THE OCCURRENCE AND DISTRIBUTION OF UMBELLULARIA CALIFORNICA IN THE BIG BASIN AREA, SANTA CRUZ MOUNTAINS, CA A Thesis Presented to the Faculty of California State University, Hayward In Partial Fulfillment of the Requirements for the Degree Master of Arts in Geography By Steven D. Guiney October 1990 THE OCCURRENCE AND DISTRIBUTION OF UMBELLULARIA CALIFORNICA IN THE BIG BASIN AREA, SANTA CRUZ MOUNTAINS, CA By Steven D. Guiney Approved: Date: s ~ /?f't1 ~7f~~/W /2 /Vt1Y6H~~ /9?a ii TABLE OF CONTENTS Chapter Page I. INTRODUCTION ·· · · · ·· · · 1 II. AN OVERVIEW ·· · · · ·· · ·· · ·· · · 6 III. BIG BASIN PHYTO-PHYSICAL GEOGRAPHY ···· 9 IV. HISTORICAL PLANT GEOGRAPHY · · 44 V. ECOLOGICAL PLANT GEOGRAPHY · · · · 47 VI. PHYSIOGRAPHIC PLANT GEOGRAPHY · · · · · · 52 VII. DISTURBANCE FACTORS · · · 54 VIII. CONCLUSIONS · · · · · ··· · · · · · 58 BIBLIOGRAPHY · · · ·· · ·· · ·· 61 iii '""-<-- LIST OF FIGURES AND TABLES Figure Page 1 Study Area .. · ·· · ··· . 4 2 Elevations . .. · ···· · 11 3 Climatograph Explanation · · · · · · 17 4 Santa Cruz Climatograph · · · 18 5 Henry Cowell Climatograph ·· · 19 6 Ben Lomond Climatograph ·· ·· · · 20 7 Big Basin Climatograph · · ·· · 21 8 Henry Cowell Transects · 24 9 Portola Transects · ·· 25 10 Big Basin Soils ···· . 26 11 Big Basin Vegetation · · ·· 28 Table 1 Individuals/Species. 34 2 Density 35 3 Coverage . 36 iv LIST OF PHOTOS Photo Page SITE 1 37 SITE 2 38 SITE 3 41 SITE 4 42 SITE 5 43 v INTRODUCTION The coastal redwood forest of Central California is composed principally of four kinds of trees: coast redwood (Sequoia sempervirens), Douglas fir (Pseudotsuga menziesii), tan oak (Lithocarpus densiflora) and California bay (Umbellularia californica). All of these are found in Big Basin Redwoods State Park and adjacent areas in the Santa Cruz Mountains. Big Basin, unlike most other areas of the Santa Cruz Mountains, has relatively few bay trees. In fact there are only ten areas where Umbellularia is found in the 16,000 plus acres of Big Basin Redwoods State Park. That the California bay has been conspicuous by its scarcity has been noted by several authors (Orr, 1936; Meadows, 1950; Cooney­ Lazaneo and Lyons, 1981), but there has been no attempt to document the location of all occurrences of Umbellularia in Big Basin nor any attempt to account for the relative absence of this tree. Purpose The purpose of this thesis is to document the location of Umbellularia in Big Basin Redwoods State Park, compare these locational occurrences with other areas outside Big Basin and attempt to determine why the California bay is so rare in Big Basin. 1 2 Methodology Several research methods were used in this investigation. Field verification was made of all the known locations of occurrence of Umbellularia in Big Basin, as listed in the Natural History Survey File at Big Basin Redwoods State Park headquarters. Likely locations of occurrence, based on preferred habitats of Umbellularia (Folwells 1953, Peattie 1953 and Stein 1965), were also field checked in Big Basin, Henry Cowell Redwoods State Park and Portola State Park. These latter two parks were investigated for comparative data. The focus was on Big Basin; no other area was checked for likely locations of occurrence as intensively as Big Basin. Surrounding flora and site conditions (slopes, indications of ground disturbance, etc.) were noted at known and found locations of occurrence, and transects were run at nine sites. The literature concerning historical or evolutionary plant geography with special reference to Umbellularia and ecological plant geography with special attention to reproductive ecology of bay was reviewed as an aid in determining likely unknown locations of occurrence, and in understanding under what conditions Umbellularia reproduces. Coincidences between occurrence of bay and old­ growth, virgin redwood forest; areas of disturbance (e.g. logging, fire, landslides); landforms; and soils were also 3 investigated. Study Area Description The study area includes Big Basin Redwoods State Park and adjacent areas in the Santa Cruz Mountains. The most intense scrutiny was given to Big Basin, the majority of which is the Waddell Creek watershed. Big Basin is located in the Santa Cruz Mountains of northwestern Santa Cruz County, California. It ranges in elevation from sea level to over 650 meters above sea level, from the marshy mouth of Waddell creek through dense redwood forest to chaparral-covered ridgetops. The other areas which are included in this study are smaller than Big Basin and do not have the variety of vegetation types nor as great relief. The study area lies between 37 0 07' North latitude and 37 0 12' North latitude and 122 0 10' West longitude and 122 0 20' West longitude (Fig. 1). The entire area consists of steeply sloping hills, mountains and canyons with few large, level areas. The main exceptions to this are the center of Big Basin, the visitor center area of Henry Cowell Redwoods State Park and along lower Waddell Creek. Even these areas are not unbroken expanses of level terrain. With the exception of the trail from the coast at Rancho del Oso, all routes into Big Basin lead down once the park boundary is reached. Big Basin is truly a descriptive 4 ~ (:) 'P 1.