State of the Science & Gaps Faith T. Campbell, Ph.D. Center for - - PowerPoint PPT Presentation

Invasive Species: State of the Science & Gaps

Faith T. Campbell, Ph.D. Center for Invasive Species Prevention

Situation – bad & getting worse

• 3,540 NIS insects established in continental US &

Canada

– ~500 phytophagous insects & pathogens that attack trees/shrubs … how many attack herbaceous plants? – HI alone – 2,651; 50% of insect fauna; 13% deliberate

• Rod Randall > 9,700 naturalized plants
• Vertebrates Pimentel - ~400
• Diseases – West Nile virus, white nose syndrome,

chytrid fungus of amphibians, whirling disease, fungal disease of snakes, highly pathogenic avian influenza …

– in Hawai`i, avian malaria & avian pox

rates of introduction

• OTA 1993 - no clear

evidence of rising #s

• ver past 50 years
• Aukema 2010 (forest

pests only) – steady rate

• f 2.5 / year since

1860s

5 10 15 20 25 30 35 40

100 200 300 400 500 600 700

1750 1800 1850 1900 1950 2000 2050 Cumulative value of imports (Trillions of 2010 $)

Cumulative Number of Pests

All Insect Pests Wood Borers Value of Imports

Leung et al. 2014

Inexorable accumulation of more invaders …

• multiple species in some regions … at least 3 in all

counties

• “Bad” pests now contained could spread to new,

vulnerable areas (e.g., ALB, PSHB & Kushiro SHB)

From Liebhold et al. 2012

Tree-killing insects & pathogens: Since 2003, >30 new tree-killing pests

20 woodborers, including:

• Redbay ambrosia beetle / laurel

wilt disease

• Sirex woodwasp
• Goldspotted oak borer;
• Walnut twig beetle and

thousand cankers disease

• Soapberry borer
• Polyphagous shot hole borer
• Kushiro shot hole borer

Other: spotted lanternfly

Palm pests:

• Red palm mite
• Red palm weevil
• South American palm weevil

On Pacific islands:

• `Ohi`a rust
• Ceratocystis on `ohi`a
• Rhinoceros beetle
• Cycad scale
• Cycad blue butterfly
• Erythrina gall wasp
• Pisonia scale

Invasive plants – high numbers

US: > 9,700

Rod Randall Western Australia

Invasive plants

• Invasive and alien plants are more widely

distributed than natives across the continental United States

• Average invasive plant now inhabits only ~ 50% of

its expected range

• Biological factors less important than human

actions in facilitating spread (Bradley, B.A., R. Early & C. J. B. Sorte. 2015.

Space to invade? Comparative range infilling and potential range of invasive and native plants. Global Ecology and Biogeography)

Courtesy Jack Mayer, U.S. Dept. of Energy Savannah River National Laboratory 3 – 8 million in 2011

Whitenose syndrome locations November 10, 2015

www.whitenosesyndrome.org

New Zealand mudsnail locations

Expect additional introductions

• Diseases -- bSal or other new strains of chytrid

fungi that kill amphibians (> 4 M amphibians imported /year)

• New invasive plants [>500 species invasive in

some region are being sold on-line; Humair et

• al. (2015)]
• Wood-borers -- Leung et al.  100 more by

2050

Role of research when

• Threat is complex
• Don’t expect increased resources for either

research or management  prioritize

• Decision-makers & stakeholders have many

demands on attention & want simple answers

• Stakeholders have conflicting goals

What most important to learn? What can be extrapolated from what have learned? How coordinate efforts to be most efficient – while not sacrificing variety of approaches & ideas?

Balancing approaches

What is “right” balance between sustained, focused research on specific questions, e.g., 1) how important a pathway is movement of wood by woodworkers? 2) How do invasive shrubs & vines – as distinct from grassland herbs – respond to higher atmospheric levels of CO2 & changing temperatures & precipitation?

Versus

Broad approaches that elucidate big management issues

• r cross-cutting issues
• Can scientists identify high-risk sites for introductions?

How handle surprises? (e.g., ALB in Clermont Co, OH; few forest pests introduced to Portland / Seattle / Vancouver)

• Can managers protect high-value sites? Or must

containment/slow-the-spread efforts focus on sites of initial introduction?

