3

•. .,•

.{ • ,l<. •

--• - • • •• 4:"."".. •

116 •,. California’s Botanical Landscapes - 3

chapter five Mono and Southeastern Great Basin The eastern fringe of California slices The crest of the Sierra Nevada defines Above: The crest of the Sierra off a thin strand at the edge of a vast the western hydrologic edge of the Great Nevada defines the western edge of interior biome, the Great Basin. Often Basin, within which waters drain into the Great Basin in central eastern California. The Mono Basin, characterized as an immense and homo­ interior basins. The entirety of the Sierra with its crown jewel Mono Lake, geneous sagebrush (Artemisia sp.) sea, Nevada was built by similar geologic exemplifies the character of the this region in fact encompasses great forces that created the Great Basin. The California part of this province, topographic, geologic, climatic, and vege­ narrative for vegetation in this chapter with expansive cold-adapted tative diversity, haunting in expansiveness starts with the lower montane (~2,500 m sagebrush steppe intermixed with hardy forbs and grasses. of landscape, surprising in richness of at the latitude of Mono Lake) and basin Robert Wick hidden canyons and wetlands. Long lines bottom environments of the eastern Opposite: A winter evening of basin and range draw the eye outward Sierra Nevada, and goes on to embrace along Hot Creek, with rubber to where land meets sky; wave after wave the entire elevation gradients from basin rabbitbrush and sagebrush of mountain ranges pounding the sage to summits of the mountain ranges east­ spread over rolling hills of the surf. If only a slice, California is fortunate ward to the California-Nevada state Long Valley Caldera. to have what it does of this Great Basin. line. Their names sing of romance Jeff Bisbee

Mono and Southeastern Great Basin 117 The great height of the Sierra and adventure: Sweetwater, Bodie, The dominant climate of the Nevada (background) creates Glass, White, Inyo, Grapevine, Coso, California Great Basin is cool and dry a rainshadow effect on lands to Panamint, Amargosa, Argus, Last (annual precipitation ranges from 52 cm the east, leaving the Great Basin Chance, Funeral. Even the most recent­ in northern uplands to 11 cm in south­ much drier than the California floristic province. Both the basin ly named range of the Great Basin, the ern basins), although low basins bor­ floors, such as the Owens Valley Zunamed Mountains (east of Ebbetts dering the Mojave province in the south south of Bishop, and the higher Pass), evokes mystery. Summits extend are warmer and drier. Farther interior slopes, such as the White and from 1,800 m in the smaller ranges to in the Great Basin, continental climates Inyo Mountains, maintain an 4,342 m atop White Mountain Peak in drive very cold winters and hot summers; arid character, and support dry-adapted plants such as the White Mountains, California’s third the California borderlands are mostly cottontop cactus (Echinocactus highest mountain. Basin bottom eleva­ buffered from these extremes. Despite polycephalus). tions generally run higher in the north semi-aridity, the region’s climate is domi­ Robert Wick (above 1,800 m), with southern basins nantly influenced by winter storm tracks averaging about 1000 m. California’s and high pressure originating from the oldest and most important land-sur­ Pacific Ocean and then moving eastward vey reference, the Mt. Diablo Baseline over the Sierra Nevada. Orographic (~38° N), runs through the Mono Basin, effects catalyze waves of precipitation on dividing the region into north and south the west slopes, contrasting with progres­ parts. Taken together, the landscape of sively stronger rain-shadows in the lee of this chapter, hereafter referred to as the mountain crests. The impressive height California Great Basin, includes nearly and location of the Sierra Nevada— 1.9 million ha (4.7 million ac) or 4.6% of as the first major range downwind California’s land area. from Pacific storms—capture and

118 California’s Botanical Landscapes hold precipitation in deep snowpacks. Precipitation declines down the moun­ tains and farther east (e.g., 70 cm annu­ ally at Tioga Pass, 35 cm in the western Mono Basin, and 13 cm in the eastern Mono Basin). Snow falls on the high peaks of the adjacent California Great Basin ranges, but in far lesser amounts than on the Sierra Nevada, leaving the lee mountains to be among the driest in the Great Basin for their latitudes. Secondary climatic influences vary with geography and season. A common winter pattern is the Great Basin High that develops over cold central Nevada. This blocks and diverts Pacific storm tracks northward, leaving the California Great Basin dry, clear, and cold for long periods. In summer, the southern California Great Basin often receives monsoon influence from the Gulf, and convectional forces deliver an artillery of thunderstorms to the uplands through­ out the region. Both result in minor amounts of summer precipitation in the mountains. Occasionally, summer storms stall over the high slopes, driving impres­ sive flash floods down mountain canyons. These environmental forces also shape the region’s vegetation. As elsewhere in California, gradients of climate create repeating changes in vegetation across the California Great Basin. Elevation is commonly associated with changes in climate and vegetation—temperatures being on average colder with increas­ ing altitude. This is not always the case, effects. The degrees of latitude (> 4) Top: Summer convectional storms however, as inversions and other types spanned by the California Great Basin blow up frequently in the California of cold-air drainage—that is, where weave a tapestry of vegetation diversity Great Basin province, delivering welcome rainbursts during the temperatures decrease as elevations from north to south. Northern commu­ otherwise long, dry summers, yet decline—are common. In depressions, nities align more with cold shrub- and also igniting fires in the woodlands valley bottoms, and basins, plant commu­ forest types, while southern communi­ and sagebrush steppe. nities must be able to tolerate super-cold ties border warm deserts and support dry Julie M. Evens temperatures that occasionally develop. scrublands. Finally, changes in substrate Above: Big sagebrush in the Latitude and longitude also correspond create their own repeating patterns of snow- covered Mono Basin. to gradients in climate and vegetation vegetation. In many basins, for instance, Connie Millar response across the region, especially gradual changes in sediment size and in regard to rain shadow and eastward salinity (often the legacy of ancient

