COMPARING SEED VIABILITY AND HARVEST CONSISTENCY ACROSS SITES AND YEARS FOR THE FEDERALLY ENDANGERED PLANT ERIASTRUM DENSIFOLIUM SPP. SANCTORUM
Ignacio Vera Jr., Darren Sandquist.
California State University Fullerton, Fullerton, CA.
The Santa Ana River woolly star, Eriastrum densifolium spp.sanctorum, is a federally listed, endangered plant species native to the Santa Ana River floodplain in Redlands, CA. Woolly star has a specific habitat preference for young sand deposits that develop after periodic flooding. A major reason for its protection is the lack of such flooding from the Santa Ana River due to regional flood control measures. Suitable woolly star habitat is now significantly reduced and only supports small populations. A seed reserve of approximately 77,000 viable woolly star seeds was collected as part of a larger project that will simulate a small flood in an attempt to artificially generate new woolly star habitat. Seed collections involved formalizing a method for harvesting, sorting, counting, testing viability, and storing the seeds. The methods were tested at three sites and across two years with slightly lower than normal precipitation (2012 and 2013). Our objective was to achieve consistent and reproducible seed recovery across years and sites. Variation across sites was larger than expected, but recovery between years was consistent. Our results indicate that the harvest method appears to be reliable for consistent seed recovery, but that seed production differs significantly between sites.