Articles on this page are available in 1 other language: Spanish (9) (learn more)

Physical Description

Type Information

Isotype for Picea chihuahuana Martínez
Catalog Number: US 1823701
Collection: Smithsonian Institution, National Museum of Natural History, Department of Botany
Verification Degree: Original publication and alleged type specimen examined
Preparation: Pressed specimen
Collector(s): M. Martínez M.
Locality: Tucheachic., Chihuahua, Mexico, North America
Elevation (m): 2400 to 2400
  • Isotype: Martínez M., M. 1942. Anales Inst. Biol. Univ. Nac. Mexico. 13: 31.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Botany

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Ecology

Habitat

Habitat and Ecology

Habitat and Ecology
Picea chihuahuana occurs in scattered relict populations on N-facing high mountain sides, often in canyons, at elevations between 2150 m and 3200(-3400) m a.s.l. It grows in poor, barren, but always moist mountain soils of alluvial origin, usually near permanent streams, but in the Sierra Madre Oriental also on calcareous lithosols. The climate is cool and moist, with annual precipitation between 800 mm and 1300 mm, mostly as summer showers, but in the western part of the range also in winter; snow only at the highest elevations. It is mainly associated with Pinus strobiformis, P. pseudostrobus, P. ayacahuite. Some other pines, Pseudotsuga menziesii var. glauca, Abies durangensis, A. vejarii (in Sierra Madre Oriental), Cupressus lindleyi (= C. lusitanica Mill.), and C. arizonica may also occur. Broad-leaved trees are e.g. Quercus castanea, Q. rugosa and Prunus serotina.

Systems
  • Terrestrial
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Molecular Biology and Genetics

Molecular Biology

Barcode data: Picea chihuahuana

The following is a representative barcode sequence, the centroid of all available sequences for this species.


Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Statistics of barcoding coverage: Picea chihuahuana

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 5
Specimens with Barcodes: 10
Species With Barcodes: 1
Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Conservation

Conservation Status

IUCN Red List Assessment


Red List Category
EN
Endangered

Red List Criteria
B2ab(ii,iii,v)

Version
3.1

Year Assessed
2013

Assessor/s
Thomas, P. & Farjon, A.

Reviewer/s
Perez de la Rosa, J.

Contributor/s

Justification
The area of occupancy of 275 km2 is well within the threshold for Endangered, subpopulations are severely fragmented and there is an ongoing decline due to fires, logging and grazing. On this basis alone Picea chihuahuana meets the B2 critieria for Endangered. The number of mature individuals is uncertain but could be less than 2,500.

History
  • 1998
    Endangered
  • 1997
    Vulnerable
    (Walter and Gillett 1998)
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Population

Population
The population of mature individuals may not exceed 2500 to 3000 mature trees with a total population including seedlings and saplinds estimated to be about 43000 in 38 stands (Jaramillo et al. 2006). Subpopulations are usually smaller than 350 trees, show significant levels of inbreeding and a lack of geneflow (Ledig el. 1997)

Population Trend
Decreasing
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Threats

Major Threats
The subpopulations of P. chihuahuana are widely scattered and very small, with a total of fewer than 100 to about 350 mature trees in each of the ca. 25 localities known. It is possible that other relict populations are hidden among the pine forests of the Sierra Madres of northern Mexico, yet its total area of occupancy (AOO) is unlikely to exceed 500 km² and is by all accounts much less than this (here calculated to be 275 km² with a 5x5 km grid); in addition it is severely fragmented. Unaware of its botanical significance, loggers have exploited this species where they have encountered it, reducing the number of mature individuals. In many stands natural regeneration has been observed to be poor or at best slow. Awareness of its significance for conservation of biodiversity is now increasing, but few subpopulations are as yet under any effective protection.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Management

Conservation Actions

Conservation Actions
More subpopulations or localities with this species are in need of being put into protected areas, as only a few are at present within such areas. According to the Secretaría de Medio Ambiente y Recursos Naturales (2010), Norma Oficial Mexicana, this species is in danger of extinction.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Wikipedia

Picea chihuahuana

Chihuahua Spruce (Picea chihuahuana) 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 Occidental mountains in Chihuahua and Durango. It grows at moderate altitudes from 2300-3200 m, growing along streamsides in mountain valleys, where moisture levels in the soil are greater than the otherwise low rainfall in the area would suggest.

The bark is thin and scaly, flaking off in small circular plates 5-10 cm across. The crown is conic, with widely spaced branches with drooping branchlets. The shoots are stout, pale buff-brown, glabrous, and with prominent pulvini. The leaves are needle-like, 17-23 mm long, stout, rhombic in cross-section, bright glaucous blue-green with conspicuous lines of stomata; the tip is viciously sharp.

The cones are pendulous, broad cylindrical, 7-12 cm long and 3 cm broad when closed, opening to 4-5 cm broad. They have stiff, bluntly rounded scales 1.5-2 cm broad, and are green, maturing pale brown 6–8 months after pollination. The seeds are black, 4 mm long, with a 10-13 mm long pale brown wing.

Chihuahua Spruce was only discovered in 1942 by the Mexican botanist Maximino Martínez, and is endangered with just 25 small populations, none comprising more than a few hundred trees. It is related to Martinez Spruce from northeast Mexico, but differs in the shorter, blue-green leaves, and the smaller, narrower cones with smaller scales. No other related spruces are found in North America, with its next-closest relatives in eastern Asia.

It is a very attractive tree and is starting to be planted as an ornamental tree in botanical gardens, particularly valued in warm areas as it is one of the most heat-tolerant of all spruces, more tolerant of summer heat than Blue Spruce, which it resembles in foliage.

References[edit]

Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

Source: Wikipedia

Unreviewed

Article rating from 0 people

Average rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!