FULL RESEARCH ARTICLE The Explicit Integration of Species Conceptual Models and Species Distribution Models as a Best Practice for Systematic Conservation Planning in California MONICA D. PARISI 1* AND STEVEN E. GRECO 1 1 Department of Human Ecology - Landscape Architecture and Environmental Design, One Shields Avenue, Davis, CA, 95616, USA *Corresponding Author: mdparisi@ucdavis.edu Natural Community Conservation Plans (NCCPs) represent the most power- ful tool in statute for regional and systematic conservation planning for species at risk in California. This study examines the use of species conceptual models (SCMs) and species distribution models (SDMs) in such planning. Eighteen Natural Community Conservation Plans (NCCPs) were analyzed to determine if or how explicit connections were made between both types of models for a covered spe- cies and key components of its conservation strategy. Results indicate plans were strong in the use of SDMs, however, each deferred preparing or using SCMs to later management and monitoring phases. A more efective best planning practice for developing a conservation strategy is to explicitly integrate SCMs and SDMs during plan preparation. Key words: endangered species, habitat conservation planning, Natural Community Con- servation Planning (NCCP), species conceptual models, species distribution models _________________________________________________________________________ This is a study of the explicit and efective integration of species models into the plan- ning processes of Natural Community Conservation Plans (NCCPs). As discussed herein, NCCPs are California’s most powerful tool in statute for species conservation on a regional scale, with a higher standard for conservation than federal Habitat Conservation Plans (HCPs). In statute, NCCPs (California Fish & G. Code § 2800 et seq.) are an alternative to the project-by-project incidental take permitting process (Fish & G. Code § 2081) under the California Endangered Species Act (CESA). Such systematic and regional conserva- tion planning is a critical ongoing need for the state and identifying “best practices” for all aspects of creating these plans is also an ongoing need. California has more than 2,000 plant species and more than 400 animal species that are considered to be at risk – meaning they are already state or federally listed as threatened or endangered or are at risk for becoming so (CDFW 2020a). The state’s population is near 40 million and is expected to reach 45 million by the year 2035 (CDOF 2019). Species models serve to gather the collective scientifc knowledge of a species (Franklin 2009). Species account models (SAMs) are verbal accounts, yet they provide www.doi.org/10.51492/cfwj.cesasi.2 California Fish and Wildlife Special CESA Issue:41-60; 2021