ecosystem function and health program problem area: quantify and predict ecosystem responses to...
Post on 14-Jan-2016
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Ecosystem Function and Health Program
Problem Area:• Quantify and predict ecosystem responses to
environmental stressors (e.g. climate change).
• Develop statistical models to help managers make informed and defensible predictions.
Haiganoush K PreislerStatistical Scientist
PSW Research Station𝑑𝑁 (𝑡 )= {𝛽 (𝑢) 𝑁 (𝑡 )−𝜀𝑁
(𝑡 )+𝐴 (𝑡 )−𝛿𝑁(𝑡 ) }+𝑑𝑉
Understanding the influence of climate on1. mountain pine beetle outbreaks in:
• Lodgepole pine forests• Whitebark pine forests
2. wildland fire occurrence and size.
How does climate influence beetle outbreaks?
Outbreaks
Beetle pressure
Remaining live trees
Drought stress
Adaptive seasonality
Winter mortalityProbability of an outbreak
Outbreak severity
USFS aerial detection surveys
A mechanistic statistical model
Y = 1 if Stress on tree > Tree toleranceY = 0 otherwise
Stress = number of attacking beetles ~ g1(birth rate) + g2(btp) + g3(live trees)
S = f1( temp, drought) + f2(btp) + f3 (live trees)
T = f4 (drought) f ( ) ~ smooth functions to be
estimated from data
Winter Mortality Adaptive Seasonality
Drought Stress
Study location (LPP study)
Washington
Oregon
Contribution of beetle pressure vs. weather
weather important during initiation, collapse
beetle pressure most important
Influence of Climate on Wildland Fire Occurrence and Size
Climate Variable – Fire Weather Index (FWI)
Other Variables – Distance to road; Forest vs Ag land
Predicted Probability of a large fire per 10km2
11
Westerling et al 2011 Climatic Change
Westerling et al 2011 Climatic Change
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