DATA SHEETS ON SPECIES UNDERGOING GENETIC IMPOVERISHMENT

As reported in FGRI No. 3, the IUFRO Working Party S2.02.2 on Gene Resource Conservation is compiling data sheets on forest species undergoing genetic impoverishment. The species covered to date are:

Abies numidica
Alnus jorullensis
Cupressus atlantica
Cupressus dupreziana
Eucalyptus deglupta
Eucalyptus globulus
Gossweilodendron balsamiferum
Irvingia gabonensis
Juniperus bermudiana
Nesogordonia papavifera
Pericopsis elata
Pinus armandii var. amamiana
Pinus koraiensis
Pinus pentaphylla
Pinus radiata
Tecleopsis glandulosa
Ulmus wallichiana

The data sheet on Eucalyptus globulus was reproduced in FGRI 3. Data sheets on Cupressus dupreziana, Pericopsis elata, Pinus armandii var. amamiana and Ulmus wallichiana are reproduced below. Other data sheets will be reproduced in future issues of FGRI, subject to availability of space.

The Chairman of the Working Party, Professor L. Roche, appeals for the submission of further data sheets from collaborators familiar with the status of species undergoing genetic impoverishment. They should be sent to him at the Department of Forestry and Wood Science, University College of North Wales, Bangor, Gwynedd LL 57 2UW, U.K.

CUPRESSUS DUPREZIANA

Compiled by P.J. Stewart

Vernacular name: Tarout (Touareg)

Family: Cupressaceae

Synonymy

Cupressus dupreziana, A. Camus 1926 in Bull.Mus.Hist.Nat., Paris, 32(1)p. 101.

C. lereddei, Gaussen 1950 in Monde des Plantes, Paris, No. 270/71, P.55.

Botanical Description

Medium-sized tree, able to attain more than 20 m height (the tallest measured, 20 m height, has lost its top) and up to 3 m diameter. All known fully grown trees are too badly mutilated for the natural form to be seen. Young specimens grown in protected conditions show bushy form at first but with development of a straight central axis. Bark reddish-brown, with deep longitudinal fissures, no decortication.

Seedling with two cotyledons and aciculate leaves, glaucous, juvenile leaves sharp, 2–3 mm long.

Ramification: branches leave trunk at large angle, curve upwards. Ramification of first and second order shoots tends strongly to be in two planes, and first order shoots are considerably flattened.

Adult Foliage: leaves are cupressoid scales, opposite, decussate, imbricate, slightly appressed, acuminate, 1 to 1.5 mm, resin gland elongated, not noticeable except on base of old leaves. Colour dull green, slightly glaucous, especially on the young tree. Foliage very dense.

Inflorescence: monoecious; male strobili terminal, yellow, elongated, c. 6 × 3 mm; female strobili terminal, purple, ovoid, c. 2.5 mm developing into elongated cone, c. 18–24 × 16–20 mm, grey-brown, matt, with 12 sometimes 10 scales with very small, rounded mucro. Seeds reddish-brown, oval, flattened 4 × 5 mm to 5 × 6 mm, with wide, thin wings. Pollen grain of 38 microns diameter - a specific character.

Habitat and Ecology

Confined to an area of some 200 sq.km on Edehi (or Tamrit) Plateau of Tassili N'Ajjer massif in Central Sahara, around 9°E and 25°N in eastern Algeria. 153 living specimens have been counted and many more dead ones. The altitude varies between 1 000 m and 1 800 m. The climate is not known by direct measurement: the average maxima and minima in summer are estimated at 30° and 20°, those in winter at 13° and 1°. Frosts down to -7° are probable. The average annual rainfall is perhaps 30 mm, with great irregularities. The trees are in wadi bottoms on alluvial gravels and sands. Only two cases of naturally occurring seedlings have ever been recorded, and there are no trees younger than at least a century (only five trees are recorded with a diameter of 50 cm or less, the smallest being 13 cm). Fossil pollen shows that the species was recently still widespread in the Sahara. The trees are extremely long-lived, the oldest being probably at least 2 000 years old.

Status

In imminent danger of complete disappearance from its natural range. Nomads often shelter under the trees and their herds destroy any regeneration. There is still sporadic exploitation of living branches for firewood, but systematic cutting of the cypresses has been brought to an end by their rarity and remoteness. There were still many living trees in 1863 according to the first European report and they were still a major source of timber for local use.

Potential Value

This is one of the most drought-resistant species know, with considerable frost tolerance. The wood is suitable for the most exacting uses, being of medium density, stable and aromatic. The stems are straight in cultivation and the branches fine. Growth is reportedly a little slower than that of Cupressus sempervirens in similar conditions. It could be a valuable species for planting in arid regions.

The older trees and the remaining dead trunks and stumps are likely to be a great value to dendrochronology, thanks to the longevity of the tree and the durability of its wood.

