Flora of the Sierra Nevada alpine zone
The flora of the U.S. Sierra Nevada alpine zone is characterized by small, low growing, cushion and mat forming plants that can survive the harsh conditions in the
Botanists have ranked the Sierra Nevada alpine zone floral bloom as one of California's foremost wildflower displays, with flowers of fantastic color and abundance.[8] Many of the alpine species are notable for large and showy flowers, which must compete for the pollinators during brief growing seasons.[5] Botanist Philip A. Munz wrote, "These natural rock gardens are spectacular sights when in full flower."[5] Botanist Laird R. Blackwell wrote, "Up here... the flowers seem to glow... perhaps only the flowers of the harsh desert can rival the alpine flowers for intensity."[4]: 214
Over 90% of California's alpine flora are
Environmental conditions influencing flora
The alpine zone, or alpine fell-field, is above the tree line, generally at 11,000 to 11,500 feet (3,400 to 3,500 m) in the south,[4][5]: 8 and 9,900 feet (3,000 m)[6]: 17 to 10,500 feet (3,200 m)[4] in the north. The plants are influenced by having to endure long and very cold winters, poor to no soils, constant high winds, intense sunlight, and a short cool and dry growing season in the summer, that lasts only about 6–8 weeks.[10]
Winds are strong and constant.[10] The constant wind makes unsheltered areas colder than sheltered spots, depositing snow in some places, while scouring the snow out of other locations.[10] The constant wind increases loss of water from the plants to the atmosphere (transpiration).[10] Sunlight is intense.[10] Soils are thin and rocky, or absent.[10] Soils are low in moisture.[10] Rainfall is rare.[10] Almost all of the 35 to 40 inches (0.89 to 1.02 m) of annual precipitation falls as snow, and growing season can be as short as just days.[6]: 17 Annual plants must quickly grow to maturity, and all plants must quickly flower and develop mature seed.[10]
Characteristic growth patterns and physiology
Above the tree line, extreme winds preclude tree-like growth.[6]: 17 Constant winds hitting the plants limits their size and flattens their shape.[10] Small size or dwarfism is therefore an adaptive feature to the extremes, and most alpine plants are just a few inches tall.[4]: 223 [9] One botanist wrote, "Plants adapt by scrunching down close to the ground where botanists have to crawl around on their bellies with hand lenses to fully appreciate the diversity of life... Plants are mere centimeters tall, forming a mat so dense that it's hard to pick out separate species".,[8] Another noted, "a world of miniature plants only a few inches high... leaves huddle near the ground or contour it with mats or cushions. Typically, the leaves of these plants are waxy or densely hairy - anything to protect them from the wind and intense solar radiation".[4]: 228
Alpine plants have many adaptations to aridity and intense sunlight in common with desert plants.[5] Alpine plants often have gray appearance from hairs covering the leaves, which reflect the intense sunlight, and protect from winds that cause high rates of water loss through transpiration.[4]: 224 Many Sierra Nevada alpine plants have reddish or whitish leaves to protect them from damage from intense ultraviolet radiation in the alpine zone.[5]: 17 [11] Fleshy roots and underground organs store food in the form of starches and sugars, allowing the plant to quickly grow when snow melts.[5] Many plants form flower buds during the summer before the summer that they open, allowing a quick bloom for the short growing season.[5]
Optimal temperatures for physiological processes may be lower than for lower elevation plants, and optimal light intensity for photosynthesis may be higher.
Evolutionary history and affinities
The flora has developed relatively recently, on its own, from western American sources.