Mono and Southeastern Great Basin 119 chain is isolated from the Sierra Nevada by the broad, low, and deep Owens Valley, so it reflects a more interior character. Smaller ranges in the south, such as Coso, Last Chance, Funeral, and Grapevine, have vegetation affini­ ties with southern Nevada and Mojave Above: The Racetrack in Death terminal lakes) can create concentric communities. Valley National Park is one of the rings of vegetation. Elsewhere, exposures old lake beds, or playas, occupying of substrates that impose nutrient defi­ Alpine Herbaceous isolated basins of the Great Basin. ciencies and toxicities to plants, such as Communities Todd Keeler-Wolf dolomites and hydrothermally altered Alpine communities—those that Top right: Royal penstemon (Penstemon speciosus) here on soils, define vegetation mosaics that can occur above climatic treeline—clothe Freel Peak in the Carson Range, have extremely abrupt boundaries. those mountains of the California Great joins other showy plants that The California Great Basin abuts Basin that rise above 3,300 m in the north provide a riot of color to the the Sierra Nevada flank at mid-low and above 3,475 m in the south. These alpine zone of the California montane elevations along a broad north- cold, arid environments are dominated Great Basin. south zone. As described in the Sierra primarily by herbaceous species, includ­ Opposite, top: The botanically Nevada chapter, bands of elevational­ ing many bunch grasses and sedges, diverse Sweetwater Mountains, north of Bridgeport, contain a ly-adapted vegetation rise in altitude although some hardy shrubs dot the suite of endemic plants, as well as latitude decreases, making the landscape, especially in sheltered loca­ as species hailing from the Sierra boundary of the Sierra Nevada and tions. Given the harshness of the envi­ Nevada to the west and Great California Great Basin regions higher in ronment, alpine species are specifically Basin provinces to the east. The the south than north. In the north, the adapted to these conditions and many former reflects upland connections among the ranges, which function smaller ranges east of the Sierra, such occur only in these elevations. Species as biogeographic corridors. as the Sweetwater, Zunamed, Bodie that are widespread across elevational Opposite, center: Pacific alpine Hills, and Glass Mountains, do not gradients and creep into the alpine zone gold dances and shimmers on show strong latitudinal effect, but reflect are discussed later. Topography, snow the high slopes of Ferris Canyon east-west rain shadows compounded by accumulation pattern, and soil depth, in the Sweetwater Mountains. biogeographic connections that their impose a patchwork pattern of deep Connie Millar photos west slopes have with the Sierra Nevada. brilliant greens, silvery grays, and cheery The latter provide access of Sierra yellows and pinks to the patterns of Nevada species into these adjacent vegetation. Soggy tussock meadows ranges, and also tend to draw storm tracks alternate with exposed gravelly alpine from the Sierra Nevada eastward into hills, steep talus slopes, and outcrops adjacent uplands. By contrast, the high dotted with occasional brilliant blues of and expansive White-Inyo Mountain sky pilot (Polemonium eximium), cushion

120 California’s Botanical Landscapes buckwheat (Eriogonum ovalifolium), or cut-leaved daisy (Erigeron compositus). In rocky fell fields of the highest ranges, such as the White and Inyo Mountains and the Sweetwater Mountains, the charming fell-fields with California heath- goldenrod and Pacific alpine gold (Ericameria discoidea–Hulsea algida) sparse­ ly vegetated alliance greet the high moun­ tain traveler with flowers beaming vibrant hues of yellow and gold. Both species scent the thin air with distinctive and pungent aromas. California heath-goldenrod is a multi-stemmed subshrub with dense and delicate inflorescences, while Pacific alpine gold stands tall on single, erect stems. The sturdy composite floral head of the latter is showy and glows a rich, incandescent orange. While California heath-golden­ rod grows commonly across rocky slopes, Pacific alpine gold seems to prefer the windiest ridge crests and most exposed alpine summits, often found grouped in cheery clusters seeming impossibly out of place amidst the harsh environment. Common co-occurring species include several buckwheats (Eriogonum spp.), in particular the widespread cushion buck­ wheat, graceful blue-flowered silverleaf phacelia (Phacelia hastata), delicate King’s sandwort (Arenaria kingii ssp. kingii), the common sub-shrub granite prickly 5 phlox (Linanthus pungens), and perennial bunch grasses such as pine needlegrass (Achnatherum pinetorum), squirreltail (Elymus elymoides), prairie junegrass (Koeleria macrantha), and Wheeler’s bluegrass (Poa wheeleri). Left: Hardy plants adapted to The expansive lunaresque alpine cold, windy, and arid conditions slopes and fell fields of the Sweetwater of Great Basin alpine ecosystems Mountains host diverse alpine species, grow in the high elevations. Here Erigeron including many rare species endemic rayless shaggy fleabane ( aphanactis) and cushion buck­ to California. A characteristic alliance wheat provide bursts of color is the cushion phlox (Phlox pulvinata) against the light soils of fell-fields, with spiny milkvetch the Sweetwater Mountains. (Astragalus kentrophyta), Gordon’s ivesia Connie Millar (Ivesia gordonii), and white ballhead gilia (Ipomopsis congesta). Cushion phlox has

