:’T Crossosoma Volume 1 8, Number 1 May, 1992 CONTENTS Descriptions of Three New Southern California Vegetation Types: Southern Cactus Scrub, Southern Coastal Needlegrass Grassland, and Scalebroom Scrub David L. Magney 1 Plants of Mediterranean-Type Climates Robert F. Thorne 13 Vegetation Survey of the Antelope Valley California Poppy Reserve Curtis Clark and Nancy A. Charest 15 Book Reviews 10,25 A New Format for Crossosoma 25 Letters to the Editor 26 Instructions for Contributors 27 LIBRARY ftUG 3 1 1992 NEW VORK BOTANICAL GARDEN Journal of the Southern California Botanists Crossosoma Curtis Clark, Editor Biological Sciences California State Polytechnic University Pomona CA 91768 (714) 869-4062 Crossosoma (ISSN 0891-9100) is published twice a year (May, November) by Southern California Botanists, Inc., a California nonprofit corporation. Subscription rate, $15 per calendar year ($8 for individual members). Back issues are available for $5 an issue or $10 a volume, postpaid (prior to Vol. 18, Crossosoma was published bimonthly, back issues are $2 each, $10 per volume). Manuscripts should be submitted to the editor. Applications for membership, requests for subscriptions or back issues should be sent to Alan Romspert, Treasurer, Department of Biology, California State University, Fullerton CA 92634. Southern California Botanists, Inc. Officers for 1992 President Vice President Terry Daubert Allan A. Schoenherr Treasurer Alan P. Romspert Secretary Board of Directors Judi Bogdanoff-Lord Gery Allan, Henry Bante, Curtis Clark, Julie Greene, Annette Ross, Paula Schiffman Copyright © 1992 by Southern California Botanists, Inc. Descriptions of Three New Southern California Vegetation Types: Southern Cactus Scrub, Southern Coastal Needlegrass Grassland, and Scalebroom Scrub by David L. Magney Jones & Stokes Associates, Inc. 2600 V Street, Suite 100 Sacramento, CA 9581 8-1914 Descriptions of three vegetation types in southern California are suggested: Southern Cactus Scrub, Southern Coastal Needlegrass Grassland, and Scalebroom Scrub. These descriptions are based on field observations throughout central and southern California during fieldwork on a variety of projects. These vegetation types are proposed to be included in the California Department of Fish and Game’s Terrestrial Natural Communities of California , which was developed by Robert F. Holland (1986), and the descriptions for each generally follow Holland’s format. Each of these vegetation types is widely scattered; however, they are never common. In fact, habitats containing these vegetation types are becoming increasingly rare as the result of loss of habitat through urbanization and flood control projects. Each of these vegetation types can easily be classified into larger categories such as coastal sage scrub for Southern Cactus Scrub, grassland for Southern Coastal Needlegrass Grassland, and alluvial scrub for Scalebroom Scrub; however, these general categories do not provide detailed understanding of the dynamics or specifics about various aspects of these vegetation types. To understand the overall ecology of a vegetation type we must first understand and recognize its parts. This understanding can be important to enable ecologists, land use planners, and decision makers to determine the significance of impacts on these vegetation types as the result of development. Therefore, I wish to present some of my personal observations on these new vegetation types. Like any hierarchical classification system such as Holland’s, we can classify the three vegetation types with their counterparts into the more Crossosoma 18(1), May 1992 1 general categories. The descriptions of each new vegetation type include a general description, site factors, dominant and characteristic species, and distribution. VEGETATION DESCRIPTION Southern Cactus Scrub Southern Cactus Scrub is a low, dense (50-85% cover) scrub dominated by succulent shrubs consisting primarily of prickly pear species ( Opuntia littoralis varieties, O. oricola , O. parryi) and Coastal Cholla ( O . prolifera). Southern Cactus Scrub occurs on sandy soils and rocky areas, primarily on south-facing cismontane slopes. It intergrades with Venturan Coastal Sage Scrub and Diegan Coastal Sage Scrub on slightly rioister sites. It is replaced by Maritime Succulent Scrub in south-central Orange County (from Newport Beach southward) and coastal San Diego County and Sonoran Mixed Woody and Succulent Scrub in transmontane southern California. Characteristic associated species include Artemisia californica , Avena barbata , Brassica geniculata, Bromus diandrus , Calochortus splendens , Chaenactis glabriuscula var. tenuifolia , Cryptantha clevelandii , Dudley a lance olata, Eriogonum fasciculatum ssp. foliosum , Mirabilis californica , Opuntia occidentals complex, O. littoralis var. austrocalifornica , O. littoralis var. littoralis , O. littoralis var. vasyi , O. oricola , O. parryi , O. prolifera , Rhus integrifolia , Salvia mellifera , Sambucus mexicana , and Stipa pulchra. Southern Cactus Scrub ranges from coastal southern Santa Barbara County southward to northern San Diego County and inland to cismontane valley areas of San Bernardino and Riverside counties, at elevations mostly below 1,500 feet. In Ventura County, the most representative occurrences are at Ventura/Rincon Hills (e.g. at Taylor Ranch west of Ventura) and the western end of the Santa Monica Mountains (along the Conejo Grade on U.S. Highway 101 to Pt. Mugu). Localized stands occur in the San Joaquin Hills of Orange County (Laguna Beach, Laguna Canyon, Laguna Niguel, Dana Point, Aliso Canyon); smaller stands exist along the coastal hills of Camp Pendleton into San Diego County and continue inland along the San Luis Rey River Drainage, where local populations are well represented between Fallbrook and Pala. At inland sites, Southern Cactus Scrub is well represented at widely scattered localities such as the San Jacinto River 2 Crossosoma 18(1), May 1992 drainage (near State Highway 79 and Gilman Springs Road) and in Elsinore (Rome Hill). The largest and most highly developed sites of this plant community, however, are in the cismontane foothill region of interior Orange Country between the Santa Ana River drainage in the north and the San Juan Creek drainage in the south. Especially large and impressive populations of Southern Cactus Scrub occur at the following sites: south-facing slopes to the north of the Santa Ana River between Yorba Linda and the Riverside County line, the steep volcanic El Modena Hills east of Orange, hillsides and canyon slopes of the Irvine Ranch in the Santiago Creek drainage (Loma Ridge, Limestone and Santiago canyons, south to El Toro Road, east of El Toro), hillsides along the Trabuco Creek drainage, and extensive occurrences on slopes and canyon bottoms of both Bell Canyon and San Juan Canyon in the Santa Ajia Mountain foothills. Indeed, the cismontane foothills and canyons of the Santa Ana Mountains may well represent the epicenter of this plant community in terms of diversity of morphotypes of the prickly pear cacti (see Crossosoma 10(2) 1984). The “type localities” used to form the basis of my description of Southern Cactus Scrub can be seen to the north of the intersection of El Toro Road and Marguerite Parkway east of El Toro in Orange County, and at the bottom of the Conejo Grade along U.S. Highway 101 between Camarillo and Thousand Oaks in Ventura County. Southern Cactus Scrub is threatened with local extirpation throughout its range, particularly in Orange County and western Riverside County where urbanization of undeveloped lands is rampant. The El Toro Road site is slated for destruction by grading for extensive housing developments, transportation corridors, and an electrical substation. Southern Cactus Scrub (at least the southern portion) is also important habitat for the San Diego Cactus Wren (i Campylorhynchus brunneicapillus sandiegoensis), which is currently being considered for federal listing as threatened or endangered pending a review of its taxonomic status (Salata pers. comm.). The north end of the San Diego Cactus Wren habitat is reported as Aliso Creek (in southern Orange County); however, the taxonomic status of coastal populations of the cactus wren further north is unclear at this time. Some taxonomic workers assign the northern populations to the desert subspecies (Rea and Weaver 1990, Willick pers. comm.). Crossosoma 18(1), May 1992 3 Southern Coastal Needlegrass Grassland Southern Coastal Needlegrass Grassland is a midheight (to 1 m) grassland dominated by perennial, tussock-forming Stipa pulchra and other species such as S. cernua and S. lepida. Native and introduced annuals occur between the perennials, often actually exceeding the bunchgrasses in cover. Southern Coastal Needlegrass Grassland usually occurs on fine-textured (often clayey) soils that are moist during winter and very dry during summer drought. It intergrades with Venturan Coastal Sage Scrub, Upper Sonoran Ceanothus Chaparral, Coast Live Oak Woodland and Savanna, and Southern Cactus Scrub on better drained sites. It intergrades and is often associated with Non-native Grassland on grazed or disturbed sites and Deer Grass Grassland in seasonal swales where Stipa pulchra is replaced by Muhlenbergia rigens. Considerable variation in species associations, dominance, richness, and occurrences and abundance of natives is observed in Southern Coastal Needlegrass Grassland due to the history of influence by the intensity of grazing and soil disturbance. Sites with relatively little or no disturbance typically contain a high number of native perennial species and are richer in species than areas with past or present disturbance. Common and characteristic associated species include Achillea millefolium , Agrostis hooveri , A. diegoensis , Avena barbata, A.fatua , Bromus calif ornicus, B. diandrus, B. hordeaceus , B.rubens , Brassica geniculata, B. nigra , B. rapa ssp. sylvestris, Dudleya blochmaniae, Elymus glaucus , Erodium ssp., Eschscholzia californica , Gilia spp., Hemizonia spp., Lasthenia spp., Layia spp., Lepidium spp., Linanthus spp., Lolium multiflorum , Lupinus spp., Melica imperfecta , Melilotus alba , Nemophila spp.. Orthocarpus spp., Pectocarya spp., Phacelia spp., Plagiobothrys spp., Platystemon californicus, Poa scabrella , and Vulpia spp. Typical associations in good-quality stands are monocot bulb species such as Bloomeria crocea, Calochortus catalinae, C. splendens , Dichelostemma pulchellum , and Sisyrinchium bellum , with localized occurrences of Fritillaria biflora , and dicot perennials such as Dodecatheon clevelandii , and to the south Jepsonia parryi and Sidalcea malvaeflora. Disturbed or grazed sites usually have greater numbers of naturalized species of such genera as Avena , Bromus , Brassica , Erodium , and Silybum. Species compositions vary considerably from site to site, from north to south, and from the coast to the more inland components. 4 Crossosoma 18(1), May 1992 Some rare species are sometimes found in Southern Coastal Needlegrass Grassland, including Calochortus catalinae , Dudleya multicaulis , and Hemizonia increscens ssp. villosa. Southern Coastal Needlegrass Grassland is found on coastal terraces, foothills and valleys of the southern coast of California, ranging from Point Conception to San Diego County. It usually occurs below 2,000 feet but reaches high elevations in the coastal Transverse Ranges. The “type locality” for Southern Coastal Needlegrass Grassland is at Gaviota in Santa Barbara County, immediately west of and behind Nick’s Place (formerly a restaurant). Southern Coastal Needlegrass Grassland occurs on both sides of U.S. Highway 101 in the Gaviota area. Thome’s (1976) description of Southern California Grassland includes Southern Coastal Needlegrass Grassland. Scalebroom Scrub Scalebroom Scrub is an open to moderately dense, broad-leaved phreatophytic evergreen scrub that attains a height of 1-1.5 m. It is dominated by Lepidospartum squamatum (Scalebroom), which is primarily restricted to floodplain habitats although it occurs rarely in other habitats such as in the Badlands of Riverside County (Hanes pers. comm.). Common subdominant shrub species include Artemisia californica or A. tridentata ssp. parishii (mainly with desert affinities), plus Sambucus mexicana , and various coastal sage scrub and chaparral species. The open understory areas are typically dominated by ruderal herbaceous species (native and non-native) usually associated with grassland communities. Scattered riparian trees and shrubs are often found in association with Scalebroom and include Platanus racemosa, Baccharis salicifolia , and sometimes Populus fremontii. Scalebroom Scrub is primarily restricted to floodplain habitats containing riverine cobbles, boulders, and sand. These areas apparently flood only occasionally (every 5 to 10 years); therefore, many upland species become established in the streamside habitat. The occasional flooding and sediment reworking, however, is the driving force that maintains this vegetation type dominated by the phreatophyte scalebroom and other nonphreatophytes. Like most vegetation types, dominance can change with time if maintenance factors are not active regularly. In the case of Scalebroom Scrub, the absence of flooding over many years allows woody upland species typical of Riversidean Alluvial Fan Sage Scrub to dominate; Crossosoma 18(1), May 1992 5 therefore, Scalebroom Scrub is likely an early serai stage of Riversidean Alluvial Fan Sage Scrub (Hanes et al. 1979). Scalebroom Scrub also intergrades with and is likely serai to Sycamore Alluvial Woodland, and other upland vegetation types on drier sites and to Mule Fat Scrub and other riparian vegetation types on wetter sites. In floodplains that are not radically altered by humans, Scalebroom Scrub is usually present in at least a portion of the channelbed where flooding occurs of a 5 to 10 year cycle. Herbaceous associates are dominant when flooding has occurred recently, and woody associates increase in dominance when flooding has not occurred recently; however, scalebroom is always present. Common and characteristic associated species of Scalebroom Scrub include Ambrosia acanthicarpa , A. psilostachya , Artemisia dracunculus , Astragalus antisellii, Brassica geniculata, Brickellia californica, Bromus diandrus , B. hordeaceus , B. rubens , B. tectorum, Camissonia bistorta, Chaenactis glabriuscula , Corethrogyne filaginifolia , Croton calif or nicus, Cucurbita foetidissima, Datisca glomerata (wetter sites). Datura wrightii, Elymus condensatus , Eriastrum densifolium, E. sapphirinum , Eriodictyon