Many species also occur in, or have close relatives in, the Cascade Range and Rocky Mountains, e.g., the Penstemons (Penstemon spp., and Polemoniums (Polemoneaceae spp.).[5]
A small group[
Diversity and taxa
Broad-leaved, erect perennials constitute about 50% of the species, with perennial graminoid (grasses or grass-like plants) species next at about 21%, and plants growing as mats or cushions at about 11%.[1] Annuals plus woody shrubs total only about 6% of the flora.[1]
There are over 500 floral species above 3,300 metres (10,800 ft), and almost 400 above 3,500 metres (11,500 ft).[1] Almost 100 species reach elevations of 4,000 metres (13,000 ft), and more than 25 reach 4,200 metres (13,800 ft).[1]
Six plant families encompass more than 50% of the alpine zone species.[1] The sunflower family (Asteraceae) is represented by about 55 species, there are almost 40 species from the grass family (Poaceae), the mustard family (Brassicaceae) has 34 species, and sedges (Cyperaceae) have over 30 species represented.[1]
The largest genus is Carex, the "true sedge", with about 50 species above 3,300 metres (10,800 ft), followed by Draba in the mustard family, then Lupinus in the legume family (Fabaceae) with about 10 species.[1]
Almost 70 species (about 17% of the flora) can be found in both
In a transectional study running from the desert near Bishop, California (elevation 1,400 metres (4,600 ft)), to Piute Pass (elevation 3,540 metres (11,610 ft)), perennials dominated, but also present were several annual species.[2] Annuals are also rare in other alpine floras, including arctic.[2]
Transpiration rates are of importance in determining local distribution patterns of flora of the Sierra Nevada alpine zone.[12]
Annuals
Annuals plus woody shrubs constitute only about 6% of the number of Sierra Nevada alpine floral species.[1]
Sierra gentian (Gentianopsis holopetala), in the gentian family (Gentianaceae), is an erect or sprawling annual or perennial, growing in wet meadows from 6,000 to 13,000 feet (1,800 to 4,000 m) elevation.[5][6]: 39
Toothed owl's clover (Orthocarpus cuspidatus) is not a true clover, but is in the broomrape family (Orobanche).[13]
Low growing pussypaws (
Perennials
Characteristic
Swamp onion (
In the carrot family (Apiaceae), Clemen's mountain parsley (Oreonana clementis) forms a dense mat of tiny plants with tiny leave that might cover several square yards the area like a blanket.[4]: 227 [5]: 18 Sierra podistera (Podistera nevadensis) is compact, stemless, and found only above the timberline to 13,000 feet (4,000 m).[5]: 199
Sunflower family (
Alpine fleabanes, or daisies, are sunflower family members. They include dwarf mountain fleabane, or cut-leaf daisy
Golden yarrow, or wooly sunflower (
Anderson's mountain crown (
The borage family (Boraginaceae) has the genus Oreocarya, with plants similar in appearance such as low cryptantha (O. humilis), a relatively small, hairy perrential with dense, leafy stems from a woody base found up to 11,900 feet (3,600 m). Sierra forget-me-not (O. nubigena) is found at even higher elevations, to 12,900 feet (3,900 m),[6]: 152 and is adapted to rigors of dry winds by being covered with long, stiff, bristly hairs.[4] Timberline phacelia (Phacelia hastata) grows to 13,000 feet (4,000 m).[4]: 218 [9] Streamside bluebells (Mertensia ciliata) grow in shaded, moist areas to 12,000 feet (3,700 m).[5]: 158
The mustard family (
Pink family (
Rosy sedum (
The legume family (Fabaceae) includes balloon milkvetch (Astragalus whitneyi), a spreading or erect perennial with papery balloon like seedpods, filled with air.[6]: 69 The mat forming perennial or subshrub, Brewer's lupine (Lupinus breweri), is well adapted to the alpine zone, low growing, with hairy silver leaves that reflect the intense alpine sunlight and trap air to reduce the drying effects of constant winds.[5]: 146–7 [6]: 33 Alpine lupine, or dwarf lupine (Lupinus lepidus), has several semi-prostrate stems.[9] Carpet clover (Trifolium monanthum) is found in moist, grassy places up to 12,500 feet (3,800 m).[5]: 108–9 King's clover (Trifolium kingii) grows on open slopes.[14]
