:''See

Sierra Nevada The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...

for general information about the mountain range in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

.'' The ecology of the Sierra Nevada, located in the

U.S. states In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sove ...

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

and

Nevada Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...

, is diverse and complex: the plants and animals are a significant part of the scenic beauty of the

mountain range A mountain range or hill range is a series of mountains or hills arranged in a line and connected by high ground. A mountain system or mountain belt is a group of mountain ranges with similarity in form, structure, and alignment that have arise ...

. The combination of

climate Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorologic ...

topography Topography is the study of the forms and features of land surfaces. The topography of an area may refer to the land forms and features themselves, or a description or depiction in maps. Topography is a field of geoscience and planetary sci ...

moisture Moisture is the presence of a liquid, especially water, often in trace amounts. Small amounts of water may be found, for example, in the air (humidity), in foods, and in some commercial products. Moisture also refers to the amount of water vapo ...

, and

soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former te ...

s influences the distribution of

ecological Ecology () is the study of the relationships between living organisms, including humans, and their physical environment. Ecology considers organisms at the individual, population, community, ecosystem, and biosphere level. Ecology overlaps wi ...

communities across an elevation gradient from . Biotic zones range from scrub and

chaparral Chaparral ( ) is a shrubland plant community and geographical feature found primarily in the U.S. state of California, in southern Oregon, and in the northern portion of the Baja California Peninsula in Mexico. It is shaped by a Mediterranean c ...

communities at lower elevations, to

subalpine Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...

forests and

alpine meadow Alpine tundra is a type of natural region or biome that does not contain trees because it is at high elevation, with an associated harsh climate. As the latitude of a location approaches the poles, the threshold elevation for alpine tundra gets ...

s at the higher elevations. Particular ecoregions that follow elevation contours are often described as a series of belts that follow the length of the Sierra Nevada. There are many

hiking trail A trail, also known as a path or track, is an unpaved lane or small road usually passing through a natural area. In the United Kingdom and the Republic of Ireland, a path or footpath is the preferred term for a pedestrian or hiking trail. The ...

s, paved and unpaved roads, and vast

public lands In all modern states, a portion of land is held by central or local governments. This is called public land, state land, or Crown land (Australia, and Canada). The system of tenure of public land, and the terminology used, varies between countrie ...

in the Sierra Nevada for exploring the many different biomes and

ecosystems An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...

. The western and eastern Sierra Nevada have substantially different species of plants and animals, because the east lies in the rain shadow of the crest. The plants and animals in the east are thus adapted to much drier conditions. The altitudes listed for the biotic zones are for the central Sierra Nevada. The climate across the north–south axis of the range varies somewhat: the boundary elevations of the biotic zones move by as much as from the north end to the south end of the range.

Western biotic zones

Foothill Woodland and Chaparral Zone

The lowest-elevation biotic zone in the Sierra Nevada is found along the boundary with the Central Valley. This zone, stretching in elevation from , is the

foothill woodland zone Foothill woodland is a California vegetation type characterized by an overstory of broadleaf and coniferous trees, generally found in areas of higher elevations and more precipitation than grasslands and oak savannah, and at lower elevations and le ...

, an area that is hot and dry in the summer with very little or no snow in the winter. The foothills are vegetated with grasslands of mostly non-native grasses, mixed grasslands and woodlands

savanna A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to ...

, a

foothill woodland Foothill woodland is a California vegetation type characterized by an overstory of broadleaf and coniferous trees, generally found in areas of higher elevations and more precipitation than grasslands and oak savannah, and at lower elevations and le ...

community of

blue oak ''Quercus douglasii'', known as blue oak, is a species of oak endemic to (and found only in) California, common in the Coast Ranges and the foothills of the Sierra Nevada. It is California's most drought-tolerant deciduous oak, and is a dominan ...

and

gray pine ''Pinus sabiniana'' (sometimes spelled ''P. sabineana''), with vernacular names including towani pine, foothill pine, gray pine, bull pine, and digger pine, is a pine endemic to California in the United States. Some sources discourage using the n ...

, and

. Many of the plant communities are similar to those found on the inner

California Coast Ranges The Coast Ranges of California span from Del Norte or Humboldt County, California, south to Santa Barbara County. The other three coastal California mountain ranges are the Transverse Ranges, Peninsular Ranges and the Klamath Mountains. P ...

. Animals typical of this zone include

black bear Black bear or Blackbear may refer to: Animals * American black bear (''Ursus americanus''), a North American bear species * Asian black bear (''Ursus thibetanus''), an Asian bear species Music * Black Bear (band), a Canadian First Nations group ...

ringtail cat The ringtail (''Bassariscus astutus'') is a mammal of the raccoon family native to arid regions of North America. It is widely distributed and well adapted to disturbed areas. It has been legally trapped for its fur. It is listed as Least Conc ...

coyote The coyote (''Canis latrans'') is a species of canis, canine native to North America. It is smaller than its close relative, the wolf, and slightly smaller than the closely related eastern wolf and red wolf. It fills much of the same ecologica ...

gray squirrel Gray squirrel or grey squirrel may refer to several species of squirrel indigenous to North America: *The eastern gray squirrel (''Sciurus carolinensis''), from the eastern United States and southeastern Canada; introduced into the United Kingdom, I ...

bobcat The bobcat (''Lynx rufus''), also known as the red lynx, is a medium-sized cat native to North America. It ranges from southern Canada through most of the contiguous United States to Oaxaca in Mexico. It is listed as Least Concern on the IUC ...

