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Part II
COUNTRY BRIEFS (continued)

KENYA (continued)


  1. FAO 1962 “Present Wood Consumption and Future Requirements in Kenya” - report No. 1503 - based on the work of J.E.M. Arnold, M.F.E. de Backer and S.L. Pringle - Rome

  2. Forest Department Intergovernmental Conference on Timber Trends and Prospects in Africa 1965 - “National Report” - Nairobi

  3. FAO 1968 “Report of the Kenya Forestry Project - Loan Application Report” - FAO/IBRD Cooperative Program - Report No. 8/68 KEN.2 - Rome

  4. Forest Department 1968 “Forest Department Annual Report 1966” - Nairobi

  5. Forest Department 1968 “Forestry Papers on Revised Development Plan, 1968–1973” - Nairobi

  6. Forest Department African Forestry Commission - 2nd Session - 1969 “Progress Report - 1966–1968” - Nairobi

  7. FAO 1970 “Development of the Forest Sector” - Report No. FAO/SWE/TF 28 - Rome

  8. Ray, R.G. 1971 “Six Forest Inventories in the Tropics - Part 6 - Kenya” - in collaboration with CIDA - Department of fisheries and forestry - Ottawa

  9. Forest Department African Forestry Commission - 3rd Session - 1972 “Progress Report 1969–1971” Nairobi

  10. FAO 1972 “Forest Resource Appraisal (Africa) - Kenya” - (letter from P.J. Vakomies, Director FOI to C.C.F. Kenya of 7/7/72) - Rome

  11. Forestry Department 1974 “Progress Report 1966–72” - prepared for the Tenth Commonwealth Forestry Conference 1974 - Nairobi

  12. Lind E.M. and Morrison 1974 “East African Vegetation” - Longman - London

  13. Royal College of Forestry 1975 “Land Use in Kenya and Tanzania” - edited by B. Lundgren - Stockholm

  14. Solberg, B. 1975 “Forestry Economics in Kenya” - in Scandinavian Forest Economics - 1975 - No. 4 - Helsinki

  15. Forest Department 1976 “Progress Report 1972–1975 for the African Forestry Commission - Fourth Session” - Nairobi

  16. University of Dar es Salaam, Division of Forestry 1979 “Growth and Yield Studies of Cupressus lusitanica in Kenya” - by W.J. Mathu and M.S. Philip - Morogoro (Tanzania)


Liberia lies along the atlantic coast over more than 500 kilometers, with Ivory Coast on the east and Sierra-Leone, on the west, between approximately 4°30'N and 8°30'N latitude. Total land area is 96 320 km2, corresponding to an average width along the coast of slightly less than 200 km.

Three main physiographic regions are distinguished, viz. (i) the belt of rolling hills over 80 km along the coast, up to 100 m high; (ii) the dissected table lands in central and south-eastern parts with a slightly undulating plateau 200–250 m high and mountains between 350 m to 600 m; (iii) the highlands in north-western and northern parts culminating at Mount Wutivi (1380 m) and the liberian part of Mount Nimba (1 385 m, before iron ore extraction started).

The climate is determined as for the rest of West Africa by the movement of the so-called Inter Tropical Front, with a main rainy season from May to September and a main dry (or relatively dry) season from October to April, and with a mid-dry season in July–August more or less marked according to the regions. Annual rainfall decreases from 4 000 mm or more along the central and northern parts of the coast to 2 000 mm or slighly less along the northern border (with the exception of Mount Nimba were rainfall reaches 3 100 mm). Monrovia is the station with higher rainfall (4 638 mm for 16 years observation) and Tappita and Suakoko in the north central part receive around 1 9 00 mm. All the country is within the rainfall range of the humid or wet evergreen or semi-deciduous climax forest. On the A.E.T.F.A.T/Unesco Vegetation Map of Africa South of the Tropic of Cancer, almost the entire country is situated in the “tropical moist forest at low and medium altitude”, while on the revised map it is divided between “lowland ombrophilous forests”, “relatively wet types” (south eastern part of the country) and “relatively dry types” (central and northwestern parts of the country).