crassifolium , E. trichocalyx , Eriogonum facsiculatum , E. davidsonii , E. gracile , E. thurberi , Gnaphalium californicum , G. microcephalum. Heterotheca echioides , Heterotheca grandiflora , Lactuca serriola, Lessingia glandulifera , Lupinus luteus , L. sparsiflorus , Marrubium vulgare , Melilotus alba , M indica , Nicotiana glauca , Oryzopsis milicea , Pectocarya spp., Penstemon centranthifolius, P. spectabilis , Phacelia tanacetifolia , Pterostegia drymarioides , trilobata, Salix sessilifolia, Schismus barbatus, Senecio douglasii, Solanum xantii , Sonchus oleraceus, Stephanomeria exigua , & virgata , Vulpia microstachys , K myuros , and Zauschneria californica. The actual species composition at any given site consists of a subset of the species above and varies from north to south and west to east. Scalebroom Scrub occurs in central and southern cismontane California from the Monterey Bay area to northern Baja California. Formerly extensive along floodplain habitats of southern and central California, it is now very much reduced by flood control, agriculture, and urban expansion. Extant populations occur along creeks and rivers in Alameda County (Sharsmith 1982): Arroyo Macho; San Joaquin County (Sharsmith 1982): Hospital Creek; Stanislaus County (Sharsmith 1982): Hospital Creek, Orestimba Creek; Monterey County (Howitt and Howell 1964): Salinas River and tributaries, Arroyo Seco; San Luis Obispo County (Hoover 1970): Estrella River; Kern County 6 Crossosoma 18(1), May 1992 (Twisselmann 1967): Buena Vista Creek, Grapevine Creek, and Cuddy Creek to Castaic Lake (Frazier Park to Lebec); Santa Barbara County (Smith 1976): Santa Maria River (Santa Maria area), Cuyama River, upper Santa Ynez River (below Gibraltar Dam), Santa Cruz Island (central valley); Ventura County (Smith 1976): Ventura River, Matilija Creek, Santa Clara River, upper and middle reaches of Sespe Creek (Potrero John Creek), upper Cuyama River, Dry Creek, lower half of Piru Creek; Los Angeles County: Santa Clara River, San Francisquito Creek, Bee Canyon Wash, Big Tujunga Wash, Castaic Creek, Topanga Canyon (Raven et al. 1986), San Gabriel River, San Antonio Creek; San Bernardino County: Cucamonga Wash, Day Creek, Etiwanda Creek, San Sevaine Wash, Cajon Creek, Santa Ana River, San Timoteo Creek; Riverside County: Santa Ana River, San Timoteo Creek, Murrieta Creek, Temescal Wash, San Jacinto River; Orange County: Santa Ana River, Santiago Creek, upper Aliso Creek (small patches), San Juan Creek (Caspers Park), Trabuco Creek (Porterville), Silverado Creek (extirpated in part by sand and gravel mining); San Diego County (Beauchamp 1986): Fallbrook, Oak Grove, Encinitas, Dodge Calley, Batiquitos Lagoon; and Baja California Norte: Cafion de San Matias; eastward to Nevada and Arizona (Hanes pers. comm.). The “type locality” for Scalebroom Scrub is along the lower portion of San Francisquito Creek in Los Angeles County (Santa Clarita-Newhall-Saugus area). Other good examples include the Ventura River (west of Meiners Oaks in the Ojai Valley), Santa Maria River (just east of U.S. Highway 101), and the lower Nacimiento River at Camp Roberts (southernmost Monterey County). Scalebroom Scrub is the primary sere of Riversidean Alluvial Fan Sage Scrub as suggested by Hanes et al. (1989). Best known examples of Alluvial Scrub are in Cajon Wash in San Bernardino County and Big Tujunga Wash in Los Angeles County (Hanes et al. 1989). The vegetation type does not fall within the U.S. Army Corps of Engineers wetlands jurisdiction (Section 404 of the Clean Water Act) and is frequently ignored as a valuable habitat type. More attention should be given to these and similar habitats in environmental documents such as those prepared under the California Environmental Quality Act. Many areas of Scalebroom Scrub have been extirpated by urbanization, recreational facilities (e.g., offroad vehicle parks and golf courses), sand and gravel mines, and flood control projects. Crossosoma 18(1), May 1992 7 ACKNOWLEDGMENTS I want to thank Robert Holland, Timothy Messick, Fred Roberts, Jr., David Bramlet, Karlin Marsh, Ted Hanes, Curtis Clark, and Geoff Smith for reviewing the manuscript and making valuable suggestions. I also wish to thank J. Robert Haller and Wayne Ferren, Jr. for giving me the tools to recognize, and hopefully understand, the natural environment better. LITERATURE CITED Beauchamp, R.M. 1986. A flora of San Diego County, California. Sweetwater River Press, National City, CA. California Natural Diversity Data Base. 1986. Natural communities: terrestrial section. (November 1986). Sacramento, CA. Hanes, T.L., R.D. Friesen, and K. Keane. 1989. Alluvial scrub vegetation in coastal southern California. In Abell, D.L. (editor) 1989. Proceedings of the California riparian systems conference. September 22-24, 1988. U.S. Forest Service. (General Technical Report PSW-1 10.) Davis, CA. Holland, R.F. 1986. Preliminary descriptions of the terrestrial natural communities of California. The Resources Agency, California Department of Fish and Game, Sacramento, CA. Hoover, R. F. 1970. The vascular plants of San Luis Obispo County, California. University of California Press, Berkeley, CA. Howitt, B.F. and J. T. Howell. 1964. The vascular plants of Monterey County, California. The Wasmann Journal of Biology 22(1). Munz, P.A. 1974. A flora of southern California. University of California Press, Berkeley, CA. Raven, P.H., H.J. Thompson and B.A. Prigge. 1986. Flora of the Santa Monica Mountains, California (2nd Edition). Southern California Botanists Special Publication No. 2. University of California, Los Angeles, CA. Rea, A.M. and K.L. Weaver. 1990. The taxonomy, distribution and status of coastal California cactus wrens. Western Birds 2 1 (3):8 1-1 26. 8 Crossosoma 18(1), May 1992 Sharsmith, H.K. 1982. Flora of the Mount Hamilton Range of California. California Native Plant Society Special Publication Number 6, Berkeley CA. Reprinted from The American Naturalist 34(2):289-367. September 1945. Smith, C.F. 1976. A flora of the Santa Barbara region, California. Santa Barbara Museum of Natural History, Santa Barbara, CA. Smith, R.L. 1980. Alluvial scrub vegetation of the San Gabriel River floodplain, California. Madrofio 23(3): 126-138. Thome, R.F. 1976. The vascular plant communities of California. In Latting, J., Plant communities of southern California; symposium proceedings. California Native Plant Society Special Publication No. 2, Berkeley, CA. Twisselmann, E.C. 1967. A flora of Kem County, California. The Wasmann Journal of Biology 25(1-2). Personal Communiciations Hanes, Ted. 1991. Professor of Botany. Department of Biological Sciences, California State University, Fullerton. Letter concerning distribution of scalebroom (Lepido spar turn squamatum) - 22 October 1991. Salata, Larry. 1990. Wildlife biologist. U.S. Fish and Wildlife Service, Laguna Niguel, CA. Telephone conversation concerning the taxonomic status of the San Diego Cactus Wren - 21 May 1990. Willick, Doug. 1991. Biologist. P&D Technologies, Orange, CA. Personal communication concerning the taxonomic status and distribution of subspecies of Campylorhynchus brunneicapillus - September 1991. Crossosoma 18(1), May 1992 9 Book Review Oaks of California by Bruce M. Pavlik, Pamela C. Muick, Sharon Johnson, and Marjorie Popper. 1991. 184 pages. Cachuma Press and the California Oak Foundation, P.O. Box 560, Los Olivos, CA 93441. Paper $19.95, Cloth $28.95. Illustrated with more than 150 color photographs, Oaks of California is an elegant new publication. In addition, color illustrations of various oak species are provided by Allison Atwill. The photographs are so beautiful, I wish the book were available in a large, coffee table style format. This book is written by knowledgeable scholars yet it should be accessible to amateurs. Even though the book has multiple authors, it does not suffer from unevenness. It is well written throughout and obviously well-edited. The book is divided into six richly illustrated chapters including such topics as the diversity of California oaks, oak landscapes (communities) of California, wildlife and oaks, oaks and the human past, preserving oaks for future generations, and a regional treatment of how to find and explore California’s oak landscapes. If I could pick the best chapter, I think it would be the section on how to identify California’s oaks. The descriptions are understandable and illustrated with photographs and artwork that show acorns and both sides of the leaves. If I could pick a weakness to the volume, it’s that the cover on my paper-bound copy keeps curling. As far as I know, this is the only book written entirely about California’s oaks. As such it is a valuable addition to anyone’s library, because a diversity of oak species is part of California’s claim to fame. I hope Cachuma Press will consider a similar treatment for other botanical treasures such as California’s conifers. Allan A. Schoenherr, Division of Biology, Fullerton College 10 Crossosoma 18(1), May 1992 Plants of Mediterranean-Type Climates1 by Robert F. Thorne Rancho Santa Ana Botanical Garden Claremont, CA 91 71 1 The mediterranean-type climate of wet, mild winters and hot, dry summers occupies only about 3% of the land area of the world. However, because this climate is so favored by man, the density of the population and the development of such large cities as Athens, Rome, Cairo, Jerusalem, Los Angeles, San Diego, Capetown, Santiago, Perth, and Adelaide make the five regions of mediterranean-type climate far more important than their limited areas would suggest. The Mediterranean Basin itself, and immediately adjacent areas, was the cradle of western civilization. The distribution of the mediterranean-type climate is widely disjunct on each of the six occupied continents, the Mediterranean Basin, the Californias, central Chile, the Cape Region of South Africa, and southwestern and southern Australia, each area lying approximately between 30° and 40° of latitude north and south of the equator on the western side of the continents, but extending east in the Mediterranean Basin and Australia. This distribution is controlled indirectly by the existence of cold ocean currents, the Portugal, Canary, California, Peruvian (Humboldt), Falkland, Benguela, and Western Australian currents; and more directly by the juxtaposition of the middle latitude cyclonic storm belts and high-pressure air masses. In winter the middle latitude cyclones and moist maritime polar air masses usually combine to create relatively adequate rainfall; in spring the subtropical high-pressure system shifts poleward, mostly preventing summer cyclonic storms and insuring hot, dry summers. This transitional regime between temperate and dry tropical climates is characterized by variable winter precipitation, summer drought, mild to hot summers, cool to cold winters, and marine fog and high humidity along the coasts. Each mediterranean area is immediately adjacent to deserts or semideserts, as From a talk given at A Mediterranean Perspective: A Symposium on the Floras and Landscape Uses of Plants from the World ’ s Mediterranean Regions , sponsored by the Santa Barbara Botanic Garden, November 8-10, 1990. Crossosoma 18(1), May 1992 11 the Sahara, Arabian-Central Asian, Mojave and Sonoran, Atacama, Central Australian, and Karoo deserts. The similar mediterranean climate has developed in these five widely disjunct areas remarkably similar vegetation types, dominated largely by woody shrubs with evergreen, sclerophyllous (leathery) leaves but varying from shrublands (variously called maquis, chaparral, matorral, renosterveld, and mallee) to sclerophyllous, broad-leaved forests, conifer forests, heathlands, and semidesert scrub. Most of this vegetation is fire-prone and fire-adapted, except in the Mediterranean Basin and central Chile. With increasing aridity or human disturbance, the vegetation becomes lower, more open and scattered, more drought-deciduous, more shrubby and subshrubby, and with more succulents and semisucculents (except in Australia). This more arid scrub is called variously garrigue, phrygana, batha, jaral, coastal sage, or renosterveld. Under more mesic conditions the shrublands merge with evergreen sclerophyllous broad-leaved woodlands and forest, and with increasing altitude with conifer woodlands and forest, and if high enough, with subalpine scrub. On acid soils low in such nutrients as phosphorous, nitrogen, and trace elements, as in South Africa and Australia, the shrublands are replaced by heathlands (called variously fynbos, sand heath, landes, brezel, and brughiera). On relatively fertile soils, herbs and grasses become more abundant in savannas, parklands, and open woodlands. On the other hand, the floras of the various mediterranean-climatic regions are very distinct due to the extreme and long isolation of each of the areas from the others and the different phylogenetic heritages of each region. Other causes of this biotic heterogeneity are the differences in topography, soil types, water availability, marine fogs, rain-shadow effects, paleoclimatic changes, and degradation and desertification by man. Although the mediterranean climate is probably no older than Pleistocene, certainly many of the plants have a long history of preadaptation to semiarid or arid conditions stretching back to Tertiary time. Many other species, especially the annuals and herbaceous perennials, appear to be of postglacial vintage. Most similar in position, physiography, oceanic currents, north-south orientation, mixture of temperate and tropical biotic elements, carbon-gaining strategies, Spanish settlement, etc., are Chile and California. Also there has been some interchange of plants via long-distance dispersal and migration along the Andean and other mountain chains. Yet their floras are very diverse, with high endemism in each flora. Central Chile has more rainfall and richer soils, is more 12 Crossosoma 18(1), May 1992 oceanic, is more isolated, has more links with southern hemisphere biota, has more diversity of growth forms and more open, diverse, stratified vegetation with more spiny shrubs and succulents, and more intensive impact by man. Also it lacks Santa Ana-like winds with less fire-prone, flammable vegetation, and no post-burn annuals. California has greater floristic links with the Mediterranean Basin, an onshore archipelago with highly developed island chaparral and many island endemics, well-developed conifer woodlands and forests and generally more montane forests, and its shrub germination is fire-stimulated. Australian and South African mediterranean-climate regions are most atypical because of their more subdued, ancient landforms, acid, nutrient-poor soils, monsoonal summer storms, mild winters and low thermal amplitude, lack of poleward contacts with temperate climates, and flora originating from some common tropical ancestors preadapted by poor soil nutrients, fire, and water stress. Their very rich mediterranean-area floras are dominated in large part by members of the Proteaceae, Fabaceae, Rutaceae, and Restionaceae, with strong representation in the Rhamnaceae, Thymelaeaceae, Santalaceae, Orchidaceae, and other families. Yet, their floras are highly distinctive with numerous endemic families restricted to Australia or Africa. The Cape Region has a more diversified topography and stronger winds, but a much more compressed mediterranean-type climatic zone. The Mediterranean Basin is more diversified and extended eastward than the other regions just discussed. Its flora is closest in affinity to the California region, with great importance of conifers, oaks, and mints, as in California. Because it abuts upon the Atlantic Ocean and several seas, and contains numerous islands, peninsulas, and other highly irregular coastline, it has 40,000 km of shore and nearly half the shrublands of all the mediterranean-climate regions. But it has long been a crossroads for humans, and has suffered greater devastation and desertification than the other regions. Over-grazing by goats and other browsers, over-cultivation, tree cutting, soil erosion (often total loss of soil with only bare rock left), marine pollution, heavy tourist visitation (about one-third of all international tourism), and other effects of over-population have had a horrendous impact on this type-region of mediterranean climate. Crossosoma 18(1), May 1992 13 SUGGESTED READINGS di Castri, F., D. W. Goodall, and R. L. Specht (Eds.)