Cupressus dupreziana by Jaroslav DOBRY
Cupressus dupreziana, the only conifer of central Sahara, is one of 12 critically endangered plants selected by IUCN's Species Survival Commission to highlight the serious threats to species around the world. Living individuals have been found only in the Tassili Range, eastward from the Oasis of Djanet, in the Aigerian Sahara. Although pollen studies indicate it was once more widespread in the region, the species is now on the verge of extinction. There are only some 153 ancient individuals surviving in the wild.
The existence of a coniferous tree in central Sahara was first reported in the west in the mid 19th century. The Tuaregs were said to be using a hard coniferous wood with a strong perfume, called "tarout". Living trees were eventually discovered in 1924.
Relict tarout populations occur at several localities in the mountains between Djanet and Ghat. The oldest individuals are thought to be comparable in age to the oldest known pines of North America. Only two cases of naturally occurring tarout seedlings have ever been recorded and probably there are no trees younger than at least 100 yeaTS. Tarout is one of the most drought ~resistant conifers known, occurring in areas which receive about 30 mm rainfall on average each year. C. dupreziana could, therefore, be a valuable species for planting in arid regions.
Favourable climatic conditions in 1973-75 enabled tarouts to fructify. From seeds brought to Czechoslovakia from Tamrit during Expedition Sahara '75, nearly 100 plants were grown, representing ca 1% germination. In 1981, the director of the National Park of Tassili invited us to transport tarouts cultivated at the Institute of Botany, Czechoslovak Academy of Sciences, to Tassili. The project, called Expedition Tarout '81, was sponsored by Czechoslovakian and Algerian authorities. 70 cypresses, about 1.2 m high, were packed into specially made cardboard barrels and transported to Djanet; 15 were planted at Akba Tafelalet near Tamrit, the Test at Djanet itself.
Besides the ex situ conservation programme, in situ conservation is also necessary to stop genetic destruction. Vegetative propagation of aIl remaining individuals by grafting, and the establishment of a clonaI plantation, would assure the maintenance of genetic diversity.
Further work is needed to evaluate the reintroduction project and to establish the clonaI plantation. Support is stiJl needed to continue efforts to conserve the valuable gene pool of this famous conifer. ''
Czechoslovak Academy of Sciences