The Sierra Madre Occidental pine–oak forests ( es, Bosques de pino-roble de la Sierra Madre Occidental) are a

Temperate broadleaf and mixed forests Temperate broadleaf and mixed forest is a temperate climate terrestrial habitat type defined by the World Wide Fund for Nature, with broadleaf tree ecoregions, and with conifer and broadleaf tree mixed coniferous forest ecoregions. These f ...

ecoregion An ecoregion (ecological region) or ecozone (ecological zone) is an ecologically and geographically defined area that is smaller than a bioregion, which in turn is smaller than a biogeographic realm. Ecoregions cover relatively large areas of ...

of the

Sierra Madre Occidental The Sierra Madre Occidental is a major mountain range system of the North American Cordillera, that runs northwest–southeast through northwestern and western Mexico, and along the Gulf of California. The Sierra Madre is part of the American ...

range from the southwest USA region to the western part of

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

. They are home to a large number of endemic plants and important habitat for wildlife.

Geography

The Sierra Madre Occidental run north to south in western Mexico from the center of the country towards the United States border. The Sierra Madre Occidental is Mexico's largest range, and the ecoregion extends approximately 1,200 kilometers from southern

Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣonak ) is a state in the Southwestern United States. It is the 6th largest and the 14th most populous of the 50 states. Its capital and largest city is Phoenix. Arizona is part of the Fou ...

to northern Jalisco. The highest peak is

Cerro Mohinora Cerro Mohinora is an extinct volcano that is part of the Sierra Madre Occidental mountain range in the Mexican state of Chihuahua (state), Chihuahua located in the municipality of Guadalupe y Calvo. Cerro Mohinora is the highest point in the stat ...

(3300 m) in southern Chihuahua. This is a dramatic landscape of steep mountains cut through with canyons including

Copper Canyon Copper Canyon (Spanish: Barrancas del Cobre) is a group of six distinct canyons in the Sierra Madre Occidental in the southwestern part of the state of Chihuahua in northwestern Mexico that is in size. The canyons were formed by six rivers tha ...

, the deepest in North America. The ecoregion consists of a complex of high-elevation pine–oak forests surrounded at lower elevations by

deserts and xeric shrublands Deserts and xeric shrublands are a biome defined by the World Wide Fund for Nature. Deserts and xeric (ancient Greek xērós, “dry") shrublands form the largest terrestrial biome, covering 19% of Earth's land surface area. Ecoregions in this h ...

and

tropical dry forests The tropical and subtropical dry broadleaf forest is a habitat type defined by the World Wide Fund for Nature and is located at tropical and subtropical latitudes. Though these forests occur in climates that are warm year-round, and may receive ...

, including the

Sonoran Desert The Sonoran Desert ( es, Desierto de Sonora) is a desert in North America and ecoregion that covers the northwestern Mexican states of Sonora, Baja California, and Baja California Sur, as well as part of the southwestern United States (in Ariz ...

to the northwest, the

Chihuahuan Desert The Chihuahuan Desert ( es, Desierto de Chihuahua, ) is a desert ecoregion designation covering parts of northern Mexico and the southwestern United States. It occupies much of far West Texas, the middle to lower Rio Grande Valley and the lo ...

to the northeast and east in Arizona, the Meseta Central matorral and

Central Mexican matorral The Central Mexican matorral is an ecoregion of the deserts and xeric shrublands biome of central Mexico. It is the southernmost ecoregion of the Nearctic realm. Geography The Central Mexican matorral covers an area of on the southern portion o ...

to the southeast, and the

Sinaloan dry forests The Sinaloan dry forests is a tropical dry broadleaf forest ecoregion in western Mexico. It is the northernmost ecoregion of the Neotropical realm. Geography The ecoregion covers an area of approximately The dry forests lie in the coastal pl ...

to the west and southwest. The Sierra Madre Occidental pine–oak forests are one of the Madrean pine–oak forests ecoregions, which are found throughout the Sierra Madre ranges of Mexico and the US Southwest. The northernmost portion of the ecoregion includes forest enclaves on the

Madrean Sky Islands The Madrean Sky Islands are enclaves of Madrean pine–oak woodlands, found at higher elevations in a complex of small mountain ranges in southern and southeastern Arizona, southwestern New Mexico, and northwestern Mexico. The sky islands are s ...

