ebook img

THE ALPINE FLORA OF THE WHITE MOUNTAINS, CALIFORNIA PDF

2008·9.6 MB·English
Save to my drive
Quick download
Download
Most books are stored in the elastic cloud where traffic is expensive. For this reason, we have a limit on daily download.

Preview THE ALPINE FLORA OF THE WHITE MOUNTAINS, CALIFORNIA

'; Madrono, Vol. 55, No. 3, pp. 202-215, 2008 THE ALPINE FLORA OF THE WHITE MOUNTAINS, CALIFORNIA Philip W. Rundel Department of Ecology and Evolutionary Biology and Center for Embedded Networked Sensing, University ofCalifornia, Los Angeles, CA 90095 [email protected] Arthur C. Gibson and M. Rasoul Sharifi Department of Ecology and Evolutionary Biology, CA University of California, Los Angeles, 90095 Abstract ThealpinezoneoftheWhiteMountainsofCalifornia,definedasnon-forestedareasabove3500 m, includes 163 native species ofvascular plants in an area of 106 km-. No invasive species have become well established. Nearly two-thirds of the native species occur in just seven families, led by the Asteraceae with 30 species. Six genera have five or more species, led by Carex with 14 species. Life forms ofthe flora are heavily dominated by broad-leaved herbaceous perennials (53%), followed in importance by graminoid perennials (22%) and mats and cushions (11%). Woody shrubs, chamaephytes (low subshrubs), and annuals are relatively few in number, and those species present are generally more characteristic of lower elevation communities. Fellfields form the characteristic habitat for41% ofthe flora, while moist meadows and open slopes habitats characterize 24 and 22% oftheflora, respectively. Only31%ofthefloraisrestrictedintheWhiteMountainstothealpinezone, while nearly a third ofthe alpine flora has a range extending to lower elevations ofthe montane or cold desert zones below 2900 m. The alpine flora of the White Mountains shares over 70% of its species with the Sierra Nevada. Only three species are endemic to the alpine zone of the White Mountains: Draba ca/ifornica, D. monoensis, and Potentilla morefieldii. Key Words: alpine biogeography, alpine flora, plant life forms. White Mountains. Generalizations about the patterns of biodi- tions of either sets of ranges. Moreover, warmer versity and life forms in alpine floras have largely and more xeric climatic conditions during the come from research conducted in relatively mesic Altithermal period ofthe early Holocene allowed alpine habitats with summer rainfall regimes, as an upward movement of subalpine conifers, forexample in the Alps ofcentral Europe and the restricting the area available for growth ofalpine Rocky Mountains of the western United States communities (Jennings and Elliot-Fisk 1991, (see reviews by Tranquillini 1979; Chapin and 1993). Thus, the White Mountains present an Korner 1995; Korner 1999; Bowman and Seast- example where both climate history and geo- edt 2001). Unhkethemajority ofalpine regions in graphic isolation have played significant roles in the Northern Hemisphere that share elements of the evolution ofthe alpine flora. a circumboreal arctic-alpine flora, the high Lying in the rain shadow ofthe Sierra Nevada, mountain ranges in CaUfornia have developed a theWhite Mountainsreceive onlyabout one-third unique alpine flora under the influence of ofthe precipitation reaching similar elevations on mediterranean-climate conditions with relatively the west slope of the Sierra Nevada. These arid dry summers added to other alpine environmen- conditions, combined with the extremes of low tal stresses. Although broad ecological studies temperature, wind, low atmospheric pressure and have been carried out in the alpine elevations of high ultraviolet radiation load that characterize the Sierra Nevada and White Mountains of most temperatealpineconditions, produce unusu- Cahfornia (Chabot and Bilhngs 1972; Major ally severe conditions ofenvironmental stress for and Taylor 1977; Morefield 1992), there is still plant growth. Adding to the habitat conditions oft a relatively poor knowledge of patterns of the range are high levels of both topographic floristic diversity and life form distribution of diversity and geologic complexity, with the latter the alpine flora for these ranges. including granites, dolomites, shales, limestones, The White Mountains of California and and metavolcanics (Nelson et al. 1991; Ernst et al. adjacent Nevada (Fig. 1) present a particularly 2003) that have strong influences on florisitic interesting area for study. This mountain range is composition (Lloyd and Mitchell 1973; Marchand positioned at the interface between two major 1973; Rundel et al. 2005). geomorphic provinces, the