FLORA OF THE SAN JOSÉ HILLS A Thesis Presented to the Faculty of California State Polytechnic University, Pomona In Partial Fulfillment Of the Requirements for the Degree Master of Science In Biological Sciences By Asseneth Eileen Berbeo 2017 SIGNATURE PAGE THESIS: FLORA OF THE SAN JOSÉ HILLS AUTHOR: Asseneth Eileen Berbeo DATE SUBMITTED: Summer 2017 Biological Sciences Department Dr. Edward G. Bobich Thesis Committee Chair Biological Sciences Dr. Curtis Clark Biological Sciences Dr. Erin Questad Biological Sciences ii ACKNOWLEDGEMENTS The conception of this flora of the San José Hills started as curiosity about the plants that could be found in the Voorhis Ecological Reserve and the hillsides surrounding the school while I was an undergraduate student at Cal Poly Pomona. That curiosity was fostered by my advisor and Committee Chair, Dr. Edward Bobich of the Biological Sciences Department at California Polytechnic University, Pomona. Dr. Bobich has been a source of encouragement throughout my educational career as an undergraduate and graduate student, and I would like to thank him for his unwavering belief in me and his outstanding support in the creation of this flora. I would also like to include special thanks to Dr. Curtis Clark of the Biological Sciences Department at California Polytechnic University, Pomona and Dr. Erin Questad of the Biological Sciences Department at California Polytechnic University, Pomona for their valuable input in the creation of this thesis. Dr. Clark’s guidance in taxonomy and nomenclature was essential in proper completion of this thesis, and I am very grateful to him for his tireless help. Dr. Questad’s direction in the use of GIS and description of ecological phenomena has been most appreciated. I would also like to thank sources of support and inspiration during the creation of this flora, including rare plant botanist Dr. Fred Roberts for information on the oaks of Southern California and encouragement for the compilation of the checklist, Dr. Naomi Fraga of Claremont Graduate University who went out on the field with me to locate a population of Dudleya multicaulis in the Hills and helped identify Petunia parviflora from my study site, and Dr. Travis Columbus of Claremont Graduate University who encouraged and supported me in the presentation of my research at the 2016 Botanical Society of America meeting. I would also like to thank the myriad of people that assisted me in the field, including Myana Anderson, Jessica Chu, Cristina Ciranda, Naomi Fraga, Erika Gardner, Jason Hebert, Carina Jimenez, Christine Lythgowe, Jeff Martinez, Mark Mazhnyy, Zobeida Merlos, Neil Negrete, Joshua Paolini, Kaia Partlow, Jena Portanova, Jessica Robles, Margaux Rutherford, Greg Straton, and Christina Varnava. Finally, I am thankful for the support of my friends and family for believing in me and encouraging me in my endeavors. Special thanks to my best friends Midori O’Hara and Julián Páez, who carried me throughout my undergraduate and graduate studies with love and support. This study would not have been possible without funding from the National Science Foundation’s BioTiER Fellowship, the Southern California Botanists’ Susan Hobbs Grant for Field Research, the Orange County Chapter of the California Native Plant Society’s Charlie O’Neill Grant, the U.S. Department of Education CCRAA grant and the California State Polytechnic University, Pomona for the Ernest Prete Jr. Environmental Science Student Research Fellowship and Student Conference Travel Award, and The Dr. Harold Lint Biological Sciences Memorial Scholarship. I am grateful to all of these fine institutions for backing my study and making possible the creation of the Flora of the San José Hills. iii ABSTRACT The San José Hills are part of an important wildlife corridor between the Peninsular and Transverse Ranges of Southern California. Over the last few centuries, the natural areas of the San José Hills have been greatly reduced because of agriculture and, more recently, urbanization. However, the stands of native coastal sage scrub, which include California Gnatcatcher breeding grounds, woodlands, much of which are dominated by the threatened Southern California black walnut, and riparian habitats have led to the recognition of much of the Hills as a Significant Ecological Area. Voucher samples were collected in all areas of the San José Hills and identified using dichotomous keys; the location and habitat of each specimen was also recorded. Vouchers were mounted and preserved to be used as representative specimens. In addition to 78 newly vouchered taxa, 1189 records of collections in the San José Hills were found through research of the historical collections in the Consortium of California Herbaria. Historical records were