Mono and Southeastern Great Basin 121 6

Above: Swathes of cushion phlox an indescribably sweet aroma when it Several sedges often co-occur in these alliance along Wheeler Peak in flowers in early summer, blanketing meadows, including Nebraska sedge the Sweetwater Mountains. dry, upper slopes of the Sweetwater (Carex nebrascensis), dark alpine sedge Opposite, top: Tufted hair Mountains visually and aromatically (C. subnigricans), and beaked sedge grass alpine communities on with intoxicating beauty. Squirreltail is (C. utriculata). Wheeler Peak of the Sweetwater Mountains often contain common in this alliance, and through­ scattered krummholz conifers, out California, where it is widespread in Alpine Shrublands such as whitebark pine, near diverse habitats. Low sage-steppe communities are upper treeline. Tufted hair grass (Deschampsia widespread in the alpine zones of the Opposite, bottom: Low sage-steppe cespitosa) meadows are common from California Great Basin and extend communities of little sagebrush sea level to high mountains, but in across high-elevation ridges in the White and Rothrock’s sagebrush the California Great Basin they are Mountains and upper slopes of the Inyo, dominate alpine slopes of Great Basin mountains, here restricted to the alpine zone. In the Cottonwood, and Panamint Mountains. in the Cottonwood Basin of White Mountains and meadows of the Little sagebrush (Artemisia arbuscula the White Mountains. Sweetwater Mountains this bunch- ssp. arbuscula) and Rothrock’s sagebrush Connie Millar photos grass grows with forbs such as fireweeds (A. rothrockii) dominate alliances of their (Epilobium spp.), yampah (Perideridia names. They occur in areas of shallow parishii), little elephant heads (Pedicularis soils, often at margins of high-elevation attollens), and others varying by locale. meadows; Rothrock’s sagebrush scrub

122 California’s Botanical Landscapes alliance grows in soils derived from a variety of bedrock types, from granitic to carbonate-rich dolomites and limestone, as in the White and Inyo Mountains. While technically a tree species, extensive thickets of stunted (krummholz) conifers grow in the alpine zone. These include whitebark pine (Pinus albicaulis), the queen of krummholzing conifers, which extends above treeline in the Sweetwater and Glass Mountains, as well as clus­ ters of wind-ravaged limber pine (Pinus flexilis) in the Bodie Hills and the Sweetwater, Glass, White-Inyo, and Last Chance Mountains. Bristlecone pine (Pinus longaeva), the other high-elevation conifer, rarely takes on a stunted form above treeline. Low thickets of shrubby aspens (Populus tremuloides), glowing

Mono and Southeastern Great Basin 123 golden in the fall, spread clonally up from subalpine meadows to surround talus slopes at even higher elevations than the bristlecone pines in McAfee Creek, Crooked Creek, and other canyons on the eastern slopes of the White Mountains.

Montane Forests Below the alpine zone a kaleidoscope of forest, shrub, and herb communi­ ties paints the California Great Basin landscape, wherein plant communities follow preferences of topography, aspect, micro-climate, soils, competition, and gradients of moisture. Forests are the major architect of vegetation in the mon­ tane zones of the eastern Sierra Nevada and northern ranges, although they are often sparse, especially near upper and lower treelines. Comprising the greatest area of forest are conifer types, and among these, pines dominate. The most common subalpine conifer vegetation in mountain ranges of the California Great Basin is limber pine woodland, which occurs in the Bodie Hills, the Sweetwater, Glass, White-Inyo, Panamint, and Last Chance Mountains—and possibly high points elsewhere, including the Grapevine Mountains. In the eastern Sierra Nevada, limber pine occurs mostly above the elevation of the California Great Basin region, and is not documented north of Sonora Pass. Limber pine woodlands range from closed forests (less common) mixed with other species such as lodge­ pole pine (Pinus contorta ssp. murrayana), as in the Glass Mountains, to open sparse woodlands of scattered old-growth trees, as on the high slopes of the Sweetwater and White-Inyo Mountains. Long-lived Top: Whitebark pine krummholz matts can extend for more than 300 m in (to 1,700 years), the limber pines’ trunks a band above upright trees at the thermal treeline, as in Sweetwater Canyon often appear wizened as strips of bark in the Sweetwater Mountains. commonly die back over time, and the Above: Limber pines growing near treeline, here in Sweetwater Canyon on the deeply furrowed stems glow golden-red east slopes of the Sweetwater Mountains, respond to harsh conditions less by with age. adopting krummholz form but more through stripbark growth and spiral grain, which gives trees a corkscrew appearance. Limber pine grows with the iconic Connie Millar photos and photogenic bristlecone pine in the