, isolated mountain ranges that rise up out of the desert of southern Arizona and

New Mexico ) , population_demonym = New Mexican ( es, Neomexicano, Neomejicano, Nuevo Mexicano) , seat = Santa Fe , LargestCity = Albuquerque , LargestMetro = Tiguex , OfficialLang = None , Languages = English, Spanish ( New Mexican), Navajo, Ke ...

in the US and northern Sonora in Mexico. The northern Sierra extends from the US-Mexico border through eastern Sonora and western Chihuahua south to the ''barranca'' (gorge) of the Urique River, between 27° and 28° N latitude. The northern Sierra has a mean elevation of 2350 m, and its climate is colder and more

continental Continental may refer to: Places * Continent, the major landmasses of Earth * Continental, Arizona, a small community in Pima County, Arizona, US * Continental, Ohio, a small town in Putnam County, US Arts and entertainment * ''Continental'' ( ...

than the rest of the range. The central Sierra extends from the Urique barranca to the valley of the San Pedro Mezquital River, which cuts through the range from north to south between 22°50’ and 23°25’ N latitude. The central Sierra covers portions of southwestern Chihuahua, southern Durango, and eastern Sinaloa. It has a mean elevation is 2650 m, and includes several peaks above 3200 m. The southern Sierra extends from the San Pedro Mezquital valley into northern Jalisco. It consists of several north–south trending ranges separated by wide canyons where lowland tropical and interior arid vegetation converge. The southern Sierra covers portions of eastern

Nayarit Nayarit (), officially the Free and Sovereign State of Nayarit ( es, Estado Libre y Soberano de Nayarit), is one of the 31 states that, along with Mexico City, comprise the Federal Entities of Mexico. It is divided in 20 municipalities and its ...

, southeastern Durango, western

Zacatecas , image_map = Zacatecas in Mexico (location map scheme).svg , map_caption = State of Zacatecas within Mexico , coordinates = , coor_pinpoint = , coordinates_footnotes = , subdivision_type ...

, northern Jalisco, and western Aguascalientes. The ecoregion also covers the western end of the

Trans-Mexican Volcanic Belt The Trans-Mexican Volcanic Belt ( es, Eje Volcánico Transversal), also known as the Transvolcanic Belt and locally as the (''Snowy Mountain Range''), is an active volcanic belt that covers central-southern Mexico. Several of its highest peaks h ...

in Nayarit, including the Sierra de San Juan.

Climate

The climate of the ecoregion varies with elevation and location. Temperatures are cooler at higher elevations, and the very highest peaks have year-round snow. The western slope of the mountains, which faces toward the

Gulf of California The Gulf of California ( es, Golfo de California), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Bermejo''), is a marginal sea of the Pacific Ocean that separates the Baja C ...

and

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the contin ...

, generally receives higher rainfall and has milder winters than the eastern slope, which faces interior desert plateaus. Mean annual rainfall averages 553 mm. Rainfall is generally higher in the summer, and August is typically the wettest month.

Flora

Species of

pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accepts ...

(''Pinus'') and

oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...

(''Quercus'') are the predominant trees in the ecoregion. Plant communities vary with rainfall, elevation, temperature, and soils, and species can vary between the sky island, northern, central, and southern portions of the range. The most common plant communities are pine forest, pine–oak forest, oak forest, and oak or pine-oak woodland, with smaller areas of mixed conifer forest, mesophytic forest, montane meadow, primary or secondary chaparral, and juniper scrub.Gonzalez-Elizondo, M. S.; Gonzalez-Elizondo, M.; Gonzalez, L. Ruacho; Enriquez, I. L. Lopez; Renteria, F. I . Retana; Flores, J. A. Tena. 2013. "Ecosystems and diversity of the Sierra Madre Occidental." In: Gottfried, Gerald J.; Ffolliott, Peter F.; Gebow, Brooke S.; Eskew, Lane G.; Collins, Loa C. ''Merging science and management in a rapidly changing world: Biodiversity and management of the Madrean Archipelago III and 7th Conference on Research and Resource Management in the Southwestern Deserts; 2012 May 1–5; Tucson, AZ. Proceedings.'' RMRS-P-67. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 204-211. * Pine forests occur from 1600 to 3200 meters elevation under a variety of conditions. The species vary with location and conditions. Arizona pine ('' Pinus arizonica''), Apache pine (''

Pinus engelmannii ''Pinus engelmannii'', commonly known as the Apache pine, is a tree of Northern Mexico, in the Sierra Madre Occidental with its range extending a short distance into the United States in southwestern New Mexico and southeastern Arizona. This pine ...

''), and

Chihuahua pine ''Pinus leiophylla'', commonly known as Chihuahua pine, smooth-leaf pine,''Pinus leiophylla'' was originally described and published in ''Linnaea'' 6:354. 1831. and yellow pine (in Mexico, tlacocote and ocote chino), is a tree with a range prima ...