California mule deer The California mule deer (''Odocoileus hemionus californicus'') is a subspecies of mule deer whose range covers much of the state of California. Anatomy One of the principal means of distinguishing the closely related black-tailed deer and whi ...

, and

skunk Skunks are mammals in the family Mephitidae. They are known for their ability to spray a liquid with a strong, unpleasant scent from their anal glands. Different species of skunk vary in appearance from black-and-white to brown, cream or ginge ...

. In the foothills of the northern portion of the Sierra Nevada,

toyon ''Heteromeles arbutifolia'' (; more commonly by Californian botanists), commonly known as toyon, is a common perennial shrub native to extreme southwest Oregon, California, and the Baja California Peninsula. It is the sole species in the genus ...

and

chamise ''Adenostoma fasciculatum'', commonly known as chamise or greasewood, is a flowering plant native to California and Baja California. This shrub is one of the most widespread plants of the California chaparral ecoregion. Chamise produces a specia ...

often co-dominate certain open serpentine chaparral communities.

Lower Montane Forest

Beginning near the elevation, the hot, dry summers and cool, moist winters of the

Mediterranean climate A Mediterranean climate (also called a dry summer temperate climate ''Cs'') is a temperate climate sub-type, generally characterized by warm, dry summers and mild, fairly wet winters; these weather conditions are typically experienced in the ...

give rise to the lower montane forest zone. This zone is also known as the

yellow pine In ecology and forestry, yellow pine refers to a number of conifer species that tend to grow in similar plant communities and yield similar strong wood. In the Western United States, yellow pine refers to Jeffrey pine or ponderosa pine. In the S ...

forest zone. The accumulation of several feet of

snow Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water throughout ...

during the winter is not uncommon and can stay on the ground for several months. The diversity of

tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...

species found in this zone make this a beautiful and interesting forest to explore. The

indicator species A bioindicator is any species (an indicator species) or group of species whose function, population, or status can reveal the qualitative status of the environment. The most common indicator species are animals. For example, copepods and other sma ...

for the lower montane forest are the

ponderosa pine ''Pinus ponderosa'', commonly known as the ponderosa pine, bull pine, blackjack pine, western yellow-pine, or filipinus pine is a very large pine tree species of variable habitat native to mountainous regions of western North America. It is the ...

and the

Jeffrey pine ''Pinus jeffreyi'', also known as Jeffrey pine, Jeffrey's pine, yellow pine and black pine, is a North American pine tree. It is mainly found in California, but also in the westernmost part of Nevada, southwestern Oregon, and northern Baja Califo ...

: the ponderosa pine generally occurs on the west side of the Sierra, while the Jeffrey pine occurs on the east. The lower montane forests also include trees such as

California black oak ''Quercus kelloggii'', the California black oak, also known as Kellogg oak, is an oak in the red oak section (genus ''Quercus'', section ''Lobatae'', series ''Agrifoliae''), native to western North America. Although genetically separated from the ...

sugar pine ''Pinus lambertiana'' (commonly known as the sugar pine or sugar cone pine) is the tallest and most massive pine tree, and has the longest cones of any conifer. The species name ''lambertiana'' was given by the Scottish botanist David Douglas, ...

incense-cedar ''Calocedrus'', the incense cedar (alternatively spelled incense-cedar), is a genus of coniferous trees in the cypress family Cupressaceae first described as a genus in 1873. It is native to eastern Asia and western North America. The gener ...

, and

white fir ''Abies concolor'', the white fir, is a coniferous tree in the pine family Pinaceae. This tree is native to the mountains of western North America, including the Cascade Range and southern Rocky Mountains, and into the isolated mountain range ...

. Animals that may be found in this zone include the

dark-eyed junco The dark-eyed junco (''Junco hyemalis'') is a species of junco, a group of small, grayish New World sparrows. This bird is common across much of temperate North America and in summer ranges far into the Arctic. It is a very variable species, much ...

mountain chickadee The mountain chickadee (''Poecile gambeli'') is a small songbird, a passerine bird in the tit family Paridae. Taxonomy The specific name honors naturalist William Gambel. The mountain chickadee was formerly placed in the genus ''Parus'' with ...

western gray squirrel The western gray squirrel (''Sciurus griseus'') is a tree squirrel found along the western coast of the United States and Mexico. In some places, this species has also been known as the silver-gray squirrel, the California gray squirrel, the Or ...

mule deer The mule deer (''Odocoileus hemionus'') is a deer indigenous to western North America; it is named for its ears, which are large like those of the mule. Two subspecies of mule deer are grouped into the black-tailed deer. Unlike the related whit ...

, and

American black bear The American black bear (''Ursus americanus''), also called simply a black bear or sometimes a baribal, is a medium-sized bear endemic to North America. It is the continent's smallest and most widely distributed bear species. American black bear ...

