California Department of Fish and Wildlife


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Department of Fish & Wildlife
Biogeographic Data Branch
1807 13th Street, Suite 202
Sacramento, CA 95811
(916) 322-2493 • Email BDB

ACE-II: GIS Data and Ecoregional Model

The ACE-II project team developed spatial data layers that depict California’s biological diversity and recreational opportunities. The GIS data layers can be displayed in the ACE-II Viewer or are available by request.

Statewide GIS Data

The ACE-II biological richness data include native richness and rarity layers developed for each of six taxonomic groups: birds, fish, amphibians, plants, mammals, and reptiles. Information on the location of four sensitive habitat types, wetlands, riparian, rare upland natural communities, and high value salmonid habitat, was also assembled. The layers can be used to view the distribution of richness and rarity, by individual taxonomic group and overall, throughout the state and within each USDA ecoregion.

The ACE II recreational data include maps of harvest species richness, recreational access opportunities, hunting demand and hunting use. These maps provide coarse-scale representations of specific recreational needs and opportunities statewide.

Tables of data layers. All data are applied to a statewide, 2.5 square mile hexagon grid.

Category Layer Source Process
Native species richness Birds CWHR ranges Count of number of species per hex.
Fish Brown & Moyle ranges
Plants Jepson Ecoregions based on The Jepson Manual (Hickman 1993).
Rarity-weighted richness index (RWI) Birds CNDDB records (excluding extirpated records and records with accuracy of >1 mile) and additional museum records. All records were buffered by 1 mile to standardize accuracy. RWI=
Σ 1/# hexes per species
(the species found in the fewest number of hexes have the highest values)
Rare Species Richness Birds Count of number of rare species per hex.
Riparian Habitat mapped by Calveg, CNDDB, DWR, NWI, local maps All hexes with a mapped location of the habitat type marked as presences (0=not present; 1=present).
Rare natural communities CNDDB mapped Rare natural communities excluding riparian and wetland habitats from CNDDB and local vegetation maps.
High value salmonid habitat COHO, steelhead, and heritage native trout watersheds.
Category Layer Source Process
Harvest species richness Bird CWHR range maps Count of number of harvest species per hex.
Fish and Amphibian Brown & Moyle ranges and CWHR range maps
Hunting demand Deer tag demand DFG data # of tags available / # of tag applications, averaged over multiple years.
Waterfowl hunt demand # available hunting spots / # of applicants, averaged over multiple years.
Recreational access Percentage public huntable lands per county Green-info ownership layer Area of public huntable lands / Total area of county
Fishing opportunity locations DFG data Presence or absence per hex of DFG fishing guide locations, DFG lands with fishing opportunity, or fish plant locations (past 8 years).
Wildlife viewing opportunity locations Green-info ownership layer and Watchable Wildlife locations Presence or absence per hex of all state and federal public lands and Watchable Wildlife locations.
Hunting use (harvest per county) Deer DFG tag returns 10- year avg of tag returns per county
Waterfowl FWS and DFG
Elk DFG tag returns
Pronghorn DFG tag returns
Wild pig DFG data
Bear DFG tag returns


Ecoregional Model

The ecoregional GIS data layers depict the biological index model results by USDA Ecoregion Section.

The ecoregional analysis combined four biological richness indices, native species richness, rare species richness, “irreplaceability” (i.e., rarity-weighted richness), and the presence of sensitive habitats, in a weighted additive model to produce the ACE II biological index surface. The model results show the areas of highest richness and rarity within each ecoregion of the state. Areas with a high biological index score would be expected to have high conservation value and meet multiple conservation goals, subject to certain assumptions and limitations. A full description of the data collection and modeling process, as well as the assumptions and limitations of this process, is available in the ACE-II Project Report.

Because each ecoregion was analyzed separately, the biological index surface is meant to be viewed only one ecoregion at a time; biological index scores are not directly comparable between ecoregions. The model results for individual ecoregions can be displayed in the ACE-II Viewer or are available by request.