- \ /~ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ Figure 1: Study Area ~ 5 name. If you walk around its rim, which is breached only where Waddell Creek passes in a deep canyon to the coast, Big Basin appears to be rather a lumpy basin for it has hills and ridges within it. Covered variously with chaparral, the more xeric species of mixed evergreen forest and knobcone pine (Pinus attenuata), the rim is a harsh environment. Although very wet in winter, the rim experiences hot, dry summers with little or no fog. Descending from the rim, one passes from this harsher environment into the wetter, cooler environment of the mesic mixed evergreen forest and in the heart of Big Basin, the redwood forest. The former is dominated by Douglas fir; the latter by coast redwood with associates such as Douglas fir and tan oak. On the Basin floor is virgin redwood forest. It shows no signs of the logger's axe, crosscut saw or chainsaw. The redwoods here are massive and spaced far apart. Interspersed among them are Douglas fir and tan oak. The understory is mostly huckleberry (Vaccinium ovatum) . There is no pungent odor of wet or crushed bay leaves; virtually nowhere does one see the shiny green leaves of the California bay tree. In fact, a very sharp lookout and some amount of luck are necessary to see any bay at all in Big Basin. AN OVERVIEW Umbellularia californica (H. & A.) Nutt. is monotypic; it is the only species in its genus. A member of the Lauraceae, or laurel family, California bay is presumably related to the sassafras (Sassafras albidum) of the Southeastern United States; the Laurus nobilis, or poet's laurel of Mediterranean Europe; and various trees of the genus Cinnamomum, including the camphor tree (Cinnamomum camphora), of East and Southeast Asia (Folwells 1953, Peattie 1953). Origins and Range As a species, bay probably developed after its genetic lineage came in contact with redwood forest members (Mason 1947). An exact area and time of origin of its genetic lineage is unknown, but leaf characteristics of fossil and living individuals are similar to leaves of present day tropical plants (Chaney, 1947). California bay is found along the Coast Ranges in a continuous distribution from the Umpqua River Valley of Oregon to the San Francisco Bay Region. South from there to southern San Diego County it has a discontinuous distribution. The tree also occurs along the Cascade Range and the Sierra Nevada from Mt. Shasta to northern Kern County. Generally found from sea level to about 1200 meters in elevation, bay grows somewhat higher in elevation in the extreme southern portion of its 6 7 range (Folwells, 1953; Critchfield and Griffin, 1972). Autecological Characteristics Umbellularia will grow on many soils if there is constant and plentiful moisture (Folwells, 1953). The most favorable sites for Umbellularia are in riparian zones, along creeks and streams. Other sites with deep, well­ drained alluvial soils, such as valley bottoms which are periodiclly flooded, are also very good habitats for the bay tree. It will grow elsewhere but, in general, bay grows in moist soils. Bay flowers at an early age although seed production is not abundant until the tree is 30 to 40 years old (Folwells, 1953). Insects are the main pollinators of the flowers which appear from December to May. Distribution of the large seed is mostly by gravity and water, but rodents and birds also play an active role. Umbellularia seeds germinate best when they are buried, but due to their large size they require disturbance of the ground or covering by silt deposition to achieve germination. Those seeds that do germinate, do so in the autumn, late winter or early spring, depending on local conditions of temperature and precipitation. Umbellularia also reproduces vegetatively by sprouting (Folwells, 1953; Stein, 1965). Cultural Uses Currently, there are no cultural uses of Umbellularia 8 within Big Basin, other than scenic ones, since there are so few trees and all plants are protected within the park. Outside of the park, especially in the adjacent San Lorenzo Valley, there are retail sales of various types of bay burls and other parts of the trunk and branches of the tree that have been made into small tables, bowls and similar objects. There is a larger trade in these items along the North Coast of California and in Southwest Oregon where the tree is commonly called Oregon Myrtle. The oil from the wood and leaves has been used as a pharmaceutical product and as an ingredient in preparations for treatment of headaches, colic and diarrhea (Peattie, 1953). Historically, in Big Basin proper there was probably very little use of the tree since the area was so remote.