. The endangered

Yosemite toad The Yosemite toad (''Anaxyrus canorus'', formerly ''Bufo canorus'') is a species of true toad in the family Bufonidae. Endemic to the Sierra Nevada of California, the species ranges from the Alpine County to Fresno County. Yosemite toads are only ...

is found in montane forests of the central Sierra Nevada, at elevations of . The character of the Lower Montane Forest changes with latitude. North of

Grass Valley A grass valley (also vega and valle) is a meadow located within a forested and relatively small drainage basin such as a headwater. Grass valleys are common in North America, where they are created and maintained principally by the work of b ...

, the lower montane forest ranges from , with less ponderosa pine and more

Douglas-fir The Douglas fir (''Pseudotsuga menziesii'') is an evergreen conifer species in the pine family, Pinaceae. It is native to western North America and is also known as Douglas-fir, Douglas spruce, Oregon pine, and Columbian pine. There are three va ...

. In the middle Sierra, south to the

Merced River The Merced River (), in the central part of the U.S. state of California, is a -long tributary of the San Joaquin River flowing from the Sierra Nevada (U.S.), Sierra Nevada into the San Joaquin Valley. It is most well known for its swift and st ...

, the lower montane forest has the same elevation, but precipitation decreases and the forest mixes with chaparral. In the southern Sierra, the lower montane forest occurs between , but can range as high as , with ponderosa pine dominating the landscape. Unlike further north, the geology of the southern lower montane forest is dominated by granite.

Mid-Montane Forest

The mid-montane forest grows on the western slopes of the Sierra Nevada at moderate elevations. North of

Lake Tahoe Lake Tahoe (; was, Dáʔaw, meaning "the lake") is a Fresh water, freshwater lake in the Sierra Nevada (U.S.), Sierra Nevada of the United States. Lying at , it straddles the state line between California and Nevada, west of Carson City, Nevad ...

, the mid-montane forest occurs from . Between Tahoe and Yosemite, the forest ranges from , while south of Yosemite, it occurs between . The mid-montane zone has a mixed forest of

live oak Live oak or evergreen oak is any of a number of oaks in several different sections of the genus ''Quercus'' that share the characteristic of evergreen foliage. These oaks are not more closely related to each other than they are to other oaks. ...

black oak Black Oak may refer to: Places in the United States * Black Oak, Arkansas * Black Oak, Daviess County, Indiana * Black Oak, Lake County, Indiana, a neighborhood of Gary, Indiana * Black Oak, Missouri Other * Black Oak Arkansas Black Oak Ar ...

, and

tanoak ''Notholithocarpus densiflorus'', commonly known as the tanoak or tanbark-oak, is a broadleaf tree in the family Fagaceae, and the type species of the genus ''Notholithocarpus''. It is native to the far western United States, particularly Oregon ...

, depending on location. North of Tahoe, the mid-montane forest has more white fir and Douglas-fir, and less ponderosa pine than further south. Jeffrey pine occurs on

ultramafic Ultramafic rocks (also referred to as ultrabasic rocks, although the terms are not wholly equivalent) are igneous and meta-igneous rocks with a very low silica content (less than 45%), generally >18% MgO, high FeO, low potassium, and are composed ...

lava soils. In Yosemite and points south,

giant sequoia ''Sequoiadendron giganteum'' (giant sequoia; also known as giant redwood, Sierra redwood, Sierran redwood, California big tree, Wellingtonia or simply big treea nickname also used by John Muir) is the sole living species in the genus ''Sequoiade ...

occurs in wetter locations.

Upper Montane Forest

The upper montane forest begins at higher elevations near , where the montane climate is characterized by short, moist, cool summers and cold, wet winters. Snow begins to fall in November and may accumulate to depths up to and remain until June. Pure stands of

red fir ''Abies magnifica'', the red fir or silvertip fir, is a western North American fir, native to the mountains of southwest Oregon and California in the United States. It is a high-elevation tree, typically occurring at elevation, though only rare ...

and

lodgepole pine ''Pinus contorta'', with the common names lodgepole pine and shore pine, and also known as twisted pine, and contorta pine, is a common tree in western North America. It is common near the ocean shore and in dry montane forests to the subalpine, ...

(the indicator species) are typical of this forest.

, which has bark that smells like

vanilla Vanilla is a spice derived from orchids of the genus ''Vanilla (genus), Vanilla'', primarily obtained from pods of the Mexican species, flat-leaved vanilla (''Vanilla planifolia, V. planifolia''). Pollination is required to make the p ...

, and the picturesque

western juniper ''Juniperus occidentalis'', known as the western juniper, is a shrub or tree native to the Western United States, growing in mountains at altitudes of and rarely down to . It is listed as Least Concern on the IUCN Red List because it is a widesp ...

can also be found in this zone.

Wildflower A wildflower (or wild flower) is a flower that grows in the wild, meaning it was not intentionally seeded or planted. The term implies that the plant probably is neither a hybrid nor a selected cultivar that is in any way different from the w ...

s bloom in meadows from June through August. Common animals in this zone include the

hermit thrush The hermit thrush (''Catharus guttatus'') is a medium-sized North American thrush. It is not very closely related to the other North American migrant species of ''Catharus'', but rather to the Mexican russet nightingale-thrush. The specific na ...

dusky grouse The dusky grouse (''Dendragapus obscurus'') is a species of forest-dwelling grouse native to the Rocky Mountains in North America.del Hoyo, J., Elliott, A., & Sargatal, J., eds. (1994). ''Handbook of the Birds of the World'' 2: 401-402. Lynx Edi ...