- 1981. Ecosystems of the World. II. Mediterranean-type Shrublands. Elsevier Scientific Publishing Co., New York. 643 pp. Kruger, F. J., D. T. Mitchell, and J. U. M. Jarvis (Eds.). 1983. Mediterranean-type Ecosystems. The Role of Nutrients. Springer-Verlag, New York. 552 pp. Mooney, H. A. (Ed.). 1977. Convergent Evolution in Chile and California. Mediterranean Climate Ecosystems. US/IBP Synthesis, Series 5. Dowden, Hutchinson & Ross, Inc., Stroudsburg, PA. 224 pp. Thrower, N. J. W. and D. E. Bradbury (Eds.). 1977. Chile-California Mediterranean Scrub Atlas. A Comparative Analysis. US/IBP Synthesis, Series 5. Dowden, Hutchinson & Ross, Inc., Stroudsburg, PA. 237 pp. 14 Crossosoma 18(1), May 1992 Vegetation Survey of the Antelope Valley California Poppy Reserve by Curtis Clark and Nancy Charest Biological Sciences, California State Polytechnic University, Pomona CA 91 768 In 1983, we carried out a study of the California poppies ( Eschscholzia calif ornica) and other vegetation in the Antelope Valley California Poppy Reserve, under contract with the California Department of Parks and Recreation (CDPR). The ultimate purpose of the study was to identify the factors responsible for floral displays of California poppies in the Reserve. Because public attention has once again been focused on the poppy displays (and their absence), we are making the results of our study known. This first part concerns the vegetation of the Reserve. Two additional papers will follow. One will address the contrast between the annual poppies of the Reserve and the perennial poppies south of the nearby small settlement of Fairmont. The other will consider the general question of the factors that promote poppy displays. MATERIALS AND METHODS On 9 April 1983 we began a line-intercept transect in the area of maximum poppy display east of the Visitors Center (at a post just east of a “No Vehicles” sign) and extending north (magnetic compass bearing 347°) for 400 m toward the Antelope buttes (Fig. 1, line “L”). This transect was completed on 16 April. We sampled every other 10 m increment of the transect, for a total of 20 individual samples totaling 200 m. The total length of the transect intercepted by each species was recorded, and from this information relative cover for each species was calculated for each sample. Since the data included the presence/absence of each species in each sample, we also calculated relative frequency for each species for the entire line. On 23 April we began a different sampling technique: at set intervals along a line a 1 m2 open wooden frame was placed (to the right or left of the line, depending on the toss of a coin), and Braun-Blanquet cover classes (Mueller-Dombois and Ellenberg, 1974) and phenology were estimated for each species. Overall cover was obtained by Crossosoma 18(1), May 1992 15 averaging the cover classes of a number of samples, and relative frequency from the number of samples containing a given species divided by the total number of samples. The following lines (Fig. 1) were sampled in this manner: 1 . Parallel to the south boundary and about 20 m north, in the region of greatest display. Twenty-three samples at 10 m intervals, 23 April. 2. Parallel to the previous line, about 20 m further north. Twenty-three samples at 10 m intervals, 23 April. 3. From the region of greatest display north to the crest of the hills and across, to the north boundary. Twenty-two samples at 20 m intervals, 23 April. 4. From the crest of “Encelia hill” (the highest point in the main ridge, dominated by Encelia actoni) to the crest of north Godde Hill. Thirty-three samples at 20 m intervals, 23 April. 5. From the eastern boundary to the top of Rattlesnake Hill, thence west into the main range of hills. Forty-three samples at 20 m intervals, 30 April. 6. Just south of the north boundary on the east slope of north Godde Hill to a point on the north slope of Encelia Hill. Thirty-five samples at 20 m intervals, 30 April. Totals: 179 samples, 3.12 km of sample line. Fig. 1 . Map of Antelope Valley California Poppy Reserve (1 982 boundaries) showing sample lines and previously tilled areas. 16 Crossosoma 18(1), May 1992 RESULTS The vegetation of the reserve at the time of the survey can best be characterized as annual grassland, although in many areas grasses were not a dominant part of the vegetation. From Tables 1 and 2, Fig. 2, and Appendix 1, it is apparent that the dominant vegetation consisted of annual forbs. Most of the plants were native. Of the nine most important species, either by cover or by frequency, three were introductions. Redstem filaree ( Erodium cicutarium ), very widespread in dry environments all over the state, and thought by some to have reached California prior to European settlement (Wester, 1981), seemed to fill in the spaces between other annuals. Cheatgrass ( Bromus tectorum), another common weed in desert environments, was more common in hilly parts of the Reserve. Red brome {Bromus rubens) was only common along trails and in other areas of human disturbance. Of the thirty-five most important identified species, only six were introductions. Line segment number Fig. 2. Relative cover from line-intercept sample. Segments 7-20 had been burned in 1981. The most important native grass was Festuca megalura (vulpia or foxtail fescue; there is some question whether this North American member of a circumboreal species group was originally found in California). The native bunchgrass, desert needlegrass {Stipa speciosa), was the eleventh most important species by cover and the fourteenth by frequency. Another bunchgrass (possibly Melica imperfecta) was seventh by cover and ninth by frequency. Crossosoma 18(1), May 1992 17 The most important native forbs were pygmy lupine ( Lupinus bicolor ), goldfields ( Lasthenia chrysostoma ), owl clover ( Orthocarpus purpurascens ), and California poppy (Eschscholzia californica). The poppy was ninth by cover and seventh by frequency, even though poppies would not be expected in many parts of the reserve, and there was only one area of display. The seedlings of a perennial wild buckwheat ( Eriogonum sp.) that flowers in the summer were ninth in importance by cover and eighth by frequency. Shrub species were uncommon; the only shrubs to show up in the vegetation analysis were Corethrogyne filaginifolia and Encelia actoni\ the latter was an artifact of one transect beginning at the highest point in the southern range of the Antelope Buttes (Encelia Hill), which is the only place in the reserve where that species occurs. Rabbitbrush (Chrysothamnus nauseosus) was not infrequent on many of the north-facing slopes, but many burned stumps gave testimony to a much greater abundance prior to a fire in 1981. Beavertail pricklypear (Opuntia basilaris) was also locally abundant and recovering from that fire. Although we did not quantify vegetational differences between north-facing and south-facing slopes, some differences were readily apparent by visual inspection: poppies were most common on south-facing slopes and goldfields on north-facing slopes, and lupine was found everywhere. As mentioned, introduced species were most common in areas of disturbance. The grounds around the Visitors Center supported large amounts of tumble-mustard (Sisymbrium altissimum ), and some species, such as pineapple weed (Matricaria matricarioides) were found only along roads and paths. Some parts of the Reserve had been previously tilled (Fig. 1). These areas had no more introduced species than untilled areas, but their species composition did differ. This was most apparent in the eastern part of the Reserve. Sampling transect 5 crossed the most recently tilled section (it appeared to be still in use in aerial photographs from 1970 supplied by CDPR) and ended on the untilled shoulders of the hills. Lupine was by far the most common species in the tilled section (and visual examination confirmed that in the rest of the tilled area), but at the edge (which still shows up as a physical ridge in the terrain), the vegetation changed dramatically, with owl clover becoming much more abundant. Further west, in the region of the poppy displays of 1983 and some previous years, the land was also tilled, but much longer ago, and vegetational differences were not as apparent. 18 Crossosoma 18(1), May 1992 Although the lack of baseline information about the vegetation hampers the comparison, it appears that fire has had a significant effect. Accounts of the Reserve before the fires of 1978, 1980, and 1981 in unpublished CDPR files implied a greater abundance of rabbitbrush and other shrub species, and aerial photographs taken by Jim Trumbly of CDPR in 1978 show a greater abundance of shrubs. Many of the charred stumps of rabbitbrush seen in our study showed considerable regrowth, but others were clearly dead, and many may have been totally burned, leaving no trace two years later. The fires may have also been in part responsible for the absence of large numbers of introduced species. Table 1. Important plants of the line-intercept transect. Species Average relative cover Relative frequency Lupinus bicolor 0.400 1.000 Erodium cicutarium 0.366 1.000 Festuca megalura 0.105 0.700 Eschscholzia calif ornica 0.091 0.850 Bromus rubens 0.018 0.600 Bromus tectorum 0.008 0.150 Table 2. Important species in descending order of cover and frequency, based on Braun-Blanquet cover class transects. Average Braun-Blanquet Cover Class Relative Frequency Lupinus bicolor 3.34 * Erodium cicutarium 0.99 * Erodium cicutarium 2.65 Lupinus bicolor 0.99 Festuca megalura 1 .42 Festuca megalura 0.68 *Bromus rubens 1.35 * Bromus rubens 0.66 Lasthenia chrysostoma 0.90 * Bromus tectorum 0.53 * Bromus tectorum 0.80 Lasthenia chrysostoma 0.46 unknown grass ( Melica ?) 0.44 Eschscholzia californica 0.34 Crossosoma 18(1), May 1992 19 Orthocarpus purpurascens 0.32 Eschscholzia californica 0.23 Eriogonum sp. (seedling) 0.23 Stipa speciosa 0.08 unknown grass 0.08 Euphorbia poly car pa 0.07 Amsinckia tessellata 0.06 Corethrogyne filaginifolia 0.05 Blatystemon californicum 0.04 *Hordeum glaucum 0.03 Allium sp. 0.02 Dichelostemma pulchella 0.02 Encelia actoni 0.02 Juncus sp. 0.02 * Sisymbrium altissimum 0.02 unknown seedling 0.02 Pectocary’a sp. 0.01 Trifolium sp. 1 0.01 Trifolium sp. 2 0.01 unknown grass 0.01 unknown seedling 0.01 *Brassica sp., Calystegia sp., Chaenactis glabriuscula , Cryptantha sp. 1, Cryptantha sp. 2, Cryptantha spp., Linanthus sp., Malacothrix calif ornica, Mirabilis sp. Eriogonum sp. (seedling) 0.24 unknown grass ( Melica ?) 0.20 Orthocarpus purpurascens 0.18 Euphorbia polycarpa 0.12 Blatystemon californicum 0.09 Trifolium sp. 1 0.07 Amsinckia tessellata 0.06 Stipa speciosa 0.06 unknown seedling 0.06 unknown grass 0.06 unknown seedling 0.06 Corethrogyne filaginifolia 0.06 Dichelostemma pulchella 0.04 * H or deum glaucum 0.03 Pectocarya sp. 0.02 Cryptantha sp. 1 0.02 Allium sp. 0.01 Chaenactis glabriuscula 0.01 Cryptantha sp. 2 0.01 Encelia actoni 0.01 unknown grass 0.01 * Bras sica sp., Calystegia sp., Cryptantha spp., Juncus sp., Linanthus sp., Malacothrix cal if ornica, Mirabilis sp., * Sisymbrium altissimum. Trifolium sp. 2 introduced species 20 Crossosoma 18(1), May 1992 CONCLUSIONS In 1983, the Antelope Valley California Poppy Reserve consisted of an annual grassland of chiefly native species, with introduced species most common in disturbed sites. Although anecdotal evidence suggests that shrubs were an important component of the vegetation during the 1970s and before, the shrub cover was not extensive in 1983, perhaps a result of fires in previous years. ACKNOWLEDGMENTS We thank Emilia Parra, Mark Patterson, Donald Sanders, and Christina Wedaa for assistance in the field, and the California Department of Parks and Recreation for financial support and access to unpublished records and photographs. REFERENCES CITED Mueller-Dombois, D. and H. Ellenberg. 