The species is close to the other two cypresses occurring naturally in Africa, Cupressus sempervirens and C. atlantica. It is likely that hydridization between them would be easy and the example of Cupressocyparis leylandii shows that considerably more distant crossings might be successful. It is very important that as much as possible of the genetic material of C. dupreziana be salvaged.

Protective Measures Already Taken and Measures Recommended

Expeditions at various dates have made unsystematic collections of cones, and seedlings have been raised at many botanic gardens in France and Algeria. The biggest collection was made by the Algerian Forest Service in 1969 and several hundreds of trees were successfully germinated. The Forest Research Centre at Ariana, Tunis, possesses a good collection of young trees.

There seems little prospect for protecting the surviving natural population, scattered over 200 square kilometres at a density of less than one tree per square kilometre. A more hopeful approach would be to take cuttings from every specimen and to grow a complete set in a number of places so as to save the whole surviving gene resource and to duplicate it as an insurance against accident.

It would not be sufficient to salvage the genetic pool without making the fullest possible use of the Saharan specimens, both living and dead. A collection of material for dendrochronological purposes should be organised at the earliest possible date: there is a danger that almost all the dead wood will be taken for local use before it can be examined scientifically.

Cultivation

The seed of the cypress is reputed to germinate with difficulty. This is possible true in the case of seed from some of the oldest trees, but it is not a general rule. Sowing can be carried out in the usual way, with thorough precautions against fungal infection.

Cuttings can be grown under mist as with other conifers. Grafting has been successfully achieved on to Cupressus sempervirens by scion-budding, by crown-grafting and by inarching. The latter method can be used for cuttings if the base of the scion dips into water and is perhaps the most successful.

Select Bibliography

Barry, J.P. et al. 1970 Essai de Monographie de Cupressus dupreziana, A. Camus. Bull.Soc. Hist.Nat.d'Afrique du Nord, Algiers. Vol. 61, pp. 95–178.

Camus, A. 1926 Le Cupressus dupreziana A. Camus, Cyprès Nouveau du Tassili, Bull. Soc.Dendrol. Franç. 58 pp. 39–44.

Franclet, A. 1967 Une Méthode de Greffage du Cupressus dupreziana sur C. sempervirens. Rev. Forest. Franç. pp. 338–42.

Hethener, R. 1967 Activité Microbiologique des Sols à Cupressus dupreziana au Tassili. Bull.Soc.Hist.Nat.Afrique du Nord. Vol. 58 pp. 39–100.

Leredde, C. 1957 Etude Ecologique et Phytosociologique du Tassili. Institut de Recherches Sahariennes, Algiers.

Simoneau, P. and Debazac, E.F. 1961 Le Cyprès des Ajjer, Rev. Forest. Franç. pp. 90–97.

Stuwart, P.J. 1970 Cupressus dupreziana, Threatened Conifer of the Sahara. Biological Conservation, Vol. 2.

PERICOPSIS ELATA Thw.

Compiled by S.P.K. Britwum

Vernacular name: Kokrodua

Family: Papilionaceae

Synonymy: Afrormosia elata Harns

Botanical Description

A tall dominant tree in the moist semi-deciduous forest of Ghana, it grows to a height of about 50 m and about 5 m in girth at breast height. The crown is fan-shaped and the bole is straight and fluted at the base rather than buttressed. The bark is light coloured and peels off in thin irregular scales to leave dull blotches which give the bole a characteristic appearance.

Flowers arranged in short terminal panicles on slender, hairy rachis are white and usually 15 mm long and 13–14 mm broad. The calyx which is pubescent outside is fine-toothed. Ten stamens are present and are free, the gynoecium consists of a subsessile or shortly stalked ovary. The fruit is a pod about 9–17 cm long and about 2.5 cm broad; it is flat, thin and light brown, usually with 1 to 3 seeds. The seed is reddish brown, almost rectangular and about 15 mm across.

Flowering takes place in April to May. The pods are to be seen in May but they are not ripe till October to January.

Illustration: C.J. Taylor, Synecology and Silviculture in Ghana 1960 Plate 83.

Habitat and Ecology

This species grows in restricted areas within the Antiaris Chlorophora Association of the moist semi-deciduous forest. It is sometimes semi-gregarious but it is generally scattered. It is a dominant tree in its locality. The annual rainfall ranges from 750 – 1 500 mm with two peaks occuring in May–June and September–October. The mean annual temperature ranges from 25° to 26°C.

Status: It is not endangered as a species though there is a decline in its distribution and genetic impoverishment is likely to have occured.

