Aliso: A Journal of Systematic and Evolutionary Botany Volume 30 | Issue 1 Article 4 2012 Naturalization of Sequoiadendron giganteum (Cupressaceae) in Montane Southern California Rudolf Schmid University of California, Berkeley Mena Schmid Follow this and additional works at: http://scholarship.claremont.edu/aliso Part of the Botany Commons, Ecology and Evolutionary Biology Commons, and the Forest Biology Commons Recommended Citation Schmid, Rudolf and Schmid, Mena (2012) "Naturalization of Sequoiadendron giganteum (Cupressaceae) in Montane Southern California," Aliso: A Journal of Systematic and Evolutionary Botany: Vol. 30: Iss. 1, Article 4. Available at: http://scholarship.claremont.edu/aliso/vol30/iss1/4 Aliso, 30(1), pp. 19–32 ’ 2012, Rancho Santa Ana Botanic Garden NATURALIZATION OF SEQUOIADENDRON GIGANTEUM (CUPRESSACEAE) IN MONTANE SOUTHERN CALIFORNIA RUDOLF SCHMID1,3 AND MENA SCHMID2 1Department of Integrative Biology, University of California, Berkeley, California 94720-3140, USA ([email protected]); 2Somerville, Massachusetts 02144, USA([email protected]) 3Corresponding author ABSTRACT After the August 1974 fire in the upper Hall Canyon area on the southwestern flank of Black Mountain in the northwestern San Jacinto Mountains, Riverside Co., California, the United States Forest Service revegetated the burn in the mixed-conifer forest with the Sierra Nevada endemic Sequoiadendron giganteum (Cupressaceae). On 1 May 2009 a GPS census starting at the head of Hall Canyon revealed both in the canyon and upslope beyond it at least 157 individuals in the vicinity of the Black Mountain Trail, plus an outlier 450 m distant near the summit. This species alien to southern California is regenerating prolifically on Black Mountain, as revealed by multiple age classes, from juveniles (seedlings and saplings) about 20– 60 cm tall to young adult trees over 6 m tall, up to about 40 years old, and reproductively mature. The naturalized population (,7 ha in 2009) also appears to be spreading from its initial ‘‘small area’’ of introduction (,2 ha in 1974). Analysis of published print and Internet literature suggests similar post-fire naturalizations of S. giganteum in the San Gabriel and San Bernardino Mountains of Los Angeles and San Bernardino Counties. State and regional floras and checklists for California should acknowledge the naturalization of this species in montane southern California in the San Jacintos and possibly elsewhere. Key words: big tree, Cupressaceae, giant sequoia, naturalized species, Riverside Co., San Jacinto Mountains, Sequoiadendron, Sequoiadendron giganteum, southern California. INTRODUCTION An Internet search for ‘‘Sequoiadendron ‘Hall Canyon’’’ readily produced the answer to question #1. According to On 3 May 2008 while hiking on the Black Mountain Trail in Keeler-Wolf (1990: 156, 2004: 128), in upper Hall Canyon ‘‘a the San Jacinto Mountains, Riverside Co., California, we saw small area of the [August] 1974 burn was revegetated with non- an interesting, reproductively mature conifer at 2144 m el. on native giant sequoia (Sequoiadendron giganteum).’’ On 1 May the northwestern flank below the summit of Black Mountain 2009 we revisited Black Mountain to obtain the answers to (el. 2369 m), in mixed-conifer forest (Lower Montane questions #2 and #3, to take additional photos (Fig. 2–5 in Coniferous Forest), just above the head of Hall Canyon. The 2009, Fig. 6 the original photo in 2008, items in Fig. 7–8 Sequoiadendron giganteum conifer turned out to be (Lindl.) collected in 2009 and photographed in 2010), and to make J.Buchholz. voucher collections. This monotypic California endemic (Sequoiadendron J.Buch- holz) is native to the western slope of the Sierra Nevada, where it METHODS occurs in isolated groves (Fig. 1) in mixed-conifer forest between 825 and 2700 m el. (Stark 1968; Rundel 1972; Nomenclature and voucher information: Taxa follow The Weatherspoon 1990; Willard 1995, 2000; Elliott-Fisk et al. Jepson manual, 2nd edition (Baldwin et al. 2012). Voucher 1997; Lanner 1999; Schellevis and Schouten 1999; Flint 2002; information is (all collections RSA, UC, UCR): 1 May 2009, Fites-Kaufman et al. 2007; Krugman and Boe 2008; Eck- Black Mountain (summit el. 2369 m/7772 ft), Riverside Co., enwalder 2009; Farjon 2010; Boyd and Griffin 2012; CCH 2012; California, at 2036 m/6680 ft to 2144 m/7034 ft: Pinus Schmid 2012; Wikipedia 2012). The groves recognized vary in lambertiana (R. Schmid and M. Schmid 2009-3), Sequoiaden- number from 65 to 80 or more, depending on how ‘‘grove’’ is dron giganteum (Idem 2009-1, 2009-2, 2009-4, 2009-5, 2009-6). defined; Willard’s (2000) ‘‘67 groves’’ is now usually accepted. For details of collection labels see Schmid and Schmid (2011). The groves are mostly of very restricted extent and/or See also Observations. threatened. They occur in a narrow strip measuring about 395 km long (northwest–southeast) and 