This dataset is a compiled meadows layer for the Sierra Nevada containing 17,039 meadow polygons (total area = 77,659 hectares, 191,900 acres).
Brief Methods: UC Davis compiled the âbest availableâ 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 AttributesÂ
We would like to acknowledge the following people for providing meadows data used in the Sierra Nevada Multi-Source Meadow Polygons Compilation (v 1.0):