1974. Aims and methods of vegetation ecology. John Wiley & Sons, New york. 547 pp. Wester, L. 1981. Composition of native grasslands in the San Joaquin Valley, California. Madrono 28:231-241. Appendix 1 . Frequency and cover of species on Braun- Blanquet transects. Transects 1 and 2 Relative frequency1 Relative frequency2 Average cover3 Amsinckia tessellata 0.03 0.07 0.03 Brassica sp. 0.00 0.03 0.00 Bromus rubens 0.26 0.42 0.55 Bromns tectorum 0.23 0.52 0.45 Erodium cicutarium 0.97 1.00 2.94 Eschscholzia californica 0.42 0.74 0.87 Euphorbia polycarpa 0.00 0.03 0.00 Festuca megalura 0.45 0.52 1.03 Hordeum glaucum 0.03 0.07 0.10 Lasthenia chrysostoma 0.00 0.07 0.00 Lupinus bicolor 0.90 0.97 3.32 Ma/acothrix californica 0.00 0.03 0.00 Crossosoma 18(1), May 1992 21 Transects 1 and 2 continued Orthocarpus purpurascens unknown seedling 2 0.00 0.00 0.03 0.13 0.00 0.00 Transect 3 Relative frequency1 Relative frequency2 Average cover3 Bromus rubens 0.78 0.87 2.39 Bromus tectorum 0.30 0.56 0.74 Chaenactis glabriuscula 0.00 0.09 0.00 Corethrogyne filaginifolia 0.04 0.04 0.09 Cryptantha sp. 1 0.00 0.04 0.00 Dichelostemma pulchella 0.00 0.04 0.00 Eriogonum sp. seedling 0.22 0.30 0.52 Erodium cicutarium 0.96 0.96 2.26 Eschscholzia calif ornica 0.09 0.52 0.17 Euphorbia polycarpa 0.00 0.26 0.00 Festuca megalura 0.52 0.61 0.83 Lasthenia chrysostoma 0.39 0.48 1.26 Lupinus bicolor 1.00 1.00 3.13 Orthocarpus purpurascens 0.04 0.13 0.17 Platystemon californicum 0.00 0.09 0.00 Trifolium sp. 1 0.00 0.09 0.00 unknown bunchgrass 0.13 0.13 0.44 unknown grass 2 0.30 0.39 0.35 unknown seedling 2 0.04 0.09 0.04 Transect 4 Relative frequency' Relative frequency2 Average cover3 Allium sp. 0.02 0.02 0.07 Bromus rubens 0.50 0.55 1.36 Bromus tectorum 0.39 0.46 0.93 Dichelostemma pulchella 0.00 0.02 0.00 Eriogonum sp. seedling 0.05 0.14 0.07 Erodium cicutarium 0.98 1.00 3.16 Eschscholzia californica 0.07 0.14 0.09 Euphorbia polycarpa 0.18 0.23 0.25 Festuca megalura 0.82 0.93 2.41 Lasthenia chrysostoma 0.46 0.68 0.96 Lupinus bicolor 1.00 1.00 3.98 Orthocarpus purpurascens 0.39 0.52 1.02 22 Crossosoma 18(1), May 1992 Transect 4 continued Peciocarya sp. 0.02 0.02 0.05 Stipa speciosa 0.09 0.11 0 16 unknown bunchgrass 0.07 0.09 0.21 unknown grass 0.02 0.05 0.05 unknown seedling 0.00 0.02 0.00 Transect 5 Relative frequency' Relative frequency2 Average cover* Amsitickia tessellata 0.16 0.19 0.23 Bromus rubcns 0.52 0.71 1.16 Bromus tectorum 0.42 0.58 0.97 Calystcgia sp. 0.00 0.03 0.00 Corethrogyne filagmi folia 0.07 0.13 0.13 Crypt ant ha sp. 1 0 00 0.07 0.00 Cryptautha sp. 2 0.00 0.07 0.00 Dichelostemma pulchella 0.03 0.07 0.07 Ence/ia actoni 0.03 0.07 0.10 Eriogonum sp. seedling 0.19 0.29 0.32 Erodium cicutarium 0.97 1.00 2.68 Eschscholzia califomica 0 07 0.23 0.10 Euphorbia polycarpa 0.00 0.03 0.00 Festuca megalura 0.26 0.32 0.55 Hordeum glaucum 0.00 0.07 0.00 Lasthenia chrysostoma 0.36 0.39 1.10 Li nan thus sp. 0.00 0.03 0.00 Lupinus bicolor 0.94 1.00 3.26 Mirabilis sp. 0.00 0.03 0.00 Pectocarya sp. 0.00 0.03 0.00 Platystemon californicum 0.03 0.16 0.07 Stipa speciosa 0.00 0.07 0.00 Trifolium sp. 1 0.00 0.19 0.00 Trifolium sp. 2 0.03 0.03 0.03 unknown bunchgrass 0.29 0.39 0.74 unknown crucifer 0.00 0.03 0.00 unknown grass 2 0.03 0.03 0.16 Crossosoma 18(1), May 1992 23 Transect 6 Relative frequency1 Relative frequency2 Average cover3 Allium sp 0.03 0.03 0.03 Amsinckia tessellata 0.03 0.06 0.06 Bromus rubens 0.60 0.83 1.51 Bromus lector urn 0.31 0.57 0.83 C orethrogyne filaginifolia 0.03 0 11 0.06 Dichelostemma pulchella 0.03 0.09 0.03 Eriogonum sp. seedling 0.23 0.49 0.37 Erodium cicutarium 0.91 1.00 1.97 Eschscholzia calif ornica 0.00 0.20 0.00 Euphorbia polycarpa 0.00 0.06 0.00 Festuca megalura 0.69 0.86 1.69 Hordeum glaucum 0.03 0.03 0.06 Junciis sp 0.03 0.03 0.09 Laslhenia chrysostoma 0.43 0.57 1.20 Lupinus bicolor 0.91 0.97 2.77 Orthocarpus purpurascens 0.03 0.06 0.09 Pectocarya sp. 0.00 0.06 0.00 Platystemon californicum 0.06 0.20 0.11 Sisymbrium altissimum 0.03 0.03 0.09 Stipa speciosa 0.09 0.09 0.17 Trifolium sp. 1 0.03 0.11 0.06 unknown bunchgrass 0.40 0.40 0 86 unknown plant/purple fls. 0.00 0.03 0.00 unknown seedling 0.03 0.11 0.06 unknown seedling 3 0.03 0.29 0.06 unknown tall fuzzy plant 000 0.03 0.00 1. Braun-Blanquet cover classes “r” and “+” omitted. 2 Braun-Blanquet cover classes “r” and “+” included. 3. Average of Braun-Blanquet cover classes. 24 Crossosoma 18(1), May 1992 Book Review Plants of the East Mojave by Adrienne Knute, drawings by Carl Faber. 1991, 207 pages, Wide Horizons Press, Cima, CA. 92323. SI 2.95, soft cover. This introductory guide to the yuccas, trees, cacti, grasses, shrubs, and “wildflowers” of the East Mojave National Scenic Area is written and illustrated by residents of the East Mojave. It includes detailed descriptions of each plant, including flower color, growth habits, size, blooming period, some local common names and uses, and locations where the plant may be found. Eight different “Plant Discovery Walks” are listed with plants that may be found on each of these walks. One hundred and forty-one black and white photographs (although not of professional quality), as well as the twenty-six different line drawings and fifteen color photographs are quite helpful in identifying the plants in the field. A list of resources including local Bureau of Land Management offices, sources for native plants and seeds, and organizations connected with the East Mojave or native plants is also a helpful addition. The two indexes of the plants covered in this book, one by plant family and the other by flower color, provide a quick access to the identification of any plant seen in the East Mojave Desert. Alan P. Romspert, Department of Biology, California State University, Fullerton A New Format for Crossosomu Starting with this volume, Crossosoma will appear twice a year, with more articles in each issue. Notices of field trips, plant sales, symposia, and such will appear in Leaflets of the Southern California Botanists. Leaflets will come out six times a year, following the same schedule that Crossosoma followed in the past. The Board of Directors began to explore possible changes to Crossosoma over a year ago, with the intent of improving the appearance and readability of the journal. We also learned that Crossosoma could not be included in Biological Abstracts because the people in charge felt that it was more of a newsletter than a journal. Since Crossosoma is a significant source of information about the botany of southern California, it is important that it be included, so that Crossosoma 18(1), May 1992 25 the articles will appear in computer literature searches. We felt that by removing the newsletter material into a separate publication, we could get Crossosoma included in Biological Abstracts in the future. We would like to hear your reactions to the new format, and your suggestions for ways to improve it. As always, we are interested in articles for Crossosoma about any aspect of the plants or plant communities of southern California. Letters to the Editor My name was included as a coauthor of a report submitted to the California Fish and Game Commission on December 5, 1991, by Mr. Tom Leslie of John Minch and Associates (JMA). At the time the report was submitted, I was under the employ of JMA as a part-time biological consultant. My job was to gather information about Ceanothus ophiochilus for Mr. Leslie. Mr. Leslie wrote the report, which I read prior to its being submitted. At that time I discussed with him several points in the report with which I disagreed. I especially disagreed with Mr. Leslie’s opinion that listing of this species should be delayed. I believe that there is no good reason not to list it as soon as possible. I was never informed that my name would appear on the report, and I never authorized Mr. Leslie to use my name on the report. I found out after the report was submitted that I was a coauthor. I would like to publicly disassociate myself from the report, and I regret that the information I supplied to JMA was used in such a misleading manner. Pamela J. MacKay Biology Department University of California Riverside CA 92521 26 Crossosoma 18(1), May 1992 Instructions to Contributors Crossosoma is open to articles, letters to the editor, and book reviews on any aspect of the native plants or plant communities of southern California, including, but not limited to, anatomy, biogeography, conservation, cultivation, ecology, history, physiology, reproductive biology, and taxonomy. All submissions are reviewed by the editor, and articles are evaluated by one or more reviewers as well. Manuscripts The form in which a manuscript is submitted will have no influence on its acceptance, but it may substantially increase or decrease the time to publication. “Electronic manuscripts” (on computer disks) are preferred. Typewritten (including computer hardcopy) and even handwritten manuscripts are also acceptable. Electronic manuscripts - Two hardcopies should be submitted initially for the review process; diskettes should not be sent until the manuscript is accepted for publication. Diskettes can be 514 inch or 314 inch, MSDOS (IBM PC and compatible) format. Some CP/M diskettes can be read, and Apple Macintosh and lie diskettes may be acceptable at the editor’s discretion (I have to use a borrowed machine to transfer these). Word-processor formats supported include Ami Pro, Microsoft Word, Word Perfect, and WordStar, as well as ASCII text files (please inquire for other file formats). Scientific names should be italicized or underlined, and boldface text may be included, but the files should otherwise be unformatted: no centering, no paragraph indentation, no special fonts, and no tabs except in tables. A hardcopy should accompany the disk, along with any figures or photos. Computer graphics may be submitted as .BMP, .TIF, .PCX, .WMF, .CGM, or .CDR files. Typewritten and computer-printed - Manuscripts should be double-spaced in a type no smaller than 12-pitch (elite), not right-justified, on one side of 814 inch x 1 1 inch white paper. Margins should be at least 1 inch on all sides, and pages should be numbered. Figures and photos should be grouped at the end of the manuscript, not placed in the text. One copy of letters and reviews and two copies of articles should be submitted. Handwritten - Illegible manuscripts will be returned; if you are not sure about legibility, please submit a sample. Manuscripts should conform as closely as possible to the format for typewritten work (lined paper is acceptable). Crossosoma 18(1), May 1992 27 Figures Line drawings, maps, and graphs should be one to two times the final printed size, but no larger than 814 inches x 1 1 inches. They should be in black, on white paper; if they are originals, they should be mounted on stiff cardboard. Good-quality black-and-white photographs may be submitted. They will ordinarily be printed without reduction or magnification, so plan their sizes accordingly. Working duplicates of all figures must be submitted. These can be photocopies. Figure legends should be on a separate sheet. Literature Citations These should match as closely as possible the style of Fremontia or American Journal of Botany. If you are not sure of the correct abbreviations for journal titles, please spell them out. 28 Crossosoma 18(1), May 1992 York Botanical Garden , Libra 3 5185 00268 0443 Southern California Botanists Special Publications No. 1. A Flora of the Santa Rosa Plateau by Earl W. Lathrop and Robert F. Thorne (39 pages) $7.00 No. 2. Flora of the Santa Monica Mountains, 2nd edition, by Peter H. Raven, Henry J. Thompson, and Barry A. Prigge (179 pages) $10.50 No. 3. Endangered Plant Communities of Southern California, Proceedings of the 1 5th Annual Symposium, edited by Allan A. Schoenherr (1 14 pages) $12.00 All prices include California state sales tax, handling, and domestic postage. Send check or money order payable to "Southern California Botanists" or "SCB" to: Southern California Botanists Department of Biology California State University Fullerton, CA 92634 New York Botanical Garden DEC92 L i b r a r y - S e r i a 1 s & E x c h a n g e B r on x NY 1 0458-5 1 26 co 3. o 3 n > |sj OJ n 0J_ O' — T 3. JU* CO s CO c 2 — < CO O o "O Cu 3. 3 o 13 C/3 o c 3" D n o -• 03 O Crq O — T CU* 03 O ST o. ’ Crossosoma Volume 1 8, Number 2 November, 1 992 CONTENTS /Distribution and Environmental Relations of California Black Walnut (Juglans califomica ) in the Eastern Santa Susana Mountains, Los Angeles County Don P. Mullally 1 / Comparison of Annual and Perennial Eschscholzia califomica (Papaveraceae) at the Antelope Valley California Poppy Reserve Curtis Clark and Nancy A. Charest 19 Book Review 27 LIBRARY JAN ■ ■ 4 1993 NEW YORK BOTANICAi , t\7f /-/f & X, Journal of the Southern California Botanists Crossosoma Curtis Clark, Editor Biological Sciences California State Polytechnic University Pomona CA 91768 (909) 869-4062 Crossosoma (ISSN 0891-9100) is published twice a year (May, November) by Southern California Botanists, Inc., a California nonprofit corporation. Subscription rate, $15 per calendar year ($8 for individual members). Back issues are available for $5 an issue or $10 a volume, postpaid (prior to Vol. 18, Crossosoma was published bimonthly; back issues are $2 each, $10 per volume). Manuscripts should be submitted to the editor. Applications for membership, requests for subscriptions or back issues should be sent to Alan Romspert, Treasurer, Department of Biology, California State University, Fullerton CA 92634. Southern California Botanists , Inc . Officers for 1992 President Vice President Terry Daubert Allan A. Schoenherr Treasurer Alan P. Romspert Secretary Board of Directors Judi Bogdanoff-Lord Gery Allan, Henry Bante, Curtis Clark, Coleen Cory, Julie Greene, Linda Harris, Annette Ross, Paula Schiffman Copyright © 1992 by Southern California Botanists, Inc. Distribution and Environmental Relations of California Black Walnut ( Juglans californica) in the Eastern Santa Susana Mountains, Los Angeles County Don P. Mullally 10418 Gothic Avenue Granada Hills, CA 91344 One of the largest remaining populations of southern California’s native walnut, Juglans californica , is found in the Santa Susana Mountains of Los Angeles County. The trees are found in some unusual vegetation types. This paper describes those associations as well as the general distribution and ecology of the species in that region. Virtually no technical biological or ecological studies, descriptive or otherwise, have been published about the eastern part of the Santa Susana Mountains. This range, one of the Transverse ranges, is situated directly west of the San Gabriel Mountains. In many respects it is biologically intermediate between the San Gabriel and Santa Monica mountains. Animals which occur in the San Gabriel and Santa Susana mountains, but not in the Santa Monica Mountains, include Stellar’s Jay (Cyanocitta stelleri) and Merriam chipmunk ( Eutamias merriami). Trees with similar distribution include canyon live oak (see Table 1 for scientific names), big cone Douglas fir, and interior live oak. Since 1976, this part of the mountain range has been included in Significant Ecological Area 20 of Los Angeles County. The study area is located between the San Fernando Valley to the south and the Santa Clarita Valley to the north. The western edge is marked by Oat Mountain, a portion of Towsley Canyon, and Brown’s Canyon, the eastern edge being Interstate 5 in Weldon Canyon and San Fernando Road. The core of the Los Angeles County portion of the Santa Susana Mountains is privately owned, and access has