Sierra-Cascade Prov- The White Mountains extend approximate- ince and the arid Basin and Range Province, yet ly 60 km from their northern end in Nevada is isolated from direct contact with high eleva- across into California and Westgard Pass in the 2008] RUNDEL ET AL.: ALPINE FLORA OF THE WHITE MOUNTAINS 203 kilometers Fig. 1. Regional view ofthe White Mountains ofeastern California and adjacent Nevada. The stippled area is m that portion ofthe range above 3500 elev. south, or three times this length if the contigu- floristic diversity and relationships of the full ous Inyo Range south of this pass is added flora ofthe White Mountains has been described (Fig. 1). The range is very narrow, however, with in considerable detail (Lloyd and Mitchell 1973; a width averaging only 20-25 km. As a result, Morefield et al. 1988; Morefield 1992). AUhough the range rises sharply from elevations of there have been ecological studies of plant-soil 1250 m in the Owens Valley to a high point of relationships in the alpine regions of the range 4343 m at White Mountain Peak over a lateral (Mooney et al. 1962; Mitchell et al. 1966; distance ofless than 10 km. This peak is tied with Marchand 1973; Ernst et al. 2003), no floristic Mount Shasta as the third highest summit in research has focused on the alpine region above m California. 3500 or analyzed its characteristics specifically. There has been a long history of floristic and In this paper we present a broad overview ofthe ecological studies in high elevations ofthe White alpine flora ofthe White Mountains by providing Mountains where alpine habitats are present. The a detailed analysis of the floristic richness. MADRONO 204 [Vol. 55 ecological diversity, and biogeographic relation- The classification of species by characteristic ships ofthe alpine flora present within this zone. elevationalzonewasdesignedto separateobligate m alpinespeciesfromthoseextendingabove 3500 Materials and Methods but also occurring at lower elevations. These five categories listed as the elevational belts oflowest Floristic Richness and Life Forms occurrence in the White Mountains are cold desert (1220-1980 m), montane (1980-2900 m), Thealpine flora oftheWhite Mountains inthis subalpine (2900-3500 m), alpine (3500-4000 m), study was considered to include all species with a and high alpine elevations (4000^332 m). The known occurrence above 3500 m, an elevation montanezoneroughlycorrespondstothepinyon- limit roughly corresponding to upper treeline, juniper zone and the subalpine belt to the upper although Pinus longaeva reaches elevations ofup pine zone ofvegetation. to about 3700 m in scattered locations. While The biogeographic range ofeach alpine species there are certainly alpine-hke communities and was classified into one of five categories. These species assemblages below this elevational limit, were: widespread speciespresentinmanyhabitats an occurrenceabovetheupperlimit forgrowth of or regions throughout the world or across North P. longaeva and P. flexilis indicates a definitive America, cordilleran species widespread in moun- alpine habitat. Our listing ofthe alpine species to tain regions ofthe western United States, Sierra/ beconsidered was based on a careful examination Cascade species, intermountain species wide- of published material (Lloyd and Mitchell 1973; spread across the Great Basin, and species Morefield et al. 1988; Morefield 1992; Hickman endemic to the White Mountains. 1993), herbarium records (Cal Flora, White Mountain Research Station), and our own field Climate Regimes observations carried out on numerous visits each summer from 1999 2006 Scientific names used Climatic data to characterize the alpine envi- . here follow those of Hickman (1993), with the ronment ofthe White Mountains was taken from exception of Poa pattersonii which has been long-term records collected at the Barcroft m divided into Poa abbreviata subsp. pattersonii Station at 3801 elev. (37°35'N lat., 18°15'W and subsp. marshii (Soreng 1991). long.) for the period 1953-1973 (Pace et al. 1974; Adapting the broad classification scheme set out Powell and Klieforth 1991). The mean monthly by Morefield (1988, 1992) fortheentire floraofthe maximum temperatures at Barcroft vary from a White Mountains, we developed a system to high of 11.9°C in July to a low of -5.3°C in categorizethealpine speciesbylife form, ecological February (Fig. 2). Record maximum tempera- habitat, elevational zone, and biogeographic distri- tures of 22°C have been reached in July and bution. Each alpine species was placed into one of August. Mean monthly maximum temperatures six life forms in a