Explorer's gentian (: 162
Fireweed (
Ladies Tresses (
Lemmon's paintbrush (Castilleja lemmonii), in the broomrape family (Orobanchaceae), is found in alipine meadows[6]: 81 or dry, rocky places[5]: 69 to 12,000 feet (3,700 m).[5]: 69 [6]: 81 Dwarf alpine Indian paintbrush (Castilleja nana) grows in dry alpine barrens to 12,000 feet (3,700 m), exhibiting the small size characteristic of alpine flora, with several short erect stems typically less than 4 inches (10 cm),[5]: 69 rarely reaching 6 inches (15 cm).[4]: 222 [9] Little elephants head (Pedicularis attollens) grows as short as 2 inches (5.1 cm) and to elevations of 13,000 feet (4,000 m).[5]: 70–1 [6]: 82 Elephant's head (Pedicularis groenlandica)is as short as 3 inches (7.6 cm) and can be found up to 12,000 feet (3,700 m).[5]: 70
The poppy family (Papaveraceae) has steer's head (Dicentra uniflora) and few-flowered bleeding heart (D. pauciflora), each growing to 12,000 feet (3,700 m).[5]: 45
In the alpine zone, the lopseed family (
In the plantain family (Plantaginaceae), Torrey's few-eyed Mary (Collinsia torreyi) can be found as high as 13,000 feet (4,000 m).[5]: 162 Davidson's penstemon, or creeping penstemon (Penstemon davidsonii), is a perennial spreading mat, with several spreading flower stems.[4]: 234 [9] The tubular blossoms are longer than the stems of the dwarfed plant that supports them.[4]: 234 (Penstemon heterodoxus) can be as small as 2 inches (5.1 cm), but usually forms mats to 8 inches (0.20 m), ranging to 12,000 feet (3,700 m) elevation.[4]: 235 [5]: 161–2 [6]: 47 John Muir's favorite wildflower, mountain pride (Penstemon newberryi), "carpets granite slopes with brilliant pink flowers".[8] Showy penstemon (Penstemon speciosus)) is a spreading perennial.[6]: 47 American alpine speedwell (Veronica wormskjoldii) is an erect perennial that grows near moist streambanks and lakeshores from an underground stem (rhizome).[6]: 48
Phlox family (
Buckwheat family (Polygonaceae) perennials include lady's thumb (Bistorta bistortoides), a perennial growing from a contorted rhizome (underground stem).[6]: 182 Butterballs,[4]: 224 or oval-leaved buckwheat (Eriogonum ovalifolium), has leaves that cluster very tightly forming almost impenetrable[4]: 224 mats or cushions on sandy or gravelly flats and in rocky soils, and grows to 12 inches (0.30 m)[6]: 183 or 13,000 feet (4,000 m)[4]: 224 elevation.[4]: 224 [6]: 183 Frosted wild buckwheat (E. incanum) is densely covered with white hairs so as to appear "frosted", and grows to 13,000 feet (4,000 m) elevation.[6]: 134 Lobb's wild buckwheat (E. lobbii), growing to 12,000 feet (3,700 m), is sprawling and grows from a thick, woody stem, with flower stalks lying on the ground.[5]: 90 [6]: 183
Another buckwheat family member found growing in 13 named varieties, from the desert floor all the way up to 12,500 feet (3,800 m), is naked stemmed eriogonum (E. nudum).[5]: 178–9 There are also alpine zone varieties of the perennial to shrub sulfur flower, or sulfur buckwheat (E. umbellatum), that can be found up to 11,800 feet (3,600 m)[6]: 136 to 12,000 feet (3,700 m)[5]: 179–80 elevation. Alpine sorrel (Oxyria digyna) grows in crevices in cliffs and other rocky places to 13,000 feet (4,000 m).[4]: 230 [5]: 40 [9] It is unusual among alpine plants in that it has leaves that are relatively large, broad, and hairless (and edible, with a tangy-tart taste - "oxyria" meaning "sour").[4]: 230
The primrose family (
In the purslane family (
