Chapter er 3 3: Old Growth, D Disturbance, e, F Forest est Succession, an and Man Manage agement in in the the Area Area of 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
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 of 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 Relative Percent Change 20 0 -20 -40 -60 -80 -100 0 25,000 50,000 75,000 100,000 125,000 150,000 175,000 200,000 225,000 250,000 LSR Area (Acres) Loss Gain Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon
Di Diversity o of O Old Gr Growth Dry Forests Moist Forests No Recent Fire History of Low severity fire Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon
Regi gion onal Vari riation on i in Histori orical l Fire re Regi gimes Regime Return Severity Characteristics interval Infrequent, high > 200 years Very large patches of high severity severity, with moderate and low severity Somewhat infrequent 50-200 Mixed severity, including to moderately years large patches of high frequent, mixed severity severity Frequent, Mixed 15-50 years Mixed severity, with Severity medium-sized patches of high severity Very Frequent, low 5-25 years Low severity, with fine severity 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 of 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 on Multiple Successional Pathways: Moist Forests 30-80 y 0-30 y 80 ~200 y 200~800 y 20 ~ 100 y Early Old Growth Successional Stages Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon
Fire re S Suppression on Acr cros oss A All ll D Disturbance R Regi gimes Fire Regime Number of starts Starts suppressed suppressed per 25,000 acres Infrequent-high 4271 12.2 severity Moderately frequent- 2350 13.4 mixed severity Frequent-mixed 2511 15.2 severity Very frequent-low 4240 17.4 severity Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon
Ecol olog ogical E Effects o of F Fire S Suppression on Dry Forests More dense old growth • Less fire-resilient old growth • Moist Forests Larger patches of high severity fire • Less Early Seral Less early seral/non-forest • • Reduced Landscape • Diversity Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon
Role o of 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 oration i on 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 ontinuity • Pat atchwork o of 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 old 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 of o old gr d growth n neede ded d for dr dry forests includi ding dr g drier pa parts o of 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 old 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 ory 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 out 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 Northwest Forest st P Plan Science S Synthesi sis s | Portland, Oregon
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