modified Raunkiaer (1934) remain below freezing for six months ofthe year, classification: phanerophytes (shrubs reaching from November through April. Mean minimum 50 cmormoreinheight),chamaephytes(subshrubs temperatures range from a high of 2.4°C in July lowerin stature), matorcushionplants(<10 cmin to a low of —14.0°C in March. Mean minimum height and prostrate in growth, perennial grami- temperatures drop below freezing for every noids (i.e., Poaceae, Cyperaceae, and Juncaceae), month ofthe year except July and August. broad-leaved herbaceous perennials (tussocks, ro- Meanannual precipitationat Barcroft Stationis mm sette perennials, biennials, and geophytes), and 478 (Fig. 2). There are elements ofa mediter- annuals (therophytes). With very few exceptions, ranean-type pattern of winter precipitation but plant species in the alpine zone have very narrow with a strong influence of summer convective leaves or leaflets with blades <10 mm wide, and storms from the east that bring scattered precip- would be classified as leptophylls with leafsurface itation events throughout the growing season. areas <25 mm- (Raunkiaer 1934). Mean mmomnthly precipitation ranges frommamhigh Designations ofecological habitatswere adapt- of 56 in December to a low of 18 in ed from characterizations of Morefield (1988, September, but year-to-year variation is high. The 1992) and our experience to provide seven extremes in annual precipitation over the record categories. Along a rough gradient of mesic to period have ranged from242 to 852 mm. With the xeric these ecological habitats are aquatic sites, exception of the summer months ofJuly through wet sites (areas with saturated soils and riparian September, all ofthis precipitation falls as snow. habitats), moist sites (e.g., wet meadows and areas with snow melt accumulation), fellfields Results with seasonal moisture availability, talus slopes, open slopes, and dry rocky slopes. Where a Native Flora species occurred broadly across more than one of these habitat categories, it was placed in what we Defining the alpine zone as non-forested areas considered its most typical habitat. occurring at or above 3500 m, the alpine flora of 2008] RUNDEL ET AL.: ALPINE FLORA OF THE WHITE MOUNTAINS 205 -20 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Time (date) Fig. 2. Meanmonthlyclimaticconditionsat the Barcroft Station at 3801 min theWhite Mountains, 1953-1973. Data from Pace et al. (1974). the White Mountains includes 163 native species that shares the characteristic of a prostrate occurring in an area of 106 km^. Rather than growth form with either a central taproot or representingtheproportionalfamily relationships multiple points of rooting through layering. ofthe Cahfornia flora overall, the alpineflora has These form an ecologically significant component just seven families that account for nearly two- ofplant cover on fellfield slopes and the margins thirds of its total species. Leading this group is ofdrainage swales. A different group ofspecies is the Asteraceae with 30 species, followed in order present, however, dominates on granitic versus by the Brassicaceae (18 species), Poaceae (17 dolomitic substrates. Common mats and cush- species), Cyperaceae (15 species), Rosaceae (9 ions on the widespread granitic substrates include species), Caryophyllaceae (9 species), and Poly- Draba oligosperma (Brassicaceae), Trifolium an- gonaceae (7 species). Genera with large numbers dersonii var. beatleyae (Fabaceae), Eriogonum of alpine species in this flora include Carex ovalifolium var. nivale (Polygonaceae), and Pen- (Cyperaceae, 14 species), Arabis (Brassicaceae, 7 stemon heterodoxusvar. heterodoxus (Scrophular- species), Draba (Brassicaceae, 7 species), Poa iaceae). On dolomitic substrates, there is a shift in (Poaceae, 6 species), Potentilla (Rosaceae, 5 dominance to species such as Erigeronpygmaeus species), and Eriogonum (Polygonaceae, 5 spe- and Stenotus acaulis (Asteraceae), Astragalus cies). Several species just miss our lower eleva- kentrophyta and Oxytropis parryi (Fabaceae), tional limit of3500 m, and thus are not included Linum lewisii (Linaceae), Eriogonum gracilipes in our figures here, although they occur in alpine (Polygonaceae), and Castilleja nana (Scrophular- fellfield and open slope habitats. These include iaceae). These dolomite species however, may , Antennaria dimorpha (Asteraceae), Tonestuspeir- occur on other soil parent materials over their sonii (Asteraceae), and Eriogonum urnbeIlaturn ranges. var. covillei (Polygonaceae). Shrubs (phanerophytes) and subshrubs (cham- The life form distribution of the native alpine