Climate Change and Forest Biodiversity: A Vulnerability Assessment and Action Plan for National Forests in Western Washington

September 2011USDA Forest Service, Pacific Northwest Region

Carol Aubry, Forest Geneticist, Olympic National Forest

Warren Devine, Forest Researcher

Andy Bower, Forest Geneticist, Olympic National Forest

Robin Shoal, Forest Ecologist, Olympic National Forest

Jeanne Miller, GIS specialist

Nicole Maggiulli, Biologist

The question: How can the three national forests in western Washington conserve biodiversity and increase resilience, given predicted changes in climate?

The goal:A 5-year, practical action plan to implement in partnership w/ NPS, WDNR, PNW Research Station

The focus: Forest tree species, both

widespread and rare Non-forested habitats

vulnerable to climate change

Topics include:

• Selecting a vulnerability assessment approach

• Compiling information

• Applying the vulnerability assessment

• Non-forested habitats

• Tools and management options

• Recommendations and action plan

Selecting a Vulnerability Assessment Approach

Objective: find a flexible, transparent system of rating vulnerability of tree species to climate change

• NatureServe Climate Change Vulnerability Index version 2.0

• Climate Change Sensitivity Database (part of the Pacific Northwest Climate Change Vulnerability Assessment)

• Forest Tree Genetic Risk Assessment System, ForGRAS (Potter & Crane; Eastern Forest Environmental Threat Assessment Center)

Vulnerability Assessment (ForGRAS model)

• Quantitatively rate and rank tree species based on predicted climate change vulnerability

• “..to help land managers and policy makers focus planning activities and thus make the most effective use of limited resources.”

• Spreadsheet model; vulnerability score of 0 to 100 (100=most vulnerable)

• Modified for our objectives and region

• We chose variables based on accepted scientific data

• Peer-review resulted in removal of habitat models

• Assumed increased temperature & summer drought; did not include large-scale disturbances

• 34 tree species

• Grouped for analysis:

• Group 1 – (15) common overstory species

• Group 2 – (15) limited distribution, or midstory/understory

• Group 3 – (4) rare in western Washington: golden chinquapin, whitebark pine, Rocky mountain juniper, ponderosa pine

• Quantitative VA (ForGRAS) applied only to Group 1

• Primary reason was data availability

Compiling Information for the Vulnerability Assessment

Group 1 Species

Pacific silver fir

Grand fir

Subalpine fir

Noble fir

Bigleaf maple

Red alder

Alaska yellow-cedar

Engelmann spruce

Sitka spruce

Western white pine

Black cottonwood

Douglas-fir

Western redcedar

Western hemlock

Mountain hemlock

• Mapped documented occurrences

• Compiled information relevant to climate change vulnerability

• Habitat, reproduction, genetics, threats

Compiling Information for the Vulnerability Assessment

Seed Seed type Cones 3 to 4 in (8 to 10 cm) long and 1.5 to 2 in (3.5 to 5 cm) wide; seeds 0.4 to 0.5 in (10 to 12 mm) long and 0.2 in (4 mm) wide; seeds have a single wing approximately the same length as the seed body; seeds often fall in pairs

Seed-bearing age

Cone production begins around age 20 to 30 years

Seed crop and frequency

Trees have low cone-bearing capacity; generally a poor seed producer, produces a low percentage of sound seed, probably a result of frequent years of low pollen production or the long period of time between pollination and fertilization; good seed crops occur approximately every 3 years

Seed dissemination

Method and dispersal agents

Seeds dispersed by gravity and wind; cones disintegrate as they mature; seeds occasionally dispersed by animals including Douglas squirrel

Distance Seeds not carried far by wind because they are relatively heavy; one third of dropped seed falls beyond 125 ft (38 m) of a stand edge; less than 10 percent falls beyond 375 ft (114 m)

Five Risk Factors (ForGRAS Model)