124 California’s Botanical Landscapes highest southern ranges of the region, the White-Inyo Mountains and the Panamint Range. Bristlecone pines are widely appreciated for their longevity, and individuals have been measured living more than 4,800 years. Tree-ring scientists have deciphered eleven mil­ lennia of climate records from annual growth rings by combining live and dead tree records. Like limber pine woodlands, bristlecone pine woodlands reach into the California Great Basin from their broader distribution out­ side California, which includes high peaks of southern-central Nevada, the transitions with their capacity to grow on Above: Aspen groves follow rocky Colorado plateau, and western Rocky dolomite and limestone, which exclude stream courses and fringe wet Mountains (including related Pinus many other species. In areas where car­ meadows in Great Basin moun­ tains, as in McGee Creek. aristata). In the California Great Basin bonate soils meet sandstones and shales, Jeff Bisbee these forests are most often very open for instance, the contact is revealed as Below: Bristlecone pines in the woodlands, with old-growth trees sep­ an abrupt boundary dividing open bris­ White and Inyo Mountains rarely arated many meters apart. In middle tlecone pine woodland with little to no take shrubby stature even near elevations, younger stands approach understory on one side and dense sage­ treeline. Their capacity to endure closed-canopy conditions, but never so brush steppe on the other. for more than five millennia dense as in ranges east of the state line. Whitebark pine forests are the most testifies to their endurance in the cold, arid environments, as here In the White and Inyo Mountains, common subalpine forest type in high in the Inyo Mountains. bristlecone pines cleanly define substrate elevations of the eastern Sierra Nevada, Robert Wick

Mono and Southwestern Great Basin 125 but the occurrence of the species in California Great Basin elevations of the Sierra Nevada is limited to admixture in forests dominated by other conifers. In several of the northern ranges, whitebark pine forests are extensive—for instance in the Zunamed, Sweetwater, and Glass Mountains, they dominate the subalpine zones and form upper treeline. In those Top: Bristlecone pines growing on dolomite soils near Patriarch Grove areas, whitebark pine forests comprise in the White Mountains. Jeff Bisbee clusters of trees established from seed caches of Clark’s Nutcracker (Nucifraga Above: Whitebark pine in the California Great Basin grows scattered on granitic knobs along the lower slopes of the Sierra Nevada, as here below Mt Dunderberg. columbiana), a handsome relative of the crow that plays an essential, co-adapted Right: Whitebark pine depends on Clark’s nutcracker to open cones and plant the seeds. role in dispersal of the pine seeds. Connie Millar photos Mixed conifer forests typical of

126 California’s Botanical Landscapes mid-elevations on the western slope of the or fire-prone sites, and with white fir Sierra Nevada are less widespread along in more mesic locales. Jeffrey pine was the eastern escarpment and their com­ prized for lumber during the early positions there are simpler. In the zone mining and settlement era of the region, of contact between the Sierra Nevada so historic harvest levels were high and and California Great Basin regions, a the largest remaining old-growth forests patchwork of conifer forests includes are in the Indiana Summit Research alliances with varying dominances of Natural Area, south of Mono Lake in lodgepole pine, white fir Abies( concolor), the Glass Mountains. An interesting and Jeffrey pine Pinus( jeffreyi). Western aspect of the Jeffrey pine forest in the white pine (Pinus monticola) and west­ southern Mono Basin are remnants of ern juniper (Juniperus occidentalis) are piagi rings, or trenches, surrounding occasional partners. These forests also the base of old-growth trees. These were grow at mid-to-upper elevations in the dug by native Paiutes to harvest the large Top: Jeffrey pine occurs in northern ranges of the California Great and nutritious larvae of the Pandora riparian corridors of the lower Basin, the Zunamed, Sweetwater, Bodie moth (Coloradia pandora), which under­ eastern Sierra Nevada, here in Hills, and Glass Mountains, where the goes irregular and episodic outbreaks Convict Canyon. intrepid botanist can find mountain in the Jeffrey pine forests. Sentinel Jeff Bisbee hemlock (Tsuga mertensiana) as a rare Meadow Research Natural Area to Above: Jeffrey pine in the Indiana component. the east along the crest of the Glass Summit Research Natural Area, In these ranges, open Jeffrey pine Mountains also contains fine stands Mono Basin. This “Piagi tree” has trenches around its stem dug forests are common, often monotypic, of Jeffrey and lodgepole pines, mixed by early Paiute people to collect but in some cases intermixed with with ancient limber pines. The Volcanic larvae from the Pandora moth. lodgepole pine, especially on dry, sterile, Tablelands of Bishop tuff south of the Connie Millar

Mono and Southeastern Great Basin 127 This is the New Image from second set

Note Caption block has changed.

Above: Jeffrey pine woodlands Glass Mountains support old-growth, if is legendary, but recent genetic research near Swall Meadows above the sparser, forests of Jeffrey pine and lodge­ suggests that seedling establishment is Owens Valley often mix with pole pine forests. also common and aspen clones can be big sagebrush steppe, where In the interior ranges south of the genetically diverse. Aspen groves provide diverse herbs and small shrubs bloom, including lupine (Lupinus Glass Mountains and the Tablelands, important hiding cover as deer fawning spp.), paintbrush (Castilleja spp.), these montane conifers are rare to absent. habitat, and many other woodland crea­ and sulphur buckwheat White fir and western white pine are tures seek shelter in aspen groves. (Eriogonum umbellatum). absent, while Jeffrey pine, lodgepole pine, Across the western U. S., concern for Wallace Woolfenden and western juniper grow only at single aspen decline has raised questions about Right: Aspen groves glowing in to a few locations each, and these in the its ecology, pathologies, and conservation, fall color along cool, moist slopes near Upper Summer Meadows White Mountains. Their presence there invoking many lines of research. Some in the eastern Sierra Nevada. is likely relictual from past wetter, cooler of the change in aspen demographics is Rollie Rodriguez climatic regimes that supported more likely natural: populations are short-lived Below: Long-eared owl (Asio otus) widespread distribution of these conifers. and dying, even-aged patches are readily in an aspen grove. At present their occurrence in these arid apparent on the landscape. Aspen are John Sterling ranges is limited to alluvial and glacially also sensitive to changes in water levels, derived soils where moisture is adequate. and climate dynamics tend to mobilize Cool slopes with high water tables and boundaries of groves readily. Sudden rocky soils support extensive aspen groves aspen decline (SAD) is of special concern, along the eastern Sierra Nevada as well and has been linked to severe drought and as in northern ranges of the California specific environmental contexts (e.g., low, Great Basin. Where conditions are flat aspects) that exacerbate hot and dry windy and exposed, these can take shrub­ conditions. SAD has been observed only by forms, growing as dense and stunted in the last decade, and then mostly in the thickets that blaze the slopes red, orange, Rocky Mountains, but conservationists and yellow in autumn. Aspen groves also are watching for signs of it in California. occur in riparian and meadow-fringe Excess livestock grazing of young sprouts contexts, where trees are upright and also inhibits persistence of aspen stands have large, straight boles. The capacity of and is a serious conservation issue. aspen to root-sprout and spread clonally Mountain mahogany shrublands,

