Cupressus dupreziana, Threatened Conifer of the Sahara

PHILIP STEWART, M.A. (Oxon.)

Centre Alg~rien de Recherche et d'Exp~rimentation Forestibre, Service des For~ts et de la D~fense et Restauration des Sols, B. P. 156, Alger, Algeria

A B S T R A C T

Cupressus dupreziana, represented today by not more than 200 adult trees in the central Sahara, is perhaps a local adaptation o f a population that until recently was continuous, and whose other living representative would be C. atlantica. These two cypresses eouM between them conserve much o f the genetic material o f the original population, making possible an interesting breeding programme. The survival in situ o f the endemic Saharan population is doubtful, but C. dupreziana is a promising species for reforestation.

according to such measurements as have been made. Trunk diameters of up to 4 m are recorded, but the greatest height is only 20 m (Fig.2). None of the trees

THE POPULATION AND ITS HABITAT

Amongst the rarest of tree species is Cupressus

dupreziana A. Camus, the Saharan Cypress. Two hundred individuals, at the most generous estimate, survive in the original habitat--the Tassili Plateau of the central Sahara (Fig. 1). The majority of these specimens are at least two thousand years of age,

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Fig. 2. Cupressus dupreziana: a tall tree on the Tassili Plateau in the central Sahara. Photo: J.-P. Barry.

Fig. 1. Map showing the positions o f the four remaining natural populations o f cypress in Africa:

1. Cupressus atlantica, Oued N'fis, Morocco; 2. Cupressus dupreziana, Tassili Plateau, Algeria," 3. Cupressus sempervirens, Maktar, Tunisia," massif in Algeria. The rainfall is exceedingly low and 4. Cupressus sempervirens, Djebel Akhdar, Libya. irregular, the annual average at Djanet being 18 mm

10

appears to be less than several centuries old, though three cases of natural seedlings are reported (Maire, 1952; Camus, 1958; Simonneau & Debazac, 1961). The Plateau, famous for its Neolithic rock paintings, has been used by Man throughout the life-time of the existing trees, all of which bear the marks of countless mutilations (Fig. 3).

The Tassili n'Ajjer is a plateau of palaeozoic sand- stone lying to the North of the Ahaggar, or Hoggar,

B i o l o g i c a l C o n s e r v a t i o n , Vol. 2, No. 1, October 1969--O Elsevier Publishing Company Ltd, England Printed in Great Britain

Stewart: Cupressus dupreziana,

and the wettest years bringing not more than 60 mm. Temperatures, though high, are relatively moderate for the Sahara. The average at Djanet is 23.3°C. No measurements are available for the area over which the Cypresses are scattered, which is situated between 9°30 ' and 10°20 ' W., and between 24°10 , and 25°10 ' N., but conditions are presumably cooler there, for the altitude varies between 1,600 m and 1,900 m, compared with 1,090 m at Djanet. The amount of moisture available to the trees is considerably greater than the rainfall would indicate, for they grow in the wadi bottoms.

The Cypresses form part of the evidence for the recent existence of more humid conditions in the Sahara. Growing in their proximity are a number of

Fig. 3. C u p r e s s u s d u p r e z i a n a : another, more mutilated and spreading tree on the Tassili Plateau to which this

threatened species is confined. Photo: J.-P. Barry.

other characteristically Mediterranean plants, notably Artemisia herba-alba Asso. and Globularia alypum L. (Leredde, 1957). Elsewhere, a dead Cypress was reported in the Hoggar massif, where a well-developed 'Saharo-Mediterranean' flora is found above 1,800 m. Pollen analysis has proved that the Saharan Cypress, like the rest of this flora, was common in the central Sahara in Neolithic times (Pons & Quezel, 1957). The other conifers represented in the local deposits, namely Pinus halepensis Mill., Juniperus phoenicea L., Juniperus oxycedrus L., and Tetraclinis articulata (Vahl) Masters, have all since disappeared from the Sahara.