been denied to the public. It has been used as open cattle range since at least 1930. The Orcutt Ranch comprises a major part, and it includes most of the crest of the range within the study area. For the past five years, grazing has been minimal outside the Orcutt Ranch; about fifteen wild cattle have been Crossosoma 18(2), November 1992 1 observed. Presently, the former ranch is a loose union of individual land owners whose objective seems to be securing profits by sales of land to developers or other interested parties. Recently, lower portions of Towsley Canyon have been acquired by the Santa Monica Mountains Conservancy. Most of the remainder of the study area on the north-facing slope has also been favorably evaluated by the California Department of Parks and Recreation and the Santa Monica Mountains Conservancy for the creation of an eight thousand acre state park tentatively referred to as the Santa Clarita Woodlands State Park. California walnut woodlands have been seriously diminished by developments in southern California. Many scientists consider it an endangered community. However, the species itself does not have endangered classification and accordant protection. Methods Observations were madexrf the California black walnut and associated vegetation in conjunction with employment by the City of Los Angeles at O’Melveny City Park. O’Melveny Park, 291 ha in size, is primarily a wilderness park and is situated in Granada Hills at the southeastern comer of the mountain range. Further studies were made to facilitate studies required by the state park agencies. Emphasis has been placed on the distribution of California black walnut and its position in major vegetation types. The information in this descriptive report is considered to be introductory to further investigations involving quantitative methods. The methods basically involved finding routes which penetrate this rugged land, exploring, making observations, keeping notes and photographing vegetation types. To measure the sizes of stands, distances were determined by pacing and lines and angles by using a compass. During 1991 and 1992, Dr. Todd Keeler-Wolf, Vegetation Ecologist for the Natural Diversity Data Base, California Department of Fish and Games requested information concerning the vegetation types. Eventually a preliminary map was made of the vegetation types of the north slope. Much of the relevant information has been incorporated into the data base. Dr. Keeler-Wolf has also examined part of the area. The results of this study and the vegetation mapping are complementary. 2 Crossosoma 18(2), November 1992 Results Results are presented in two sections. The first describes the distribution and habitats of California black walnut and associated vegetation types on the southern and northern aspects of the mountain ranges. The second describes the principal vegetation types which include walnuts, as well as other aspects of the ecology of this tree. Ecology and Distribution On the South and East Slopes The California black walnut sparsely populates the warm and relatively dry south slope facing the San Fernando Valley. Ground cover and understory usually consist of non-native grasslands or coastal sage scrub. Chaparral communities are scarce and have been found only in Brown’s Canyon and a portion of Limekiln Canyon within the Aliso Gas Field owned by the Southern California Gas Company. Laurel sumac and walnut frequently occur together in draws and on alluvium at the base of hills and in canyons. The sumac matures to an arborescent shrub, and the walnut frequently exists as a shrubby tree. The major stems of both species are killed by fire, and both regenerate vigorously. Following fire, however, the sumac demonstrates ad advantage by reproducing vigorously under walnut trees through seedlings. The reverse does not occur. Laurel sumac is confined to the southern exposure by minimum temperatures. At 639 m, a freeze killed some sumac on a ridge above Sunshine Canyon. The survivors resprouted from their crowns. Walnut trees and woodland are common along the borders of the more permanent intermittent streams. The woodlands are composed of walnut and coast live oak, arroyo willow, flowering ash, toyon, and Mexican elderberry. Ash is usually confined to dry upslope perimeters. Western sycamores are occasional, and big leaf maples are scarce. The canopy is a mixture of the tree species of the stream bed, the banks, and the riparian zone. The California walnuts are interspersed in the woodlands and on the borders of stands of oaks or willows. These patterns of distribution are found along Bee Canyon Creek in the northern half of O’Melveny City Park and along Limekiln Canyon Creek within the Aliso Gas Field. They are also repeated on the north slope of the range. Occasionally a walnut tree is found growing down to within one or two vertical meters of stream beds; however, the beds change elevation frequently by at least 1 m due to erosion and deposition. When rooted near the beds of the wetter intermittent streams, native walnuts not only Crossosoma 18(2), November 1992 3 acquire sufficient moisture but apparently avoid root immersion and fungal disease by sending roots upslope into drier soil. Similarly, walnuts which exist on the periphery of park lawns usually thrive. At O’Melveny Park, mature native walnuts which were left to exist in irrigated lawns died within 10 years. The density of walnut woodlands increases in the drier intermittent streams and canyons which channelize rainwater only during major rainstorms. With the exception of Mexican elderberry, other tree species are scarce in this environment. Essentially pure stands of walnut woodland frequently occupy such canyons. This pattern is represented along Bull Creek above Neon Way in O’Melveny Park, above Bull Creek, and in canyons west of the buildings and lawns in the park. In arid locations on mountainsides, even relatively small canyons or ravines have more California walnuts than the surrounding slopes. The species seems to be particularly well adapted to relatively dry canyons. On the south slope, the trees are relatively abundant in small canyons with one side facing to some degree east. They occur in small woodlands and savannas. These patterns may be observed in portions of the Aliso Gas Field and in O’Melveny City Park. Though populations of walnuts are sparse on south and west slopes, Juglans calif ornica is the principal tree species on these slopes. Mexican elderberry is usually the only other tree present. The ecological requirements of the California walnut seem to be more similar to those of Mexican elderberry and flowering ash than to any other species of local trees. The north slopes of east-west canyons frequently support dense vegetation, including walnuts, scattered coast live oak, toyon, poison oak, hollyleaf redberry, and coastal sage scrub. Along intermittent streams, California walnut and associated plants tolerate high salinity and alkalinity throughout the dry season. The salinity becomes evident as intermittent stream beds become white with evaporite salts as surface water disappears. The salts are derived from marine sedimentary rocks Miocene in age or younger which form these mountains. Locally the most common substrates are soft shale, sandstone, and mudstone. No mature California walnut trees were observed to die from brush fires or the severe drought of 1986-1991 in O’Melveny or Limekiln city parks. Though fire frequently killed all the stems, new stems invariably grew from the crowns. Following the Limekiln fire, a riparian tree 4 Crossosoma 18(2), November 1992 developed new stems up to 4.5 m long during the following growing season. Ecology and Distribution on the North Slope East of Oat Mountain, the north slope of the Santa Susana Mountains holds one of the largest and most unusual hardwood forests in southern California. Big cone Douglas fir is abundant and a member of these mixed evergreen forests in the higher parts of major canyons. According to the environmental impact report for Sunshine Canyon (Ultrasystems, 1989-90), 577 ha located in Sunshine Canyon support at least 7,742 Coast live oaks, 2,700 Canyon live oaks, and 1,300 big cone Douglas firs. A similar report for the Towsley canyon drainage, 1062 ha in size, lists 20,854 valley oaks, 5,801 canyon live oaks, 28,467 coast live oaks, 9,670 big cone Douglas firs, and 1,410 western sycamores (McClelland Consultants, 1990). Most of the trees exist in the southern (upper) one third of the canyon. Species of trees not counted in the Towsley report are California black walnut, interior live oak, scrub oak, flowering ash, big leaf maple, Mexican elderberry, toyon, and arroyo willow. All of these are also common. Between Sunshine and Towsley canyons, a much larger number of trees of these species exist principally within Rice, East, Wiley, and upper Bee canyons. Black cottonwood occurs on the north side of The Old Road near the Weldon overpass on Interstate 5. White alder and hollyleaf cherry are notable for their absence from the study area. On the north slope, walnut is primarily a member of open woodlands of various types, including riparian, and grasslands. It is frequent in coastal sage scrub on north, west, and east slopes but very scarce in chaparral. Walnuts are found within or on the borders of coastal sage scrub in East and Rice Canyons, along San Fernando Road, and in the lower parts of Towsley Canyon. South facing slopes of scrub located on this side of the range are nearly devoid of walnut except near canyon bottoms; walnuts are more abundant on west than south slopes. Mature coast live and valley oak woodlands commonly have a thin understory which may include young trees such as oaks, Mexican elderberry, toyon and flowering ash. Understory shrubs often include poison oak, hillside gooseberry, hollyleaf redberry, snowberry, white nightshade, and purple nightshade. With sufficient sunlight, bush monkey flower, California sagebrush, and hairy leaf ceanothus may be present. A correspondence seems to exist between availability of soil moisture and the quantity of understory. Openings in the woodland Crossosoma 18(2), November 1992 5 frequently support, in addition to the above, California buckwheat, yerba santa, white sage, chaparral yucca, and heart-leaved penstemon. California walnut trees and woodland usually have little understory vegetation other than grasses. Scrub vegetation is common between widely separated walnuts but is replaced beneath them by grasses. Shrubs are more abundant near walnuts with increased soil moisture; that is, near streams, springs, and slopes with high levels of underground moisture. Fire seems to be important to the establishment of large populations of Juglans californica. The species recovers faster following fire than does coastal sage scrub. Following fires, scrub is often replaced by grasses which require less water. In woodland, fires kill many young trees and shrubs, lessening competition. Fires also cause local “hot spots” wherein mature oaks and other trees are destroyed. Opening are thus created in the forest which are ideal for colonization by California walnut. One conclusion resulting from this study is that repeated fires have opened large areas of woodland in the headwaters of Rice Canyon for colonization by walnut. As a result, this tree is found in association with most of the dominant forest trees of these mountains. Some of these associations are unusual if not unique and are described later in this paper. The results of fire are also evident in other canyons and on the north-northeast side of Oat Mountain. The situation on Oat Mountain is particularly unusual because fire enable the development of a unique, extensive community of snowberry chaparral. Walnut, young oaks, and other trees are numerous in this chaparral and are converting this chaparral, which is evidently a serai stage, back to woodland. Major fires burned through the study area in 1937 and 1970. Localized fires occur much more frequently. Fires have promoted colonization by walnuts and otherwise affected the vegetation on the steep north slope just south of the Weldon Overpass on Interstate 5. Evidence of fires includes occasional charred logs and tree bark, old fire scars on mature oaks, standing dead large Pseudotsuga , ramets of walnut and toyon, and abundant poison oak. Gaps in the woodland near Weldon Overpass are usually occupied by walnut trees and stands. Under the canopy, seedlings of walnut, coast live oak, and toyon are unusually abundant for the study area as a whole. Cattle have seldom grazed these steep slopes, perhaps accounting for the abundance of seedlings. A shortage of old oaks near the Weldon Overpass may constitute evidence of purposeful removal of oaks from this accessible location. It 6 Crossosoma 18(2), November 1992 is a matter of record that Mission San Fernando had great need of oak and harvested throughout northwestern San Fernando Valley. The foothills of the San Gabriel and Santa Susana Mountains were probably major sources. Community Patterns Stands of California black walnut — These include pure stands and stands which include a very few trees of other species, namely flowering ash, coast live oak, and Mexican elderberry. Understory is usually herbaceous, dominated by annual grass, and less often by shrubs and sub-shrubs. Some of the stands have over 80% canopy and are sufficiently dense to be described as forest. Walnut savannas are particularly characteristic of south and west slopes; woodland exist in relatively dry canyons on the south slope of the range. On the northern exposure of the range, larger stands of walnut woodland and forest are located at intervals throughout the area: Oat Mountain at 900-1100 m, Bee Canyon at 480-700 m. Rice Canyon at 600-840 m, East Canyon at 500-660 m, Wiley Canyon at 540-690 m, and lower Towsley Canyon at 390-700 m. Several large woodlands are located in Towsley Canyon near Interstate 5 and the park. Two of them are approximately 3.3 and 2.5 ha in size. Large stands of walnut are also located in upper Rice Canyon, one being at the head of the canyon west of the intersection of the Oat Mountain Motorway and the Corral Sunshine Motorway. Walnut woodlands and forest seldom exceed 2 ha in size. They are usually surrounded by savanna, grasslands, or coastal sage scrub. Having been through fires, nearly all the trees grow as ramets. Within the life spans of the trees, there is no evidence to indicate that relatively dry stands of walnut are successional stages or precursors of oak or other woodlands. Under such conditions, large stands of California black walnut are climax vegetation. If