• Compare efforts to persuade visitors to avoid moving

firewood, aquatic organisms on boats & gear, weed seeds on trucks, etc. to find synergies

breakthroughs

• eDNA detection of aquatic organisms
• Baited leaves in streams to detect

Phytophtoras

• Increasingly sophisticated climate matching

models

• PRE system (UCDavis & UW) to predict

invasiveness of “new” plant species

• CRISPR-Cas9 gene-splicing technology

Topics for scientific study

• Evaluating programs’ efficacy
• Determining propagule pressure
• Invasive species’ impacts
• Management & prevention strategies
• Tools and technologies
• Economic consequences
• Change the culture to make IAS everyone’s

business

Complexity (biological)

Structure & chemistry of soil & associated leaf litter – they can be altered by

• Rooting by feral hogs
• Activity of alien earthworms

& other soil organisms

• Rain of insect excreta
• Changes in above-ground plant composition as

result of either or both

– Invasion by alien plants – High mortality of some plant taxa caused by alien insects or pathogens

… Complexity (biological)

insect / host plant interactions in period of heightened atmospheric CO2 - leaf chemistry (in addition to changing temperatures, precipitation patterns, phenological mismatches associated with climate change )

• Evan DeLucia (U. of IL)  forest studies with

elevated CO2 saw decreased herbivore populations, increased predator populations

… Complexity (socio-economic)

Role of research in determining pathways, detection & control methods … evaluating program options & relative efficacy

• 3 pest pathways studied – but information dated

(2009)

– SWPM  Haack & Leung  approach rate reduced but still “leaks”; likely triple #s of woodborers by 2050; rules changed – need to update analysis – Plants  Liebhold  high pest approach rates on a subset of imports; how representative was that set? How relevant to US natural systems? Changes since? – Firewood  Koch et al. distance travelled by campers

… Complexity (socio-economic)

Role of research in determining & documenting invasive species’ impacts

• E.g., insects & pathogens attacking trees in

urban areas, affecting

– removal costs for homeowners & municipalities – ecosystem services (& their economic values) – human health – setbacks to efforts to counter climate change (=urban “greening”)

Can research reduce the # of “unknown unknowns”?

• 1998, Mycological Society of America:

… estimated that 95 percent of fungal species in the world remain undescribed, let alone understood in terms of ecological function.” Current status? Progress in predicting impacts? Rapid ohia death; Ceratocystis fimbriata

Broaden efficacy evaluations of programs?

• USDA plans to rely on HACCP programs to

reduce pest risk associated with nursery stock … should we study reasons for failures of HACCP programs in other areas, e.g., food safety, in order to anticipate & forestall weaknesses in plant nursery HACCP programs?

How address social constraints?

• Possible loss of biologically effective controls

… e.g., neonicotenoids … or biocontrol agents

• Managing popular animals

– Cats – Feral hogs – 2nd most popular big-game trophy in North America

• - Non-native game fish

Other topics …

• Pursue understudied pathways
• Strengthen global invasive plant datasets &

models for predicting future ranges of invasive plants within US

• Quantifying/monetizing invasive plant impacts

Nancy Loewenstein, Auburn University bugwood

Ecological restoration of forest trees decimated by alien pests

a multiple-step procedure requiring long-term commitment, strong infrastructure, & funds

Each activity …

– Preparation:

• Achieve control of the invasive pest
• Collect, store & evaluate germplasm

– breeding and selection – traditional & molecular techniques – production of propagules – in large numbers/mass propagation – site preparation of former habitat – planting; and – post-planting maintenance

requires own skill sets, protocols, equipment, facilities, & infrastructure

Gaps

• For most taxonomic groups, lack nation-wide

picture – numbers, species, where established … much less potential range

Need national-level mapping of invasive species – helps set priorities, coordinate landscape-level efforts, demonstrate success

• Digests that synthesize numerous studies
• Collaborate with Canadian & Mexican

colleagues since species, pathways, forest systems cross borders

… Communication

• Determine decision-makers’ & stakeholders’

perspectives & package scientific findings to address them Relevance to management (including prevention) should guide selection of research topics/agenda; decision-makers’ & stakeholders’ perspectives guide much of presentation -- but NEITHER guides research approach or – esp. – findings/conclusions