aephytes) are few in the alpine flora ofthe White flora of the White Mountains is strongly domi- Mountains. Just three shrub species reaching nated by herbaceous perennials, as is typical of heights of50 cm have a range that extends above temperate alpine habitats elsewhere. Within 3500 m: Ribes cereum (Grossulariaceae), Poten- herbaceous perennials, the assemblage of peren- tilla fruticosa (Rosaceae), and Salix orestera nial graminoids (mostnotablygrasses and sedges) (Salicaceae). All of these shrub species are more form 22% of the total flora, mats and cushions typical of lower elevations. Only Ribes cereum is form 11%, and other herbaceous perennials such common in the alpine zone, and its distribution is as broad-leaved tussocks, rosettes, and biennials highly correlated with large granite outcrops form 53% (Fig. 3). Combined, herbaceous peren- where thermal and hydrologic characteristics nials thus comprise 86% ofthe flora. may be significant in providing favorable micro- There are 18 native species of mats and sites for this species. cushions, all low in stature and mostly relatively Seven species of low woody subshrubs are smallin size, thatmakeup a heterogeneousgroup present, representingjust two families. These are MADRONO 206 [Vol. 55 100 shrub subshrub mat/ herb. graminoid annual cushion perennial perennial Fig. 3. Life form distribution ofthe native vascular plant species in the alpine zone above 3500 m in the White Mountains. Artemisia rothrockii, Chrysothamnus viscidiflorus many categories, however, is too small for subsp. viscidiflorus, Ericameria discoidea, and E. relevant statistical tests of association. Broad- suffruticosa (Asteraceae), and Leptodactylonpun- leaved herbaceous perennials, the most common gens, Linanthus nuttallii subsp. pubescens, and life form, have virtually the same proportional Phlox pulvinata (Polemoniaceae). These three distribution among habitats as does the entire Polemoniaceae are quite low in stature in their flora (Table 1). Perennial graminoids, likewise, alpine habitats and approach becoming mats in generally match the overall pattern but with an life form. The highest elevation reached by any of over-representation of species in moist and wet these woody species occurred with Chrysotham- habitats and an under-representation in drier nus viscidiflorus, which extends to near 4000 m at open habitats. Among the lesscommon lifeforms the top of Barcroft Peak. there is a much stronger association with specific Thirteen annual species are present, makingup habitats. Annual plant species are strongly 8% of the flora. The majority of the annual associated with fellfield habitats (77% ofspecies). species that extend their range into the alpine Cushion plants and mats are over represented in zone are more typical of open habitats at lower open spaces and rocky habitats, rare in moist montane or subalpine elevations. Most of the habitats, and absent from wet habitats. Both annuals are relatively uncommon. chamaephytes and shrubs favor open slopes and The greatest numbers of alpine species in the moist sites. White Mountain occur in habitats intermediate Separating species into categories of eleva- along a moisture gradient between wet sites with tional ranges overwhich they occurdemonstrates saturated soils and dry slopes (Fig. 4). Drainage that 51 species (31% of the flora) are alpine courses and associated fellfield habitats with specialists in the White Mountains that are m seasonal moisture availability are the typical largely restricted to sites above 3500 (Fig. 5). habitat for 67 species (41% of the flora). Open However, a few of these alpine-restricted species slopes that become relatively dry in summer are in the White Mountains, as for example the second in significance as thecharacteristic habitat aquatic Callitriche verna and the wet site Juncus for 34 species (21% ofthe flora). Moist meadows hryoides, occur at lower elevations in wetter are home to 39 species (24% ofthe flora), mostly mountain ranges. Among the alpine species are graminoids. Only a small number of species seven high-elevation alpine specialists that occur m typically occur on wet sites with saturated soils only above 3960 (Morefield et al. 1988). These (11 species), aquatic habitats (1 species), or dry species are Erigeron vagus (Asteraceae) Anelsonia slopes (4 species). eurycarpa (Brassicaceae), Cerastium beeringianum Plant life forms showed mixed patterns of (Caryophyllaceae), Polemonium chartaceum (Po- correlation with alpine habitats across a moisture lemoniaceae), and three grasses; Elymusscribneri, gradient. The number of species represented in Poa