Distribution

The species is known to occur in many West African countries and in Zaire. The West African countries are Ivory Coast, Ghana, Nigeria and Cameroons Republic. In Ivory Coast it occurs on the eastern frontier and is continuous with the range in Ghana. The species occurs in the mid-west of Ghana between Lat. 6°45' and 7°30' N and between Long. 3° and 1°30'W.

Reasons for Decline

Lumbering and poor natural regeneration of the species are the reasons for the decline in population. The price for the wood is one of the highest among the tropical hardwoods on the world timber market with the result that the species is being heavily cut for export in the form of logs and sawn timber.

The species is not being planted on a large scale and natural regeneration is poor. In Ghana it has been reported (Quist-Arcton, unpublished) that there is a deficiency of seedlings and saplings in forests and that natural regeneration is negligible or nil. This agrees with Aubreville's (1938) observation in the Ivory Coast. A statement made by Aubreville on this matter is that “… we searched for a long time without finding a tree of this species small enough to enable a specimen to be cut easily and we had to fell a big tree. The local people claimed that this species does not make small ones.” Taylor (1960) also reports “a sufficient quantity of seed is produced annually to expect a noticeable amount of regeneration from it, however, annual seedlings are remarkably rare, it is a fact that this species is going through a period of sparse recruitment.” In the natural forest, most of the trees are in upper girth classes and only a few trees are saplings and poles. A table showing the distribution of stockings by girth classes in the natural forest is attached.

Biology and Potential Value

The species has been popular on the world timber market since 1948. The wood is a good substitute for Teak (Tectona grandis) in ships deckings and rails. Other uses of the wood include cabinet making, furniture panelling and joinery. The species has been exported from West Africa either as logs or sawn timber. It is an important species in the timber trade. The species fetches higher prices than the world known African Mahogany on the world timber market.

Protective Measures Already Taken and Measures Recommended

In forest reserves in Ghana where the species occurs, exploitation is on the basis of the “Modified Selection System” and trees of the species 9 ft and above are exploited leaving the lower girth classes. It is recommended that about 1 sq. mile of a forest reserve containing the species should be conserved in situ without exploitation. Establishment of plantations of the species is necessary to increase the gene resources.

Cultivation

The species can be easily propagated from seed. Germination takes place between 8–10 days. It can also be propagated by rooting of stem cuttings. Mean annual girth increment of a small plantation 8 years old has been found to be 1.20 inches.

References

Aubreville 1938 La forêt coloniale: les forêts de l'Afrique Occidentale Francaise. Ann. Accid. Sci. Colon Paris.

Hutchison, J. and Dalziel, J.M. Flora 1958 of West Tropical Africa. Crown Agents, London.

Keay, R.W.J., Onochie, C.F.A. and Stanfield, D.P. 1964 Nigerian Trees. Dept. For. Res. Ibadan.

Taylor, C.J. 1960 Synecology and Silviculture in Ghana. Edinburgh, Nelson.

Twum Ampofo, J. 1969 Autecological Studies on Afrormosia elata. (Unpublished M.Sc. thesis).

Quist Arcton (Unpublished) Some observations on Afrormosia elata.

TABLE 6: DISTRIBUTION OF PERICOPSIS ELATA TREES IN THE NATURAL FOREST OF GHANA

PINUS ARMANDII Franchet var. AMAMIANA Hatusima

Compiled by H. Takehara

Japanese name: Yakutane-goyo, Amami-goyo

Synonymy: Pinus amamiana Koidzumi

Botanical Description

Tree up to 25 m height, 1 m in diameter; bark of young tree greyish, smooth; of older tree scaly; branchlet brown, glabrous; buds oblong-ovoid with brown scales; leaves five in basal sheath, 5 – 8 cm long, resin canals 3; cones short stalked, oblong-ovoid, 5 – 8 cm long; seeds about 12 mm long, have no wing.

Ilustration: Yato, Kenichi: Illustrated dendrology, I. conifers, 122, 123 (1964).

Habitat and Ecology

It is growing mixed with evergreen broad-leaved trees (Macnilus thunbergii, Castanopsis cuspidata, and evergreen Quercus spp.) or deciduous broad-leaved trees (Alnus firma, Kalopanax pictum, Cornus kousa, etc.). It is scattered in the forest, does not make a pure forest, and is almost confined to hill ridges or rocky sites.

Status: endangered.

Present distribution

Natural distribution of this tree is limited to Yaku-shima and Tanega-shima, two small islands off southern Kyushu, Japan. The typical Pinus armandii is distributed in continental China and Formosa.

Reason for decline

Lumbering has been a major reason for the decreasing population of this species but now these two islands belong to one of the National Parks so that careless cutting of trees is stopped.

Biology and potential value

It produces a good quality of timber; however it is not so important for timber production because of its limited population. It is important as a material for forest tree breeding of the white pine group and also for its phytogeographical and taxonomical interest.