(''Pinus leiophylla'' var. ''chihuahuana'') are common in the northern and central portions of the range. ''

Pinus durangensis ''Pinus durangensis'', the Durango pine, is a pine tree species endemic to the Sierra Madre Occidental mountain range of north-western Mexico. This species is related to ''Pinus ponderosa'' (Ponderosa pine), and included in the same subsection ...

'' and '' Pinus teocote'' are found from the Sierra of central Chihuahua to the southern end of the range. ''

Pinus lumholtzii ''Pinus lumholtzii'', the Lumholtz's pine or pino triste ('sad pine' in Spanish), is a species of conifer in the family Pinaceae. It is endemic to northwestern Mexico. It is named after Norwegian explorer Carl Sofus Lumholtz. This pine occurs o ...

'' and '' Pinus luzmariae'' are found on thin, rocky, and acidic soils. ''

Pinus cooperi ''Pinus cooperi'', sometimes called Cooper's pine or Cooper pine, is a medium-sized pine which is endemic to Mexico Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country i ...

'' can form single-species stands in mountain valleys with deep soils. ''

Pinus oocarpa ''Pinus oocarpa'' is a species of pine tree native to Mexico and Central America. It is the national tree of Honduras, where it is known as ocote. Common names include ocote chino, pino amarillo, pino avellano, Mexican yellow pine, egg-cone pine ...

, Pinus pseudostrobus, Pinus douglasiana,

Pinus herrerae ''Pinus herrerae'', Herrera's pine, is a species of conifer in the family Pinaceae. It is found only in Mexico Mexico (Spanish language, Spanish: México), officially the United Mexican States, is a List of sovereign states, country in the ...

Pinus devoniana ''Pinus devoniana'' is a species of conifer in the family Pinaceae. It is found in more than 15 states of Mexico - from S. Sinaloa to Chiapas - and Guatemala in montane, relatively open pine or pine-oak forests at altitudes from .Farjon et al. 19 ...

'', and ''

Pinus maximinoi ''Pinus maximinoi'', commonly known as thinleaf pine, is a species of conifer in the family Pinaceae. It is found in El Salvador, Guatemala, Honduras, and Mexico Mexico (Spanish language, Spanish: México), officially the United Mexican St ...

'' are found in more humid areas on the western slope of the mountains. * Mixed conifer forests are found in small patches on humid slopes and canyons in the northern portion of the range from 1900 to 3300 meters elevation. Trees include

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 ...

–

Rocky Mountain Douglas-fir ''Pseudotsuga menziesii'' var. ''glauca'', or Rocky Mountain Douglas-fir, is an evergreen conifer native to the interior mountainous regions of western North America, from central British Columbia and southwest Alberta in Canada southward through ...

(''Pseudotsuga menziesii'' var. ''glauca'') in the north, and

Mexican Douglas-fir ''Pseudotsuga menziesii var. lindleyana'', commonly known as the Mexican Douglas-fir, is a conifer in the genus '' Pseudotsuga'' that is endemic to Mexico. DNA sequence and morphological evidence suggests it is most closely related to Rocky Mou ...

(''Pseudotsuga lindleyana'') extending further south – along with species of pine, fir ('' Abies durangensis'' and ''

Abies concolor ''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 ranges ...

'') and spruce (''

Picea chihuahuana ''Picea chihuahuana'', the Chihuahua spruce, is a medium-sized evergreen tree growing to 25–35 m tall, and with a trunk diameter of up to 1 m. It is native to northwest Mexico, where it occurs in 25 small populations in the Sierra Madre Occide ...

'' and ''

Picea engelmannii ''Picea engelmannii'', with the common names Engelmann spruce, white spruce, mountain spruce, and silver spruce, is a species of spruce native to western North America. It is mostly a high-altitude mountain tree but also appears in watered cany ...

'' var. ''mexicana''), and sometimes oaks. * Pine-oak forests are the most widespread plant community in the ecoregion, occurring from 1250 to 3200 meters elevation. In the northern Sierra, ''Pinus arizonica, Pinus engelmannii'', and ''Pinus leiophylla'' var. ''chihuahuana'' are typically found with '' Quercus rugosa'' and/or ''

Quercus gambelii ''Quercus gambelii'', with the common name Gambel oak, is a deciduous small tree or large shrub that is widespread in the foothills and lower mountains of western North America. It is also regionally called scrub oak, oak brush, and white oak. ...

