Source: California Invasive Plant Council

URL of this page:

Invasive Plant Mapping

CalWeedMapper screenshot
CalWeedMapper displays statewide maps on invasive plants.

Mapping invasive plant populations is critical for strategic management and monitoring. It is also essential for effective early detection. Knowing where a plant currently grows is the foundation for knowing where to survey for new occurrences.


Cal-IPC combined expert knowledge and GIS datasets to produce statewide maps for all species in the Cal-IPC Inventory. We also modeled the potential suitable range of some species based on climate data to project where species might spread in the future. Users can download reports by species or region as well as contribute information for their area. Visit CalWeedMapper to view maps, download reports, and contribute data.

Sierra Nevada Regional Priorities

This report presents statewide risk maps and priority management recommendations for 43 invasive plant species selected to be of special importance for the Sierra Nevada region of California. Maps include current distribution, suitable range in 2010, and projected suitable range for 2050. Recommendations include priority eradication, containment, and surveillance opportunities for each Weed Management Area in the region.

Arundo Mapping and Impacts

In 2007-10, Cal-IPC mapped Arundo donax (giant reed) in coastal watersheds from Monterey Bay to the Mexican border. Arundo has a major impact on these watersheds, and the state has undertaken extensive removal efforts along the Santa Ana River. These detailed maps provide land managers with information to plan similar projects. In addition, the project endeavors to quantify impacts on these watersheds by combining impact metrics with spatial extent. Maps, GIS data, and the impacts report can be accessed from our Arundo mapping page.

Mapping Resources

Cal-IPC Field Course - Cal-IPC periodically offers a field course on Mapping Invasive Plants.

California Weed Mapping Handbook - Provides resources and methods for field collection of weed observation and monitoring data that can be analyzed and shared. Originally published 2002, updated 2012.

North American Weed Management Association - National data standards for mapping invasive plants.

GeoWeed - Mapping database system for GPS/GIS integration maintained by the Sonoma Ecology Center.

Bay Area Early Detection Network (BAEDN) - Collaborative regional effort to identify and treat high-priority early detection targets in the San Francisco Bay Area.

California Dept. of Fish & Game's BIOS - Statewide database and mapper for a range of biological data.

iMap Invasives - Online tool for invasive species reporting and data management nationwide.

EDDMapS - Started in 2005 with Southeastern U.S. focus, is now providing a picture of the distribution of invasive species across the U.S.

Oregon WeedMapper - Oregon Department of Agriculture's site for weed data.

Cal-Atlas - The first place to look for California GIS layers.