Land Cover/Vegetation - PWS, Copper River

Data Type: Vegetation/Land Cover/Soils; This data layer is a composite of vegetation and land cover data encompassing all of Prince William Sound and the Copper River drainage and eastern portions of the Kenai Peninsula. Original data sources include the Chugach National Forest Timber Type database, Interim Land Cover Program and Copper River Land Cover images from USGS EROS Alaska Field Office, and the Alaska Land and Resource Mapping System (ALARM) from the Alaska Department of Natural Resources (DNR). All of the original datasets were generalized; merged, and classified according to the Alaska Vegetation Classification, resulting in a generalized layer that broadly characterizes vegetation patterns throughout the area. Characteristics of the original data bases are outlined below; the data sets used to create this composite vegetation layer are documented separately The Chugach NF Timber Type database is a timber oriented vegetation layer based on interpretation of aerial photography. It is the most detailed digital vegetation information available for substantial areas within the greater Prince William Sound ecosystem. The database contains detailed information about timbered areas including species composition, stand density, stocking levels, stand class size, and volume. Many of these timber-oriented descriptions can be useful as surrogates for important ecological variables such as structural information about a given stand. The database also contains less detailed information on non- forest vegetation and cover types. Both the Interim Land Cover and Copper River Land Cover datasets are based on Landsat Multispectral Sensor (MSS) satellite imagery with an original resolution of 80 meters. The Copper River Land Cover data contains more detailed information on shrub and herbaceous communities than the Interim Land Cover Program and the Chugach NF Timber Type datasets. The ALARM datasets are based in part on interpretation of Landsat MSS imagery and aerial photography but have been generalized considerably; the minimum mapping unit used in the ALARM program was 640 acres. Each dataset used to compile this data layer uses a different vegetation classification scheme, a result of intended use and method of data automation. All but the Chugach National Forest Timber Type database use modifications of the Alaska Vegetation Classification scheme (Viereck et al. 1992). Pacific GIS developed a cross-walk from the vegetation types in each data source to the closest equivalent vegetation type in the Alaska Vegetation Classification scheme to provide a common classification that can be used across the ecosystem. Deposited content: descriptive metadata only; underlying research data are not included.