concentrated mainly in the Voorhis Ecological Reserve (Cal Poly Pomona) and Puddingstone Reservoir and Dam in Bonelli Regional Park. A total of 571 minimum rank taxa have been catalogued from field research and record searches. Although the Hills have a relatively large number of native species, non-native species make up a third of the flora. Perennials are in higher abundance in the hills than annuals. Approximately 3% of the flora is included in the California Native Plant Society’s Inventory of Rare and Endangered Plants. Thirteen percent of the species in the Hills were not recorded before this study. iv TABLE OF CONTENTS Signature Page……………………………………………………………………………ii Acknowledgements………………………………………………………………………iii Abstract…………………………………………………………………………………...iv List of Tables…………………………………………………………………...………...vi List of Figures………………………………………………………………...……….…vii INTRODUCTION…………………………………………………………….…………..1 METHODS………………………………………………………………………………13 RESULTS………………………………………………………………………………..14 DISCUSSION……………………………………………………………………………30 REFERENCES…………………………………………………………………………..25 v LIST OF TABLES Table 1. Institutions that house vouchers from the San José Hills used in this study …23 Table 2. Five largest families and six largest genera in the San José Hills flora ……….24 Table 3. Numerical summary of the San José Hills flora ….….….….….….….….…...25 Table 4. CNPS listed plants in the San José Hills ….….….….….….….….…...………26 vi LIST OF FIGURES Figure 1 Map of the San José Hills and its location in Southern California ….……..…11 Figure 2 Surveyed areas within the study site of the San José Hills ……………………12 Figure 3 Map showing the San José Fault ……………………………………………....13 Figure 4 USGS map of Glendora Volcanic Formation within the San José Hills.............14 Figure 5 Klimadiagramm of average monthly total precipitation and average monthly temperature within the San José Hills …………………………………….......15 vii INTRODUCTION The San José Hills are a unique geologic formation that provides habitat for a large number of organisms within the megalopolis that is Southern California. The hills are at the intersection of the Transverse Ranges, the Peninsular Ranges and the Los Angeles Basin (McCulloh et al. 2001; Yeats 2004) and, along with the Puente and Chino Hills, are an important component of the wildlife corridor connecting the San Gabriel Mountains to the Santa Ana Mountains by forming a string of natural habitat islands in the urbanized landscapes of the San Gabriel Watershed and Pomona Valley (PCR Services Corporation 2006; Moore and Iacofano, Inc. 2006; CSUPUP [sic] 2011; Fig. 1). Portions of the San José Hills, including Bonelli Regional Park, Walnut Creek, the Buzzard Peak Open Space, the Voorhis Ecological Reserve on the campus of California State Polytechnic University, Pomona (Cal Poly Pomona), and unincorporated open spaces, have been designated as part of the planned East San Gabriel Valley Significant Ecological Area (SEA), which is proposed to include the existing Buzzard Peak-San José Hills SEA. These areas were given such a designation by Los Angeles County because they are irreplaceable, unique, of relatively limited distribution, and of particular value to wildlife (AHBE 2011; LACDORP 2017). Thus, cataloging the flora of the San José Hills is important for understanding the overall diversity of the region and as evidence for the continued protection of open spaces within the hills. The California Floristic Province is designated a Biodiversity Hotspot because it has a relatively high abundance of endemic and rare species in sensitive habitats (Dugger & Ambrose 2012). It is one of only 34 regions around the world that support 1500 endemic plant species and/or have lost > 70% of their original habitat (Dugger & 1 Ambrose 2012). As the region has historically only recently been disturbed by humans, the relatively short interval of habitat loss and fragmentation has allowed for a higher retention of plant diversity (Foley et al. 2005). An unusually high diversity of annuals as compared to worldwide numbers and low extinction rates in California lineages also contribute to high diversity in native species (Baldwin 2014). The steep ecological gradient created by geology, topography, and geography allows for migration of species provides edaphic heterogeneity, and forms a wide variety of habitats related to elevation, promoting evolutionary divergence (Lozano and Schwartz 2005; Baldwin 2014). With a growing biodiversity crisis around the world, attention is focused on vegetation types rich in species, including threatened communities (Hernandez and Knudsen 2012). The coastal sage scrub and the Southern California black walnut woodlands, both of which occur in the San José Hills, are listed as threatened communities because they