Whitebark Pine Status and the Potential

Role of Biotechnology in Restoration

Diana F. TombackDept. Integrative Biology

University of Colorado Denver

Webinar, Committee on Forest Health and

Biotechnology, NASEM, April 2, 2018.

• Four case histories illustrating the threat posed by

Cronartium ribicola

• Restoration approaches

• How biotechnology can expedite restoration efforts

• The National Whitebark Pine Restoration Plan

Willmore Wilderness Park, Alberta, Canada

• Distribution

• ESA status review

• Ecology

• Foundation and

keystone roles

• Threats and trends.

Outline of presentation

Taxonomy: Pinus albicaulis Engelm., whitebark pine

Family Pinaceae, Genus Pinus, Subgenus Strobus, Section Quinquefoliae.*

• Subsect. Strobus -“five-needle pines” (revised)*.

• Most recent phylogenies for subgenus Strobus constructed from nuclear,

mitochondrial, and chloroplast gene sequences show diverse affinities between

P. albicaulis and species native to North America, Asia, or Europe (Hao et al. 2015).

• Hao et al. (2015)—“…ancient and relatively recent introgressive hybridization

events…particularly in northeastern Asia and northwestern North America.”

Genome of whitebark pine characterized as extremely large and highly repetitive.

*New Subsect. Strobus from combined subsects. Strobus and Cembrae, Gernandt et al. 2005;

Syring et al. 2007.

Whitebark pine range

• Upper subalpine and treeline forest zones.

• Western U.S. and Canada.

• 96% of the U.S. distribution is on federally

owned/managed lands.

• 37o to 55o N lat.

• 107o to 128o W long.

• Elevation: 900-3,660 m

• Estimated areal coverage:

Keane et al. 2012, Table 4.1

-ca. 5,770,000 ha

-ca. 14,252,000 acres

Whitebark pine range by Government Jurisdiction

Total estimated area ~ 5,770,000 ha

0 500,000 1,000,000 1,500,000 2,000,000 2,500,000 3,000,000

Forest Service

Wilderness (all agencies)

National Park Service

Private and State Lands

Native American Tribal Lands

Bureau of Land Management

Other (misc.)

Range area (ha)

47%

10%1%

1%

3%

38%

0%

Forest Service

National Park Service

Bureau of Land Management

Native American Tribal Lands

Private and State Lands

Wilderness (all agencies)

Other (misc.)

Data from Keane et al. 2012, Table 4.1

Events leading to ESA status review

Whitebark pine paradox: How can a species that inhabits remote locations and so widely-distributed be declining?

• December 8, 2008: Natural Resources Defense Council (NRDC) petition to U.S. Fish & Wildlife Service to list whitebark pine under the Endangered Species Act.”

• July 19, 2011: Fish & Wildlife Service 12-month finding: “…we find that the listing of P. albicaulis as threatened or endangered is warranted. However, currently listing P. albicaulis is precluded by higher priority actions to amend the Lists of Endangered and Threatened Wildlife and Plants.” “.…we will add P. albicaulis to our candidate species list.” Federal Register, Vol. 76, NO. 138, July 19, 2011.

Threats cited: Fire suppression and advancing succession, climate change and its interactions with mountain pine beetle and fire, white pine blister rust, and mountain pine beetles.

White Calf Mountain, Glacier National Park, MT

View: Blackfeet Reservation

Ecology

Foundation and keystone roles

Whitebark pine community types

• Successional communities on favorable sites, upper subalpine zone.

• Climax (self-replacing) communities on exposed upper subalpine sites.

• Treeline communities on cold sites in the alpine treeline ecotone.

Beartooth Plateau, WYBanff National Park, AB

Grand Teton NP, WY

Adaptations of whitebark pine for seed dispersal by nutcrackers

• Large, wingless seeds.

• Cones remain closed after seeds ripen: obligate

mutualism.

• Horizontally-oriented cones on upswept branches.

• Seeds adapted for caching: viable for

several years under soil. Don Pigott

Seed dispersal by nutcrackers

Nutcrackers

• Place seeds in caches of 1 to 15 seeds.

• Bury seed caches 1 to 3 cm under substrate.

