Type: report

Article abstract: In 2002, Marine Corps Air Station (MCAS) Miramar constructed a new rifle range in San Clemente Canyon along a tributary of the ephemeral drainage that runs through the canyon. One of the conditions for approval of the Rifle Range was that the Federally listed Endangered Species, willowy monardella (Monardella viminea), be monitored for one mile downstream of the rifle range construction. The monitoring was to determine if the altered hydrology from the rifle range construction had any measurable negative impacts to the listed species. The rifle range was built to minimize impacts to the tributary ephemeral drainage of the San Clemente Canyon drainage. During construction the majority of the ephemeral drainage was left intact, however there were places where berms and fences had to cross the drainage and in these spots drainage was culverted. The San Diego Natural History Museum was at the time working on developing a long term willowy monardella monitoring program for MCAS Miramar and was asked to provide monitoring for the requirements of the rifle range that would be compatible with the overall monitoring effort. The dual purpose of this study is: • To see if construction of the rifle range had any negative impacts to the occurrences of willowy monardella downstream • To supplement the data for monitoring willowy monardella on the station as a whole. The project followed the same counting methodology as was used in the larger overall willowy monardella monitoring effort, so demographic data between the two studies is comparable. There are three recent studies of willowy monardella at MCAS Miramar in addition to this one. The largest most comprehensive study is (Long-Term Monitoring Plan and Baseline Survey of Willowy Monardella at MCAS Miramar, San Diego, CA, Rebman and Dossey, 2006). Two smaller related studies are (Willowy Monardella Monitoring Survey 2005, Tierra Data Inc., 2005 and 2006 Willowy Monardella Census and Long-term Monitoring Program Status Review, Dossey and Rebman, 2006). A generalized discussion of how this study relates to those studies and a comparison of conclusions is provided at the end of this document.