128 California’s Botanical Landscapes a dry, upland counterpart to aspen, extend across low-to-mid elevation slopes of the California Great Basin. Two alliances form these dense shrublands in our region. Curl leaf mountain mahoga­ ny (Cercocarpus ledifolius) scrub is wide­ spread at cooler middle elevations of the eastern Sierra Nevada and in other north­ ern ranges extending south to the White, Inyo, and Panamint mountains, where they occur on and off carbonate soils. Shrublands have expanded significantly in recent decades, creating fire risk and also serving as cover for mountain lion (Puma concolor), mule deer (Odocoileus hemionus), and Sierra Nevada big­ horn sheep (Ovis canadensis sierrae). Conservation plans for recovery of this

Top: Evergreen curl leaf mountain mahogany forms dense stands of large shrubs or small trees along dry slopes of California Great Basin ranges, as here in Lundy Canyon of the eastern Sierra Nevada. Right: Shrubby aspen stands provide hiding cover for hares, rabbits, young of mule deer, and bighorn sheep high in Parker Canyon. Connie Millar photos

Mono and Southeastern Great Basin 129 adornment, the delightful effect of hundreds of plume-like styles protruding from the many small flowers. The lowest elevation conifer for­ ests in the California Great Basin are dominated by singleleaf pinyon (Pinus monophylla) woodlands and, with less representation in this region, Utah juni­ per (Juniperus osteosperma) woodlands. Singleleaf pinyon and Utah juniper might be thought of as tree counterparts of sagebrush for their ubiquity across the Great Basin. Short-lived, fire-prone, and prized by native people and wild­ Above: Lower slopes with curl leaf endangered bighorn sheep include burn­ life for large, wingless, and protein-rich mountain mahogany scrub are ing stands of mahogany along eastern seeds, singleleaf pinyon are currently found commonly along the eastside Sierra Nevada canyons. considered by some range managers of the Sierra Nevada, as in Big and ranchers as weedy and disruptive Pine Canyon. Small leaf mountain mahogany Julie M. Evens (C. intricatus) scrub is found on warmer, of native shrublands. Conditions of the Below: Singleleaf pinyon forms drier, and generally lower sites. This late twentieth century, including climate extensive woodlands throughout alliance is far less abundant in the change, invasive species, and historic land the low elevations of Great Basin California Great Basin than curl leaf uses, have created a golden opportunity mountains, often in pure stands, mahogany scrub, and restricted to car­ for singleleaf pinyon and Utah juniper as in the southern White bonate substrates in the southeast ranges. establishment and woodland expansion. Mountains looking west to the Sierra Nevada. When in bloom and backlit by the sun, Along historic range margins, the forest Connie Millar both species display a shimmering lacey type is rapidly expanding, and infill is

130 California’s Botanical Landscapes common. Concern for displacement of of limber pine, Jeffrey pine, and lodge­ Above: Pinyon and juniper sagebrush steppe—the prime habitat pole pine. The red-to-yellow-to-greenish woodlands expanding into of greater sage-grouse (Centrocercus soils are highly erosive, and reveal severe sagebrush scrub. Connie Millar urophasianus)—directly or by height­ chemical alterations. Nutrient sterility ening fire risk has become a contentious and toxicities exclude most understory Below: Greater sage-grouse male forages near Crowley Lake. conservation topic. Aggressive forest species, making these sites appear even John Sterling management actions are attempting to more dramatic. To California botanists limit spread and reduce the area of these these patches might be reminiscent woodlands throughout the Great Basin. of other pine/cypress types occurring Pinyon-juniper woodlands grade most on isolated exposures of sterile ultra­ commonly to sagebrush and other shrub mafic or sandstone derived soils in the communities at their low-elevation ecotone, western regions. In the California Great creating distinctive lower treelines on Basin, altered soils and exceptional pine many California Great Basin ranges. stands occur in the northern ranges. The extensive and rather low-diver­ They can be found on low slopes of sity singleleaf pinyon and Utah juniper the Sweetwater Mountains and Bodie woodlands are sometimes displaced by Hills, where volcanism was extensive scattered stands of montane conifers and hydrothermal activity common. growing far lower than would be expect­ Joshua tree (Yucca brevifolia) woodlands, ed from their typical range limits. These widespread in southeastern California populations occur on isolated patch­ and indicator of the lower tree limit in es of hydrothermally-altered andesitic Mojave Desert mountains, are scattered soils. These exceptional habitats have in the California Great Basin in the chemical deficiencies strong enough Coso, Cottonwood, and Inyo Mountains. to exclude many shrubs and herbs, yet There they mix with stands of big montane conifers are able to establish sagebrush (Artemisia tridentata), shad- secure if sparse footholds. The wood­ scale (Atriplex confertifolia), and black lands occur as pure or mixed stands brush (Coleogyne ramosissima). Long-