19–21 km at the widest Mapping aids: Mapping aids included: (1) Garmin Map- point (east–west). The groves extend over seven counties from Source version 6.15.11 with Topo US 2008 used to plot GPS southern Placer Co. southeasterly to southern Tulare Co. and data from a Garmin eTrex Legend HCx hiking GPS receiver vary in size from 6 to over 20,000 adult trees. (Fig. 9), (2) San Jacinto Wilderness trail map (Tom Harrison Our discovery of this Sierran species in the wilds of montane Maps 2006), (3–4) the Internet-based Google Earth (2012: southern California posed these questions: (1) When and how version 6.1.0.5001) and United States Geological Survey did this Sierran endemic get to southern California, some 280 Geographic Names Information System (GNIS) (2012), (5) air km south of its closest native occurrence (Fig. 1)? (2) How atlases for California (Benchmark Maps 2007; DeLorme extensively is this alien species distributed on Black Mountain? 2008), and (6) national-forest maps (print and downloadable (3) Is the species regenerating itself or naturalizing there? PDF versions) of the United States Forest Service (2012). 20 Schmid and Schmid ALISO Fig. 1. Distribution of Sequoiadendron giganteum showing the 8 northern (arrows) and 67 southern (dots) native groves recognized by Weatherspoon [1990: 553, the map source; since Willard (2000), the current numbers are 8 northern and 59 southern groves] and, on the overview map, the naturalized population on Black Mountain, northwestern San Jacinto Mountains, Riverside Co. On 1 May 2009 we used the Garmin GPS receiver to create ,1.3 cm/0.5 in. diameter, not reproductive; sapling,shoot waypoints for individuals of Sequoiadendron giganteum that we 30.5–137 cm/1–4.5 ft tall, main stem $1.3 cm/0.5 in. encountered in the vicinity of Black Mountain Trail. We made diameter, usually not reproductive. These are essentially most of our field observations over a ca. 0.7 km linear distance taxonomic-horticultural definitions, for example, by Flora between 2036 m and 2236 m el. North America (Lewis 1971: 18): ‘‘sapling: a young tree, Except in quotations, we express GPS coordinates in DDD usually several feet high and less than 4 inches [10.2 cm] in (decimal degrees) format to four decimal places (e.g., 37.9151u, diameter.’’ The respective dimensions are appreciably greater 2122.2866u 5 latitude, longitude; 173 m el.) because they seem when defined by foresters, for instance, by Northwest Illinois simpler and less error-prone in transcribing than either the Forestry Association (2012): ‘‘seedlings: trees that are less traditional DMS (degrees, minutes, and seconds) or usual GPS- than 4.5 feet [1.4 m] tall’’ and ‘‘sapling[s]: trees taller than device DMM (degrees, minutes with decimal seconds) for- 4.5 feet [1.4 m] but less than 5.0 inches [12.7 cm] dbh’’ (see mats (respectively, 37u549540N, 122u179110Wand37u54.9069N, also SORTIE-ND 2011). [We checked some 20 dictionaries 122u17.1989W for the previous example). Computer Support of biology and botany for ‘‘seedling’’ and ‘‘sapling’’ and Group (2012) makes available on the Internet a GPS latitude/ found only Lewis (1971) using actual dimensions to define longitude coordinate converter and distance calculator. these terms.] Terminology: We define seedlings and saplings of trees as Criteria for naturalization or regeneration of introduced follows: seedling,shoot,30.5 cm/1 ft tall, main stem plants.—The critical question regarding the introduction of VOLUME 30, NUMBER 1 Sequoiadendron Naturalization 21 Fig. 2–8. Sequoiadendron giganteum.—2–6. Naturalized on Black Mountain (summit el. 2369 m), northwestern San Jacinto Mountains, Riverside Co., California.—2. Outlier sapling (#49) at 2361 m el.—3. Trees up to ca. 30 years old and ca. 5.5–6 m tall at the sloping plateau or saddle at 2144 m el.; tree (#28) left of center enlarged in Fig. 4, 6. Note the classic conical or pyramidal form of these uncrowded trees.—4, 6. Tree (#28) ca. 5.5 m tall, with Rudolf Schmid and male and female cones.—5. Male cones from tree (#c1) at 2066.5 m el.—Fig. 7–8. Items collected 1 May 2009 from the ground on Black Mountain at ca. 2070 m el.—7. Mature seed cones (70, 57 mm long).—8. Winged seeds (50) retrieved from 8 seed cones; mix of sandy granitic soil and sparse duff with needles (Abies concolor) and shoot segments (Calocedrus decurrens). Photos taken 1 May 2009 (Fig. 2–5), 3 May 2008 (Fig. 6), 31 Jan 2010 (Fig. 7), and 16 Apr 2010 (Fig. 8). Photos by M. Schmid (Fig. 2–4, 6) and R. Schmid (Fig. 5, 7, 8). 22 Schmid and Schmid ALISO Fig. 9. Map showing GPS plots of specimens of Sequoiadendron giganteum encountered 1 May 2009 along and near Black Mountain Trail, Black Mountain (summit el. 2369 m).—At least 157 individuals were seen from 2036 to 2236 m el. (respectively, individuals #1, #48, a total of ca. 0.7 km linear distance, ca. 0.066 km2 or 6.6 ha) downslope from Boulder Basin Campground.