lettermanii, and P. suksdorfii. i 1 2008] RUNDEL ET AL.: ALPINE FLORA OF THE WHITE MOUNTAINS 207 Another large group of 59 species (36% ofthe viscidiflorus subsp. viscidiflorus that occurs com- flora) has a range extending into the alpine zone monly from 1550^000 elevation. from subalpine forests and shrublands at eleva- It is instructive to combine the data on life tions above 2900 m. Forty-two species (26% of form and elevational range of occurrence to the flora) present in the alpine zone ofthe White assess if certain life forms are more likely than Mountainscan also be found inmontane habitats others to have broad elevational ranges. Among as low as 1980 m. Finally, there are six species in the alpine flora described here, broad-leaved the alpine that reach to cold desert elevations as herbaceous perennials, graminoids, and cushions low as 1220 m, as exemplified by Chrysothamnus and mats have 75%, 72% and 81%, respectively. Table RelationshipBetween Plant Lieeformand HabitatoeCharacteristicOccurrenceeorthe 1. Alpine Plant Speciesoethe White Mountains, California. Cushion/ Broad-leaved Perennial Total Shrub Chamaephyte mat herbaceous perennial graminoid Annual flora Number ofspecies Aquatic 0 0 0 0 0 1 1 Wet 0 0 0 7 4 0 1 Moist 2 2 2 20 11 2 39 Tallus slope 0 0 4 2 0 7 Fellfield 0 1 4 36 16 10 67 Open slope 1 3 9 18 3 0 37 Rocky site 0 0 3 1 0 0 4 Total 3 7 18 86 36 13 163 Relative values (%) Aquatic 8 0.6 i^ Wet 8 11 7 Moist 50 29 11 23 31 15 24 Tallus slope 14 5 6 4 , Fellfield 14 22 42 44 77 41 Open slope 50 43 50 21 8 21 Rocky site 17 1 2 Total 100 100 100 100 100 100 99.6 MADRONO 208 [Vol. 55 70 cold desert montane subalpine alpine high alpine (>1220 m) (>1980 m) (>2895 m) (>3500 m) (>3960 m) m Fig. 5. Typical habitat occurrence ofthe native vascular plant species in the alpine zone above 3500 in the White Mountains. oftheir species restricted to subalpine and alpine the Intermountain Ranges arecharacteristic of41 habitats (i.e., elevations above 2900 m). This is a species (25% ofthe flora). far greater proportion than that present in Just three species are endemic to the alpine phanerophytes, chamaephytes and annuals where zone of the White Mountains, while three other only 50%, 38%, and 54% of species respectively species come close to being endemic. The are limited to these higher elevations. Obligately endemics are Draba californica, D. monoensis, alpine species in the White Mountains fall almost and PotentUla morefieldii. The high alpine Pole- entirely into just three life forms - broad-leaved monium chartaceum occurs principally in the herbaceous perennials (33 species), graminoid White-Inyo Range with a disjunct occurrence in perennials (17 species), and cushions/mats (3 the Klamath Region of northern California. species). Only one chamaephyte. Phlox conden- Recent studies have shown that thesepopulations sata, hasthiselevational restriction, anditisquite are morphologically distinct and deserve more mat-like in its growth habit. The two other alpine careful study (Pritchett and Patterson 1998). specialists are the wetland annuals Callitriche Draba siibumbellata and Arabispinzlae reachjust verna and Juncus bryoides that would be expected beyond the White Mountains into the eastern to occur at lower elevations in the White slope ofthe Sierra Nevada in northwestern Inyo Mountains if suitable habitats were present. County, and D. sierrae extends only slightly These data are consistent with the generalization further into the Sierra Nevada (Price and Rollins that upright woody plants and annuals have 1988; Rollins and Price 1988; Constance-Shull relatively low abundance and diversity in alpine and Sawyer 2000). habitats. The biogeographic affinities ofthe alpine flora Introduced Flora show strong links throughout the mountains of the western United States. Only 26 species in the Alpine habitats are generally inhospitable for alpine flora are widespread or transcontinental alien plant species, and the White Mountains are species. The largest group, 55 species (34% ofthe no exception. Seven species of introduced plants flora), has broad linkages to western cordilleran have been reported from the alpine zone: Senecio regions including the Rocky Mountains and/or vulgaris (Asteraceae), Capsella bursa-pastoris. Pacific Northwest (Fig. 6). Another 36 species Sisymbrium irio, S. orientale, and Descurainia (22% ofthe flora) are linked directly to the Sierra Sophia (Brassicaceae), Stellaria media (Caryo- Nevada/Cascade Ranges. Together then, more phyllaceae), and Chenopodium rubrum (Cheno- than 70% of the alpine flora of the White podiaceae). The first six of these