Mono and Southeastern Great Basin 131 25

lived and fast growing, Joshua trees are conspicuous, picturesque, but relatively short-lived, with individuals persisting only 15–200 years. When stands are dense, mature trees scatter across the landscape rather than growing in clus­ ters, which suggests that Joshua trees compete for water taken up by their dense networks of fibrous roots and stored

Above: Joshua tree woodlands, here in the Inyo Mountains, are scattered in disjunct parts of the California southern Great Basin. They can extend to mid-slope elevations in areas that do not get extensive sub-freezing temperatures. Julie M. Evens Left: Scattered patches of hydrothermally altered soils in the western Great Basin can support montane conifers at elevations lower than typical ranges—Jeffrey pines grow with Utah juniper and singleleaf pinyon in the Bodie Hills. Connie Millar

132 California’s Botanical Landscapes between rains in the plants. Curiously, dispersal of seeds was at one time provided by the now-extinct Shasta ground sloth (Nothrotheriops shastensis), suggesting that adaptive range shifts under present changing climates may be difficult now that the species lacks its dispersal partner.

Montane Shrublands While forest and woodlands are keystone habitats in California Great Basin mid-montane ecosystems, upland shrublands are extensive and diverse across lower slopes and basins, especially in the more arid south. Most common are the various sagebrush communi­ ties, and best known among them is big sagebrush shrubland alliance, which blankets plains, valley bottoms, alluvial fans, ridge slopes, and openings in forests and woodlands. Big sagebrush domi­ nates where soils are sandy, well-drained, non-saline, and deep. The bouquet of sagebrush foliage is beloved widely as the incense of the steppe, and sage is prized by native people for curative powers. Big sagebrush shrubland is critical habitat to many signature Great Basin animals, of particular concern for greater sage- grouse and pygmy rabbit (Brachylagus idahoensis), both of which depend on old-growth sage stands. Many sub­ species of big sagebrush exist whose identifications challenge the most deter­ mined botanist. Bitter brush (Purshia tridentata) often is a companion in big sagebrush communities, and, where common, bitter brush forms commu­ nities of its own, a situation typical also of rubber rabbitbrush (Ericameria nauseosa) and pink-flowering desert peach (Prunus andersonii). Mormon Top: Extensive shrublands of big sagebrush, the iconic plant of the Great Basin, tea ( ), with its striking Ephedra viridis form sagebrush seas from the valley basins below the singleleaf pinyon woodland yellow-green stems, also commonly zone to upland high plateaus; along County Line Hill in the White Mountains. comingles with big sagebrush, as does Above: Fire is an important component to keeping native shrublands healthy, roundleaf snowberry (Symphoricarpos although cheatgrass invasion is drastically altering natural fire regimes in the region. rotundifolius), whose white berries Connie Millar photos

Mono and Southeastern Great Basin 133 Above: Rubber rabbitbrush provide important forage for shrubland Sweetwater Mountains, and Carson/ and bitter brush often mix with birds, but are poisonous to humans. Walker drainages. Adjacent to willows big sagebrush to form textured Mixed in mesic swales and watered slopes (e.g., ), water sedge and colorful steppe, as along Salix exigua, S. lutea Mono Lake. of the northern uplands are montane and lakeshore sedge (Carex [aquatilis, Connie Millar chaparral communities of tobacco brush lenticularis]) meadows are common Below: Silver sagebrush (Ceanothus velutinus), and mountain at many elevations of the eastern (Artemisia cana) with Douglas’ whitethorn (C. cordulatus), such as in Sierra Nevada, Glass Mountains, and sedge (Carex douglasii) in a moist the Glass and Sweetwater Mountains. Sweetwater Mountains. Other wet­ meadow below Convict Lake. land sedge communities are common at Julie M. Evens Montane Herbaceous middle elevations in the northern Communities California Great Basin, including Forests and shrublands of the Nebraska sedge (Carex nebrascensis) montane California Great Basin zones meadows and beaked sedge meadows are broken by many openings with around fens, and in seeps and swales herbaceous alliances. Often these are of the Truckee, Carson, and Walker highly diverse wet to dry meadows, and drainages and the Sweetwater Mountains. species mixes depend on soils, eleva­ Mimicking fields of corn to which tion, and degree of moisture saturation. the common name attests, tall-growing Sedge meadows abound in seasonally or white corn lily (Veratrum californicum) permanently saturated soils of wet unfurls long, corrugated, and deep- meadows, lakeshores, and creeksides at green leaves with showy clusters of white middle to subalpine elevations; these flowers tightly packed along branched include Sierra alpine sedge (Carex floral stems. The white corn lily scopulorum) turf in Sierra Nevada, patches alliance occurs on wet soils

