Remote Sensing Projects at the UC Stebbins Cold Canyon Preserve Vegetation Mapping on Hardwood Rangelands in California  Spectral Mixture Analysis (SMA) was used to distinguish the fractional abundance of green foliage, dry grass, and soil in Airborne Visible Infrared Imaging Spectrometer (AVIRIS) data. Three maximum likelihood classifications were performed using topographic data only, SMA fractions only, and both topographic and SMA fractions. The predictions were compared to a field based vegetation map and to an aerial photograph of the scene. The combined data set produced the highest correspondence with the vegetation map for an overall correlation of 57% for five classes. Part of the difference was attributed to misclassification in the field based map.   Ustin, S.L., Q.J. Hart, L. Duan and G.J. Scheer (1995) Vegetation Mapping on Hardwood Rangelands in California. International Journal of Remote Sensing  17: 3015-3036.  Estimating Dry Grass Biomass Residues Using AVIRIS Image Analysis  The amount of dry grass residue remaining in grasslands in the autumn is indicative of land management  practices, especially grazing, and for predicting future fire and erosion potentials.  This study has examined factors necessary to provide a remote assessment of grassland condition (biomass, patch distribution), based on a linear spectral mixing analysis of Advanced Visible Infrared Imaging Spectrometer (AVIRIS) images calibrated to surface reflectance for an 80 km2 area east of Lake Berryessa, California.  We have used the endmember fractions of dry grass (mixed annual grasses), green vegetation  (Heteromeles arbitufolia, Toyon), and soils (Sehorn Clay series), contained in a spectral library of common plant and soil materials of the area for the analysis.  The endmember fractions were combined with topographic data (digital elevation model (DEM), slope, aspect, and cumulative drainage) in a Geographic Information System (GIS) and used to produce a maximum likelihood classification of vegetation of the region.  Prediction accuracy of the vegetation map was estimated to be 0.58 overall. Comparison of the predicted vegetation map to high spatial resolution aerial photographs indicated that much of the disparity was due to inaccuracies in the SCCR vegetation map. The finer spatial resolution resolved in the image-based map relative to the field surveyed map, the potential for enclosed classes within larger polygons in the image datasets, and environmental changes occurring after the map was produced (e.g. a 1990 fire), account for most of the inaccuracies relative to the ground map.  Hart, Q.J., S.L. Ustin, G.J. Scheer, and L. Duan (1994), Estimating Dry Grass Biomass Residues Using AVIRIS Image Analysis.  IGARSS '94: Proceedings of the International Geoscience and Remote Sensing Symposium.  August 8-12, 1994, California Institute of Technology.     Estimating Dry Grass Residues Using Landscape Integration Analysis  The acreage of grassland and grassland-savannah is extensive in California, making direct measurement and assessment logistically impossible. The goal of this study was to examine the use of high spectral resolution sensors to distinguish between dry grass and soil in remotely sensed images. Spectral features that distinguish soils and dry plant material in the shortwave infrared (SWIR) region are thought to be primarily caused by cellulose and lignin, biochemicals which are absent from soils or occur as breakdown products in humid substances that lack the narrow-band features. We have used spectral mixing analysis (SMA) combined with Geographic Information Systems (GIS) analysis to characterize plant communities and dry grass biomass. The GIS was used to overlay elevation maps, and vegetation maps with the SMA results. The advantage of non-image data is that it provides an independent source of information for the community classification.   Hart, Q. J., S. L. Ustin, L. Duan, and G. Scheer. (1993). Estimating Dry Grass Residues Using Landscape Integration Analysis. Summaries of the Fourth Annual JPL Airborne Geoscience Workshop, Washington, D. C., 93-26, 89-92.     Measuring Dry Plant Residues in Grasslands: A Case Study Using AVIRIS  Grasslands, savannah, and hardwood rangelands are critical ecosystems and sensitive to disturbance. Estimating the dry biomass residue remaining on rangelands at the end of the growing season provides a basis for evaluating the effectiveness of land management practices. Remote sensing presents a possible method for measuring dry residue. We have investigated the use of AVIRIS to measure dry plant residues over an oak savannah on the eastern slopes of the Coast Range in central California and have asked what spatial and spectral resolutions are needed to quantitatively measure dry plant biomass in this ecosystem.   Fitzgerald, M., and S. L. Ustin. (1992). Measuring Dry Plant Residues in Grasslands: A Case Study Using AVIRIS. Summaries of the Third Annual JPL Airborne Geoscience Workshop, Pasadena, CA, 92-14, 91-93.