(''Dendragapus obscurus''),

great grey owl The great grey owl (''Strix nebulosa'') (also great gray owl in American English) is a very large owl, documented as the world's largest species of owl by length. It is distributed across the Northern Hemisphere, and it is the only species in the ...

golden-mantled ground squirrel The golden-mantled ground squirrel (''Callospermophilus lateralis'') is a ground squirrel native to western North America. It is distributed in the Rocky Mountains of British Columbia and Alberta, and through much of the western United States. ...

, and (more rarely) the

marten A marten is a weasel-like mammal in the genus ''Martes'' within the subfamily Guloninae, in the family Mustelidae. They have bushy tails and large paws with partially retractile claws. The fur varies from yellowish to dark brown, depending on t ...

. Upper montane forests may be viewed from the

Tioga Pass Road State Route 120 (SR 120) is a state highway in the central part of California, connecting the San Joaquin Valley with the Sierra Nevada, Yosemite National Park, and the Mono Lake area. Its western terminus is at Interstate 5 in Lathrop, and its ...

east of Crane Flat,

Glacier Point Glacier Point is a viewpoint above Yosemite Valley in the U.S. state of California. It is located on the south wall of Yosemite Valley at an elevation of , above Curry Village. The point offers a superb view of several of Yosemite National Park ...

Road, and State Route 108. The elevation of the upper montane zone shifts with latitude: it occurs from north of Yosemite, and to the south.

Subalpine Forest

The upper montane forest is replaced by the

subalpine forest Montane ecosystems are found on the slopes of mountains. The alpine climate in these regions strongly affects the ecosystem because temperatures fall as elevation increases, causing the ecosystem to stratify. This stratification is a crucial f ...

near , where the climate is cooler with an even shorter growing season due to long, cold, and snowy winters. Accumulations of three to nine feet (1 to 2.5 m) of snow are typical. The most common tree in the subalpine forest is the

whitebark pine ''Pinus albicaulis'', known by the common names whitebark pine, white bark pine, white pine, pitch pine, scrub pine, and creeping pine, is a conifer tree native to the mountains of the western United States and Canada, specifically subalpine ...

. The

western white pine Western white pine (''Pinus monticola''), also called silver pine and California mountain pine, is a species of pine in the family Pinaceae. It occurs in mountain ranges of northwestern North America. It is the state tree of Idaho. Description ...

mountain hemlock ''Tsuga mertensiana'', known as mountain hemlock, is a species of hemlock native to the west coast of North America, found between Southcentral Alaska and south-central California. Description ''Tsuga mertensiana'' is a large evergreen conifer ...

, and lodgepole pine are also found in this forest with many subalpine meadows that

flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...

from July through August. Many species live in, or are transient in, this zone, including

Clark's nutcracker Clark's nutcracker (''Nucifraga columbiana''), sometimes referred to as Clark's crow or woodpecker crow, is a passerine bird in the family Corvidae, native to the mountains of western North America. The nutcracker is an omnivore, but subsists mai ...

. The vegetation and ecology is determined by the harsh climate, with extensive snow and wind. In addition, soils are thin and nutrient-poor. Due to these harsh conditions, vegetation grows slowly and at low temperatures. In addition, the stressful environment suppress species competition and promotes mutualism. The marginal conditions make the Sierra Nevada subalpine zone sensitive to environmental changes, such as

climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...

and

pollution Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the ...

. South of

Bridgeport Bridgeport is the most populous city and a major port in the U.S. state of Connecticut. With a population of 148,654 in 2020, it is also the fifth-most populous in New England. Located in eastern Fairfield County at the mouth of the Pequonnoc ...

, the subalpine forest ranges from of elevation and contains

foxtail pine ''Pinus balfouriana'', the foxtail pine, is a rare high-elevation pine that is endemic to California, United States. It is closely related to the Great Basin and Rocky Mountain bristlecone pines, in the subsection '' Balfourianae''. Descriptio ...

s, while to the north, the subalpine forest ranges from and the foxtail pine is absent.

Alpine Zone

The

alpine zone Alpine tundra is a type of natural region or biome that does not contain trees because it is at high elevation, with an associated harsh climate. As the latitude of a location approaches the poles, the threshold elevation for alpine tundra gets ...

begins near elevation (in the southern Sierra) and near (in the north). This zone is easily distinguished as it is above the

tree line The tree line is the edge of the habitat at which trees are capable of growing. It is found at high elevations and high latitudes. Beyond the tree line, trees cannot tolerate the environmental conditions (usually cold temperatures, extreme snowp ...

