2000. The most obvious component of which was the Exotic Plant Management Teams (EPMTs). The broader program was officially named the Invasive Plant Program (IPP) only in 2014. The IPP provides leadership to individual parks, regions, and the park system on invasive plant management, restoration, and landscape level protection. The IPP released its strategic plan in December 2016. (Ok! More than a year ago. I am tardy.)

Despite the large size of the program – 15 EMPTs across the country – and the clear and recognized threat that invasive plants pose to NPS values, I got the impression that the program struggles to gain  support from the Service. In that way, the situation is similar to the challenges to efforts on animal invasives described above.

   removing Miconia to protect Haleakala National Park

The Strategic Plan identifies goals and actions to optimize the program’s effectiveness, while increasing program and park capacity and leveraging human and fiscal resources with state, federal, and private entities.

The plan articulates a mission, a vision, five broad goals, and actions for the next 10 years. It’s intended to guide annual planning and major projects, as well as to identify and help prioritize funding needs and initiatives.

The overall vision is for the Invasive Plant Program to guide park service efforts to enhance landscape level stewardship of resources by applying “technically sound, holistic, collaborative, adaptive, and innovative approaches.” The hope is that other NPS units will increasingly rely on the IPP’s expertise in implementing their programs and building partnerships.

The strategic plan lays out five broad goals, each supplemented by a list of detailed activities. Priority actions have been identified for the first 5 years (2017-2021) with the expectation that actions will be re-prioritized during annual reviews. These five goals are:

  1. Develop program standards

Clarify and standardize administrative and operational roles and tasks. Improve data management and train colleagues in those standards. Incorporate science-informed procedures to support park management of invasive plants.

Interestingly, the Plan calls for IPP staff to quantify the invasive plant threat and effort needed to manage it and then to communicate the gap between effort needed and resources available to decision makers.

2. Promote the Invasive Plant Program by highlighting the services it provides and the significance of the invasive plant issue both internally and with stakeholders. Assure that IPP efforts parallel those in the Department of Interior Action Plan for invasive species.

  1. Build capacity of individual parks and the Service to prevent the arrival of invasive plants and manage infestations that are already present

Enhance resource and information sharing and field-based training. Find ways to encourage parks to continue managing the invaders after the EMPT completes the initial eradication. Also find ways to increase the EPMT Program’s efficiency. Possibly develop an NPS pesticide applicators’ certification course (the Bureau of Land Management and Department of Defense already have one).

Increase partnerships to deal with actions that are outside parks’ control. Specifically, participate in regional and state invasive plant councils, and collaborate with a full range of external partners to identify successful techniques, conduct control and restoration campaigns, improve and implement efficient plant management across park boundaries, and recruit and manage youth and volunteers.

  1. Promote holistic and integrated invasive plant management

Work with other NPS programs and parks (across all divisions) to establish resource stewardship and landscape preservation / restoration goals. Integrate integrated pest management strategies in management actions. Continue close collaboration with Climate Change Response Program (if it still exists!). Identify research needs and get the research done.

  1. Collaborate on invasive plant management

Foster and encourage internal and external collaboration and coordination to leverage available resources, expertise, and knowledge.

Identify parks, NPS programs, partner agencies, organizations, and related initiatives with similar objectives to increase efficiency and effectiveness. Coordinate with NPS monitoring programs (although the invasive animal study authors thought the monitoring program is not structured to serve invasive species needs). Partner with BLM and US Fish and Wildlife Service and non-federal partners to cooperatively manage invasive plants on the landscape. Coordinate compliance with National Environmental Policy Act (NEPA) and National Historic Preservation Act.

 

Each IPP unit is expected to develop an annual work plan that aligns with an annual financial plan. Priorities will be reviewed annually. Each IPP unit will also submit an annual accomplishment report. IPP might develop a tracking system to be applied to each assigned action.

Plus the IPP strategic plan will be reviewed annually and actions will be re-prioritized as needed. The annual status reports will be made available to stakeholders and partners on the Web.

 

Posted by Faith Campbell

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