Habitat and Ecology
Trees grow on the summits of mountains or in the bottoms of valleys and gorges, where precipitation is estimated to be 30 mm per year (Dubief 1963). Sixty-eight percent of the trees are located in Wadi beds, 22% in rock (palaeozoic sandstone) fissures and 8% on ridges, there are very few associated species.
Grows in a temperate semi-arid to dry Mediterranean climate with periods of drought and snow. All stands occur on steep-sided mountain slopes in an altitudinal range of between 1,000 and 2,200 m. The substrate is shale or schist and crystalline soils of granites and occasionally of calcareous soils which are unstable and constantly eroding (Bellefontaine 1979, Achhal 1986). Associated woody species include: Juniperus phoenicea and Tetraclinis articulata with the shrubs Lavandula dentata. var. dentata, L. maroccana, Launaea arborescens and Waronia saharae.
Molecular Biology and Genetics
Barcode data: Cupressus dupreziana
Statistics of barcoding coverage: Cupressus dupreziana
Public Records: 1
Specimens with Barcodes: 1
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
- 1998Critically Endangered(Oldfield et al. 1998)
- 1997Endangered(Walter and Gillett 1998)
Restricted to an area 120 km in length and between 6 and 15 km wide and contains 46 sites. Trees occur as a few scattered individuals which survive on exposed mountainside sites or hidden in ravines, while, north and south of this zone trees occur in groups of four to fifteen together, mostly confined to the less accessible wadis (Abdoun and Beddiaf 2002). In 1860 there were records of this species occurring 100 km further north than it is today (almost at latitude 26° N. from the Touaregs of Ghat) but by 1926 much of this range had become reduced. Up until the 1940s it was thought that there were no more than ten living individuals, however by 1949 the population estimate increased to 200 (Abdoun and Beddiaf 2002) and today the number is 233 living trees. The population decline is estimated to be 8% over a period of 30 years (Abdoun and Beddiaf 2002). Natural regeneration of 2 to 3 trees per century is obviously not sufficient to sustain the population under current conditions.
Here it consists of a single subpopulation in a single location. A ground survey (using binoculars) of four of the eight known stands estimated that the number of individuals is at least 6,650 trees (Griffiths 1998). Estimates of the AOO indicates a reduction from c.55 km² (Boudy 1950) to only 14.58 km² (Achhal 1986) which over a 36 year period gives a reduction of ca 73% (Griffiths 1998).
The major threats which have contributed to decline of this species are fire, grazing, seed collecting, firewood collection and tourism. Climate change is now also having a negative effect on the population.
Algeria: Historically (from the mid 1850s onwards) caravans were organized to extract and transport the wood for carpentry and construction (Abdoun and Beddiaf 2002). Despite its adaptation to the extremely arid conditions of the Tassili Plateau, this species is under serious threat from climate change, fire and the collection of firewood. Tourists and the animals (horses and dromedaries) of the guides have also degraded the area due to excessive trampling. Grazing by the animals has again had a detrimental effect.
Morocco: Threats include seed collecting, grazing and climate change. A survey undertaken by Griffiths in 1998 found that much damage was caused to the trees by local Berbers who were collecting seed unsustainably for commercial horticultural use in Marrakech. Grazing by goats and donkeys in all stands is on a large scale; such grazing pressures have had a detrimental effect on regeneration (Bellefontaine 1979, Achhal 1986, Griffiths 1998). Germination tests concluded that the seeds from all sampled locations were viable but regeneration was hampered not only by excessive grazing but also by the steep, constantly eroding slopes. According to the Direction des Eaux et Forêts State the climate has changed noticeably over recent years with less rainfall and higher summer temperatures (Griffiths 1998).
The sub-population is in Tassili N'Ajjer National Park, which has been designated a World Heritage Site, but despite this protection the sub-popualtion is in decline. There needs to be an increase in the number of National Park staff to protect the area and preventative measures put in place to stop the degradation of the trees and their environment and there is a considerable amount of work to be done in order to raise public awareness of this species. Organizations such as the National Institute of Forest Research have been harvesting seed, cultivating them in nurseries and establishing plantations. Recent research relating to regeneration and dendrology has improved our knowledge of its biology and should assist with its conservation.
Some conservation strategies have been implemented by the Direction des Eaux et Forêts including fencing off the sub-populations of Rikt and Achachi. At the former, some replanting has been carried out but due to lack of after care the survival rate has been low (Griffiths 1998). It is cultivated in botanic gardens and arboreta in Europe and the USA.
Cupressus dupreziana, the Saharan Cypress or tarout, is a very rare coniferous tree native to the Tassili n'Ajjer mountains in the central Sahara Desert, southeast Algeria, where it forms a unique population of trees hundreds of kilometres from any other trees. There are only 233 specimens of this critically endangered species, the largest about 22 m tall. The majority are very old, estimated to be over 2000 years old, with very little regeneration due to the increasing desertification of the Sahara. Rainfall totals in the area are estimated to be about 30 mm annually. The largest one is named Tin-Balalan is believed to be the oldest tarout trees with a circumference of 12 meters or 36 feet.
This species is distinct from the allied Cupressus sempervirens (Mediterranean Cypress) in its much bluer foliage with a white resin spot on each leaf, the smaller shoots often being flattened in a single plane. It also has smaller cones, only 1.5-2.5 cm long. Cupressus atlantica (Moroccan Cypress) is more similar, and is treated as a variety of the Saharan Cypress (C. dupreziana var. atlantica) by some authors.
Probably as a result of its isolation and low population, the Saharan Cypress has evolved a unique reproductive system of male apomixis whereby the seeds develop entirely from the genetic content of the pollen. There is no genetic input from the female "parent", which only provides nutritional sustenance (Pichot et al., 2000). The Moroccan Cypress does not share this characteristic.
An International Arboretum is being established in Canberra, Australian Capital Territory (ACT), Australia within which will be established forests of rare and endangered species from throughout the world. One of these forests is dedicated to Cupressus dupreziana and 1300 of the trees have been propagated for planting in late 2007.
- Conifer Specialist Group (1998). Cupressus dupreziana var. dupreziana. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 10 June 2006. Listed as Critical (CR A2c, C1 v2.3)
- Stewart, P.J. 1969. Cupressus dupreziana, threatened conifer of the Sahara. Biological Conservation 2: 10-12.
- Pichot, C., Fady, B., & Hochu, I. 2000. Lack of mother tree alleles in zymograms of Cupressus dupreziana A. Camus embryos. Ann. For. Sci. 57: 17–22. Full article (pdf file)
- Pichot, C., El Maátaoui, M., Raddi, S. & Raddi, P. 2001. Surrogate mother for endangered Cupressus. Nature 412: 39.
- Zsolt Debreczy, Istvan Racz (2012). Kathy Musial, ed. Conifers Around the World (1st ed.). DendroPress. p. 1089. ISBN 9632190610.
- Abdoun, F., Gardner, M. & Griffiths, A. 2013. Cupressus dupreziana. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1. <www.iucnredlist.org>. Downloaded on 11 November 2013.
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