The Influence of Mountain Pine Beetle Damage on the 1988 Yellowstone Fires

Heather J. Lynch

Paul R. Moorcroft

Remote sensing of fire & insect damage

1972-1975

1979-1982

mountain pine beetle damage

covariatesregression coefficients to be estimated

Spatial Logistic Regression Model:

What is the relationship between previous insect damage and the probability of burning in 1988?

burn/no burn

weather

geographic factors

insect damage

latitude

longitude

€

P(burn) =exp(β 0 + βX)

1+ exp(β 0 + βX)

€

β0 + βX

mean95% confidence interval

Palmer Drought Severity Index

A more negative PDSI is associated with more severe drought. Therefore, as we might expect, more severe drought is associated with a higher probability of burning.

(estimated model coefficients)

Resultsafter model selection, 3 variables remained

(=autocorr)

mean95% confidence interval

Results (cont.)

(estimated model coefficients)

northeast-facing aspect

northeast facing slopes are more likely to burn than southwest facing slopes.

mean95% confidence interval

Results (cont.)

(estimated model coefficients)

repeated mountain pine beetle damage

1972-1975

Repeated mountain pine beetle damage of any intensity during 1972-1975 is associated with an increased risk of burning in the 1988 fires.

mean95% confidence interval

Results (cont.)

(estimated model coefficients)

autocorrelation coefficient

The coefficient associated with the strength of auto-correlation is most dominant.

non-spatial model

Left: burn prob. (red = burned) Right: mis-classified pixels (pink)

auto-correlation only

Left: burn prob. (red = burned) Right: mis-classified pixels (pink)

best-fit model with a random border: 61.0%

of all pixels correctly predicted

Left: burn prob. (red = burned) Right: mis-classified pixels (pink)

best-fit model with a known border: 87.3% of

all pixels correctly predicted

Left: burn prob. (red = burned) Right: mis-classified pixels (pink)

mountain pine beetle activity significantly affects the spatial patterning of forest fires, but only after a time lag of ~15 years

mountain pine beetle activity impacts fire risk primarily through a change in stand structure and not as a direct result of increased fuel loading

Conclusions

Publications: Lynch, H.J. RA Renkin, R.L. Crabtree & P.R. Moorcroft (2006).The Influence of Previous Mountain Pine Beetle Activity on the 1988 Yellowstone Fires. Ecosystems 9: 1318-1327.

HyMap (5.7 m resolution, 126 wavelength bands, airplane mounted)

Satellite-derived estimates of forest insect damage

non-photosynthetic vegetation in red