• Distribution

frequency of occurrence, distribution of occurrences

• Reproductive Capacity

seed production, min. seed-bearing age, seed dispersal distance

• Adaptive Genetic Variation

generalist vs. specialist, disjunct populations

• Habitat Affinities

drought tolerance, successional stage

• Insect and Disease Threats

ID’d by USFS Forest Health Protection

• Trend in increasing vulnerability with increasing mean elevation

• But not sensitive to the elevation variable

• Important findings appeared during the process

• Knowledge gaps

• Some did not influence model, but were part of recommendations

Vulnerability Assessment Results

Tools and Management Options

• Gene conservation• Ex situ and In situ genetic resources (e.g., seed orchards

and seed in storage)

• Monitoring• Tree phenology and growth• Genetic variation and population structure

• Vegetation management options• Thinning and planting• Assisted migration

Non-Forested Habitats

• Most-vulnerable habitats selected and analyzed (non-quantitatively) based on scientific literature and interviews with scientists from the major land management agencies

• Recommendations focused on:

• Need for baseline data

• Improved maps and inventories

• Prioritization of sites for restoration and monitoring

Alpine and subalpine Native dry grasslands Wetlands

Recommendations and Management Actions

Three themes:

1. Learn about and track changes in plant communities as the climate changes

2. Maintain and increase biodiversity and increase resilience

3. Prepare for the future

1. Learn about and track changes in plant communities as the climate changes

Assess health and regeneration of high-elevation species: subalpine fir, mountain hemlock, and Alaska yellow-cedar

Assess genetic variation and population structure of species with disjunct populations:

Noble fir and Pacific silver fir in the Willapa Hills

Engelmann spruce on the Olympic Peninsula

Measure population genetics of golden chinquapin

Establish a pilot program to monitor vegetative and reproductive phenology in seed orchards (with PNW and WDNR)

2. Maintain and increase biodiversity and increase resilience

Develop a pilot project to plant blister rust-resistant western white pine in openings created in young stands

Develop a partnership between the Forest Service, WDNR, and private landowners to map, conserve, and restore the sensitive species golden chinquapin on the Olympic Peninsula

3. Prepare for the future

Partner with other land managers in western Washington to create a virtual cooperative tree seed bank to facilitate large-scale reforestation

Maintain an inventory of high-quality seed for tree species likely to be needed over the next 20 years; assess viability of stored seed

Maintain seed orchards which serve as gene conservation areas and are the national forests’ most efficient source of high-quality tree seed

What’s next?

Analyze five other subregions in OR and WA (2011)

Refine the approach Sensitivity analysis Plant Association

Groups (PAGs)

Combine all results and recommendations into final report (2012)

Acknowledgments

Vicky Erickson, Tom DeMeo, and Kathy O’Halloran for providing financial and program support for this project.

Technical support and advice: Dominique Bachelet, Cheryl Bartlett, Kristen Chadwick, Rex Crawford, Chris Dowling, Gregory Filip, Jeffrey Foster, Joe Gates, Lise Grace, Andrew Gray, Jessica Halofsky, William Hargrove, Bruce Hostetler, Robin Lesher, Laura Potash Martin, Mike Messier, Jeff Muehleck, Marshall Murray, David Peter, Kevin Potter, Iral Ragenovich, Ann Risvold, Joe Rocchio, Regina Rochefort, Andrea Ruchty, Mark Senger, Linda Swartz, Karen Wells, and Beth Willhite.

We thank the following people for reviews: Dominique Bachelet, Cheryl Bartlett, Rex Crawford, Tom DeSpain, Vicky Erickson, Jeffrey Foster, Sharon Friedman, John Gross, Jessica Halofsky, Constance Harrington, Matt Horning, Glenn Howe, Laura Potash Martin, Kathy O’Halloran, Greg O’Neill, David Peterson, Susan Piper, Kevin Potter, Iral Ragenovich, Bryce Richardson, Ann Risvold, Joe Rocchio, Regina Rochefort, Brad St. Clair, Marcus Warwell, and Beth Willhite.

We thank Mary Carr of Forest Service Publishing Arts Staff for editorial support.

For more information, contact Carol Aubry, Olympic National Forest, Olympia, Washington; caubry@fs.fed.us

Subalpine Meadow, Norse Peak Wilderness, Mt. Baker-Snoqualmie National Forest Photo credit-Robin Shoal, USFS