stems are killed by fire, the walnuts regenerate as ramets. On mesic north-facing slopes, pure stands of walnut woodland and forest may include a few seedling or sapling coast live oaks. These stands may evolve into woodlands composed of both walnut and oak. On the north slope of Oat Mountain and again 1.8 km to the east and 100 m north of Oat Mountain Motorway, walnuts exist within an unusual chaparral dominated by snowberry. Western chokecherry is a component of the chaparral, and this species has not been observed elsewhere in this range. Crossosoma 18(2), November 1992 7 Above about 900 m, walnut trees are smaller than those growing in the foothills. Reduced size may result from a shortened growing season and reduced average temperatures during the growing season. Mexican elderberry shows similar stunting. Cold winters and considerable snow characterize elevations above 800 m. However, there is no evidence that sub-freezing temperatures have destroyed tissues of sizable walnut trees. The effect on seedlings is unknown. The largest and probably the oldest tree trunks are genets located to the east and west of the Nature Center in the lower portion of Towsley Canyon, elevation 450 m. Genets of large size also exist on the relatively broad bottom of Rice and East Canyons (45-490 m). In these locations, oak woodlands seem to have sheltered many walnut trees from the worst effects of fire. In addition, the trees are sheltered from upslope firestorms. Ramets predominate on the surrounding hillsides. In the study area many more walnut trees exist in mixed associations of trees than in pure stands. Occurrence with coast live oak — Woodland dominated by coast live oak and California black walnut is one of the most common vegetation types in the Santa Susana Mountains. It is best developed in canyons and on the north slope of the range occurring as intervals from the base of the mountains to at least 790 m. Occasionally this vegetation type is in the riparian zone. One of the better accessible examples is located on the north slope near the Weldon Canyon Overpass on Interstate 5. Few of these woodlands are even mixtures. Usually they are weighted toward either walnut or oak. Furthermore, flowering ash is usually present as an important member of the woodland, introducing an unusual configuration to the community. A few woodlands of coast live oak have essentially full canopies and do not admit sufficient sunlight to support walnuts. Technically they are forests. Examples are located at the confluence of East and Rice canyons, in upper Bee Canyon, lower Learning Canyon, Sunshine Canyon and in a small tributary of Towsley Canyon situated one ridge to the west of Wiley Canyon. In oak-walnut woodlands, Juglans califomica commonly creates a pattern which may be termed an edge effect: Walnuts exist beside or surround a tree or small stand of another species, most commonly Coast live oak. However, the edge effect has also been noted in conjunction with valley and canyon oaks, California bay laurel and big cone Douglas fir. For the edge effect to be expressed, an opening for walnuts must 8 Crossosoma 18(2), November 1992 exist in the woodland with sufficient sunlight. The borders of woodland communities are particularly favorable. In open or unforested locations, young specimens of both walnut and coast live oak are abundant on the banks of streams. Small meadows in woodland and the banks of roads are also excellent habitat for oak and walnut seedlings. Young oaks are also common beneath the canopy of mature oaks and several meters in the open beyond the canopy. Apparently much germination of this species occurs close to seed trees, resulting in the enlargement of stands as well as replacement of trees that have died. This process seems to be most effective in small stands or groves. However, walnut seedlings and saplings are rare under oaks, and they do not seem to grow beyond sapling size unless an oak succumbs. Young walnuts are frequent peripheral to the canopies of mature oak and walnut trees which are located in openings in the riparian zone near the bottoms of canyons and on slopes with abundant subsurface moisture. In drier woodlands, the origin of stands of walnut is obscured by the relative absence of seedlings and young trees. This study coincided with the severe drought of 1986-1991. It is possible, perhaps probable, that the drought was responsible for the scarcity of seedlings. In O’Melveny City Park, seedling walnuts were noted near seed trees during the summer following the fire of December, 1988. They had disappeared by November. Predators, of course, cannot be ruled out. Preliminary observations indicate increases in numbers of seedlings this year. If this finding is substantiated, the increase is probably due to the heavy rains of January to April, 1991. Walnut and oaks frequently establish as seedlings only a few meters apart. The walnuts remain on the outer margin of enlarging oaks by being faster growing and by sending forth long stems which are more horizontal than vertical. Thus an edge effect is maintained. No dead large walnut trees which obviously died from inadequate light have been found beneath large oaks. From September, 1991, to February, 1992, large numbers of walnut seeds were observed on the surface of a thatch of dead, horizontal non-native annual grasses some 7-12 cm deep. Heavy rains had failed to dislodge most of the seeds or cause their burial in thatch or soil. This thatch factor may be partially responsible for poor recruitment of Juglans californica. Occurrence with valley oak — The valley oak tends to form pure stands of savanna and woodland. A few stands 0.5-1 .0 ha in size are Crossosoma 18(2), November 1992 9 sufficiently dense to be termed forest. Most of the stands are located on the summit of the axis of the range and on low angle north slopes above 700m. The species is also commonly a constituent of old growth woodlands on low angle north slopes at similar elevations. These include canyon and coast live oaks, big cone Douglas fir, and other trees. California walnuts rarely exist within stands of valley oak woodland and forest. However, they are frequent on edges, including road banks, and in woodland bordering intermittent streams which traverse stands of oaks. In the western headwaters of Rice Canyon located 1 km northeast of the intersection of the Oat Mountain Motorway and the fire road, mixed hardwood woodlands exist adjacent to valley oak woodlands. Dominant trees include valley, coast live, and canyon oaks, California black walnut, flowering ash, and California bay laurel. The understory includes young trees, poison oak, snowberry, hollyleaf redberry, and hillside gooseberry. Extensive understory rarely exists beneath pure stands of valley oaks within these mountains. Woodlands of the type described above are rare. A few mature valley oaks are embedded in walnut-ash woodlands located beside the East Canyon Motorway near the top of that canyon. Along the Corral Sunshine Motorway located on the ridge south of Bee Canyon, walnuts border valley oaks and form stands in grasslands surrounded by oak woodlands. Similar vegetation occurs west of the junction of the Sunshine and Oat Mountain motorways. It is evident that past fires have created large openings in oak woodlands enabling colonization by walnuts and other trees. The scarcity of walnut and understory in many stands of valley oak is attributed to marginal soil moisture during dry weather, aggravated by competition with oaks for soil moisture. With the exception of the north slope, Oat Mountain at 1034-1094 m holds woodland and savanna composed of valley oak and California lack walnut, with the oak more abundant. Occurrence in the big cone Douglas fir-canyon live oak-coast live oak forest — This vegetation type forms dense forests on steep slopes at the heads of canyons and in narrow canyons with permanent streams. Examples are at the heads of Sunshine, East and Wiley canyons and at several locations in the large Rice Canyon drainage and in Bee Canyon. California bay laurel and big leaf maple are frequently present in the community. Apparently California walnut is excluded due to 10 Crossosoma 18(2), November 1992 insufficient sunlight. However, walnuts exist in ecotones on the borders of the community which receive more sunlight. Pseudotsuga-oak woodlands which have been severely damaged by fire have openings which occasionally have been colonized by walnuts. Though such locations are scarce, an excellent example is present near the crest of the north slope located south of the Weldon Overpass on Interstate 5. Occurrence with flowering ash — Flowering ash locally attains an unusually large size. Trees of 30 cm DBH and approximate heights of 14 m are not unusual. Ash trees are distributed throughout the study area at elevations of 420-1000 m. However, optimal growth occurs on the north slope at 480-660 m. Ashes seem to be more tolerant than walnuts to low soil moisture and tend to be located on drier slopes than walnut. They are scarce on south slopes. However, ashes may be peripheral to the riparian zone along streams. Woodlands dominated by walnut and ash exist on easterly and northerly slopes in East Canyon at 500-600 m, on northerly and westerly slopes at the head of Learning Canyon at 547-665 m, on two northerly slopes in the middle of Rice Canyon at 500-630 m, in upper Rice Canyon at 699-851 m, and on two northerly slopes in Towsley Canyon near the old oil field at 517-669 m. The woodlands in Towsley are approximately 2.3 and 3.5 ha in size. Other such woodlands occur in O’Melveny Park. Coast live oak and toyon are frequently minor elements in the woodlands. Small groves of walnut or ash are frequently embedded in the middle of the larger stands of walnut-ash woodland. All of the walnut trees in walnut-ash woodlands exist in ramet form. The trunks of ash trees seem to survive fire better than those of walnut. Fire possibly had an important role in community formation by eliminating previously existing forms of vegetation. This community seems to be unique and confined to this part of the Santa Susana Mountains. Occurrence with California bay-laurel — Bay-laurel is found near sufficient soil moisture in all of the major canyons and is particularly abundant near springs, permanent water, and the more reliable intermittent streams. It is usually in association with canyon, coast live, and valley oaks, big leaf maple, and big cone Douglas fir. Occasionally, however, it forms vegetation types with California black walnut, floering ash, and walnut-coast live oak. Small areas (Vi ha or less) of this association are embedded in the walnut-ash woodlands in Towsley and East and Rice canyons and on the north and west slopes of Oat Mountain. However, it is more extensive and distinct along streams in Crossosoma 18(2), November 1992 11 the central and western portions of the headwaters of Rice Canyon Creek, at 700-850 m. The woodlands are surrounded by valley and coast live oak savanna and woodlands and mixed hardwood woodlands. Bay laurel forms ramets following fire. Flowering ash and California bay laurel also frequently form groves or pure stands one hectare or less in size. Discussion It has been established that Juglans californica can be locally dominant in woodlands of coastal southern California (Swanson, 1967; Leskinen, 1972; Griffin and Critchfield, 1972; Griffin, 1977; Campbell, 1980; Keeley, 1990). These woodlands have been classified as “the coast live oak phase” (Griffin, 1977) of the “southern oak woodland” (Munz and Keck, 1959). The present study has revealed that California black walnut also exists as a co-dominant in valley oak woodlands and mixed evergreen forests which have been opened by fires. Trees of the mixed evergreen forest include Pseudotsuga macrocarpa, Quercus chrysolepis , Umbellularia californica , and Acer macrophyllum. From his studies, Quinn (1989) states that the walnut is the only tree present in many stands located in the San Jose and Puente Hills, and that the stands attain a vegetative cover of 100%. He calls such stands forests and notes that the Natural Diversity Data Base (Holland, 1986) includes the category California Walnut Forest. Walnut forests were also observed in the Santa Susana Mountains. They are usually less than two hectares in size and rarely have understory other than grasses and other herbaceous plants. All of the walnut forests and woodland situated in the eastern Santa Susana Mountains have experience fires, and most of the trees have multiple trunks. Keeley (1990) has suggested that at Mount Washington, closed canopies constitute evidence of a fire-free environment. Sizable California walnut trees with single trunks (genets) were found to be most abundant in relatively broad canyon bottoms. Quinn (1989) concluded that walnuts in canyon bottoms have a fewer number of trunks than hillside trees. Quinn (1989) also emphasized that burned walnuts invariably resprout to form new trees with multiple trunks. The results of this study agree with those conclusions. Walnut woodlands develop optimally on northern exposures in soil derived from Tertiary (Miocene-Pliocene) marine shales (Leskinen, 1972; Keeley, 1990). This study is in agreement but also stresses the 12 Crossosoma 18(2), November 1992 occurrence of woodland on east slopes and in canyons with intermittent streams draining in easterly directions. The woodlands may be almost pure stands or mixed hardwood stands. During the drought of 1986-1990, seedlings and saplings were most common on stream banks and in the riparian zone. They were practically absent on drier slopes supporting oak and walnut woodlands. The lack of seedlings at Brea (Swanson, 1967) was attributed to low precipitation in that region. Keeley (1990) attributed gaps in age classes of walnut trees to annual variations in recruitment and mortality due to precipitation. Thus, it is evident that years of insufficient precipitation and droughts interfere with the ability of Juglans californica to form seeds, or with the ability of the seedlings to grow deep roots reaching sufficient moisture to survive the first dry season. Some of the ecological requirements of California black walnut are characteristic of other species in the genus. As described, Juglans californica is a prominent tree in the riparian zone as well as on dry slopes. Juglans hindsii of central California always occurs on moist valley soils (Jepson, 1917). Peattie (1990) states that the tree is confined to the banks of rivers and streams. In the southwest, Juglans major and J. rupestris grow on the banks of streams and in bottom lands, washes, and draws (Peattie, 1990; Vines, 1960). These species also form groves (stands), and J. rupestris is frequently the only tree in dry washes (Peattie, 1990). Along the Flambeau River of Wisconsin, Juglans cinerea is part of the streamside community (Braun, 1950). Thus many species in Juglans are adapted to conditions along rivers and stream which course through canyons, draws, and bottom lands. Juglans californica is no exception to this general rule even though it may be scarce along rivers which course through broad valleys. However, it is exceptional to the degree that it successfully exists on dry hillsides and uplands as pure stands, single trees and as a constituent of woodland communities. Axelrod (1937) concluded from his studies of the Pliocene Mt. Eden beds that ancestral Juglans californica , though abundant, was confined to the banks and edges of streams, marshes and lakes. Ancestral walnuts most likely existed in washes, along stream banks, and in the riparian zone. Evidence now indicates that since Mt. Eden times, this walnut has evolved to tolerate dry summers and exist upon dry slopes presently characteristic of the hills of cismontane southern California. The characteristic of forming pure stands seems to have existed in the ancestor of J. californica , J. rupestris, and 7. major. These species exist in arid southwestern climates, grow best in full sun, reproduce Crossosoma 18(2), November 1992 13 poorly or sporadically from seeds, and are capable of developing multiple stems (Peattie, 1990). In the Santa Susana Mountains, deposits of limestone are frequent and are favorable to growth of J. californica. [Editor's note: This is also true in the San Jose Hills west of Pomona.] Juglans rupestris is confined to streams in limestone regions (Peattie, 1990). Ancestral flowering ash was also present at Mt. Eden (Axelrod, 1937). However, Axelrod does not indicate that this tree existed near water in association with walnut trees. It may be that in the Pliocene ash was already adapted to exist in chaparral or woodland communities. Summary California black walnut is abundant in the Santa Susana Mountains within Los Angeles County. The species is thinly distributed on arid and hot slopes on the southern side of the range. In the canyons, however, walnuts are relatively abundant along intermittent streams and small canyons which conduct runoff during major rainstorms. During the dry season, the species tolerates high alkalinity and salinity. On the north slope, the tree is a component of one of the largest and most unusual mixed evergreen and hardwood forests in southern California. Pure and nearly pure woodlands and forests of California black walnut are common. It grows in woodland and savanna with Quercus agrifolia , Q. lobata , Fraxinus dipetala , and Umbellularia californica. Walnut also borders other vegetation types including chaparral, arroyo willow, coast live oak forest, dense valley oak woodland and forest and big cone Douglas fir-canyon oak forest. Following fire or other disturbance, walnut colonizes openings in these vegetation types. Walnuts are particularly well adapted to existing in openings and on the edges of other plant communities. Vegetation types dominated by combinations of California black walnut, flowering ash, and California bay laurel are considered to be very rare, perhaps even confined to the Santa Susana Mountains. All of these species also segregate to form pure stands. Walnut woodlands are also common on east slopes and in canyons with intermittent streams draining in easterly directions. The woodlands may be almost pure stands or walnut-oak stands. Though walnuts are common on dry hillsides and occasionally form pure stands, they are also a component of riparian woodlands. They exist down to within 2 m of the beds of major intermittent streams. Conditions of marginal soil moisture during the dry season are 14 Crossosoma 18(2), November 1992 considered to usually preclude the existence of walnuts in valley oak woodlands. Fires have created openings in oak and big cone Douglas fir woodlands, coastal sage scrub, and chaparral. These openings facilitate colonization by California black walnut. All of the walnut woodlands have experienced fire, and the trees resprout following the fire. Large pure stands are not destroyed by fire, and stands occurring on relatively dry slopes apparently are not sites for the germination of other species of trees or the process of succession. Stands are climax vegetation for at least the life span of the trees. On mesic north slopes, coast live oaks may develop within mature walnut woodland. Genets are common on the broad bottoms of major canyons. Because of fires, ramets are predominate on hills and canyon walls. During the drought of 1986-1991, seedlings were most abundant in riparian zones. In this zone large numbers were observed near the periphery of the canopies of mature walnuts and Quercus agrifolia. On arid hillsides, seedlings were very scarce near these trees. Insufficient precipitation and droughts seems to be major causes for years of poor recruitment in Juglans calif 'ornica. Locally walnut trees rarely exist within stands of chaparral dominated by Adenostema, Ceanothus , and Arctostaphylos. Near the summit of Oat Mountain, they are common in chaparral composed of Symphoricarpos mollis. In common with Juglans major and J. rupestris of the southwest, Juglans calif ornica exists in streamside and riparian environments. These species are also similar in that they can form essentially pure stands. Of the three species, Juglans californica is the only one that exists on dry hillsides as stands and as a dominant and co-dominant component of woodland communities. Acknowledgments I am grateful to a number of people who have provided assistance: Dr. Todd Keeler-Wolf and Dr. Jon E. Keeley accompanied me on inspections of the vegetation and encouraged me to finish this report. My wife, Mary Patterson, gave of her time and expertise on the computer to type and retype the manuscript. Steve Hartman and the California Native Plant Society diverted me into a stronger interest in botany. Hank Aubin and Gary Cordova, Supervisors of Aliso Gas Field of the Southern California Gas Company, allowed me to use the company road to reach the summits of the Santa Susana Mountains. Crossosoma 18(2), November 1992 15 No appreciation is expressed to hired hands of the so-called Orcutt Ranch for accosting me on the ranch and trying to keep me out of their woods. References Axelrod, D. I. 1937. A Pliocene flora from the Mount Eden beds, southern California. Carnegie Inst. Wash. Publ. 476:125-183. Braun, E. L. 1950. Deciduous forests of eastern North America. Blakiston Co., Philadelphia, PA. pp. 54-300. Campbell, B. 1980. Some mixed hardwood forest communities of the coastal ranges of southern California. Phytocoenologia 8:297-320. Griffin, J. R. 1977. Oak woodland, pp 303-415 in Terrestrial vegetation of California. M. J. Barbour and J. Major, eds. John Wiley and Sons, New York. 1002 pp. Griffin, J. R. and W. B. Critchfield. 1972. The distribution of forest trees in California. USDA Forest Service, Pacific Southwest Forest and Range Experiment Station, Research Paper PSW-82/1972. Berkeley, California. 1 14 pp. Holland, R. F. 1986. Preliminary descriptions of the terrestrial natural communities of California. Nongame Heritage Program. California Department of Fish and Game, Sacramento. 156 pp. Jepson, W. L. 1917. The native walnuts of California. Madrono 1:55-57. Keeley, J. E. 1990. Demographic structure of California black walnut (Juglans californica) woodlands in southern California. Madrono 37:237-248. Leskinen, C. A. 1972. Juglans californica. Local patterns of southern California. M.A. Thesis, University of California, Los Angeles. 58 pp. McClelland Consultants (West) Inc. 1990. Biological resources impact and mitigation studies, alternative landfill sites, Los Angeles County. State Clearinghouse # 89010419. Munz, P. A. and D. C. Keck. 1959. A California flora. University of California Press, Berkeley. 1681 pp. Peattie, D. C. 1990. A natural history of western trees. University of Nebraska Press, Lincoln and London. 751 pp. 16 Crossosoma 18(2), November 1992 Quinn, R. D. 1989. The status of walnut forests and woodlands (Juglans californica) in southern California, pp 42-54. In A. A. Schoenherr, ed.. Endangered plant communities of southern California. Southern Calif. Botanists Spec. Pub. No. 3. 1 14 pp. Swanson, J. C. 1967. The ecology and distribution of Juglans californica Wats, in southern California. M.S. Thesis, California State College, Los Angeles. 1 1 5 pp. Ultrasystems Inc. 1989. Sunshine Canyon landfill extension, draft environmental impact report. Prepared by Ralph Oesterling Consultants, Inc. for County of Los Angeles, Dept. Regional Planning. State Clearinghouse # 84082908. Vines, R. A. 1960. Trees, shrubs and woody vines of the southwest. Univ. Texas Press, Austin, p. 123. Crossosoma 18(2), November 1992 17 Table 1 . List of species mentioned in text with their scientific names. Arroyo willow Salix lasiolepis Big cone Douglas fir Pseudotsuga macrocarpa Big leaf maple Acer macrophyllum Black cottonwood Populus trichocarpa Blue oak Quercus douglasii Bush monkey flower Mimulus longiflorus California bay-laurel Umbellularia califomica California buckwheat Eriogonum fasciculatum California sagebrush Artemisia califomica Canyon live oak Quercus chrysolepis Chaparral yucca Yucca whipplei Coast live oak Quercus agrifolia Flowering ash Fraxinus dipetala Hairy leaf ceanothus Ceanothus oliganthus Heart-leaved penstemon Keckiella cordifolia Hillside gooseberry Ribes califomicum Hollyleaf cherry Prunus ilicifolia Hollyleaf redberry Rhamnus illicifolia Interior live oak Quercus wislizenii Laurel sumac Rhus laurina Mexican elderberry Sambucus mexicana Poison oak Toxicodendron diversilobum Purple nightshade Solanum xantii Scrub oak Quercus berberidifolia Snowberry Symphoricarpus mollis Toyon Heteromeles arbutifolia Valley oak Quercus lobata Western chokecherry Prunus virginiana Western sycamore Platanus racemosa White alder Alnus rhombifolia White nightshade Solanum douglasii White sage Salvia apiana Yerba santa Eriodictyon crassifolium 18 Crossosoma 18(2), November 1992 Comparison of Annual and Perennial Eschscholzia calif ornica (Papaveraceae) at the Antelope Valley California Poppy Reserve1 Curtis Clark and Nancy A. Charest Biological Sciences California State Polytechnic University Pomona CA 91768 Many visitors to the Antelope Valley California Poppy Reserve (west of Lancaster in Los Angeles Co.) are aware that the poppies just outside the Reserve on the slopes across the road from Fairmont Store (the Fairmont site) are larger than the poppies in the Reserve, and often flower for a longer period. It has also been apparent to botanists who have studied the plants that those of the Reserve grow as annuals, dying completely after seeds are shed, whereas those of the Fairmont site are perennial, resprouting each year from a persistent crown of stem tissue at soil level or slightly below. There has been much disagreement about the relative extent of annual and perennial forms of California Poppy. Cook (1962) found clear-cut differences between the two; he characterized annuals as having short, slender taproots and a mean stamen number per flower of 22 or fewer, and perennials as having a much thicker, longer taproot and a mean stamen number of more than 22 per flower. Clark (unpublished) showed that the stamen number was not always a consistent indicator (some long-lived perennials of the Big Sur Coast having a mean stamen number of 16, for example), and, more important, that many poppies that behaved as annuals in the natural environment were not only capable of perennating in cultivation, but also occasionally in the natural environment in favorable microsites. At the conclusion of these initial studies, Clark was convinced that all California poppies were capable of perennating under proper conditions, and that there existed a This is the second paper based on a study of the California poppies and other vegetation in the Antelope Valley California Poppy Reserve. The first paper (Clark & Charest, 1992) concerned the vegetation of the Reserve. Crossosoma 18(2), November 1992 19 continuum in nature from those plants that routinely devoted a large amount of resources to surviving another season, to those that held back only the slightest amount against the improbable occurrence of favorable conditions, devoting the rest to producing seeds. Further studies suggested, however, that there might indeed be obligately annual populations of California Poppy in the extreme desert parts of its range. The one population Clark had studied in the Antelope Valley, farther west than the Reserve, was perennial and had a high mean stamen number. The population studied by Cook (1962) was north of this, and was also perennial. It is clear that the plants at the Fairmont site are actively perennial, since they resprout from the base among the dead stalks of previous years' growth. Although it remains to be demonstrated conclusively that the Reserve poppies are obligate annuals, their growth in nature is in sharp contrast to those of the Fairmont site. The purpose of this study was to compare the poppies and the soils of the two sites. Materials and Methods Flowering Phenology of Eschscholzia On 17 April 1983, and again on 22 May, we gathered data on flowering phenology both in the Reserve in the area of maximum display (east of the Visitors Center, south of the main range of hills, and just north of the south boundary) and at the Fairmont site (the hillslope southeast of and across the road from the Fairmont Store). For nine samples from the Reserve and four from the Fairmont site, each consisting of 10 to 30 plants, we recorded height of plant, average width of plant, number of buds, flowers, and fruits, number of stamens in one representative flower, and distance to nearest neighbor (the latter item was never used). Statistical analysis was performed with the MINITAB statistical package. Soil Analysis Soil was collected from the region of maximum display in the Reserve, from the region upslope from the display across the 1981 firebreak, and from the Fairmont site, on 22 May 1983, and again on 23 October. AJ1 soil samples were air-dried and then fine-sifted (less than 2 mm) before analyses were carried out. 20 Crossosoma 18(2), November 1992 Analyses of the collections of 22 May: 1. Available Potassium — hot nitric acid extraction (method S: 1 3. 1 , CFA-SIC, 1980). Three replicates/sample. 2. Saturation Percentage (method S:2.0, CFA-SIC, 1980). 