Work Accomplished in FY2009 and Findings
Eight Landsat- and eight AWiFS-based habitat-component models were
completed for the WLCI area, including estimates of cover percentage
for shrub, herbs, litter, sagebrush, big 48 sagebrush, Wyoming
sagebrush, and bare ground, and for shrub height. According to an
independent accuracy assessment, primary root mean square error (RMSE)
values for habitat components based on QuickBird (2.4-m resolution)
ranged from 4.90 to 10.16; those based on Landsat (30-m resolution)
ranged from 6.04 to 15.85; and those based on AWiFS (56-m resolution)
ranged from 6.97 to 16.14. The models improved the state-wide
characterization of categorical landcover classes by 8 percent over
the National Land Cover Database for percent shrub, herbaceous, and
bare ground cover, and RMSEs for percent shrub and herbaceous cover
improved a total of 8.34 over LANDFIRE products. Using a direct
cross-year comparison, Xian and others (in press) identified changes
in sagebrush habitat components between 1988 and 2006 for the western
WLCI area. Results indicated that, between 1988 and 2006, a net
increase of 98.83 km2 (0.7 percent) for bare ground was measured over
the entire study area (24,954 km2). Over the same period, the other
four components had net losses of 20.17 km2 (0.6 percent) for
herbaceous vegetation, 30.16 km2 (0.7 percent) for litter, 32.81 km2
(1.5 percent) for sagebrush, and 33.34 km2 (1.2 percent) for shrubs.
Products Completed in FY2009
- Four Landsat-based models for the WLCI area, including
estimates of percentage of cover for shrubs, herbs, litter, and
Wyoming sagebrush canopy.
- Eight AWiFS-based component models for the WLCI area, including
estimates of the percentage of cover for shrub, herbs, litter,
sagebrush, big sagebrush, Wyoming sagebrush, and bare ground canopy,
and for shrub height.
- Data from sampling vegetation at 147 sites across 2 of the 17
WLCI long-term monitoring QuickBird scenes (sites were also sampled
in 2008); the distribution of sites is structured by landscape-scale
patterns of variability as detected in remote-sensing imagery.
- Data from re-sampling permanent monitoring plots at 238 sites
across four QuickBird scenes (sites were also sampled in 2006 and 2008).
- Data from permanent monitoring plots in the QuickBird scene
(site 1), sampled on a seasonal basis (early summer, summer, fall).
- Analysis of change in sagebrush, herbaceous, and bare ground
canopy between 1988 and 2006 for the Landsat scene 37/31 (western
half of the WLCI area) to calculate amount of 18-yr change.
- Trend analysis to detect change in sagebrush components across
four years of permanent plot sampling. Trend analysis incorporated
field plot data, QuickBird imagery, and Landsat imagery.
- Preliminary analyses on associations of vegetation cover (and
variability in cover) with environmental variables (ecosystem
drivers) across the region, based on field sampling.
- Homer, C.G., Aldridge, C.L., Meyer, D.K., and Schell, S., in
press, Implementing a multi-scale remote sensing sagebrush habitat
quantification and monitoring framework across Wyoming: Applied
Earth Observation and Geoinformation, v. X, no. x, p. xx-xx.