. No trees grow in this zone due to the harsh climatic conditions. Short, cool summers with long, cold, and snowy winters are typical at these elevations. Many exposed

granitic A granitoid is a generic term for a diverse category of coarse-grained igneous rocks that consist predominantly of quartz, plagioclase, and alkali feldspar. Granitoids range from plagioclase-rich tonalites to alkali-rich syenites and from quart ...

outcroppings, talus slopes, and boulder fields limit the amount of vegetation that grows here. The herbaceous plants need to flower and produce their

seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...

s quickly during the short, frost-free period of summer. Flora includes

cushion plant A cushion plant is a compact, low-growing, mat-forming plant that is found in alpine, subalpine, arctic, or subarctic environments around the world. The term "cushion" is usually applied to woody plants that grow as spreading mats, are limited in ...

s, grasses, willows, and

sedge The Cyperaceae are a family of graminoid (grass-like), monocotyledonous flowering plants known as sedges. The family is large, with some 5,500 known species described in about 90 genera, the largest being the "true sedges" genus ''Carex'' wit ...

s. The macrolichen flora in the Sierra Nevada alpine zone is not well developed as compared to neighboring alpine zones in the

Rocky Mountains The Rocky Mountains, also known as the Rockies, are a major mountain range and the largest mountain system in North America. The Rocky Mountains stretch in straight-line distance from the northernmost part of western Canada, to New Mexico in ...

and mountains of the

Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though ...

. Some animal species that are adapted to this zone include the

American pika The American pika (''Ochotona princeps''), a diurnality, diurnal species of pika, is found in the mountains of western North America, usually in boulder fields at or above the tree line. They are herbivorous, smaller relatives of rabbits and ha ...

Belding's ground squirrel Belding's ground squirrel (''Urocitellus beldingi''), also called pot gut, sage rat or picket-pin, is a squirrel that lives on mountains in the western United States. In California, it often is found at in meadows between Lake Tahoe Lake Ta ...

, the

yellow-bellied marmot The yellow-bellied marmot (''Marmota flaviventris''), also known as the rock chuck, is a large, stout-bodied ground squirrel in the marmot genus. It is one of fourteen species of marmots, and is native to mountainous regions of southwestern Cana ...

, and the endangered

Sierra Nevada bighorn sheep The Sierra Nevada bighorn sheep (''Ovis canadensis sierrae'') is subspecies of bighorn sheep unique to the Sierra Nevada (U.S.), Sierra Nevada mountains of California. A 2016 genetics study confirmed significant divergence between the three subsp ...

. This zone can be viewed up close by

hiking Hiking is a long, vigorous walk, usually on trails or footpaths in the countryside. Walking for pleasure developed in Europe during the eighteenth century.AMATO, JOSEPH A. "Mind over Foot: Romantic Walking and Rambling." In ''On Foot: A Histor ...

or climbing into the high elevations of the Sierra.

Eastern biotic zones

The four highest eastern biotic zones are the same as the western zones, but at a higher elevation, due to less

precipitation In meteorology, precipitation is any product of the condensation of atmospheric water vapor that falls under gravitational pull from clouds. The main forms of precipitation include drizzle, rain, sleet, snow, ice pellets, graupel and hail. ...

. The elevation of these zones in the Central Sierra are: * Alpine zone: and above * Subalpine forest: * Upper montane forest: * Lower montane forest: (heavily dominated by

s). In the

Owens Valley Owens Valley (Numic Numic is a branch of the Uto-Aztecan language family. It includes seven languages spoken by Native American peoples traditionally living in the Great Basin, Colorado River basin, Snake River basin, and southern Great Pl ...

, the Foothill Woodland Zone is replaced by a Pinyon-

Juniper Junipers are coniferous trees and shrubs in the genus ''Juniperus'' () of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere, from the Arcti ...

Woodland Zone, characterized by

single-leaf pinyon ''Pinus monophylla'', the single-leaf pinyon, (alternatively spelled piñon) is a pine in the pinyon pine group, native to North America. The range is in southernmost Idaho, western Utah, Arizona, southwest New Mexico, Nevada, eastern and southe ...

pines and sierra

juniper Junipers are coniferous trees and shrubs in the genus ''Juniperus'' () of the cypress family Cupressaceae. Depending on the taxonomy, between 50 and 67 species of junipers are widely distributed throughout the Northern Hemisphere, from the Arcti ...

s. The underbrush contains

big sagebrush ''Artemisia tridentata'', commonly called big sagebrush,MacKay, Pam (2013), ''Mojave Desert Wildflowers'', 2nd ed., , p. 264. Great Basin sagebrush or (locally) simply sagebrush, is an aromatic shrub from the family Asteraceae, which grows in ari ...

(''Artemisia tridentata'') and

blackbrush ''Coleogyne ramosissima'' or blackbrush, is a low lying, dark grayish-green, aromatic,Turner, Raymond M. 1982. Great Basin desertscrub. In: Brown, David E., ed. Biotic communities of the American Southwest--United States and Mexico. Desert Plan ...

(''Coleogyne ramosissima'').

s may occur along streams. Notable animals in this zone include the

pinyon jay The pinyon jay (''Gymnorhinus cyanocephalus'') is a species of jay, and is the only member of the genus ''Gymnorhinus''. Native to Western North America, the species ranges from central Oregon to northern Baja California, and eastward as far as ...

and the

desert bighorn sheep The desert bighorn sheep (''Ovis canadensis nelsoni'') is a subspecies of bighorn sheep (''Ovis canadensis'') that is native to the deserts of the United States' intermountain west and southwestern regions, as well as northwestern Mexico. The Bu ...