Protective measures already taken: measures recommended

In Yaku-shima the habitat of this tree belongs to the species preservation area of the National Park, but the whole of this species is quite limited, therefore, more strong preservation measures will be necessary. This species should be nominated as a Natural Monument under the law. There are several planted specimens in arboreta or gardens, for example, in Asakawa arboretum of the government forest experiment station, Shimazu memorial garden of Kagoshima city, etc.

Cultivation: Propagation from seeds is not difficult and nursery work is similar to other white pines.

References

Iwata, Toshiharu and Masao Kusaka. 1952 Coniferae Japonicae illustratae, 150.

Hayashi, Yasaka 1960. Taxonomical and phytogeographical study of Japanese conifers, 38, 147.

Yato, Kenichi. 1964 Illustrated dendrology l.conifers, 122.

ULMUS WALLICHIANA Planch

Compiled by H.M. Heybroek

Vernacular names: brare, himri, imroi, mair, marai.

Family: Ulmaceae

Botanical Description

A deciduous tree up to 30 m high and over 1.25 m in diameter with elliptic-acuminate leaves with unequal base, 6–15 cm long (or longer on watershoots), margin doubly-serrate. Inflorescences on leafless twigs in spring, with elongated axis of 7–12 mm and 15–30 flowers, perianth lobes 5–6, stamens 5–6. Fruit a samara, 10–13 mm in diameter, seed central. Samara and inflorescence axis glabrous in ssp. xanthoderma Melv. and Heyb., with some hairs over the seed only in ssp. wallichiana, densely hirsute all-over in var. tomentosa Melv. and Heybr.

Illustrations: See Melville and Heybroek (1971).

Habitat and Ecology

Member of the Temperate Oak and Coniferous Mixed Forest-, of the Temperate Coniferous Forest and of the Cedrus deodara Forest-zones in the Western Himalaya(Schweinfurth 1957). In humid sites, mainly in mixed stands with many other deciduous species near streams, sometimes as an admixture of Abies-forest.

Status: endangered.

Present Distribution

From NE Afghanistan through Pakistan and India into Nepal, between 1 500 and 3 000 m over sea level. The western part of the area is occupied by spp. xanthoderma, the eastern half by spp. wallichiana; the var. tomentosa is rare and has been found in the upper Ravi valley only. Occurs mainly as a specimen tree in mixed stands and is nowhere common.

Reasons for Decline

The elm is preferred over most other tree species for the use of fodder for cattle (sheep, goat, cow). Wandering shepherds lop every elm in the forest severely, which leads to their destruction while they cannot reproduce as the developing water-sprouts bear no flowers. This happens large-scale over the whole area. Trees in game reserves and those at inaccessible places (cliffs etc.) are the only ones to escape. This used to be counteracted in part by the fact that villagers planted elms near the house for a sustained yield of fodder, which is being dried and kept for winter usage (Heybroek 1965). For this purpose, however, often hybrids are taken (U. x brandisiana); moreover, new types of fodder will mostly replace elm.

Biology and Potential Value

It produces a good quality timber, with many uses (Gamble 1922, Pearson and Brown, 1932). Its potential to produce a high quality fodder may still be utilised under certain conditions. It is being used in programmes to breed elms for city and landscape use in the temperate climates, as it exhibits a certain degree of resistance to Dutch elm disease.

Protective Measures Already Taken and Measures Recommended

The fact that the species flourishes and is able to complete its regeneration in the Dachigam game reserve near Srinagar, Kashmir, shows that keeping the cattle out of its area may suffice to save the species. In establishing new game and forest reservations in the Himalayas, attention should be paid to including elms and elm habitats. Small stands of elms could be planted near foresters and wardens homes, where they are protected from lopping. This would make their precious status clear to all while producing seed for forestry use. Groups should consist of at least ten seedlings (clones) of local origin to provide sufficient cross-pollination.

Special care should be taken to preserve a wide range of forms in the upper Ravi valley area, including the var. tomentosa.

A small collection of clones of the two main subspecies is being maintained at the Forest Research Station in Wageningen, Netherlands.

Cultivation

Plants can easily be grown from seed, which however is not available where trees are lopped regularly. Like in most other elms, the seed germinates in a few days after being sown in late spring. Various methods of vegetative propagation are effective, such as grafting, layering and rooting cuttings under mist in summer.

References

Gamble, J.S. 1922 Manual of Indian Timbers.

Melville, R. and H.M. Heybroek. 1971 The Elms of the Himalaya. Kew Bull. 26(1) 5–28.

Heybroek, H.M. 1963 Diseases and lopping for fodder as possible causes of a prehistoric decline of Ulmus, Acta bot. neerl. 12(1) 1–11; Forest Research Station, Korte Meded. 54.

Pearson, R.S. and Brown, H.B. 1932 Commercial Timbers of India 2: 894–902.