A FLORA OF LAVA BEDS NATIONAL MONUMENT by Sean Bryan Smith A project submitted to the Department of Biology and the Graduate School at Southern Oregon University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE in ENVIRONMENTAL EDUCATION Ashland, Oregon 2008 PROJECT APPROVAL PAGE Approved: Date Dr. Steve Jessup, Committee Chair Date Dr. Frank Lang, Committee Member Date Dr. Charles Welden, Committee Member Date Dr. Josie Wilson, Acting Dean, College of Arts and Sciences ii AKNOWLEDGEMENTS I would like to thank my graduate committee Drs. Steve Jessup, Charles Welden, and Frank Lang for their advice and review of this thesis. Also, thanks to Dave Larson, Chief of Resource Management, and Dave Hays, Resource Specialist, Lava Beds National Monument, for sharing their knowledge of the monument and its resources, and for putting up with a plant geek. This project would not have been possible without funding from the Klamath Inventory and Monitoring Network, National Park Service. A special thanks to Drs. Daniel Sarr and Dennis Odion, of the Klamath Network, for their advice and review of this thesis during the home stretch. iii ABSTRACT A FLORA OF LAVA BEDS NATIONAL MONUMENT By Sean Bryan Smith Lava Beds National Monument, CA, located near the junction of the Sierra, Klamath, Cascade, and Great Basin geological provinces, straddles the boundary between the Modoc Plateau region of the Great Basin floristic province and the Cascade Range region of the California floristic province. The resulting flora, while largely representative of the Great Basin floristic province, also reflects elements of the Cascade and Klamath/Siskiyou regions. Further adding to the floristic diversity are recent geologic phenomena such as cindercones, lava flows, and associated lava tubes, which provide unique topography, edaphic conditions, and microclimates facilitating the existence of disjunct plant populations and species range extensions within the Monument. My effort to inventory all vascular plants occurring in the Monument lasted three seasons (2005-2007). During the course of this project 91 species were added to the Lava Beds National Monument vascular plant list. In total, 368 vascular plant species (including subspecific taxa) have been collected from Lava Beds National Monument. iv TABLE OF CONTENTS I. INTRODUCTION ......................................................................................................... 8 Geography and Topography ......................................................................................... 9 Natural History............................................................................................................ 12 Climate ........................................................................................................................ 21 Modoc History ............................................................................................................ 22 Land Use History ........................................................................................................ 24 Past Vegetation Studies............................................................................................... 25 II. METHODS................................................................................................................. 27 III. RESULTS ................................................................................................................. 30 IV. DISCUSSION ........................................................................................................... 50 Species Categories ...................................................................................................... 50 Chance or Ephemeral Species ................................................................................. 50 Misidentified Species .............................................................................................. 51 Rare or Uncommon Species.................................................................................... 51 Extirpated Species ................................................................................................... 52 Locally Extinct Species........................................................................................... 52 Lava Beds Phytogeography ........................................................................................ 52 Vegetation Zones and Habitat Types .......................................................................... 54 Sagebrush Steppe Zone ........................................................................................... 55 Lava Flows, Caves, and Cindercones ..................................................................... 57 Juniper and Mountain Brush Zone .......................................................................... 58 Pine Forest Zone ..................................................................................................... 60 V. SUMMARY ............................................................................................................... 64 VI. REFERENCES ......................................................................................................... 65 VII. APPENDICES ......................................................................................................... 71 Appendix A. Intended Use of Flora ............................................................................ 72 Appendix B. Taxonomy and Plant Names .................................................................. 74 Appendix C. Key to the Vascular Plants of Lava Beds National Monument ............. 77 Appendix D. Glossary to Key ................................................................................... 169 v LIST OF FIGURES Figure 1. Location of Lava Beds National Monument. ................................................. 10 Figure 2. Map of Lava Beds National Monument. ......................................................... 11 Figure 3. Geologic Map of Lava Beds National Monument.. ........................................ 19 Figure 4. Correlation of map units in Figure 3. .............................................................. 20 Figure 5. A Climograph of annual precipitation and temperature by month.. ................ 22 Figure 6. Habitat types of Lava Beds National Monument. ........................................... 62 vi LIST OF TABLES Table 1. Summary of vascular plants at Lava Beds NM. ............................................... 30 Table 2. Largest vascular plant families at Lava Beds NM. ........................................... 31 Table 3. List of non-native species at Lava Beds National Monument ......................... 31 Table 4. Summary of new species and vouchers ............................................................ 35 Table 5. Rare plants listed by the California Native Plant Society (CNPS) from Lava Beds NM or the immediate vicinity. ............................................................................... 42 Table 6. Species excluded from the Flora of Lava Beds. ............................................... 43 Table 7. Species not observed at Lava Beds during this study and included in the flora. ......................................................................................................................................... 48 vii INTRODUCTION Lava Beds National Monument straddles the geologic boundary of the Modoc Plateau and Cascade Range. As a result, it contains two distinct physiographic regions. The Modoc region is vegetated by sagebrush steppe and the Cascade region by coniferous forest. Recent geologic phenomena such as cindercones, lava flows, and associated lava tubes, provide unique topography, edaphic conditions, and microclimates facilitating the existence of disjunct plant populations and species range extensions within the Monument. The resulting floral elements largely represent the Great Basin Floristic Province, but also include the Cascade, Sierra and Northwestern California regions of the California Floristic Province. Past floristic studies of Lava Beds, while providing an extremely valuable baseline, have become out of date and difficult to obtain. The need for a current comprehensive floristic inventory and dichotomous key detailing species distribution, abundance, and habitat affinities at Lava Beds NM instigated this project. This flora will provide managers and seasonal staff with a comprehensive and professional tool to better identify and manage park resources in the foreseeable future. This project was initiated when the Klamath Inventory and Monitoring Network provided funding to Dr. Steve Jessup to recruit a graduate student to develop a flora of Lava Beds National Monument as a partial fulfillment of MS degree requirements in Environmental Education at Southern Oregon University. Dr. Jessup and the Klamath 8 9 I&M Network selected me for this project. I initiated field work at Lava Beds in late May 2005. A second field season began April 2006. A third field season began in April 2007 Project Objectives: Thoroughly search Lava Beds and compile a list of all vascular plants occurring in the Monument. Locate existing voucher specimens and/or collect voucher specimens for each vascular plant species occurring at Lava Beds. Develop a dichotomous key for all vascular plants collected or known in the Monument. Provide descriptions of distribution, location, and habitat affinities of species within the Monument. Geography and Topography Lava Beds