are ahen to Mountains is shared with the Sierra Nevada. CaHfornia, while the last in this list is now Strong biogeographic connections to the flora of questionably considered to be native. All seven 2008] RUNDEL ET AL.: ALPINE FLORA OF THE WHITE MOUNTAINS 209 70 species, however, owe their presence in the alpine in carbohydrate storage over the winter months zone of the White Mountains to unintentional (Mooney and Billings 1960; Billings 1974). human introduction. None ofthese species is well The herbaceous perennials include species with established, with only Capsella bursa-pastoris a variety of ecological forms and life history reported in multiple small colonies along the strategies of carbon allocation to belowground, roadside. Six of these species are annuals aboveground vegetative, and reproductive tissues attempting to survive near theirupper elevational (Rundel et al. 2005). Within this broadly defined limits. The one exception is Chenopodium rubrum, category are perennial graminoids, broad-leaved which although an annual at lower elevations, tussocks, mats and cushions, rosettes, and takes on a biennial growth form in the alpine biennials (Raunkiaer 1934). Many of these are zone ofthe White Mountains (Spira and Wagner relatively long-lived plants surviving for decades 1988). (Billings 1974; Pollak 1991), while others are biennials living for only two years. Perennial Discussion graminoids commonly dominate plant communi- ties ofwet meadows that dry earlier than fellfield Floristic Richness and Life Forms communities. Incontrast, fellfield habitatsexhibit a mixed dominance ofmats and cushions, broad- The total flora of the White Mountains leaved tussocks, perennial graminoids, and ro- includes 988 species (Morefield 1992), and thus sette plants (Rundel et al. 2005). the alpine flora as defined here thus includes 16% The perennial graminoids themselves include a ofthis flora. diverse set ofecological strategies. Whereas these Although conditions of the total and seasonal species comprise a large portion of the species distribution ofrains differ in alpine habitats from and heavily dominate the cover ofwet areas with the Sierra Nevada eastward across the Great saturated soils and moist meadows, they also Basin to the Rocky Mountains, the relative include a number of more drought-adapted dominance of a few life forms does not change fellfield species as well. The fellfield grass dramatically across this gradient (Billings 1978, Muhlenbergia richardsonis, a species with C4 2000). Herbaceous perennials represent the dom- metabolism, reaches a remarkable elevation of inant life form in all ofthese alpine regions. This nearly 4000 m at the summit of Mount Barcroft Hfeformin alpine regionshas thecharacteristic of (Sage and Sage 2002). This is likely the highest maintaining large proportions of total biomass elevation reached by any C4 species in the United belowground where they play an important role States or Canada. MADRONO 210 [Vol. 55 Longer-lived species commonly allocate less to vascular plant species (Scott 1995). Although a reproductive tissues than shorter-lived species. specific enumeration of the alpine flora of the This can be illustrated by the alpine gentians of Sierra Nevada has not been made, it has been the White Mountains, forexample, where relative estimated to be about 600 species (Chabot and allocation to reproduction in the broad-leaved Billings 1972). tussock Gentiana newberryi is significantly lower Alpine floras of smaller ranges across the than in the biennial Gentianella tenella and Great Basin vary in size depending on not only Gentianaprostrata (Spira and Pollak 1986). Such the area ofhabitat present, but also the degree of biennial growth forms, however, are relatively isolation ofthe mountain range. In general, these uncommon in the alpine flora White Moun- small ranges with relatively low rainfall have tains where harsh growing conditions select smaller alpine floras than comparable areas of against plants with short life spans. Beyond alpine habitat in either ofthe larger and less xeric these two gentians, the other six species of Sierra Nevada or Rocky Mountains. Ranges biennials are all members of the Brassicaceae. lying closer to the Rocky Mountains generally These are Arabis divaricarpa, A. holboelii var. show strong florisitic linkages to this range, while peduncuocarpa, A. inyoensis, Descurainia incana, those lying on the western margins of the Draba albertina, and Halimolobus virgata (More- Intermountain Region have floras more strongly field et al. 1988). linked to the Sierra Nevada. Loope (1969) Annual plants, for the same