Site Establishment Survey - Terrestrial Species Stressor Monitoring [ds2831]

A grid of hexagons adapted from the USDA Forest Inventory and Analysis program, each having an approximate radius of 2,600 meters, was used as the sampling frame. Initially, a spatially-balanced, stratified random sampling approach was used to identify hexagons to be included in the study.

Vegetation maps from a variety of sources were used to calculate the total cover of key lifeforms within each ecoregion. These lifeforms were determined based not only on distinct categories of vegetation, but also on habitats or features known or thought to be important to wildlife. A spatially-balanced random sample was drawn for the Mojave Desert ecoregion, while site selection in the Great Valley was more opportunistic based on the greater proportion of private land ownership.To select discrete survey locations within the hexagons, a finer-scale grid of approximately 2,400 points spaced 100 meters apart was created within each selected hexagon; for parcels that did not encompass an entire hexagon, the 100-meter grid was limited to the area within the parcel boundary.