. The Pinyon-Juniper Woodland Zone extends down to elevation. Below , there is not enough precipitation to support trees. The zones below this elevation are the Sagebrush Scrub Zone, Saltbush Scrub Zone, and the Alkali Sink Zone. These zones are distinguished by

soil salinity Soil salinity is the salt content in the soil; the process of increasing the salt content is known as salinization. Salts occur naturally within soils and water. Salination can be caused by natural processes such as mineral weathering or by the ...

Threats

Exotic Plants in Yosemite National Park

Yosemite National Park has documented more than 130 non-native plant

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

within park boundaries. These non-native plants were introduced into Yosemite following the migration of early settlers in the late 1850s. Natural and

human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...

-caused disturbances, such as wildland fires and construction activities, have contributed to a rapid increase in the spread of non-native plants. A number of these species aggressively invade and displace the native plant communities, resulting in impacts on the park's resources. Non-native plants can bring about significant changes in park ecosystems by altering the native plant communities and the processes that support them. Some non-native species may cause an increase in the fire frequency of an area or increase the available nitrogen in the soil that may allow more non-native plants to become established. Many non-native species, such as

yellow starthistle ''Centaurea solstitialis'', the yellow star-thistle, is a species of thorny plant in the genus ''Centaurea'', which is part of the family Asteraceae. A winter annual, it is native to the Mediterranean Basin region and invasive in many other ...

(''Centaurea solstitialis''), are able to produce a long

tap root A taproot is a large, central, and dominant root from which other roots sprout laterally. Typically a taproot is somewhat straight and very thick, is tapering in shape, and grows directly downward. In some plants, such as the carrot, the taproo ...

that allows them to out-compete the native plants for available water.

Bull thistle ''Cirsium vulgare'', the spear thistle, bull thistle, or common thistle, is a species of the Asteraceae genus ''Cirsium'', native throughout most of Europe (north to 66°N, locally 68°N), Western Asia (east to the Yenisei Valley), and North Afr ...

(''Cirsium vulgare''), common mullein (''Verbascum thapsus''), and

Klamath weed ''Hypericum perforatum'', known as St. John's wort, is a flowering plant in the family Hypericaceae and the type species of the genus '' Hypericum''. Possibly a hybrid between '' H. maculatum'' and '' H. attenuatum'', the species can be found ...

(''Hypericum perforatum'') have been identified as noxious pests in Yosemite since the 1940s. Additional species that have been recognized more recently as aggressive and requiring control are yellow starthistle,

sweet clover ''Melilotus'', known as melilot, sweet clover, and kumoniga (from the Cumans),Bulgarian Folk Customs, Mercia MacDermott, pg 27 is a genus in the family Fabaceae (the same family that also includes the ''Trifolium'' clovers). Members are known a ...

s (''Melilotus'' spp.),

Himalayan blackberry ''Rubus armeniacus'', the Himalayan blackberry or Armenian blackberry, is a species of ''Rubus'' in the blackberry group ''Rubus'' subgenus ''Rubus'' series ''Discolores'' (P.J. Müll.) Focke. It is native to Armenia and Northern Iran, and wide ...

(''Rubus discolor''), cut-leaved blackberry (''Rubus laciniatus'') and periwinkle (''

Vinca major ''Vinca major'', with the common names bigleaf periwinkle, large periwinkle, greater periwinkle and blue periwinkle, is a species of flowering plant in the family Apocynaceae, native to the western Mediterranean. Growing to tall and spreading i ...

'').

Lodgepole needle miner

The lodgepole needle miner ('' Coleotechnites milleri'') is an

insect Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...

, endemic to the upper Tuolumne and

watersheds of Yosemite National Park and one small headwaters drainage of the

San Joaquin River The San Joaquin River (; es, Río San Joaquín) is the longest river of Central California. The long river starts in the high Sierra Nevada, and flows through the rich agricultural region of the northern San Joaquin Valley before reaching Suis ...

(

Sierra National Forest Sierra National Forest is a U.S. national forest located on the western slope of central Sierra Nevada in Central California and bounded on the northwest by Yosemite National Park and the south by Kings Canyon National Park. The forest is kno ...

). It lives mostly within the needles of lodgepole pine for two years, emerging as a little gray

moth Moths are a paraphyletic group of insects that includes all members of the order Lepidoptera that are not butterflies, with moths making up the vast majority of the order. There are thought to be approximately 160,000 species of moth, many of w ...

for a few weeks in July of odd-numbered years. This keeps any

predator Predation is a biological interaction where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill th ...

s from becoming effective control agents and allows populations to escalate rapidly. While regular prehistoric outbreaks of lodgepole needle miners have been confirmed through

dendrochronology Dendrochronology (or tree-ring dating) is the scientific method of dating tree rings (also called growth rings) to the exact year they were formed. As well as dating them, this can give data for dendroclimatology, the study of climate and atmos ...