reasons of short reported 189 alpine species from the Ruby and severe growing conditions, are generally rare Mountains in northeastern Nevada, with this in the typical circumboreal arctic-alpine floras of flora showing a strong affinity to alpine floras of the Northern Hemisphere, comprising only 1-2% the Rocky Mountains. The isolated San Fran- of the flora (Billings 2000). Although not cisco Mountain in Arizona with only 5.2 km^ of abundant, annuals, nevertheless, are relatively alpine habitat has 80 species and likewise shows more common in the summer dry alpine of the strong floristic relationships to the Rocky Moun- Sierra Nevada and White Mountains where they tains despite its separation (Schaak 1983). In comprise about 8% of the floras (Jackson and contrast, the Sweetwater Mountains lying 33 km Bliss 1982; Jackson 1985; Spira 1987; Spira and west ofthe Sierra Nevada supports a flora of 173 Wagner 1988). Annual plants are largely restrict- species in 16 km^ of alpine habitat, with 94% of ed to specific habitats in the alpine zone of the this flora common to the Sierra Nevada (Bell White Mountains. Sandy drainage channels are Hunter and Johnson 1983). The small alpinezone the habitat for such annuals as Cryptantha on Mt. Grant to the north of the Sweetwater glomeriflora (Boraginaceae), Gayophytum race- Mountains in western Nevada is just 2.6 km^ in mosum (Onagraceae), Gymnosteris parvula (Po- area supports a flora of70 species dominated by lemoniaceae), and Mimulus suksdorfii (Scrophu- Sierra Nevadan elements (Bell and Johnson lariaceae) (Morefield 1988; Spira 1991). Such 1980). microsites provide relatively high growing tem- Comparing checklists at the species level (i.e., peratures and available water early in the ignoring subspecific taxa), the alpine flora ofthe growing season, a time critical for annual plants White Mountains exhibits a much stronger to complete their life cycle. biogeographic relationship to the Sierra Nevada Subshrubs and shrubs are less rich in species in than to the central Rocky Mountains. Thus, 87% the White Mountains alpine than typical circum- of the species in the alpine flora of the White boreal arctic-alpine floras. Their unusually low Mountains are also found in the Sierra Nevada diversity in the alpine flora of the White (Hickman 1993) compared with only 58% that Mountains reflects perhaps the relatively dry occur in the ranges of the central Rocky conditions and low nutrient availability in this Mountains (Scott 1995). These values are signif- area. There has been little study to date of these icantly higher for both ranges than earlier species in the White Mountains. estimates made on incomplete data (Lloyd and Mitchell 1973). The alpine flora of the White Biogeographic Patterns ofSpecies Richness Mountains, like the Sierra Nevada, lacks many of the typical circumboreal alpine species commonly A number ofchecklists ofregional alpinefloras present in other alpine regions ofNorth America exist for the western United States, and these can (Billings 2000). aid in examining patterns of biogeographic relationships. It is interestingto compare patterns Acknowledgments of species richness among these alpine areas, We greatly acknowledge the financial and logistical adilftfheoruignhg smoamnencearustioinnishnoecwessaalrpyinbeecazuosneesofatrhee sRuepspeoarrtchoffSetrateidont.o tIhins ppraorjteicctulbary twhee WthhiatnekMCoautnhteariinnse defined. Alpine regions of the central Rocky Kleier, Frank Powell, Dave Trydahl, and Mike Mountains that extend over an extensive area of Morrison for the assistance with various parts of this hundreds of square kilometers include 609 research. Two anonymous reviewers provided invalu- 2008] RUNDEL ET AL.: ALPINE FLORA OF THE WHITE MOUNTAINS 211 able data in their comments on an earlier draft ofthis Lloyd, R. M. and R. S. Mitchell. 1973. A flora of manuscript. the White Mountains of California. University of California Press, Berkeley, CA. Literature Cited LOOPE, L. L. 1969. Subalpine and alpine vegetation of Bell, K. L. and R. E. Johnson. 1980. Alpine flora of nUonirvtehresaisttye,rnDuNrehvaamd,a.NCP.h.D. dissertation. Duke the Wassuk Range, Mineral County, Nevada. Major, J. and D. W. Taylor. 1977. Alpine. Pp. 601- BellAMlapdHirunoneftifeolro,r2a7:oK2f.5-t3hL5e..SawneedtwRa.terE.MoJuonhtnasionsn,. M1o9n83o. T6Ye7or5rrke,sitnrNiYaMl..veGg.etaBtiaornbooufrCaalnidforJn.ia.MaWjiolrey,(edNse.)w. County, Nevada. Madrono 30:89-105. Marchand, D. E. 1973. Edaphic control of plant Billings, W. D. 1974. Adaptations and origins of distributions in the White Mountains of eastern alpine plants. Arctic and Alpine Research 6:129 California. Ecology 54:233-250. 