'', and with other oaks in semi-dry temperate zones. On thin soils and rocky slopes, ''Pinus lumholtzii'' grows with ''

Quercus crassifolia ''Quercus crassifolia'' is a species of oak. It is widespread in Mexico from Sonora and Chihuahua to Veracruz Veracruz (), formally Veracruz de Ignacio de la Llave (), officially the Free and Sovereign State of Veracruz de Ignacio de la Ll ...

'', and with '' Quercus radiata'' in the southern Sierra, and the shrubs ''

Arctostaphylos pungens ''Arctostaphylos pungens'', with the common name pointleaf manzanita, is a species of manzanita. It is native to the Southwestern United States and to northern and central Mexico, where it grows in chaparral and woodland habitats, and on desert ...

Juniperus deppeana ''Juniperus deppeana'' (alligator juniper or checkerbark juniper) is a small to medium-sized tree reaching in height. It is native to central and northern Mexico and the southwestern United States. Description The tree reaches , rarely , in h ...

'', and ''

Juniperus durangensis ''Juniperus durangensis'' is a species of conifer in the family Cupressaceae. It is endemism, endemic to Mexico, in the states of Aguascalientes, Chihuahua (state), Chihuahua, Durango, Jalisco, Sonora, Zacatecas. References Current IUCN Red Li ...

''. Mixed forests of ''

Quercus jonesii ''Quercus jonesii'' is a species of oak tree native to Mexico. It is commonly known as palo manzano. It is placed in ''Quercus'' section ''Lobatae''. Description ''Quercus jonesii'' is small tree which typically reaches in height. Distributi ...

, Pinus lumholtzii,

Quercus resinosa ''Quercus resinosa'' is a species of oak. It is native to central and western Mexico, from Nayarit south to Michoacán and east as far as San Luis Potosí. It is placed in ''Quercus'' section ''Quercus''. Description ''Quercus resinosa'' is a ...

, Quercus crassifolia'', and ''Quercus viminea'' grow between 1800 and 2300 meters elevation. On the lower slopes of the western Sierra, ''

'' grows with ''

, Pinus douglasiana, Quercus viminea, Quercus gentryi'', and other species. In the southern Sierra of Durango, Jalisco, and Zacatecas, ''Pinus oocarpa, Quercus resinosa'', and '' Quercus praineana'' occur together at lower elevations. * Oak forests are typically found at lower elevations in the western Sierra, occurring in pockets among the dry forests as low as 350 meters elevation, and in some places extending up to 2900 meters elevation. '' Quercus fulva, Quercus mcvaughii'', and '' Quercus scytophylla'' grow together at lower elevations, and higher-elevation forests of ''

Quercus sideroxyla ''Quercus sideroxyla'', called the Santa Rosa oak and encino colorado, is a species of oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of o ...

'' and '' Quercus rugosa'' are found up to 2900 meters. ''Quercus viminea'' or '' Quercus castanea'' are common oak forest species in the northern Sierra, joined by '' Quercus diversifolia'' and ''Q. gentryi''. '' Quercus albocincta'' occurs at lower elevations.

Mesophytic Mesophytes are terrestrial plants which are neither adapted to particularly dry nor particularly wet environments. An example of a mesophytic habitat would be a rural temperate meadow, which might contain goldenrod, clover, oxeye daisy, and ''Rosa m ...

oak forests of '' Quercus candicans, Quercus crassifolia, Quercus diversifolia'', and ''Quercus scytophylla'' are found in humid areas, joined by species of '' Clethra'' and by '' Quercus subspathulata'' at low elevations. * Oak and pine–oak woodlands, with an open tree canopy, are found in the drier east and north, in the transition to the lower-elevation dry grasslands and desert plateaus. In the northern Sierra of northern Sonora and Chihuahua, blue oak (''Q. oblongifolia''), Emory oak (''Q. emoryi'') or Arizona oak (''Q. arizonica'') grow in pure stands, or mixed stands with

Mexican pinyon ''Pinus cembroides'', also known as pinyon pine, Mexican pinyon, Mexican nut pine, and Mexican stone pine, is a pine in the pinyon pine group, native to western North America. It grows in areas with low levels of rainfall and its range extends so ...

(''Pinus cembroides''), ''Pinus leiophylla'' var. ''chihuahuana'', madroño (''

Arbutus arizonica ''Arbutus arizonica'', commonly known as Arizona madrone, is a tree species in the heath family that is native to the southwestern United States and northwestern Mexico. Its range extends along the Sierra Madre Occidental cordillera from the M ...

