|Scientific Name:||Quercus gravesii Sudw.|
|Taxonomic Source(s):||Trehane, P. 2007-2015. The Oak Names Checklist. Available at: http://oaknames.org/search/goodnames.asp. (Accessed: 2 February 2016).|
|Red List Category & Criteria:||Least Concern ver 3.1|
The Chisos Red Oak (Quercus gravesii) is found in moderate densities in Mexico. While it is currently thought to be stable further information should be gathered regarding fragmentation and land-use change to determine the intensity of future threats. With no reports of decline Quercus gravesii is of Least Concern.
|Previously published Red List assessments:|
|Range Description:||Quercus gravesii can be found from 1,200 to 2,300 m Asl in the Chihuahuan Desert region in Mexico and in Texas, USA. It is found throughout the valleys and high elevation areas of the Davis, Glass, Chianti, and Chisos mountains of Big Bend National Park and southward in the majority of the mountains of the north, northwest and center of Coahuila (Sierra del Carmen, La Encantada, del Burro, La Madera, La Gloria, and La Paila) and in isolated pockets distributed in the Sierra de Zapalinamé, southeast of Coahuila (Villarreal 2008, eFloras 2008).|
Native:Mexico (Chihuahua, Coahuila, Nuevo León); United States (Texas)
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||Quercus gravesii is a dominant species in pinyon-juniper-oak and mixed conifer woodland; it is found in moderate densities in mesic woodlands at high elevations on moist sites (Poulos and Camp 2005). Q. gravesii is considered to be semi-endemic both to the state of Coahuila and to the northern Altiplano Mexicano (Torres-Miranda et al. 2011).|
|Current Population Trend:||Unknown|
|Habitat and Ecology:||Quercus gravesii is small to medium deciduous tree that flowers in spring. Q. gravesii is found on medium and high slopes, with north and northwest exposure, in valleys or next to streams in humid canyons, frequently forming dense forests. It is found in the canyons of the Maderas del Carmen in montane or boreal cold-deciduous forest and Madrean Upper Montane Oak Forests (Villarreal 2008).|
|Continuing decline in area, extent and/or quality of habitat:||Yes|
|Use and Trade:||The species is not used.|
Quercus graversii is very sensitive to water inundation. In 1968 the Amistad Dam was built 12 m upstream (northwest) of Del Rio, Texas and less than ten years later the local population of Q. gravesii was severely impacted, if not extirpated, by reservoir inundation (Schmidly and Ditton 1978). In the mountains of Coahuila, where Quercus gravesii is common, livestock is the most common means of sustenance, this has lead to a decline in habitat quality (Delgadillo-Villalobos 2001). The Chihuahuan Desert region has been heavily disturbed by human land use. Overgrazing, water diversion, aquifer “mining," and over collecting of native plants and animals are considered the greatest threats to biodiversity (Hoyt 2002).
Droughts followed by freezing events have caused both rapid tree mortality, as well as lagged tree mortality in the Chisos mountains. Future acute drought events are likely to occur with greater frequency as global mean temperatures rise in the coming decades, and the climate becomes more unpredictable subsequent droughts are likely to cause even greater damage to trees that survived this record drought in Texas, especially if future drought events are coupled with severe freezes (Poulos 2014).
|Conservation Actions:||Much of Quercus graverii's is found in Big Bend National Park in Texas. Q. gravesii is found in 18 botanical gardens worldwide according to BGCI (2016).|
|Citation:||Jerome, D. 2017. Quercus gravesii. The IUCN Red List of Threatened Species 2017: e.T34665A2854060.Downloaded on 20 March 2018.|