• Carry seeds from a few meters to >32 km.

• Store >35,000 whitebark pine seeds per year per bird.

• Retrieve caches using highly accurate spatial memory.

Unretrieved caches germinate, leading to regeneration.

Seed dispersal by nutcrackers determines:

• The distribution of whitebark pine on the landscape—elevation and topography.

• Where whitebark pine grows locally—nutcracker cache site selection and environmental suitability.

• Rise of treeline with climate change—because nutcrackers cache seeds above tree limits.

• Fine-scale population genetic structure.

• Watershed and regional population structure. Tomback and Linhart 1990, Tomback 2001

Rogers et al. 1999, Tomback 2005

Stanley Glacier, Kootenay NP, BC, CA

• Wide spectrum of community types.

• 7 recognized SAF cover types.

• High elevation wildlife habitat, shelter,

and nest sites.

• Seeds provide wildlife food (birds, small

mammals, bears,. & foxes)

Whitebark pineKeystone species

Promotes biodiversity

Willmore Wilderness Park, AB, CA

Whitebark pine

Foundation species (Dayton 1972, Ellison et al. 2005)

“…a single species that defines much of the structure of a community

by creating locally stable conditions for other species and by

modulating and stabilizing fundamental ecosystem processes.”

Defines ecosystem structure and function• Early establishment after disturbance.

• Fosters community development through

mitigation of harsh conditions and facilitation.

• Nurse tree on harsh sites (facilitation).

• Tree island initiator (facilitation).

Grand Teton National Park

Whitebark Pine Ecosystem Services

• High elevation forests and treeline communities

redistribute and retain snow.

• Shade from these forests slows summer snowmelt,

regulating downstream flow.

• Roots stabilize soil, reducing soil erosion.

• Trees stabilize snow, reducing avalanche hazard.

Wind River Mtns., WYBlackfeet Indian Reservation, MT

Role of treeline communities in snow redistribution and retention (Fig. 6 from Tomback et al. 2016)

Threats, status, and trends

Henderson Mtn., Custer Gallatin NF, MT

The four major threats to whitebark pine

• Cronartium ribicola—exotic fungal pathogen that causes white pine blister rust.

• Mountain pine beetle (Dendroctonusponderosae) outbreaks.

• Altered fire regimes—successional replacement from fire exclusion actions.

• Climate warming—driving bark beetle outbreaks, drought stress and mortality, larger, more frequent, and severe fires.

https://en.wikipedia.org/wiki/Mountain_pine_beetle

White Pine Blister rust (WPBR): an exotic disease naturalizedto North America

• Accidental introduction(s) to the Northwest around 1910.

• First detected in PNW in1921.

• Conditions (pine hosts, alternate host Ribes spp., and climate) highly favorable to its spread.

• Infects and kills all age classes.

• Continues to spread geographically and intensify locally.

• Now in regions once believed to be too cold, warm, or dry.

• Spread facilitated by wave years.

Life Cycle of white pine blister rust

R. Hunt 1983.

Canadian Forestry

Service

These spores may blow

500 km or farther

Only infects five-needle white

pines (subgenus Strobus taxa).

Most common alternate hosts:

Ribes spp.

• Five spore stages in life cycle.

• Aeciospores—transmission

from pines to alternate hosts.

• Basidiospores—transmission

from alternate hosts to pines.

U. S. distribution of WPBR

U S Forest Service, Forest Health ProtectionU.S. & Canadian

pines impacted:

• Whitebark pine

• Limber pine

• Southwestern

white pine

• Sugar pine

• Western white

pine

• Foxtail pine

• Rocky Mountain

bristlecone pine

Not yet infected:

• Great Basin

bristlecone pine

0%

Roughly estimated

percent blister rust

infection across each

region

Mountain Pine Beetle

20 year outbreak

Mountain pine beetle MPB mortality in whitebark pine

• Major losses of mature, cone-bearing trees over two decades.

• Loss of trees resistant to WPBR.

• Some research shows preference by MPB for trees weakened by WPBR.

• Outbreak still active: diminishing in Rockies, active in the western distribution.