''), ''

Quercus grisea ''Quercus grisea'', commonly known as the gray oak, shin oak or scrub oak, is a North American species deciduous or evergreen shrub or medium-sized tree in the white oak group. It is native to the mountains of the southwestern United States and ...

'', and ''

Quercus chihuahuensis ''Quercus chihuahuensis'', the Chihuahua oak, is a species of oak in the beech family.Trelease, Memoirs of the National Academy of Science vol 20. 1924. It is native to the region from extreme western Texas west to Sonora, Mexico, and south to ...

''. In the eastern foothills of the Sierra woodlands of ''P. cembroides'' and ''Q. grisea'' or ''Q. eduardii'' are common. ''P. leiophylla'' var. ''chihuahuana, P. engelmannii'', and '' Q. durifolia'' commonly occur in the eastern Sierra at the transition between lower-elevation woodlands and higher-elevation forests. ''Juniperus deppeana'' is a common woodland shrub, and the woodlands are interspersed with areas of primary or secondary montane chaparral, characterized by woody shrubs. *

forests are found in small areas of the western Sierra with moister microclimates from 1000 to 2350 meters elevation. Characteristic trees include '' Magnolia tarahumara,

Ostrya virginiana ''Ostrya virginiana'', the American hophornbeam, is a species of '' Ostrya'' native to eastern North America, from Nova Scotia west to southern Manitoba and eastern Wyoming, southeast to northern Florida and southwest to eastern Texas. Population ...

, Tilia mexicana, Cedrela odorata'', and ''Styrax argenteus'' var. ''ramirezii'', together with trees in the laurel family ( Lauraceae) like '' Persea liebmannii'' and species of ''

Nectandra ''Nectandra'' is a genus of plant in the family Lauraceae. They are primarily Neotropical, with '' Nectandra coriacea'' being the only species reaching the southernmost United States. They have fruit with various medical effects. Sweetwood is a c ...

'' and ''

Litsea ''Litsea'' is a genus of evergreen or deciduous trees or shrubs belonging to the laurel family, Lauraceae. The genus includes a large number of accepted species in tropical and subtropical areas of North America and Asia. Characteristics They a ...

'', along with the oaks ''Q. candicans, Q. crassifolia, Q. castanea, Q. rugosa, Q. scytophylla'', and ''Q. splendens''. Characteristic shrubs and small trees include ''

Arbutus xalapensis ''Arbutus xalapensis'', commonly known as the Texas madrone, Amazaquitl, or Texas madroño, is a species of flowering plant in the heather family. It is native to Central America, the southwestern United States (western Texas and New Mexico), an ...

, Garrya laurifolia, Cornus disciflora, Cornus excelsa, Peltostigma pteleoides,

Ilex quercetorum ''Ilex quercetorum'' is a species of plant in the family Aquifoliaceae. It is found in Guatemala and Mexico. It is threatened by habitat loss. Description ''Ilex quercetorum'' is tree which grows from 6 to 15 meters tall, with a trunk up to 25 ...

, Ilex tolucana, Cleyera integrifolia'', species of ''Clethra'' and ''

Prunus ''Prunus'' is a genus of trees and shrubs, which includes (among many others) the fruits plums, Cherry, cherries, peaches, Peach#Nectarine, nectarines, apricots, and almonds. Native to the North American temperate regions, the neotropics of Sou ...

'', and the palm '' Brahea aculeata''. Conifers in the mesophytic forests can include ''Pinus maximinoi, P. devoniana, P. douglasiana, P. herrerae, P. strobiformis, P. durangensis, Abies durangensis'', and/or ''Pseudotsuga lindleyana''. * Montane meadow, which includes many endemic species, is found in small areas between 2300 and 3100 meters elevation. The pines and oaks are especially important as there are so many different species of each including a number of endemics. Predominant conifers among the 27 species found here include

Apache pine ''Pinus engelmannii'', commonly known as the Apache pine, is a tree of Northern Mexico, in the Sierra Madre Occidental with its range extending a short distance into the United States in southwestern New Mexico and southeastern Arizona. This pine ...

