Record Details

Analyzing fire mosaics in temperate coniferous forests with GIS and remote sensing

ScholarsArchive at Oregon State University

Field Value
Title Analyzing fire mosaics in temperate coniferous forests with GIS and remote sensing
Names Kushla, John D. (creator)
Ripple, William J. (advisor)
Date Issued 1996-02-16 (iso8601)
Note Graduation date: 1996
Abstract This investigation on fire mosaics addressed several aspects:
(1) quantifying the role of terrain variables in fire-related
mortality and historical mean fire return interval (MFRI), (2)
comparing post-burn Landsat Thematic Mapper (TM) imagery, TM
difference imagery, and aerial photo interpretation to map forest
survival after wildfire, and (3) to describe and discuss wildfire
effects on successional stage patterns and wildlife habitat.
The two study sites were located on the Willamette National
Forest in the Oregon Cascades. The Warner Creek burn was the location
of a 1991 wildfire covering 3669 ha; the Upper McKenzie site was the
location of ecological and historical fire studies.
Historical MFRI, terrain, and vegetation data were input into a
geographical information system. Random sampling was conducted on all
layers, and was also used to ground truth forest survival, primarily
with aerial photography. Relationships of terrain to forest survival
and historical MFRI were analyzed with regression. Regression was
also used to model forest survival with TM data. Error matrices were
used to compare classified TM data and aerial photo interpretation in
mapping survival.
At both sites, terrain variables accounted for more variation in
forest survival (12-62%) or historical MFRI (4.8-21.9%) within
individual physiographic areas, than across the respective study
areas. Moreover, the significant topographic variables differed among
individual physiographic areas.
Regressions of TM band transformations were used to evaluate
forest survival. The TM difference imagery with stratification by
pre-f ire tasseled cap (TC) wetness explained 75% of the variation in
live canopy ratio, and post-burn TM Structural Index (SI) accounted
for 72%. Classification of the TM difference imagery with pre-f ire TC
wetness had an overall accuracy of 68%, that of the post-burn SI was
63%, and that from aerial photo interpretation was 56%.
Before the burn, landscape matrix was closed mature/old-growth.
After the burn, the early seral/rock stage expanded, the open
mature/old-growth stage was created, and the closed mature/old-growth
was reduced and fragmented. Thus, overall habitat diversity and edge
increased, but interior habitat decreased. Also, patches of early
seral/rock were more variable in size and complex in shape than
staggered setting clearcuts on public lands.
Genre Thesis
Topic Fire ecology -- Oregon -- Willamette National Forest
Identifier http://hdl.handle.net/1957/10320

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