142. Mitchell, R. S., V. C. Lamarche, and R. M. . 1978. Alpine phytogeography across the Lloyd. 1966. Alpine vegetation and active frost Great Basin. Great Basin Naturalist Memoirs features of Pellsier Flats, White Mountains, Cali- 2:105-117. fornia. American Midland Naturalist 75:516-525. . 2000. Alpine vegetation. Pp. 536-572 in M. G. MooNEY, H. A. AND W. D. BiLLiNGS. 1960. The BarbourandW. D. Billings(eds.). NorthAmerican annual carbohydrate cycle of alpine plants as terrestrial vegetation. 2nd ed. Cambridge Univer- related to growth. American Journal of Botany sity Press, Cambridge, United Kingdom. 47:594-598. Bowmanadn,fuWnc.tiDo.naofndanT.alRpi.neSeeacsotseysdtte.m:20N0i1.woSttrRuicdtguer,e Alp,inGe. aSnt.d Asunbdarlepi,neanvedgeRt.atiDo.n Wpartitgerhnts.in196t2h.e Colorado. Oxford University Press, Oxford, Unit- White MountainsofCahfornia. American Midland ed Kingdom. Naturalist 68:257-273. Chabot, B. F. andW. D. Billings. 1972. Origins and MOREFIELD, J. D. 1988. Floristic habitats ofthe White ecology ofthe Sierran alpine flora and vegetation. Mountains, California and Nevada: a local ap- Ecological Monographs 42:163-199. proach to plant communities. Pp. 1-18 in C. A. Chapin, F. S. and C. Korner (eds). 1995. Arctic Hall and V. Doyle-Jones (eds.). Plant biology of and alpine biodiversity: patterns, causes and eastern California. Natural history of the White- ecosystem consequences. Springer Verlag, Berlin, Inyo range. Symposium Volume 2, White Moun- Germany. tains Research Station. University of California, Constance-Shull, H. a. and J. O. Sawyer. 2000. Los Angeles, CA. Arabis pinzlae Rollins (Brassicaceae). Madrono . 1992. Spatial and ecologic segregation of 47:209. phytogeographic elements in the White Mountains Ernst, W. G., C. M. Van de Ven, and R. J. P. of California and Nevada. Journal of Biogeogra- Lyon. 2003. Relationships among vegetation, phy 19:33-50. gIenoyloogyR,anagned,cleimaasttiecrnzonCeasliifnortnhiea.cenBturlalletWihniteo-f Vas,cDu.laWr.flToraayloofrt,heaWnhditMe.MNo.unDteadiensckoefrC.al1i9f8o8r.- the Geological Society of America 115:1583- nia and Nevada: an updated synonymized working 1597. checklist. Pp. 310-364 in C. A. Hall and V. Doyle- Hickman, J. (ed). 1993. The Jepson manual: higher Jones (eds.). Plant biology of eastern California. plantsofCalifornia. University ofCalifornia Press, Natural history of the White-Inyo range. Sympo- Berkeley, CA. sium Volume 2, White Mountains Research Jackson, J. L. 1985. Floristic analysis ofthe distribu- Station. University ofCalifornia, LosAngeles, CA. tion of ephemeral plants in treeline areas of the Nelson, C. A., C. A. Hall, and W. G. Ernst. 1991. western USA. Arctic and Alpine Research 17:251- Geologichistory oftheWhite-Inyo Range. Pp. 42- 260. 74in C. A. Hall (ed.). Natural historyoftheWhite- AND L. C. Bliss. 1982. Distribution of Inyo range. University ofCalifornia Press, Berke- ephemeral herbaceous plants near treeline in the ley, CA. SierraNevada, California, USA. Arcticand Alpine Pace, N., D. W. Kiepert, and E. M. Nissen. 1974. Research 14:33^4. Climatological data summary for the Crooked Jennings, S. A. and D. L. Elliot-Fisk. 1991. Late Creek Laboratory, 1949-1973, and the Barcroft Pleistocene and Holocene changes in plant com- Laboratory, 1953-1973. White Mountain Research munitycompositionin theWhiteMountain region. Station Special Publication, Bishop, CA. Pp. 1-17 in C. A. Hall, V. Doyle-Jones, and B. Pollack, O. 1991. Morphology and dynamics in Widawski (eds.), Natural history of eastern Cali- alpine populations of Ivesia lycopodioides subsp. forniaandhigh-altituderesearch. WhiteMountains scandularis from the White Mountains of Califor- Research Station, Symposium 3. University of nia. Pp. 97-116 in C. A. Hall, V. Doyle-Jones, and Cahfornia, Los Angeles, CA. B. Widawski (eds.). Natural history of eastern AND . 1993. Packrat midden evidence of California and high-altitude research. White late Quaternary vegetation change in the White Mountains Research Station, Symposium 3. Uni- Mountains, California-Nevada. Quaternary Re- versity ofCalifornia, Los Angeles, CA. search 39:214-221. Powell, D. R. and H. E. Klieforth. 1991. Weather Korner, C. 1999. Alpine plant life: functional plant and climate. Pp. 3 26 in C. A. Hall (ed.). Natural ecology of high mountain ecosystems. Springer history of the White-Inyo Range. University of Verlag, Berlin, Germany. California Press, Berkeley CA.

See more

The list of books you might like

Most books are stored in the elastic cloud where traffic is expensive. For this reason, we have a limit on daily download.