(''Pinus engelmannii''),

(''Pinus leiophylla''),

(''Pinus cembroides''), Lumholtz's pine (''Pinus lumholtzii''), Yécora pine (''Pinus pseudostrobus''),

(''Pseudotsuga menziesii'' subsp. ''glauca''), and

(''Pseudotsuga lindleyana''). Oaks (''Quercus'') are the dominant broadleaf trees, with 21 different species found including '' Quercus albocincta'', Arizona oak (''Q. arizonica'') '' Q. carmenensis'', '' Q. chihuahuensis'', '' Q. cordifolia'', '' Q. durifolia'', Emory oak ('' Q. emoryi''), '' Q. grisea'', Mexican blue oak ('' Q. oblongifolia''), '' Q. santaclarensis'', and '' Q. tarahumara''. Madroño (''

'' and '' A. arizonica'') is found in association with oaks. '' Q. carmenensis'' and '' Q. deliquescens'' are two oaks endemic to the sky islands portion of the ecoregion.

Fauna

The forests are home to more than 300 species of birds, including

golden eagle The golden eagle (''Aquila chrysaetos'') is a bird of prey living in the Northern Hemisphere. It is the most widely distributed species of eagle. Like all eagles, it belongs to the family Accipitridae. They are one of the best-known birds of ...

(''Aquila chrysaetos'')

military macaw The military macaw (''Ara militaris'') is a large parrot and a medium-sized macaw that gets its name from its predominantly green plumage resembling a military parade uniform. It is native to forests of Mexico and South America and though conside ...

(''Ara militaris''),

acorn woodpecker The acorn woodpecker (''Melanerpes formicivorus'') is a medium-sized woodpecker, long, with an average weight of . Taxonomy The acorn woodpecker was formally described in 1827 by the English naturalist William John Swainson under the binomi ...

(''Melanerpes formicivorus''), and Mexican spotted owl (''Strix occidentalis lucida''). Endemic species include the tufted jay (''Cyanocorax dickeyi''), green-striped brushfinch (''Arremon virenticeps''), and

thick-billed parrot The thick-billed parrot (''Rhynchopsitta pachyrhyncha'') is a medium-sized parrot endemic to Mexico that formerly ranged into the southwestern United States. Its position in parrot phylogeny is the subject of ongoing discussion; it is sometimes ...

(''Rhynchopsitta pachyrhyncha'') which is now endangered from trapping for collections. The

eared quetzal The eared quetzal (''Euptilotis neoxenus''), also known as the eared trogon, is a near passerine bird in the trogon family, Trogonidae. It is native to streamside pine-oak forests and canyons in the Sierra Madre Occidental of Mexico south to ...

(''Euptilptis neoxenus'') is a near-endemic, ranging from the sky islands of southern Arizona through the Sierra Madre Occidental to the western

Trans-Mexican Volcanic Belt pine–oak forests The Trans-Mexican Volcanic Belt pine–oak forests is a subtropical coniferous forest ecoregion of the Trans-Mexican Volcanic Belt of central Mexico. Setting The Trans-Mexican Volcanic Belt pine–oak forests occupy an area of , extending from ...

. The

imperial woodpecker The imperial woodpecker (''Campephilus imperialis'') is a woodpecker species endemic to Mexico. If it is not extinct, it is the world's largest woodpecker species, at long. Researchers have discovered that the imperial woodpecker has slow climb ...

(''Campephilus imperialis''), once native to the mountains, is now thought to be extinct. Mammals include the Coues deer (''Odocoileus virginianus couesi''), American black bear (''Ursus americanus''), cougar (''Puma concolor''), and jaguar (''Panthera onca''). The

Mexican grizzly bear The Mexican grizzly bear (''Ursus arctos horribilis'', formerly ''Ursus arctos nelsoni'') is an extinct population of the grizzly bear in Mexico. The holotype was shot by H. A. Cluff at Colonia Garcia, Chihuahua in 1899. The extinct California g ...

(''Ursus arctos horribilis'') is now thought to be extinct. The

Mexican wolf The Mexican wolf (''Canis lupus baileyi''), also known as the lobo,; nah, Cuetlāchcoyōtl is a subspecies of gray wolf native to southeastern Arizona and southern New Mexico in the United States, and northern Mexico; it also previously rang ...

(''Canis lupus baileyi'') was once common in the mountains but by the late 20th century was thought to be extinct in the wild. They were saved from extinction by a joint US-Mexican captive breeding program. The wolves were reintroduced to the wild in the US in 1998 and Mexico in 2011, and now inhabit portions of the ecoregion in Arizona, New Mexico, Chihuahua, and Sonora.U.S. Fish and Wildlife Service (2017). "Mexican Wolf Recovery Plan: First Revision". Southwest Region (Region 2), U.S. Fish and Wildlife Service, November 201

/ref> The many reptiles include the rock rattlesnake (''

Crotalus lepidus ''Crotalus lepidus'' is a venomous pit viper species found in the southwestern United States and northern central Mexico. Four subspecies are currently recognized, including the nominate subspecies described here. Description This small spe ...

