Sierra Nevada Meadows, California

Brief Methods: UC Davis compiled the “best available” meadow polygon layers into a single data layer. Data layers were collected from various agencies, individuals, and organizations. Data layer quality varied based on compilation methods and age; some layers were excluded due to poor data quality. A confidence rank (1 = low, 10 = high) was assigned to the remaining layers which were rasterized at a 10m resolution. The layers were combined and combined raster cells with a summed rank of 2 or less were excluded. Raster cells representing open water were also excluded. A majority filter was run on the resulting remaining cells to reduce boundary heterogeneity, which replaced cell values based on the majority of the eight neighboring cells. Individual meadow polygons were created through a raster to vector conversion that treated all contiguous cells as a single part meadow feature with boundaries smoothed using the Polynomial Approximation with Exponential Kernel (PAEK) method (20 m tolerance to reduce edge complexity). Polygons with an area less than 0.4 ha (< 1 acre) were removed from the final meadow composite. Original IDs and other attributes were attached to the meadow polygons. Meadow Polygon Attributes