, historic records document outbreaks from 1903 to 1921, 1933 to 1941, and 1947 to 1963. Extensive stands of " ghost forest" and jackstrawed trees are still conspicuous throughout Sierra Nevada. Annual monitoring of lodgepole needle miner density began in 1966, and 28 permanent plots are scattered north of the

Cathedral Range The Cathedral Range is a mountain range immediately to the south of Tuolumne Meadows in Yosemite National Park. The range is an offshoot of the Sierra Nevada. The range is named after Cathedral Peak, which resembles a cathedral spire. Geograp ...

. The current outbreak began in 1973 and has been sweeping around the south side of the Cathedral Range, arriving at Sunrise High Sierra Camp in 2001. The Ghost Forest which was evident at the crest between Tenaya Lake and Tuolumne Meadows in the late 1970s was noticeably reforested by 2000. Lodgepole needle miner defoliation currently extends over approximately , with nearly of low to high mortality each year. While

lightning Lightning is a naturally occurring electrostatic discharge during which two electric charge, electrically charged regions, both in the atmosphere or with one on the land, ground, temporarily neutralize themselves, causing the instantaneous ...

fires are frequent in lodgepole pine communities, they usually remain small, with estimated fire return intervals at Yosemite National Park that are long (relative to most other forest types). Thus,

fire suppression Wildfire suppression is a range of firefighting tactics used to suppress wildfires. Firefighting efforts in wild land areas require different techniques, equipment, and training from the more familiar structure fire fighting found in populated a ...

activities are thought to have had little influence upon species composition, structure, fuels, and natural processes in lodgepole forests. Also, in comparison with

lodgepole pine forests, fire plays a smaller role, and so the needle miner assumes greater importance in lodgepole pine forest population dynamics in the Sierra Nevada. However, Rocky Mountain lodgepole forest dynamics are also heavily influenced by insect outbreaks, primarily bark beetles.

Special-status species

There are at least 1,300

vascular plant Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They al ...

species in the Sierra Nevada, along with numerous

bryophyte The Bryophyta s.l. are a proposed taxonomic division containing three groups of non-vascular land plants (embryophytes): the liverworts, hornworts and mosses. Bryophyta s.s. consists of the mosses only. They are characteristically limited in ...

s and

lichen A lichen ( , ) is a composite organism that arises from algae or cyanobacteria living among filaments of multiple fungi species in a mutualistic relationship.Endangered Species Act The Endangered Species Act of 1973 (ESA or "The Act"; 16 U.S.C. § 1531 et seq.) is the primary law in the United States for protecting imperiled species. Designed to protect critically imperiled species from extinction as a "consequence of ec ...

include: # Three-bracted onion (''Allium tribracteatum''), # Yosemite woolly sunflower (''Eriophyllum nubigenum''), # Congdon's lomatium (''Lomatium congdonii''), # Tiehm's rock-cress (''Arabis tiehmii''), # Slender-stemmed monkeyflower (''Mimulus filicaulis''), and # Bolander's clover (''Trifolium bolanderi''). Although Category 2 was abolished in 1996, ''species of concern'' refers to those species that might be declining or be in need of concentrated conservation actions to prevent decline. Therefore, these six species continue to be evaluated and managed by the National Park Service. Four state-listed rare plant species are considered restricted and limited throughout all or a significant portion of their range, and may represent disjunct populations at the extreme end of their range: # Yosemite onion (''Allium yosemitense''), # Tompkin's sedge (''Carex tompkinsii''), # Congdon's woolly sunflower (''Eriophyllum congdonii''), and # Congdon's lewisia (''Lewisia congdonii''). Endangered or threatened species of animals that occur in the Sierra Nevada include: #

(''Ovis canadensis sierrae''), endangered (2000) #

California condor The California condor (''Gymnogyps californianus'') is a New World vulture and the largest North American land bird. It became extinct in the wild in 1987 when all remaining wild individuals were captured, but has since been reintroduced to nor ...

(''Gymnogyps californianus''), endangered (1967) #

Southwestern willow flycatcher The willow flycatcher (''Empidonax traillii'') is a small insect-eating, neotropical migrant bird of the tyrant flycatcher family. There are four subspecies of the willow flycatcher currently recognized, all of which breed in North America (inc ...

(''Empidonax traillii extimus''), endangered (1995) #

Paiute cutthroat trout Paiute cutthroat trout (''Oncorhynchus clarkii seleniris'') is one of fourteen subspecies of cutthroat trout. Paiute Cutthroat are native only to Silver King Creek, a headwater tributary of the Carson River in the Sierra Nevada, in California. ...

(''Oncorhynchus clarki seleniris''), threatened (1975) #

Lahontan cutthroat trout Lahontan cutthroat trout (''Oncorhynchus clarkii henshawi'') is the largest subspecies of cutthroat trout, and the state fish of Nevada. It is one of three subspecies of cutthroat trout that are listed as federally threatened. Natural history ...

(''Oncorhynchus clarki henshawi''), threatened (1975) #

Owens Tui chub The Owens tui chub (''Siphateles bicolor snyderi'') was described in 1973 as a subspecies of tui chub endemic to the Owens River Basin in Eastern California, United States. The Owens tui chub is distinguished from its closest relative, the La ...