Whitebark Pine Mortality from MPB 1997-2016

45,891 85,257 91,037

218,121

679,372

939,450

1,088,748

-

200,000

400,000

600,000

800,000

1,000,000

1,200,000

NV CA OR WA ID MT WY

1997-2016 Cumulative Whitebark Pine MPB Footprint: Total 3,147,876 Acres (~25% range)

FHP National Risk Maps FHP National Risk Maps

Fire exclusion leads to advancing succession

• Aggressive fire exclusion since early

20th century.

• Altered fire regimes have led to

successional replacement of whitebark

pine in several regions.

(Warwell et al. 2007)

Climate change CC

and whitebark pine

• Predictions based on

Species Distribution Models

(Bioclimatic Envelope

Models): WP upwards and

northwards.

We need to add cc mitigation

to restoration:

• Rely on resilience in

established whitebark pine.

• Find local refugia.

• Use genetic diversity.

Four case histories

• Northern U.S. Rocky Mountains

• The Greater Yellowstone Area

• Treeline and northern edge communities

• The southern Sierra Nevada

All case histories demonstrate that Cronartium ribicola is still spreading geographically and intensifying within communities.

Currently, WPBR is an existential threat to whitebark pine.

Northern Rocky Mountains

The northern Rocky Mountains, US, and southern Rocky Mountains, Canada, are the epicenter of whitebark pine decline. Climate eminently suited to the survival and spread of Cronartium ribicola (BR). Brief history (McDonald and Hoff 2001):

• BR introduced to Pacific NW around 1910.

• Climatic “Wave years”: 1913, 1917, 1921, 1923, 1927, 1936.

• First detected on WP in 1926 in coastal range, BC.

• Idaho 1923 in western white pine.

• Northern Idaho 1938.

• Continental Divide, Glacier National Park 1939.

The Northern Rocky Mountains has many areas with little to no living whitebark pine or trees so damaged, the communities are non-functional.

Northern Rocky

Mountains, USForest Health Protection

Risk Map

Surveys Living trees, Mean percent BR

Smith et al. 2008:

Glacier NP 67% (1-100%)

Waterton Lakes 71.5 (22-97%)

Elk, Flathead Valleys 67.4% (41-95%)

Zeglen 2002:

Cranbrook region 44.9%

Keane et al. 1994:

Bob Marshall WA 48% (10-99%)

Keane & Arno 1993:

Western Montana 61% (20-90%)

FHP National Risk Maps

Greater Yellowstone Area

Yellowstone was originally considered to be too cold and dry to support BR (Kendall and Asebrook 1998)

• BR found on Ribes in the Gallatin NF in 1937; found at Mammoth Hot Springs in YNP in 1944.

• BR began to spread through the YNP.

• Survey in 1961 found 7% infection.

• BR management through Ribes control 1945-1977.

• 8 million Ribes shrubs removed over 175,000 acres.

• $2,420,238 (>$11,112,000 in 1994 dollars).

Monitoring in the GYE since 2007

Greater Yellowstone Whitebark Pine

Monitoring Working Group

2017 report (2016 data), based on

Panel 1 (of 4 panels), 43 transects,

809 trees tagged in 2012:

• 20-30% of whitebark pine infected

by BR

• 6% increase in BR since Panel 1

was surveyed in 2012.

• Distribution of infected (yellow) and

dead trees (black) across the GYE,

monitored since 2013.

Treeline and the northern edge

Willmore Wilderness Park, AB

Divide Mountain, Blackfeet Tribal Lands

The conditions at treeline and at the northern

edge of whitebark pine’s distribution (54.5° N)

should be even less conducive than the GYE to

the establishment and spread of WPBR.

Since 2006, we (L. M. Resler, Virginia Tech,

students) have been studying whitebark pine’s

ecological role at treeline throughout the Rocky

Mountains.

Blister rust at treeline and at the northern edge

Study area

Infection

percent

Willmore Wilderness, AB 1.1

Gibbon Pass, Banff NP 0

Stanley Glacier, Kootenay NP 16.2

Divide Mountain, Glacier NP 23.6

Line Creek, Beartooth Plateau 19.2

Tibbs Butte, Beartooth Plateau 0.6

Paintbrush Divide, Grand Teton NP 18.1

Hurricane Pass, Grand Teton NP 14.1

Christina Mountain, Wind River Range 2.0

The southern Sierra Nevada

BR has been detected in the southern

Sierra Nevada since the 1960’s.

