View source for Madrean pine–oak woodlands

{{Short description|Subtropical woodlands in the US and Mexico}}
[[File:Madrean Pine-Oak Woodlands Hotspot 2005 Print.tif|thumb|325px|Distribution of Madrean pine–oak woodlands.]]
The '''Madrean pine–oak woodlands''' are [[subtropical]] [[woodland]]s found in the mountains of [[Mexico]] and the [[southwestern United States]]. They are a [[biogeography|biogeographic region]] of the [[tropical and subtropical coniferous forests]] and [[temperate broadleaf and mixed forests]] [[biomes]], located in [[North America]].
[[Conservation International]] estimates the woodlands' original area at 461,265&nbsp;km<sup>2</sup>. The woodlands are surrounded at lower elevations by other [[ecoregion]]s, mostly tropical and subtropical [[deserts and xeric shrublands]], forests, and [[grassland]]s. Woodland areas were isolated from one another and from the pine–oak woodlands of the Sierra Madre Occidental to the south by the warming and drying of the climate since the 1st century CE.
==Distribution==
===Mexico===
[[File:Pino-encino.jpg|right|thumb|300px|Pines and oaks coexist in the Nealtican [[Malpaís (landform)|Malpaís]] ([[Tianguismanalco]], [[Puebla]])]]
The Madrean pine–oak woodlands are found at higher elevations in Mexico's major mountain ranges, the [[Sierra Madre Occidental]], the [[Sierra Madre Oriental]], the [[Trans-Mexican Volcanic Belt]], the [[Sierra Madre del Sur]], the [[Sierra Madre de Oaxaca]], the [[Peninsular Ranges]] of the [[Baja California Peninsula]].
===Madrean sky islands===
There are also approximately 27 enclaves in southern [[Arizona]] and [[New Mexico]] and in western [[Texas]], where they are known as the "[[Madrean sky islands]]".  The major Madrean "sky island" ranges in Arizona are the [[Dragoon Mountains]], [[Chiricahua Mountains]], [[Pinaleno Mountains|Pinaleño Mountains]], [[Santa Catalina Mountains]], [[Rincon Mountains]], [[Santa Rita Mountains]], and Tumacacori Highlands. In New Mexico, the [[Sacramento Mountains (New Mexico)|Sacramento Mountains]] and [[Guadalupe Mountains]], which extend into Texas, as well as the [[Davis Mountains]] and [[Chisos Mountains]], are also forested Madrean sky islands.
[[File:Bosque Cajonos.JPG|right|thumb|300px|Madrean pine–oak woodlands in the [[Sierra Madre de Oaxaca]], México.]]
==Flora==
The pine–oak woodlands are composed of stands of [[oak]] (''Quercus''), [[pine]] (''Pinus''), [[douglas-fir]] (''Pseudotsuga'') and [[fir]] (''Abies''). The trees generally occur in mixed stands, though monospecific stands are sometimes found.
The pine–oak woodlands are home to one-quarter of Mexico's plant species, and Mexico is home to 44 of the 110 species of pine and over 135 species of oak, over 28% of the world's oak species.
Plant species descended from Madro-Tertiary flora, Madrean ancestor species, are an important element of the [[California chaparral and woodlands]] ecoregion.
==Madrean pine–oak woodlands ecoregions==
The [[World Wildlife Fund]] recognizes several distinct Madrean pine–oak woodlands ecoregions, based on geographic distribution and species mix.<br/>
They include:
* [[Sierra Juárez and San Pedro Mártir pine–oak forests]] of the [[Sierra de Juárez]] and [[Sierra de San Pedro Mártir]] ranges of the northern [[Baja California peninsula]].
* [[Sierra de la Laguna pine–oak forests]] of the [[Sierra de la Laguna]] in the southern Baja California peninsula.
* [[Sierra Madre Occidental pine–oak forests]] extend along the Sierra Madre Occidental range from the [[Rio Grande de Santiago]] in Mexico's [[Jalisco]] state through [[Nayarit]], [[Sinaloa]], [[Durango]], [[Sonora]], and [[Chihuahua (state)|Chihuahua]], and include the Madrean Sky Islands of Arizona and New Mexico.
* [[Sierra Madre Oriental pine–oak forests]] extend along the Sierra Madre Oriental ranges of Texas and Mexico, from mountaintop enclaves in west [[Texas]] through [[Coahuila]], [[Tamaulipas]], [[Nuevo León]], [[San Luis Potosí]], [[Querétaro]] and [[Guanajuato]].
* [[Trans-Mexican Volcanic Belt pine–oak forests]]
* [[Sierra Madre del Sur pine–oak forests]]
* [[Sierra Madre de Oaxaca pine–oak forests]]
==See also==
* [[Conifers of Mexico]]
*[[:Category:Ecoregions of Mexico|Ecoregions of Mexico]]
==External links==
*[https://web.archive.org/web/20050306014436/http://www.biodiversityhotspots.org/xp/Hotspots/pine_oak/ Madrean Pine-Oak Woodlands (Conservation International)]
*{{WWF ecoregion|id=na0526|name=Sierra Juarez and San Pedro Martir pine-oak forests}}
*{{WWF ecoregion|id=nt0307|name=Sierra de la Laguna pine-oak forests}}
*{{WWF ecoregion|name=Sierra Madre Occidental pine-oak woodlands|id=na0302}}
*{{WWF ecoregion|name=Sierra Madre Oriental pine-oak forests|id=na0303}}
*[http://www.cas.vanderbilt.edu/bioimages/ecoregions/50302frame.htm Sierra Madre Occidental Pine-Oak Forests images at bioimages.vanderbilt.edu] ([http://www.cas.vanderbilt.edu/bioimages/ecoregions/50302.htm slow modem version])
*{{WWF ecoregion|id=nt0310|name=Trans-Mexican Volcanic Belt pine-oak forests}}
*{{WWF ecoregion|id=nt0309|name=Sierra Madre del Sur pine-oak forests}}
*{{WWF ecoregion|id=nt0308|name=Sierra Madre de Oaxaca pine-oak forests}}
[[Category:Tropical and subtropical coniferous forests]]
[[Category:Temperate broadleaf and mixed forests]]
[[Category:Ecoregions of Mexico]]
[[Category:Madrean Region|*]]
[[Category:Madrean Sky Islands mountain ranges|*]]
[[Category:Flora of Mexico|*]]
[[Category:Forests of Mexico]]
[[Category:Montane forests]]
[[Category:Flora of Baja California|*]]
[[Category:Flora of Central Mexico|*]]
[[Category:Flora of Northeastern Mexico|*]]
[[Category:Flora of Northwestern Mexico|*]]
[[Category:Flora of Southwestern Mexico|*]]
[[Category:Flora of Southern Mexico|*]]
[[Category:Sierra Madre de Chiapas]]
[[Category:Sierra Madre de Oaxaca]]
[[Category:Sierra Madre del Sur]]
[[Category:Sierra Madre Occidental]]
[[Category:Sierra Madre Oriental]]
[[Category:Trans-Mexican Volcanic Belt]]
[[Category:Natural history of the Peninsular Ranges|.]]
[[Category:Tropical and subtropical coniferous forests of the United States]]<!---sky islands--->
[[Category:Ecoregions of the United States]]<!---sky islands--->
[[Category:Flora of Arizona|*]]<!---sky islands--->
[[Category:Flora of New Mexico|*]]<!---sky islands--->
[[Category:Nearctic ecoregions]]
[[Category:Neotropical ecoregions]]