''), twin-spotted rattlesnake (''

Crotalus pricei :''Common names: twin-spotted rattlesnake,Campbell JA, Lamar WW (2004). ''The Venomous Reptiles of the Western Hemisphere''. Ithaca and London: Comstock Publishing Associates. 870 pp., 1500 plates. . western twin-spotted rattlesnake, Klauber LM ...

''), ridgenose rattlesnake (''

Crotalus willardi :''Common names: ridge-nosed rattlesnake, Willard's rattlesnake, Willard's rattler Wright AH, Wright AA (1957). ''Handbook of Snakes of the United States and Canada''. Ithaca and London: Comstock Publishing Associates. 1,105 pp. (in 2 volumes). ...

''), and some

spiny lizard Spiny lizards is a common name for the genus ''Sceloporus'' in the family Phrynosomatidae. The genus is endemic to North America, with various species ranging from New York, to Washington, and one occurring as far south as northern Panama. Köh ...

s (''Sceloporus clarki'', '' S. jarrovii'', ''S. scalaris'' and ''S. virgatus''). Finally, the mountains are an important stage in the migration route of

monarch butterflies The monarch butterfly or simply monarch (''Danaus plexippus'') is a milkweed butterfly (subfamily Danainae) in the family Nymphalidae. Other common names, depending on region, include milkweed, common tiger, wanderer, and black-veined brown. ...

Conservation and threats

The pine forests have been cleared by the logging and paper industries since the 1800s and only a very small percentage of original forest remains. This removal of habitat has resulted in the presumed extinction of the

, once the largest woodpecker on earth. The increase of global warming is expected to have some devastating effects on the pine trees located in the Sierra Madre Occidental. The predicted outcome of global warming in this subtropical region, is the reduction of plant/animal productivity and growth. Another effect would be that the increase of climate warming would also lead to tree mortality affecting not only the pine trees located in the Sierra Madre Occidental but also other pine trees in the surrounding areas.

Protected areas

13.5% of the ecoregion is in protected areas. Protected areas in Mexico include Cascada de Basaseachi National Park,

Cumbres de Majalca National Park The Cumbres de Majalca National Park is a national park in the Mexican state of Chihuahua located 88 km northwest of the city of Chihuahua. The park showcases extraordinary rock formations that have been shaped by wind and water erosion. T ...

La Michilía Biosphere Reserve La Michilía Biosphere Reserve is a protected area in northwestern Mexico. It is located in the Sierra Madre Occidental range in southern Durango state. Geography The reserve covers an area of 350 km2. The reserve spans two ranges, the Sierra Mic ...

, Sierra de San Juan Biosphere Reserve,

Bavispe Flora and Fauna Protection Area Bavispe Flora and Fauna Protection Area is a protected area in the state of Sonora in northwestern Mexico. The protected area consists of five separate areas, with a combined area of 2009 km2, which covers portions of three ranges in northe ...

, Sierra de Álamos–Río Cuchujaqui Flora and Fauna Protection Area,

Campo Verde Flora and Fauna Protection Area Campo Verde Flora and Fauna Protection Area is a protected area in northern Mexico. It covers an area of 1080.67 km2 in northwestern Chihuahua, on the border with Sinaloa. It is at the eastern edge of the Sierra Madre Occidental, where it meets ...

Papigochic Flora and Fauna Protection Area Papigochic Flora and Fauna Protection Area is a protected area in Chihuahua state of Mexico. It covers an area of 2227.64 km2 in the eastern Sierra Madre Occidental. To the northwest it adjoins Tutuaca Flora and Fauna Protection Area. Flora an ...

, Sierra de Órganos National Park,

Tutuaca Flora and Fauna Protection Area Tutuaca Flora and Fauna Protection Area is a protected area in the states of Chihuahua and Sonora in northwestern Mexico. It lies in the Sierra Madre Occidental, and covers an area of 4369.86 km2. To the southeast it adjoins Papigochic Flor ...

, and Cerro Mohinora Flora and Fauna Protection Area. The Cuenca Alimentadora del Distrito Nacional de Riego 043 Estado de Nayarit, established in 1949 to protect forests and watersheds, is now a natural resources protection area which conserves much of the southern Sierra. There are a number of protected areas of Madrean sky islands in Arizona which are part of the ecoregion although not the Sierra Madre Occidental themselves, including

Chiricahua National Monument Chiricahua National Monument is a unit of the National Park System located in the Chiricahua Mountains of southeastern Arizona. The monument was established on April 18, 1924, to protect its extensive hoodoos and balancing rocks. The Faraway Ra ...

