Conserving Old Forest Biodiversity in Fire-prone Landscapes: Implications

for the Northwest Forest PlanThomas Spies

PNW Research Station

Plan Emphasized

• Threats to old growth from timber production

• Protection of existing older forests • Increasing area of dense,

structurally complex forests• Increasing landscape connectivity

of older forest

Less Recognition of:

• Processes that create and maintain old growth

• Landscape patterns and strategies that reduce risk to loss of old-growth types

Objectives

• Review older forest goals of Northwest Forest Plan

• Review key findings from status and trends report

• Characterize challenges in meeting goals in fire-prone forests

• Discuss alternatives

1. Washington Olympic Peninsula2. Washington Western Lowlands3. Washington Western Cascades4. Washington Eastern Cascades5. Oregon Western Cascades6. Oregon Eastern Cascades7. Oregon Coast Range8. Oregon Willamette Valley9. Oregon Klamath10. California Klamath 11. California Coast Range12. California Cascades

4

Land Use Allocations

Mapped by the Pacific Northwest Interagency Regional Monitoring Program

March 11, 2005

1

2

3

4

5

67

8

9

12

10

11

PHYSIOGRAPHIC PROVINCES

0 50 100 150 20025 Miles

0 80 160 240 32040 Kilometers

Congressionally Reserved (CR)

Administratively Withdrawn (AW)

Late-Successional Reserve (LSR*)

Managed Late-Successional Area (MLSA)

Matrix or Riparian Reserve (MATRR)

Adaptive Management Area (AMA)

Not Designated

* Includes LSRs associated with marbled murrelet or known owl activity centers. Also includes lands with overlapping LSRand AMA designations.

A Variety of Land Allocations WithSeveral Kinds ofReserves

Current Late Successional Reserve-Matrix Concept

Reserve

Older Forest

Plantation

Activities Allowed:

Matrix

All ProvincesThin Plantations

TimberProduction

FuelReduction

Fire Prone Provinces

Younger Natural Forest

FEMATPanel Assessment of

Likelihood of Achieving Old Growth Outcomes

• Outcomes: Within historical range• Fire-infrequent provinces—77 %• Fire-frequent provinces—63 %

Concerns

• Risk of loss of older forest and owl habitat to high severity fire in fire-prone provinces

• Not clear how to reconcile potentially contradictory ecological goals in dry provinces

• Climate change effects--probably most significant in dry provinces

How Have Old Forests Fared Under the Plan?

• So far, so good:• Losses from logging are less than

expected• Losses from wildfire less than

expected• Net increase in older forest greater

than what was expected

14 % (incl B & B)

3.6 %

3 %

9.5 %

2.3 %

0.4 %

0 %

0 %

0 %

Fire Regimes Differ by Province

Percent Loss of Older Forest on a Decadal Basis By Province

1.4 %

0 %

Fuel Reduction in Fire-prone Vegetation Types

• 131,000 acres treated with mechanical or prescribed fire 2003—data is incomplete

• Landscape distribution and effectiveness? • Pre Euro-American settlement

– Mean fire return intervals 3 ~ 50 years for low to moderate severity fire

– Minority of landscape probably in dense old-growth forest types

Mature and Old Growth in High Severity Regimes in Wetter Provinces

Landscape Patterns in High Severity Regimes

Major Types of Old Growth in Fire-Frequent Provinces

Pine with shade tolerant understory--Fire Exclusion

Open Ponderosa Pine--frequent low-severity fire

Courtesy of Norm Johnson

Patchy Douglas-fir/Mixed Conifer/Hardwood--Mixed severity fire

With Fire Exclusion

Heterogeneity in a mixed-conifer forest under a low to moderate severity fire regime

Franklin et al. 1996

Low Moderate High

Low Severity Regime

High SeverityRegime

Per

cent

age

of A

rea

Fire Severity

With Fire Suppression

Fire Severity Distribution Shift with Fire Exclusion

0

10

20

30

40

50

60

70

80

90

100

East West

Low

Mod

High

0

10

20

30

40

50

60

70

80

East West

Low

Mod

High

Lower Slopes

Aspect

Upper Slopes

HistoricalFire SeverityDiffered byTopographyAnd Aspect

Distribution (%)of fire severity 1850-1950in relation toslope positionand aspectKlamath MountainsCalifornia

Taylor and Skinner 1998

% A

rea

% A

rea

NBiscuit Fire2002

Fire Suppression

Time

Str

uctu

ral C

ompl

exit

yHigh SeverityFire

High Severity Fire

High Severity Fire

ff

f

f

Owl Habitat

Structural Dynamics

Hypothesized Risks of High Severity Fire and Risks to Population Viability of in Relation to Area

of Dense Older Forest

Increasing Proportion of open old growth

Increasing Proportion of Owl habitat/dense older forest

Ris

k o

f L

oss

to H

igh

Sev

erit

y F

ire

Ris

k t

o lo

ss o

f O

wl P

opu

lati

ons

Low

High

Low

High

Alternatives on Federal Lands to Current Reserve Strategy

• Implement fuel reduction at landscape levels as allowed in standards and guides

• Make adjustments to land allocations to produce a lower risk pattern of reserves and matrix

• Eliminate allocation boundaries. Use entire landscape to achieve ecological goals. Commodities a by-product of fuel reductions

Fuel TreatmentOpen Old Growth

Limited or no fuel TreatmentDense Old Growth

Matrix = Owl habitat/Dense OGMatrix = Treated forest/Open OG

Alternative Landscape Designs for Maintaining Owl Habitat and Old-growth

Diversity in Fire Prone Forests

Summary

• So far so good, but short and long-term risks to habitat remain and may be increasing

• Landscape-level strategies and implementation are needed

• Alternatives to allocations exist and may be more effective at achieving ecological goals

Mixed Severity Fire Regimes

Fire-frequent ForestsIntegrated Landscape-level strategies

• Consider landscape as a whole• Desired seral stage distribution and pattern

of owl habitat and open older forest• Advantages

– Reduce risk of habitat loss to high severity fire– Provides for open old growth types– May be more cost effective

• Disadvantages ?

Keith Pohs