(''Gila bicolor snyderi''), endangered (1985)

Wetlands

Wetlands A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The ...

in the Sierra Nevada occur in

valley A valley is an elongated low area often running between Hill, hills or Mountain, mountains, which will typically contain a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers ...

bottoms throughout the range, and are often hydrologically linked to nearby

lake A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much large ...

s and

river A river is a natural flowing watercourse, usually freshwater, flowing towards an ocean, sea, lake or another river. In some cases, a river flows into the ground and becomes dry at the end of its course without reaching another body of wate ...

s through seasonal

flood A flood is an overflow of water ( or rarely other fluids) that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are an area of study of the discipline hydrol ...

ing and

groundwater Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidate ...

movement.

Meadow A meadow ( ) is an open habitat, or field, vegetated by grasses, herbs, and other non-woody plants. Trees or shrubs may sparsely populate meadows, as long as these areas maintain an open character. Meadows may be naturally occurring or artifi ...

habitats In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

, distributed at elevations from , are generally wetlands, as are the

riparian A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the terrestrial biomes of the Earth. Plant habitats and communities along the river margins and banks ar ...

habitats found on the banks of numerous streams and rivers. The Sierra contains three major types of wetland: #Riverine, #Lacustrine, and #Palustrine Each of these types of wetlands varies in geographic distribution, duration of saturation, vegetation community, and overall

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...

function. All three types of wetlands provide rich habitat for plant and

animal Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...

species, delay and store seasonal floodwaters, minimize downstream

erosion Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...

, and improve

water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...

quality. ''Riverine'' wetlands are found within river and stream channels and are strongly influenced by seasonal runoff patterns. When inundated, riverine wetlands provide habitat for water-tolerant plants such as

willow Willows, also called sallows and osiers, from the genus ''Salix'', comprise around 400 speciesMabberley, D.J. 1997. The Plant Book, Cambridge University Press #2: Cambridge. of typically deciduous trees and shrubs, found primarily on moist s ...

s, and aquatic animals such as

tadpole A tadpole is the larval stage in the biological life cycle of an amphibian. Most tadpoles are fully aquatic, though some species of amphibians have tadpoles that are terrestrial. Tadpoles have some fish-like features that may not be found i ...

s and immature

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

. ''Lacustrine'' wetlands generally occur on river

floodplain A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...

s and along lakeshores and are influenced by seasonal variations in groundwater levels. These wetlands are rare in the mountain range, but support an abundance of warm-water loving plant and animal species. ''Palustrine'' wetlands are typically distinguished from riverine and lacustrine systems by the presence of very dense covers of trees, shrubs, or emergent plants. This wetland type includes wet meadows, densely vegetated riparian habitats, and shallow

pond A pond is an area filled with water, either natural or artificial, that is smaller than a lake. Defining them to be less than in area, less than deep, and with less than 30% emergent vegetation helps in distinguishing their ecology from th ...

s. They provide cover and forage for wildlife traveling between upland and aquatic habitats. Cathedral Lake pond

Since the 1970s the

has made substantial progress toward protecting and restoring wetland habitats. All federal land in the Sierra Nevada complies with a 1990 Presidential Executive Order that mandates '

no net loss "No net loss" is the United States government's overall policy goal regarding wetlands preservation. The goal of the policy is to balance wetland loss due to economic development with wetlands land reclamation, reclamation, mitigation, and ecologic ...

' of wetlands, and requires federal agencies to map and protect all existing wetlands. In 1996 the

United States Fish and Wildlife Service The United States Fish and Wildlife Service (USFWS or FWS) is an agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats. The mission of the agency is "working with othe ...

delineated and classified some of the wetlands of the Sierra Nevada, including all of Yosemite National Park. This was performed through an analysis of

aerial photograph Aerial photography (or airborne imagery) is the taking of photographs from an aircraft or other airborne platforms. When taking motion pictures, it is also known as aerial videography. Platforms for aerial photography include fixed-wing ai ...

s and

topographic map In modern mapping, a topographic map or topographic sheet is a type of map characterized by large- scale detail and quantitative representation of relief features, usually using contour lines (connecting points of equal elevation), but historic ...

s, as a part of the National Wetlands Inventory Web Site (NWI). The NWI maps have not been rigorously ground-truthed and only delineate wetlands larger than in size. The

National Park Service The National Park Service (NPS) is an agency of the United States federal government within the U.S. Department of the Interior that manages all national parks, most national monuments, and other natural, historical, and recreational propertie ...

restores to natural conditions wetlands that have been drained or filled in the past. Most recently in Yosemite Valley, the Cook's Meadow restoration project involved filling old drainage ditches that were draining the meadow and removing an old roadbed that was inhibiting water flow. These actions are currently being monitored with vegetation transects and mapping of surface water to determine how successful the project was in restoring the wetland.

References

External links

Sierra Nevada Forests images at bioimages.vanderbilt.edu

{{DEFAULTSORT:Sierra Nevada Plant communities of California Nearctic realm

Western biotic zones

Foothill Woodland and Chaparral Zone

Lower Montane Forest

Mid-Montane Forest

Upper Montane Forest

Subalpine Forest

Alpine Zone

Eastern biotic zones

Threats

Exotic Plants in Yosemite National Park

Lodgepole needle miner

Special-status species

Wetlands

References

Further reading

External links