134 California’s Botanical Landscapes near streams, wet meadows, and forest and in seeps and springs of the Inyo Above: Glass Creek Meadow in borders. White corn lily is often associat­ Mountains. Similarly, American bul­ the Owens River Headwaters ed with livestock grazing, given that high rush (Schoenoplectus americanus), and Wilderness has a mosaic of soil types, from saturated to dry, which levels of alkaloids in its foliage are toxic California bulrush ( ) S. californicus are colonized respectively by sedges, to large mammals, as a result they are not marshes are common in many parts of grasses, and many flowering herbs. grazed. An extract from white corn lily, California, and grow, for instance, in Rollie Rodriguez cyclopamine, is being tested as an anti- Fish Slough, Benton region, and springs Below: White corn lilies spring up tumor drug for humans. of the Argus Range in the California along streams and in wet meadows Occupying diverse wetland Great Basin. of the Great Basin. sites, including wet meadows, fens, At mid-montane elevations of the east­ Connie Millar marshes, and sloughs, Baltic and ern Sierra Nevada, grass communities Mexican rush (Juncus [arcticus ssp. are common. Widely distributed meadow littoralis, mexicanus]) marshes range barley (Hordeum brachyantherum) patch­ from lowlands to high mountains with es, for instance, form moist meadows, circumboreal distribution. Plants of swales, and associate with wetland woody Baltic rush lack leaf blades and grow vegetation. Broad ecological tolerance up to 1 m tall. In the California Great gives this grassland frequent appear­ Basin, rush marshes occur in Bridgeport ance in wet upland habitats of the Valley, and Fish Slough. Pale spike California Great Basin. Also common rush (Eleocharis macrostachya) is a matt­ and widespread across many elevations in forming rush, with tall stems and long California, curly blue grass (Poa secunda) floral spikes. Stands are common in grasslands extend along meadow edges sloughs and slow-moving waters near and California Great Basin habitats in Benton and Bridgeport, for instance, situations where water tables are shallow.

Mono and Southeastern Great Basin 135 Top: Meadows are common in wetlands of the region, often with diverse sedge species, as in Swauger Canyon, Sweetwater Mountains. Connie Millar Above: Yellow-headed blackbird (Xanthocephalus xanthocephalus) at Mono Lake. John Sterling Left: Baltic rush, American bulrush, and California bulrush grow in sloughs and still waters of the low basins from Bridgeport through to Death Valley. Wallace Woolfenden

136 California’s Botanical Landscapes Riparian Communities In more arid mountains, from the Above: Narrow riparian corridors In the cooler, more mesic northern Glass Mountains southward, riparian along perennial streams are mountains of the California Great Basin, communities are commonly dominated almost always dominated by willow species. riparian communities are mostly dom­ by dense corridors of water birch (Betula Connie Millar inated by angiosperm trees, including, occidentalis) thickets, whose lime-green, Below: In a water birch thicket, as noted above for higher elevations, silver-dollar-sized leaves shimmer in the trees have characteristic orange- aspen. Well-watered upland riparian clear sunlight, illuminating the glowing hued bark and lime-green leaves communities are dominated by black orange bark of the birch stems. Buffalo in summer. and narrowleaf cottonwoods (Populus berry (Shepherdia argentea), with leathery Julie M. Evens trichocarpa and P. angustifolia). They blue-grey leaves, is a welcome indicator grow with an assortment of willows, of high water table in riparian, spring, or most often sandbar willow (Salix exigua) wet locations such as in the Bridgeport and arroyo willow (S. lasiolepis), as well and Mono Basins, and scattered loca­ as Sierran willow (S. eastwoodiae) in the tions along the eastern escarpment Carson and Walker drainages, and yellow south to about Big Pine Creek. Black willow (S. lutea) and greenleaf willow willow (Salix gooddingii) thickets replace (S. lucida ssp. caudata) in the Sweetwater riparian shrubs along the upper Owens Mountains. Bitter cherry (Prunus Valley and scattered locations farther emarginata), with its red, shiny bark and south. Prior to water extraction, black delicate white flowers, dots the edges willows once formed extensive riparian of riparian forests. gallery forests along the Owens River.

Mono and Southeastern Great Basin 137 With newly restored water supplies, new Basins, Bajadas, and Playas young stands are growing in the lower In lower, drier, and more southerly reaches of the river north of Owens Lake. reaches of the California Great Basin, Along a number of low canyons in the sagebrush steppe is replaced by or inter­ eastern Sierra Nevada from lower Rock mingles with black sagebrush (Artemisia Creek southward, ponderosa pine (Pinus nova) scrub mixed with shadscale and ponderosa) forms gallery forests that other salt bush (Atriplex spp.). These extend into Owens Valley. California extend broadly across low slopes, rocky black oak (Quercus kelloggii) often hills, and bajadas, and along basin associates with this forest, giving the bottoms and playa edges. The wide- visitor a feeling of being in a western ranging community crosses diverse soils, Sierra Nevada forest, but with an eastern including carbonates, sand, clay, and even California escarpment backdrop. desert pavement, occupying a spectrum of successional roles, from seral to climax. Above: Riparian vegetation in the wetter areas of Occasionally intermingling with salt the eastern Sierra Nevada, such as lower McGee bush are scrublands dominated by spiny Canyon, often contain black cottonwood as well hop sage (Grayia spinosa). Like shadscale, as water birch. Together with moist lower slopes spiny hop sage grows in diverse but warm, of aspen, they form a palette of gold in autumn. John O. Sawyer dry locations, ranging across mountain Left: Creosote bush and white bursage in the slopes to basin bottoms, preferring deep Haiwee area, south of Lone Pine. alluvial soils that vary from alkaline to Wallace Woolfenden calcareous, to sandy. Large stands of