• Primarily in sugar pine and western

white pine.

• A puzzle why Cronartium ribicola

has been slow to infect whitebark

pine, but this is changing.

• Kliejunas and Adams 2003: North

to south spread of BR in the Sierra

Nevada.

• MPB-killed and BR-infected

whitebark pine at Minaret Summit,

near Mammoth Mountain, Inyo

National Forest, southern Sierra,

2016.

Jon Nesmith, NPS

D. F. Tomback

0

5000

10000

15000

20000

25000

30000

35000

40000

45000

1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016

Whitebark Pine MPB ADS Acres by Year 1997-2016

California Nevada Oregon Washington

Surveys of whitebark pine

Duriscoe & Duriscoe 2002

Sequoia and Kings Canyon National Park

• Infection on whitebark pine = 0%

Dunlap 2012, n = 49 plots

Southern Sierra Nevada; scattered plots

in northern California

• Overall mean percent BR = 12% (0-76)

• Northern Sierra plots had higher rust

incidence than southern = 24%

• Southern Sierra Nevada = 4%

FHP National Risk Maps

Whitebark pine restoration• Speed up natural selection by developing and

planting blister-rust resistant seedlings.

• Protect against MPB; reset succession; mitigate

climate change.

Steps in developing blister rust resistance

Protect ripening cones.

Harvest cones.

Grow

seedlings.

Screen

seedlings for resistance.

Protect resistant seed

sources against

mountain pine beetles.

Plant

seedlings.

R. Sniezko

Restoration actions that can benefit from biotechnology*

Developing rust resistance: high priority

Current protocol

• Select putative resistant trees

• Harvest cones

• Grow seedlings until 2-3 years of age

• Screen for genetic resistance through WPBR inoculations

• Score resistance responses for 1 to 5 years

• Outplant field trials

• Goal: Establish seed orchards

(*Tomback and Sniezko. 2017 Western Five-needle White Pine Knowledge Gaps/Priority Needs Informational Brief for WWETAC)

Genomic approaches would shortcut this process

• Blister rust resistance in whitebark pine is highly polygenic.

• Resistance varies geographically (Sniezko et al. 2011; Mahalovich and Hipkins 2011).

• Identification of the genes and their interaction; understanding variation across whitebark pine’s geographic distribution.

Need a high quality genome reference sequence for whitebark pine, likePineRefSeq Project funded by USDA/NRI in 2011.

• Consortium effort to provide high quality genome reference sequences for conifers: Loblolly pine, sugar pine, Douglas-fir.

• Cost to construct a reference sequence for whitebark pine, building on the sugar pine sequence: estimated at about $1 million by D. Neale.

(Mangold, R. 2014. Expansion of whitebark pine restoration methods through tree genomics. Forest Service Briefing Paper. Pacific Northwest Research Station, October 28, 2014.)

Other genomic/biotech applications to facilitate restoration and climate change mitigation

Products expected • Shortcuts for identifying parent trees with blister rust resistance--for example,

rapid tests for resistance, bar-coding.

• Possible ways to identify parent trees with resistance to mountain pine beetle.

• Refined seed transfer zones.

• Determining which genes vary with environment and which environmental factors.

• Determining adaptive potential within populations.

• Determining appropriate genotypes for assisted genotype migration or transfer to mitigate climate change in appropriate steps.

• Identifying genes for resistance in Eurasian stone pines to increase options.

• Strategic breeding programs to develop durable resistance without losing adaptation.

Genomics/biotechnology should be applied to identifying and sorting natural genotypes to attain better adapted phenotypes

Caveats in relation to genomic manipulation:

• Hybridization could result in loss of ESA protection.

• May not have public support.

• May have unintended consequences because of pleiotropic effects.

R. Sniezko, Dorena Genetic Resource Center

Canadian-U.S. collaboration

Interaction and collaboration with Canadian colleagues concerning whitebark pine management and restoration has taken multiple forms.