Galiuro Wilderness Galiuro Wilderness is a wilderness area encompassing the mid to upper slopes of the Galiuro Mountains. It is located within the Safford Ranger District of the Coronado National Forest in the United States, American state of Arizona.Saguaro National Park Saguaro National Park is an American national park in Pima County, southeastern Arizona. The park consists of two separate areas—the Tucson Mountain District (TMD) about west of the city of Tucson and the Rincon Mountain District (RMD) about ...

, the

Huachuca Mountains The Huachuca Mountains are part of the Sierra Vista Ranger District of the Coronado National Forest in Cochise County in southeastern Arizona, approximately south-southeast of Tucson and southwest of the city of Sierra Vista. Included in this a ...

Pusch Ridge Wilderness Area Pusch Ridge Wilderness Area is a 56,430 acre (228.36 km2) wilderness area. It is located within the Coronado National Forest in the Santa Catalina Mountains north of Tucson, Arizona, United States. Established in 1978, the area varies great ...

, the

Santa Teresa Mountains The Santa Teresa Mountains are a mountain range located within the Coronado National Forest and partly within the San Carlos Apache Indian Reservation, in western Graham County, Arizona Arizona ( ; nv, Hoozdo Hahoodzo ; ood, Alĭ ṣona ...

and the Pajarito Mountains. In 2000 CONABIO, a Mexico's wildlife conservation agency, identified priority areas for conservation, based on exceptional biodiversity and the integrity of the remaining habitat. Priorties in the northern Sierra include Cananea–San Pedro, Sierras los Ajos–Buenos Aires–La Púrica, Cañada Mazocahui, Sierras el Maviro–Santo Niño,

Bavispe Bavispe is a small town and a municipality in the northeast part of the Mexican state of Sonora. Location The municipality is located in the northeast of the state at . The elevation of the administrative seat is 902 meters above sea level. It ...

El Tigre El Tigre () is a city of Venezuela located in the state Anzoátegui. It is the capital of Simón Rodríguez Municipality and it is located south in Anzoategui state, equidistant from the Orinoco River and the Caribbean Sea in the Guanipa Mesa a ...

, Babícora, Yécora–El Reparo, Bassaseachic, and Lago los Mexicanos. In the central Sierra, priority areas include Alta Tarahumara–Barrancas, Cañón de Chínipas, Sierra Álamos–El Cuchujaqui, Barranca Sinforosa, Rocahuachi–Nanaruchi, Río Humaya, Guadalupe y Calvo–Mohinora, San Juan de Camarones, Pueblo Nuevo, and Santiaguillo–Promontorio. Priority areas in the southern Sierra include Guacamayita, the Río Jesús María basin (cuenca del Río Jesús María), Sierra los Huicholes,

Sierra de Morones The Sierra de Morones is a mountain range in west-central Mexico. Geography The Sierra de Morones extends north and south through the state of Zacatecas. The Sierra, together with the Sierra Fría to the east and the Sierra los Huicholes to th ...

, and Sierra Fría."Regiones Terrestres Prioritarias de México". CONABIO. Accessed 12 September 2021

/ref>

References

* González-Cásares, Marcos, Marín Pompa-García, and J Camarero. "Differences in Climate-growth Relationship Indicate Diverse Drought Tolerances Among Five Pine Species Coexisting in Northwestern Mexico." ''Trees: Structure & Function'', 31.2 (2017): 531–544. * González-Elizondo, Martha, Enrique Jurado, José Návar, M. Socorro González-Elizondo, José Villanueva, Oscar Aguirre, and Javier Jiménez. "Tree-rings and Climate Relationships for Douglas-fir Chronologies from the Sierra Madre Occidental, Mexico: A 1681–2001 Rain Reconstruction." ''Forest Ecology & Management'', 213.1-3 (2005): 39–53.

External links

*
Madrean pine-oak woodlands (Conservation International)
{{DEFAULTSORT:Sierra Madre Occidental pine-oak forests Pine-oak forests Ecoregions of Mexico Ecoregions of the United States * * Forests of Mexico Forests of Arizona Forests of New Mexico * Montane forests Natural history of Chihuahua (state) Natural history of Durango Natural history of Jalisco Natural history of Sonora Natural history of Zacatecas Nearctic ecoregions Temperate broadleaf and mixed forests Tropical and subtropical coniferous forests of the United States

Geography

Climate

Flora

Fauna

Conservation and threats

Protected areas

See also

References

External links