Chapter er 3 3: Old Growth, D Disturbance, e, F Forest est - - PowerPoint PPT Presentation

Chapter er 3 3: Old Growth, D Disturbance, e, F Forest est Succession, an and Man Manage agement in in the the Area Area

• f t

the N Northwest est F Forest rest P Plan

Lea ead A Author: Thomas S Spi pies es, E Emer meritus S Scien entist, P PNW Res esea earch S Station Co-Authors: P. Hessburg, C. Skinner, K. Puettmann, M. Reilly, R. Davis, J. Kertis, J. Long, D. Shaw

Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon

Timber ber Manag agemen ement T Threat at t to Old Growth

Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon

Dynami mics o

• f O

Old Growth S wth Since 1 1994

Dynamics of Old growth in Late Successional Reserves 1994-2013

• Currently 6-12 million ac of OG on federal land

(definition dependent)

• Gains and losses
• Losses to fire were expected
• Regionally variable
• Small net overall decline (~3%)

Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon

Large e Reserves es A Are M e More e Stabl ble T e Than Sma mall Ones es

• 100
• 80
• 60
• 40
• 20

20 40 60 80 100 25,000 50,000 75,000 100,000 125,000 150,000 175,000 200,000 225,000 250,000

Relative Percent Change LSR Area (Acres)

Loss Gain

Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon

Di Diversity o

• f O

Old Gr Growth

Moist Forests Dry Forests No Recent Fire History of Low severity fire

Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon

Regi gion

• nal Vari

riation

• n i

in Histori

• rical

l Fire re Regi gimes

Regime Return interval Severity Characteristics Infrequent, high severity > 200 years Very large patches of high severity, with moderate and low severity Somewhat infrequent to moderately frequent, mixed severity 50-200 years Mixed severity, including large patches of high severity Frequent, Mixed Severity 15-50 years Mixed severity, with medium-sized patches of high severity Very Frequent, low severity 5-25 years Low severity, with fine grained pattern of high severity

Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon

Ideal alized ed vegetat ation mosai aics o

• f differ

eren ent disturban ance r e regimes mes

Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon

Biodiver ersity is M More t e than an t the e Old ld-gr growt wth S Stage ge of Succ ccession

• n

Multiple Successional Pathways: Moist Forests

0-30 y 30-80 y 20 ~ 100 y 80 ~200 y 200~800 y

Early Successional Stages Old Growth

Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon

Fire re S Suppression

• n Acr

cros

• ss A

All ll D Disturbance R Regi gimes

Fire Regime Number of starts suppressed Starts suppressed per 25,000 acres Infrequent-high severity 4271 12.2 Moderately frequent- mixed severity 2350 13.4 Frequent-mixed severity 2511 15.2 Very frequent-low severity 4240 17.4

Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon

Ecol

• log
• gical E

Effects o

• f F

Fire S Suppression

• n

Dry Forests

• More dense old growth
• Less fire-resilient old growth
• Larger patches of high severity fire
• Less early seral/non-forest

Moist Forests

• Less Early Seral
• Reduced Landscape

Diversity

Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon

Role o

• f Ecological History
• History as a guide not a target
• Value of history: understanding how climate

disturbance, succession, and species interact

• Managing for “ecological resilience” to fire

and climate change more tractable framework than restoring to some past condition or process

• But, resilience concept has limitations

Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon

Restor

• ration i
• n in Moist Forests

Plantations in a late-successional reserve Variable Density Thinning

Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon

Cr Crea eating E Ear arly S Ser eral on the W Wes est S Side

Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon

Managi ging f g for R Resili lience ce to Fire re and C Climat mate e Chan ange i e in D Dry F Fores ests

• Thin

inning an and d pr prescribed f d fir ire

• Promo

motin ing l large f fire-re resistant t trees

• Reducing fu

fuel c l con

• ntinuity
• Pat

atchwork o

• f ope

pen an and c d close sed f forest

• Use

se t topo pograp aphy as as a a guid ide

Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon

Summar ary

• NWFP s

stoppe pped l d logg gging of o

• ld g

d growth—slight declines

• Old

d growth ec ecology and and cons nservat atio ion d n dif iffer ers regi gionally ly

• Consider using historical fire regimes for regional

stratification

• New de

definitions o

• f o
• ld gr

d growth n neede ded d for dr dry forests includi ding dr g drier pa parts o

• f the moist f

forests

• Requires both a stand and landscape level component

Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon

Summar ary

• Cons

nser ervatio ion n is more than pr protect cting o

• ld g

d growth

• Importance of other successional stages
• Important role for fire in dry and some “moist” forests
• Ecolo

logica cal h l history i impo portant but b be careful l in how hist stor

• ry i

is s use sed

• Activ

ive m e managem anagement ent f for bio iodiv iver ersit ity and and res esil ilienc ience e ins insid ide and e and o

• ut

utsid ide e res eser erves

• Approaches differ by fire regime and forest type
• Consider creating early seral on west side --factor in wildfire
• Fire suppression still important to protect older forests
• Salvage logging does not typically generate ecological benefits