• Participation in joint professional meetings and exchange of information annually.

• Invitations for U.S. scientists to share expertise, collaborate on projects, and participate in graduate education in Canada, and reciprocal invitations from the U.S.

-- Beginning: 2003 Parks Canada Whitebark Pine and Limber Pine Workshop, Calgary.

--Transboundary: Crown of the Continent High Five Working Group, chartered in 2016.

• Shared participation through the Whitebark Pine Ecosystem Foundation and the establishment of the Whitebark Pine Ecosystem Foundation of Canada.

--Annual Whitebark Pine Ecosystem Foundation Science and Management Workshop, held in Canada every third year (Jasper National Park, Alberta, 2017)

• Coauthorship on U.S. reports and research.

• U.S. scientist and manager review of provincial and Environmental Canada documents related to whitebark pine (and limber pine, which is approved for endangered status under COSEWIC), and requested contribution to U.S. F&WS status review.

Canada has taken leadership in providing protected status for whitebark pine at provincial (Alberta) and national levels (SARA).

• Canada has also been at the conceptual forefront on both application of genomics and forest management under climate change (e.g., Aitken et al. 2008, McLane and Aitken 2012).

The U.S. Forest Service has nearly 70 years’ experience in developing planting stock with blister rust resistance, dating to the early 1950s.

• The U.S. Forest Service has the expertise, infrastructure, capacity, and protocols.

• Primarily two western U.S. facilities which also engage in operational production of seedlings for planting: Dorena Genetic Resource Center and Coeur d’Alene Nursery.

• Canadian agencies, including Parks Canada and BC Forestry are now utilizing our expertise and screening facilities.

• They are at the early stages in developing their own capacity.

• Previously, they relied on field trials, which is more definitive but restricts their capacity. Canada’s natural resource agencies face funding limitations similar to the U.S.

Canadian-U.S. differences in strengths

National Whitebark Pine

Restoration Plan Strategic Plan Approach and Vision

Inyo National Forest, CA

The U.S. Forest Service, Washington Office, American Forests, the Whitebark Pine Ecosystem Foundation are partnering to develop a core area restoration plan for the U.S. distribution of whitebark pine.

Collaborators include all federal and state agencies and tribes with whitebark pine under their jusrisdiction.

This strategic plan will identify selected areas within the U.S. range of whitebark pine for priority restoration, focusing resources.

Components to plan: tentative 10-20 year timeline

Core area restoration

plan

Nominated core areas from each

jurisdiction

Priority designation within each nominated

area

Criteria used to identify core areas

Proposed restoration actions within core areas

Implementation costs for restoration

action across nominated area

Monitoring and adaptive

management strategies

Cost of restoration

One deliverable from the National Whitebark Pine Restoration Plan is estimation of restoration costs for implementation. Funding restoration is anticipated as the outcome of a partnership between government and NGO organizations.

• American Forests develops corporate sponsorships and can work towards restoration goals.

• Restoration on the rangewide scale for whitebark pine will entail costs for:

--Accelerated identification of resistance to WPBR (currently at $1200/family.)

--Seed orchard establishment and maintenance ($15,000/acre).

--Better characterization of adaptive genetic variation across the range.

--Development of restoration strategies considering climate change mitigation.

--Infrastructure development to support resistance development.

--Infrastructure support for operational seedling production.

• Efforts will absorb as much funding as we can raise (several $ million per year).

• Estimated costs per management/restoration action are available from me.

Rob Mutch

The overarching goal of whitebark pine

conservation and restoration is to develop

and sustain healthy and resilient whitebark

pine communities in the face of current and

future challenges.

The National Whitebark Pine Restoration Plan

Thanks to

• Gregg DeNitto, Annalisa Ingegno, Frank Sapio – USFS, R1 Forest Health

Protection

• Jeanine Paschke – USFS, Forest Health Assessment & Applied Sciences

Team, Ft. Collins

• Bob Keane, Lisa Holsinger, Molly Retzlaff – USFS, RMRS, Missoula Fire

Sciences Lab

• Lynn Resler-Virginia Tech, George Malanson-University of Iowa.

• Many research colleagues and students over the years.