The buttercup family (Ranunculaceae) has Drummond's anemone (Anemone drummondii), a showy perennial.[6]: 184 Alpine columbine, or sierra yellow columbine (Aquilegia pubescens), "among the most spectacular eastern sierra flowers",[4]: 222 grows as a 20 inches (0.51 m) or smaller cushion, to 12,000 feet (3,700 m).[5]: 96 [6]: 185 Unlike lower elevations, which are pollinated by hummingbirds that do not reach alpine elevations, alpine columbine is pollinated by moths, so are upright and totally ultraviolet reflecting white.[4]: 222 Mountain larkspur (Delphinium glaucum) grows in wet meadows to 12,000 feet (3,700 m).[5]: 144–5 High mountain larkspur grows among willows and rocks along creeks, also up to 12,000 feet (3,700 m) elevation.[5]: 145–6 Buttercups (Ranunculus) are among the earliest blooming of the alpine zone.[4]: 225 Water plantain buttercup (Ranunculus alismifolius) grows in wet meadows and banks up to 12,000 feet (3,700 m),[5]: 177–78 elevation. Alpine buttercup, or Eschscholtz's buttercup (R. eschscholtzii) can be found in rocky areas and meadows up to 13,000 feet (4,000 m)[4]: 225 [6]: 137 or 13,500 feet (4,100 m)[5]: 178 elevation.[4]: 225 [5]: 178 [6]: 137 Alpine buttercup is conspicuous with its bright lemon yellow flowers, which contrast with their rock environment.[4]: 225
Gordon's Ivesia (
Pink heuchera (
Perennial grasslike plants
Perennial grasslike plants (graminoids) constitute 21% of the Sierra Nevada alpine species.[1]
A characteristic grass family (Poaceae) is squirreltail (Elymus elymoides).[6]: 17 Timberline bluegrass (Poa glauca) grows in the Central and Southern Sierra Nevada from 11,000 to 13,000 feet (3,400 to 4,000 m).[5]: 34
Sierra sedge (Carex helleri), in the sedge family (Cyperaceae), grows on gravelly and rocky slopes up to 13,600 feet (4,100 m).[5]: 35 A characteristic sedge family member is alpine sedge (Carex subnigricans).[6]: 17
Parry's rush (Juncus parryi) of the rush family (Juncaceae) grows in dry, rocky places to 12,500 feet (3,800 m).[5]: 83
Shrubs
Shrubs tend to be small, and low growing to cope with high wind conditions and dense snowcovering, forming mats and cushions. Woody shrubs together with annuals constitute only about 6% of the number of Sierra Nevada alpine floral species.[1]
Whitestem goldenbush (Ericameria discoidea) is a compact woody-based shrub in the sunflower family (Asteraceae), grows on open rocky slopes to 12,000 feet (3,700 m).[5][6]: 114
In the heath family (Ericaceae), white mountain heather (Cassiope mertensiana) is 1 foot (0.30 m) tall, tiny-leaved, densely branching shrub growing on rocky ledges and in crevices up to elevations of 12,000 feet (3,700 m).[5]: 119–120 [6]: 157 [9] Swamp laurel (Kalmia polifolia) is a low (to 8 inches (0.20 m) tall), branching, mat-forming evergreen shrub that grows in boggy alpine meadows or at the edge of water, up to 12,000 feet (3,700 m).[5]: 58 [6]: 67
Also in the heath family is purple mountain heather (
Mountain goosberry (
Cliffbush (Jamesia americana) is in the mock-orange family (Hydrangeaceae), and can be found to 12,000 feet (3,700 m).[5]: 45
White globe gilia, or ballhead gilia
Sierra primrose (Primula suffrutescens) is in the primrose family (Primulaceae), and is a sprawling, low growing subshrub found under overhanging rocks, and reaching only 5 inches (0.13 m).[5]: 54–5 [6]: 88
Creambush (
The mat forming Rocky Mountain willow (
Ferns, bryophytes, lichens, fungi, and interacting animals
The
See also
- Alpine plant
- Alpine tundra
- Montane ecology
- Sierra Nevada
- Sierra Nevada subalpine zone
References
- ^ S2CID 86541487.
- ^ JSTOR 1942262.
- ^ ISBN 0878423885.
- ^ ISBN 978-1-55105-281-6
- ^ ISBN 0520236351.
- ^ ISBN 978-0762780341.
- .
- ^ a b c d e Lukas, David. Sierra Alpine Wildflowers. University of California Press.
- ^ ISBN 9780520239142.
- ^ a b c d e f g h i j "Life in the Zone - Habitat Zones of the Sierra Nevada, Alpine Zone" (PDF). National Park Service Ranger class.
- PMID 15577195.
- JSTOR 2423268.
- ^ a b "Alpine Plants--part 2". Sierra Plants Project.
- ^ Sharnoff, Stephen. "Alpine Plants--part 1". Sierra Plants Project.
- ^ "Lewisia". Jepson Herbariaum Taxon Page.
- ^ Alpine lichens of western United States and adjacent Canada, I. The Macrolichens, H.A. Imshaug, Bryologist, 60:177-272
- ^ McCune, Bruce; Grenon, Jill; Martin, Erin. "Lichens in Relation to Management Issues in the Sierra Nevada National Parks" (PDF). Inventory & Monitoring, Sierra Nevada Network Sequoia & Kings Canyon National Parks. University of Washington College of the Environment. Archived from the original (PDF) on 2014-08-21.
External links
- Media related to Sierra Nevada flora (category) at Wikimedia Commons