3. Soil pH — determined from saturated soil paste (method S:3.0, CFA-SIC, 1980). 4. Electrical Conductivity — from saturation extract (method S:5.0, CFA-SIC, 1980). 5. Phosphorus — Olsen sodium bicarbonate extraction method for neutral to basic soils (method S: 12.0, CFA-SIC, 1980). Three replicates/sample. 6. Soluble Calcium and Magnesium — from saturation extract (method S:7.0, CFA-SIC, 1980). Two replicates/sample. Analyses of the collections of 23 October: 1 . Soil Texture Class — determined by the Bouyoucos method (Kilmer & Alexander, 1949). 2. Organic Matter — dichromate reduction (method S: 1 8.0, CFA-SIC, 1980). Three replicates/sample. 3. Available Zinc — DTPA extraction (method s:14.0, CFA-SIC, 1980). Three replicates/sample. 4. Total Nitrogen — Kjeldahl analysis (Jackson, 1958). Soil classifications and other published data were obtained from Soil Survey of the Antelope Valley Area (U. S. Department of Agriculture, 1970). Results Phenology The mean stamen numbers at the two sites are consistent with Cook's prediction: the Reserve poppies average 19.88 stamens per flower and the Fairmont poppies 23.27. This is a significant difference when all samples from each site are grouped (one-way analysis of variance), although pairs of samples from the Reserve and the Fairmont site can be selected that do not show significant differences (Table 1). The Fairmont plants are larger, with a mean height of 30.3 cm and width of 26.1 cm, versus 20.7 cm and 13.6 cm for the Reserve; the differences are highly significant (p<0.0005, two-sample t test). They also have a significantly iarger number of "floral units" (buds + flowers Crossosoma 18(2), November 1992 21 + fruits) per plant than the Reserve plants, 34.0 per plant versus 12.0 per plant (p<0.0005, Mann-Whitney U test). As might be expected, there are significant correlations between the number of buds, flowers, and fruit and the height and width of the plants, both within the Reserve and Fairmont samples and with the two combined (Table 2). Table 1. Analysis of stamens per flower Sample n mean s.d. Sample n mean s.d. Reserve 1 10 22.10 4.53 Fairmont 1 2 17.50 6.36 Reserve 2 15 17.80 5.27 Fairmont 2 24 25.88 3.04 Reserve 3 14 25.86 4.26 Fairmont 3 15 20.60 2.56 Reserve 4 17 21.35 6.11 Fairmont 4 19 22.68 4.01 Reserve 5 14 16.64 5.50 all Reserve 125 19.88 5.46 Reserve 6 7 22.71 3.09 all Fairmont 60 23.27 4.07 Reserve 7 18 20.72 2.78 Reserve 8 11 17.55 4.80 Reserve 9 19 16.53 4.29 Table 2. Correlations of height, width, number of buds, and number of flowers (asterisk denotes value significant at p<0.05). Reserve poppies, n = 198 Height Width Buds Flowers Width .684* Buds .530* .715* Flowers .543* .689* .722* Fruits .581* .677* .405* .784* 22 Crossosoma 18(2), November 1992 Fairmont poppies, n = 85 Height Width Buds Flowers Width .741* Buds .297* .532* Flowers .534* .754* .633* Fruits .674* .840* .426* .828* All poppies, n = 283 Height Width Buds Flowers Width .756* Buds .482* .651* Flowers .502* .680* .635* Fruits .619* .752* .458* .696* The Fairmont plants also flower later in the season. Although we did not quantify this in a manner that could be tested for significance, we calculated from the data of 17 April the average ratio of flowers to buds on a single plant, which was 0.553 for Fairmont and 0.745 for the Reserve. Thus, at this point in the season, a greater proportion of the flowers had opened at the Fairmont site than on the Reserve. The difference was very apparent in the field; the Fairmont site was reaching maximum bloom as the reserve began to wane, and later when we collected many dry fruits in the Reserve, very few Fairmont site fruits were yet ripe. Soils The soils of both the Reserve and the Fairmont site are derived from granitic rock. The soils are well-drained and easily infiltrated, and with the exception of road cuts and some gully systems outside the Reserve, not easily eroded. The south slope of the Antelope Buttes, a site of poppy displays prior to the 1980 and 1981 fires, is of the Greenfield series, as is the tilled area in the southeast of the Reserve, parts of the western Reserve, and the Fairmont site. The 1983 display was located in Ramona series soil, which is also found south of South Godde Hill. The hills themselves are of the Vista series, shallower soils than the Crossosoma 18(2), November 1992 23 previous two, except for North Godde Hill, which is of the Amargosa series, shallowest of all (U. S. Department of Agriculture, 1970). The soil analyses (Table 3) were designed to look for differences between the Fairmont site, the display area in the Reserve, and the area just across the 1981 fire line from the display. Among the analyses that were replicated and thus subject to statistical tests, there were no significant differences. Table 3. Soil Analyses Samples of 22 May 1983 Reserve display area 1 Reserve display area 2 Reserve above display Fairmont Electrical conductivity (mmho/cm) 0.32 0.40 0.56 0.20 PH 6.70 6.80 6.60 6.80 Saturation percentage 30 24 20 19 Available potassium* (ppm) 813 713 913 772 Phosphorus* (ppm) 29.80 35.30 25.00 22.30 Calcium + Magnesium* (me/1) 2.20 3.10 4.00 2.10 Samples of 23 October 1983 Reserve display area Reserve above display Fairmont Percent sand 75.70 75.80 75.50 Percent silt 13.50 13.00 15.30 Percent clay 10.80 11.20 9.20 Percent organic matter* 2.12 1.77 1.34 Available zinc (ppm) 2.60 2.80 2.20 Total organic nitrogen(percent) 0.12 0.12 0.10 * replicated experiment, no significant difference among samples 24 Crossosoma 18(2), November 1992 Discussion In addition to their difference in growth habit, the poppies of the two sites are physically dissimilar. The dissimilarities are consistent with those expected between annual and perennial Eschscholzia californica. It is very unusual for poppies so different to be in such close proximity . Excluding instances where cultivated poppies have escaped and coexist with morphologically different native populations, such occurrences are usually found along the coast, where the plants of the coastal bluffs and dunes differ from those of a few kilometers inland. In these cases, however, the environments in which the different populations grow are very dissimilar. The environmental differences between the south slopes of the Antelope Buttes in the Reserve and the Fairmont site are not immediately apparent. We have shown that the soils do not differ significantly in physical or chemical attributes. The areas are close enough to one another (about 2V2 km) that they would be expected to have similar climatic regimes. The Fairmont site has more north-facing exposures than the area of the Reserve sampled in this study, but annual poppies can be found on north-facing exposures in the Reserve. Plants of neither site are especially similar to the poppies growing further to the west in the Antelope Valley. The poppies of the Reserve are similar to the annual poppies of other inland areas in Southern California, and presumably to the annuals that spring up around Lancaster in a good year. As far as we have determined, the poppies growing in recently cultivated fields in the area are of the same type. The Fairmont poppies are most reminiscent of poppies growing around Kemville in Kern County, which have been treated (unnecessarily, in our estimation) as E. procera Greene; the most pronounced similarity is their very thick stems. Nevertheless, the environment at Kemville is very different. The perennial poppies further to the west in the Antelope Valley have somewhat more slender stems than the Fairmont plants, but are similar in other respects. We conceive of two alternate hypotheses for the presence of dissimilar poppies on the Reserve and the Fairmont site. The first is that either the Fairmont form or the Reserve form, or both, have been introduced as seed by humans, either intentionally as ornamentals, or inadvertently, as an agricultural weed. The second is that the co-occurrence antedates European settlement. The Reserve poppies are of the type that most likely extended across what is now the Mojave Desert during the height of the Wisconsinan glaciation, when the region Crossosoma 18(2), November 1992 25 was a pinyon-juniper woodland (Wells & Berger, 1967). Poppies of the Kemville tvpe must have lived at lower elevation, and the Fairmont poppies may be a remnant of this. As conditions became warmer and drier with the retreat of the glaciers and basin lakes, the annual forms could have retreated up the Antelope Valley, coming in contact with the perennials that had formerly inhabited the region. We have considered that differing land use may have allowed the persistence of the different poppies on the two sites, and may maintain them still. A possible candidate for this influence is grazing at the Fairmont site, as overall herbaceous cover seems to be less. Flowever, grazing was restricted on the Reserve only in recent decades, and the differences between the poppies at the two sites are possibly much older. Acknowledgments We thank Mark Patterson for the soil analyses, Emilia Parra, Mark Patterson, Donald Sanders, and Christina Wedaa for assistance in the field, and the California Department of Parks and Recreation for financial support and access to unpublished records and photographs. References Cited CFA-SIC Publication. 1980. Soil testing procedures for California. California Fertilizer Association, Sacramento. Clark, C., and N. A. Charest. 1992. Vegetation survey of the Antelope Valley California Poppy Reserve. Crossosoma 18(1): 15-24. Cook, S. A. 1962. Genetic system, variation, and adaptation in Eschscholzia calif ornica. Evolution 16:278-299. Jackson, M. L. 1958. Soil chemical analysis. Prentice-Hall Inc., Inglewood Cliffs, N.J. Kilmer, V. J., and L. T. Alexander. 1949. Methods of making mechanical analysis of soils. Soil Sci. 68:15-24. U. S. Department of Agriculture. 1970. Soil Survey, Antelope Valley Area, California. Wells, P. V. and R. Berger. 1967. Late Pleistocene history of coniferous woodland in the Mohave Desert. Science 155:1640-1647. 26 Crossosoma 18(2), November 1992 Book Review California's Eastern Sierra, A Visitor's Guide , by Sue Irwin. 1991 . 144 pages. Cachuma Press, in cooperation with the Eastern Sierra Interpretive Association. $15.95, paper. Here is another beautiful but affordable book published by Cachuma Press. It has 165 color photos, many of which were taken by famous photographers such as David Muench and Galen Rowell. Without question, this will be a volume against which other travel guides will be measured. When I first saw it, I assumed that this was going to be a colorful guide to Sierra Nevada backpacking. That is not what the book is at all. Rather, after two introductory chapters on natural history and traditional history, the book divides lands east of the Sierra Nevada, between Fossil Falls and Sonora Pass, into six geographic regions and describes the scenic wonders that can be reached by road or short hikes. Each regional chapter begins with a brief history of the area and then describes its significant landmarks or natural wonders. Although I wonder why she omitted the area around Kennedy Meadows in the southern Sierra Nevada, locations in the Inyo and White Mountains east of Owens Valley are also included. In total, over 100 such destinations are described. Seven full-page color road maps, without unnecessary clutter, depict the access routes. Sue Irwin has done a wonderful job on the text for this book. In a clearly written, efficient style she has packed a wealth of information into this volume. In addition, at appropriate locations, short contributions from other well known experts are inserted into the text. For example, a beautiful section on Wildflowers of the Eastern Sierra is authored by Mary DeDecker, herself an Owen’s Valley resident. When I realized that this was actually a road guide, my first reaction was, “Oh no, someone is actually going to reveal my secret places to the unappreciative masses.” I have been visiting the area for nearly 40 years, and I have a house at about 8500 feet elevation on the South Fork of Bishop Creek. The main thing I appreciate about the eastern Sierra Nevada and its environs is the uncluttered space, the grand vistas. To visit the area, unquestionably one of the most beautiful in the world, a person does not have to drive through a single city the likes of Fresno or Phoenix. I didn’t like the thought that such a beautiful book in its thoroughness would attract hordes of visitors. Crossosoma 18(2), November 1992 27 A sentiment similar to mine is eloquently expressed in the introduction by Gordon Wiltsie, a respected native of the Owen’s Valley. He aptly points out that most of the acreage is either public land or owned by the Los Angeles Department of Water and Power, and that there simply isn’t enough private land in the area to support much development. He also points out that by fostering appreciation for its scenic beauty the book helps to preserve the eastern Sierra in its present wild state. He explains that appreciative visitors can bring more life to the area’s economy than all the boom-and bust mining, ranching, and hydroelectric power the region has ever produced. So, I put aside my selfish interests. I encourage everyone to buy this book and visit the country that my friends and I simply call “The East Side.” Spend some money there so the shakers and movers of Inyo and Mono Counties will realize that tourism is the most important long-term aspect of the region’s economy. Anyway, Sue Irwin did fail to mention some of the places I find particularly special. But the truly appreciative visitors will find those for themselves because an important part of the eastern Sierra experience is exploration. Allan A. Schoenherr, Division of Natural Sciences, Fullerton College 28 Crossosoma 18(2), November 1992 Southern California Botanists Special Publications No. 1. A Flora of the Santa Rosa Plateau by Earl W. Lathrop and Robert F. Thome (39 pages) $7.00 No. 2. Flora of the Santa Monica Mountains, 2nd edition, by Peter H. Raven, Henry J. Thompson, and Barry A. Prigge (179 pages) $10.50 No. 3. Endangered Plant Communities of Southern California, Proceedings of the 15th Annual Symposium, edited by Allan A. Schoenherr (1 14 pages) $12.00 All prices include California state sales tax, handling, and domestic postage. Send check or money order payable to “Southern California Botanists” or “SCB” to: Southern California Botanists Department of Biology California State University Fullerton, CA 92634 w r z i h. ro G O" S 3 1 x a=. < •- ~ o •< " Z I - < ! a « w ►* ro 0 o i rt- 4* h- su LH & D 03 i-5 5^- i m n Ul Oi —• ^ 4 ro ' ’ 0s- m g x Dj n i =r a & G 3 G iD ro a m n •4j Cm