This project was developed out of research by University of California Cooperative Extension Specialists Luke Macaulay and Van Butsic at UC Berkeley’s Department of Environmental Science, Policy and Management Department.
UC Agriculture and Natural Resources Informatics and GIS Statewide Program developers Shane Feirer, Robert Johnson, and Andy Lyons developed the interface and website. The project was funded through a grant associated with the Renewable Resource Extension Act (RREA) administered by the U.S. Department of Agriculture’s National Institute of Food and Agriculture (NIFA).
Cropland data is derived from the USDA Cropland Data Layer 2016
Forest and Rangeland data is derived from the USGS GAP Land Cover dataset
Ownership data: Parcel data was assembled for all 58 California counties. Parcel data with ownership information for 49 counties was derived from Boundary Solutions Inc., with the remaining nine counties assembled by contacting individual county governments. These county parcel data sets came from varying years, with 49 counties from 2011 to 2015 and nine counties from 2005 to 2010.
After assembling county parcel maps for the entire state, we then dissolved parcels by owner name within each county to remove interior borders of parcels owned by the same entity in the county and to calculate total area under each ownership. After this effort approximately 8% of the state had unknown ownership, so the authors overlaid three separate ownership maps that cover public land and conservation easements to assign ownership to parcels that did not have ownership information from original parcel data (CCED 2015; CDFFP 2014; CPAD 2015). This process reduced unknown ownership to approximately 2.7% of California's total land area (∼2.85 million acres). Ownership information has been left anonymous. The final ownership map was composed of approximately 543,495 properties greater than 5 acres across the state of California.
This study excluded properties smaller than 5 acres under the assumption that properties of less than 5 acres were not oriented towards production agriculture. Ownership statistics are heavily skewed to many small properties and few very large properties, and as such, acreage statistics are greatly affected by the cutoff value of the minimum size of cropland ownership (in this case 5 acres). Raising or lowering the minimum size property in the dataset increases or decreases the mean and median statistics correspondingly.
Researchers interested in collaborating to perform additional analyses of this ownership map can contact Luke Macaulay and Van Butsic.
Macaulay, L.T. & V. Butsic. 2017. Ownership characteristics and crop selection in California cropland. California Agriculture 71(4):221-230.
CCED [California Conservation Easement Database]. California Protected Areas Data Portal 2015. www.calands.org/cced (accessed Apr. 28, 2016)
CDFFP [California Department of Forestry and Fire Protection]. FRAP – CAL FIRE Ownership Download 2014. http://frap.fire.ca.gov/data/frapgisdata-swownership13_2_download (accessed Apr. 28, 2016)
CPAD [California Protected Areas Database]. California Protected Areas Data Portal 2015. www.calands.org/data (accessed Apr. 28, 2016)