138 California’s Botanical Landscapes desert holly (Atriplex hymenelytra) scrub occur on cinder fields and other volcanic and alkaline soils east of Owens Lake and widely through the southeastern parts of the California Great Basin. Another shrub alliance of dry, lower slopes and upper bajadas is black brush scrub, which is common in the upper Owens drainage north of Bishop, and throughout the southern ranges of the California Great Basin. Scattered stands of Nevada joint fir Ephedra( nevadensis) scrub occur in the Alabama Hills above Independence and the southeastern ranges. This clonal species spreads read­ ily and individuals live as long as 100 years. Nevada joint fir scrub stands have extremely high shrub richness, often with as many as 35 associated species within the community. The dominant shrubland type of American low deserts, creosote bush (Larrea tridentata) scrub reaches from the Mojave province into the California Great Basin in low basins such as Eureka Valley and Saline Valley, and finds its northernmost extent just south of Bishop. White bursage (Ambrosia dumosa) is a common associate and also dominates the white bursage scrub alliance along old washes and river terraces of dry low-elevation environ­ ments, extending down fans, bajadas, and stabilized sand dunes. In the far eastern section, white bur- sage scrub occurs on limestone outcrops, but usually these are on sandy or clay- rich soils. In disturbed areas adjacent to creosote bush scrub, especially those heavily grazed, needleleaf rabbitbrush (Ericameria teretifolia) scrub spreads from acidic to saline soils. White-flowered Top: Spiny hop sage scrub with spring-blooming annual plants such as pincushion flower rabbitbrush (Ericameria albida) is (Chaenactis fremontii) along an intermontane valley and slope of the Last Chance Range, Death Valley National Park. perhaps one of the most restricted of Julie M. Evens the rabbitbrush clan, only forming stands Above: Shadscale shrub replaces sagebrush steppe in lower drier basins and slopes around the edges of alkaline meadows of the southern Great Basin in California, here in Titus Canyon in the Grapevine and springs as at Fish Slough and Mountains of Death Valley National Park. Grapevine Springs. Wallace Woolfenden

Mono and Southeastern Great Basin 139 Above: Nevada joint fir, spiny Conservation and Restoration unnatural regimes that further promote hop sage, and Anderson’s Primary among conservation chal­ spread of cheatgrass at the expense of Lycium andersonii boxthorn ( ) lenges at low-to-mid-elevations through­ natives. Cheatgrass emerges, blooms, intermix in diverse shrublands above Eureka Valley in the out the California Great Basin is the and dries early in the warm season, Saline Range. expanding tide of invasive cheatgrass creating continuous fuels in otherwise Julie M. Evens and red brome (Bromus tectorum and discontinuous vegetation. Fires spread Opposite, top: The east slopes B. rubens, respectively). In their native rapidly, eliminating native herbs, shrubs, of the Sweetwater Mountains dry, arid-Mediterranean environments, and pines, and enhancing conditions for overlook singleleaf pinyon these annual grasses evolved in the further cheatgrass spread. In Nevada, woodlands that are recruiting presence of grazing mammals and are cheatgrass and red brome have con­ into sagebrush scrub. Scattered Jeffrey pines in the middle slope highly adapted to thrive where grazing verted vast slopes and basins of native dot this eastward view toward pressure is high and fire frequent. plant communities into depleted mono- the Pine Grove Mountains and Cheatgrass has infiltrated ecosystems cultures. Control efforts in the wake of Wassuk Range in Nevada. of the Great Basin widely over the past these invasions have been mostly futile. Connie Millar century, displacing native herbs and The primary management goals are Opposite, bottom: Non-native shrubs, altering natural fire regimes, and to minimize entry of cheatgrass and grasses including cheatgrass vastly transforming ecological structure red brome into virgin habitats, or to quickly invade areas after fire that previously contained lush stands and function. The main culprit in the decelerate the rate of spread of exotics. of bitter brush, sagebrush, and California Great Basin is cheatgrass, Another issue on center stage is spread singleleaf pinyon and other native which sets up a highly successful feed­ of two native tree species, singleleaf vegetation in the eastern Sierra back cycle by converting natural fire pinyon and Utah juniper, into sagebrush Nevada along Highway 89 below regimes (responsible for maintaining steppe, which some conservationists and Monitor Pass, Mono County. Julie M. Evens ecosystem health in native scrub and pine managers interpret as unnatural behavior woodlands) into more frequent and flashy catalyzed by improper land-use practices.

140 California’s Botanical Landscapes As mentioned before, these tree spe­ cies have accelerated in their capacity to recruit, establish, and expand within the past 150 years. The resulting fragmen­ tation and loss of intact sagebrush com­ munities have been considered partly to blame for declining populations of native vertebrates that depend on the shrublands for habitat. In particular, greater sage- grouse is a candidate endangered species under federal law, promoting widespread management efforts to eradicate pine and juniper in areas where they are spreading. Complex interactions uncertainly related to climate change, modified fire regimes, expansion of non-native invasives, and altered hydrology have motivated a wide­ spread yet controversial effort to remove these species where they are expanding.

Constance I. Millar

Mono and Southeastern Great Basin 141