Natural Variability as a Natural Variability as a Management ParadigmManagement Paradigm

Paleo-Landscape Ecology: Paleo-Landscape Ecology: Reconstructing the Spatial Reconstructing the Spatial and Temporal Dynamics of and Temporal Dynamics of Pacific Northwest ForestsPacific Northwest Forests

Natural Resources Management ParadigmsNatural Resources Management Paradigms

Commodity Production

Species Preservation

Natural Variability

Commodity ProductionCommodity Production

Maximize the production of one or Maximize the production of one or more commoditiesmore commodities

Minimize impacts on other resourcesMinimize impacts on other resources

Species PreservationSpecies Preservation

“…“…maintain viable populations of all maintain viable populations of all native and desirable non-native native and desirable non-native species well distributed throughout species well distributed throughout their range.” (NFMA)their range.” (NFMA)

Economic and social consequences Economic and social consequences are secondaryare secondary

Essentially, this represents reversal Essentially, this represents reversal of priorities of Commodity Production of priorities of Commodity Production ParadigmParadigm

Natural Variability: The Natural Variability: The Precautionary Principle of Precautionary Principle of Ecosystem ManagementEcosystem Management

Describe the range of stand and Describe the range of stand and landscape-level conditions that existed in landscape-level conditions that existed in these forests prior to Euro-American these forests prior to Euro-American settlementsettlement

Design management plans that maintain Design management plans that maintain the system somewhere within this rangethe system somewhere within this range

Natural Resources Management ParadigmsNatural Resources Management Paradigms

Commodity Production

Species Preservation

Natural Variability

1950’s

1980’s

1990’s

“Old” Forestry: circa 1950’s – 1980’s

“New” Forestry: circa mid 1990’s

Return Interval

Swanson et al. 1993

Implementing the Natural Implementing the Natural Variability ConceptVariability Concept

How do you quantify How do you quantify ““The Range of Natural The Range of Natural

Variability”Variability”

Reconstructing Fire History

Number of firesNumber of fires

Fire Frequency and SizeFire Frequency and Size

Fire vs. Timber Harvest: Impact on Fire vs. Timber Harvest: Impact on disturbance ratedisturbance rate

100 yr disp rotation

100 yr disp rotation

50 yr agg rotation

50 yr agg rotation

50 and 100 yr rotations

50 and 100 yr rotations