Global Model Reference Data, 0.5 x 0.5 degree grid-cell

The elevation data layer is used in models to determine high-elevation snow cover, or may be used to determine landscape properties or the direction of overland runoff. Landcover Dataset: The Landcover dataset contains the variable "potential vegetation", which is a classification of each grid cell as a natural vegetation type. This data layer does not contain any type of crop, pasture, urban, or other non-natural vegetation types.

This data layer has been used to estimate the upper range of net primary production and other ecosystem processes in the absence of human intervention. The Soils Dataset: The Soils dataset contains a soil texture variable used to determine many water-related plant processes, including the depth of the root layer and the water-holding capacity of the soil. Because wetland ecosystems function very differently from dry-land ecosystems, we have included a wetland designation data layer to be used along with the potential vegetation data layer: in some models, such as TEM, wetland areas are not included in global or regional model runs.