RELATIONSHIP WITH OTHER CYPRESSES

A problem that remains to be solved is the relation- ship between Cupressus dupreziana and C. atlantica

Threatened Conifer of the Sahara 11

H. Gaussen, the cypress of the Moroccan High Atlas. The latter is endemic to the upper valley of the Oued N'fis (30°55 ' N., 8°20 ' to 8°40 ' W.--see Fig. 1), where it occupies some 6,000 ha. The Moroccan Cypress grows on a variety of soils at altitudes between 1,100 and 2,000 m having an annual rainfall of 250 to 400 mm and an average temperature of about 14°C, frosts being frequent in the winter. In its natural habitat it is a big tree, specimens of up to 40 m having been reported (Watier, 1921).

In spite of their very different present-day habitats, the two cypresses resemble each other so closely that it is hard to justify their classification as separate species, though for a final verdict it will be necessary to raise specimens unmutilated to maturity in a variety of situations. They share a number of features that dis- tinguish them markedly from Cupressus sempervirens L., their closest relative and the only other species of the genus known to occur naturally anywhere in Africa (Fig. 1). These features include the flattened, distichous branchlet systems, the dense, somewhat glaucous foliage, the very active resin glands of the young tree, the small cones, the upward-curving branches, and the absence of fastigiate forms.

It seems reasonable to suppose that a continuous population of Cupressus dupreziana/atlantica extended until recently from the coastal mountains of North Africa to the central Sahara, and that the Oued N'fis and the Tassili Plateau are the last refuges of two extreme adaptations. If this should be so, then it is probable that the two populations between them con- serve a considerable part of the original genetic material of the species. A breeding programme of remarkable scope and interest suggests itself.

CONSERVATION PROSPECTS

The Cypress forest of the Oued N'fis seems to be out of danger. The ancient Cypresses of Tassili, on the other hand, are likely to die without regenerating themselves in situ. It is an open question whether natural regeneration would have continued had Man not exercised a heavy pressure of grazing and cutting in the Tassili Plateau over the past two or three thousand years (Hethener, 1968). There is a chance that it will be possible, in the framework of the Tassili National Park which is shortly to be created, to regenerate the species by removing this adverse pressure in one or two intensively treated and protected sites.

There is less doubt about the survival of the Saharan Cypress outside its present habitat. Specimens have long been successfully planted in Algeria and in France. The Algerian Forest Service in 1967 organized the

12 Biological Conservation

collection o f several k i logrammes o f seed and plans to create a 'seed orchard ' . Small quanti t ies of seed have been sent to a number o f Medi te r ranean countries. It is to be hoped that p rog rammes of exper imenta t ion will be carried out in as many countr ies as possible.

As a species for reforestat ion, Cupressus dupreziana, whether pure or crossed with C. atlantica, is potent ia l ly very impor tan t . Of the coniferous genera represented in the arid and semi-ar id regions, Cupressus appears to be the genus most likely to have played an impor- tant pa r t in the cl imax vegetat ion, perhaps having been dominan t in mixtures with evergreen oaks (Jouber t & Burollet, 1934). By their shade-tolerance, their prefer- ence for developed soils, and their regression under pressure f rom Man, the cypresses cont ras t s t rongly with the pines which are at present so widely used for p lanta t ion . F o r the creat ion o f balanced forests the cypresses are likely to be invaluable. Cupressus dupreziana may yet become a c o m m o n tree.

References

CAMUS, A. (1958). Sur un Cupressus relique de la For6t du Tassili. J. Ag. Trop. & Bot. Appl., 5, 766-7.

H~THENE~, P. (1968). Activit6 microbiologique des sols/~ Cupressus dupreziana A.Camus au Tassili n'Ajjer. Bn. Soc. Hist. Nat. Afrique du Nord, 58, 39-100, map and figs.

JOUBERT, A. & BtrROLLET, P.-A. (1934). Biologie et r61e forestier du Cypr/~s. Rev. Eaux & For., 73, 3-30.

LEREDDE, C. (1957). E, tude Ocologique et phytogkographique du Tassili n'Ajjer. Inst. Rech. Sahar., Alger, 455 pp., illustr.

MAtRE, R. (1952). Flore de l'Afrique du Nord, L Paul Lechevalier, Paris, 366 pp., illustr.

PONS, A. & QUEZEL, P. (1957). Premiers r6sultats de l 'analyse palynologique de quelques pal6osols sahariens. C. R. Acad. Sci., Paris, 243, 1656--66.

SIMONNEAU, P. & DEBAZAC, E.-F. (1961). Les cyprus des Ajjer. Rev. Fores. Fran~., 1961, 90-97.

WATIER, CH. (1921). Les Cupressin6es dans le Maroc meridional. Bn. Stat. Reeh. Fores. Nord de l'Afrique, 1,222-40.

IUCN Education Commission Development

With the appointment of a prominent Czechoslovakian conservation scientist and educator, Dr Jan Cerovsky of Prague, who in February 1969 joined the staff of the International Union for Conservation of Nature and Natural Resources as Executive Officer of the Commission on Education, further developments in this vital sphere are to be expected.

Creation of the new staff post, located at the Union's headquarters in Morges, Switzerland, reflects the growing work of IUCN in advancing conservation education throughout the world. Operating through regional com- mittees of prominent educators in West Europe, East Europe, and North America, the Commission works to develop educational techniques and materials which relate to conservation of nature and natural resources. Regional groups in other areas are being planned.

Prior to coming to Morges, Dr Cerovsky was chief of research for the Czechoslovak State Institute for Protection of Monuments and Conservation of Nature, and editor of the conservation magazine Oehrana Prirody; concurrently he taught at Charles IV University, Prague, and at the University of Agriculture, Brno. He is the author of many books and articles on plant geography, ecology, and environmental education, and has travelled widely in Europe, Asia, and Latin America.

As a volunteer, Dr Cerovsky served as a Vice-Chairman of the Commission on Education, along with Dr Tom Pritchard, UK, and Prof. O. A. Hoeg, Norway. Chairman of the Commission is Mr L. K. Shaposhnikov, USSR.

In 1968, Dr Cerovsky was chairman of the commission dealing with education at the Biosphere Conference held in the Unesco headquarters in Paris, France. His qualifica- tions for this important new post are thus probably unique.

ROBERT I. STANDISH, Pubfic Information Officer, IUCN, 1110 Morges, Switzerland.

Judge Russell Train for US Department of the Interior

That the quality of the environment is a highly sensitive issue in the United States was recently emphasized by the fact that President Nixon's nominee for the key post of Secretary of the Interior, Walter J. Hickel, was questioned intensively for several days by the Senate Committee on Interior and Insular Affairs and some other senators-- mainly on his views concerning conservation--before being finally confirmed. For it was felt that as Governor of Alaska he had shown more concern for industrial develop- ment and exploitation of natural resources than for their conservation and wise use. It is accordingly gratifying to note that he was able to satisfy his questioners in such matters as his views on water quality and his opposition to opening up wildlife refuges to commercial oil drilling.

Now we learn with deep satisfaction of the appointment of our Consulting Editor Judge Russell E. Train, President of the Conservation Foundation, as Under Secretary of the Interior, which should ensure sound and practical advice on these vital matters going to the right quarters from one who, in the apt words of a writer in Science (vol. 163, p. 455, 31 January 1969), 'is respected by conservationists and others as an able, articulate man who believes that people ignore ecological considerations at their peril. '

As chairman of Mr Nixon's task force on resources and environment, Russell Train comes to his new job with a set of policy recommendations including the appointment of a Presidential Assistant for Environmental Affairs, inter alia to help deal with 'problems of compartmentation and conflict' which are inevitable in a great and vigorous nation. Conservationists the world over will watch develop- ments in the United States with eager expectations of effective leadership in the control of pollution and the ultimate enhancement of environmental quality.