Total population was estimated in 1970 at 1 523 000 habitants growing at that time at an annual rate of 2.9%. Agricultural population was reported in 1971 at 682 000 and in 1975 at 813 000 (11), or an annual growth rate of 4.5%. Total population should be in 1980 just around 2 million inhabitants with an agricultural population very close to 1 million.

1. Present situation

1.1 Natural woody vegetation

1.1.1 Description of the vegetation types

The following description is taken from chapter III of “Liberian High Forest Trees” by A.G. Voorhoeve (4).

Closed broadleaved forests (NHC)

Under normal conditions of site and soil, two main types can be distinguished, viz. evergreen forests and moist semi-deciduous forests. Evergreen forests are found when rainfall is higher than 2 000 mm, with no marked dry season, that is in a belt parallel to the coast in the eastern and central parts of the country, while it is practically absent in the north-western part where the dry season is more marked. The limit with moist semi-deciduous forest is neither sharp nor continuous.

Characteristic species of mixed evergreen forests are Lophira alata, Heritiera utilis, Sacoglottis gabonensis, Calpocalyx aubrevillei, and Dialium spp. The only Meliaceae present, though in small numbers, are lovoa (Lovoa trichilicides) and bosse (Guarea cedrata) whereas species of Khaya and Entandrophrogma are absent.

Some patches of evergreen forests, with a dominance of one single species in one or all storeys are found, sometimes in the form of almost pure stands. Most of these species are Caesalpiniaceae such as Cynometra spp., Gilbertiodendron preussii, Monopetalanthus compactus and Tetraberlinia tubmaniana. Parinari excelsa, a Rosaceae, is also found dominant in some forests.

The moist semi-deciduous forest which occupies the northern half of the country is a transition between the evergreen forest and the semi-deciduous forest as found in Ivory Coast. Species from both types are present. Meliaceae are more abundant than in the evergreen forest and typical trees of the semi-deciduous forest such as danta (Nesogordonia papaverifera) and Aningeria robusta are present.

Semi-deciduous forests similar to those found in Ivory Coast with such species as Celtis spp., Mansonia altissima and many others Sterouliaceae (like Pterygota spp., Steroulia spp.) are extremely rare in Liberia. As a whole, Liberian forests are closer by their composition to those of Gabon and south-west Cameroon than those of Ivory Coast, mainly because of the high rainfall.

In terms of evolution the present high forest can be subdivided into three groups, primary high forest, old secondary forest which has reached the climax and old secondary forest which has not yet reached the climax. There is indeed no sharp division between the two last groups, which differ only by species composition, average diameter of the trees of the upper canopy and the development of the strata. The first group is extremely rare and restricted to remote sites like the gorges in the Nimba mountains, where steep slopes and belief in spirits prevented agriculture and penetration by people. The third group, corresponding to forests still relatively young, is characterised by a dominance of light demanding species such as Albizia spp., Fagara spp., Terminalia spp., Pycnanthus angolensis. Other species are characteristic of older forests, such as Erythrophleum ivorense, Uapaca guineensis and U. corbisieri, Antiaris toxicaria var. welwitschii, Parinari excelsa. The dominance of (at least when young) shade tolerant species increases with age: Lophira alata, Strombosia glaucescens, Klainedoxa gabonensis, many Caesalpiniaceae and Sapotaceae.

Mangrove forests are characteristic of the silty lagoons and along some rivers in the immediate vicinity of the atlantic coast. The main species are Rhizophora racemosa, R. harrisonii, R. mangle and Avicennia africana. Probably owing to the poor soil condition these trees rarely grow taller than 6 metres and they are always higher close to the river channels than in other inundated areas where growth usually stagnates at 2–2.5 m height (2). Their total area is estimated very tentatively at 40 000 ha.

The most common fresh-water swamp forests are the Mitragyna ciliata forests in those swamp valleys which are not flooded during the whole year but where the roots have always access to the ground water. In the permanently inundated areas the forest cover is poor and low with few or no large trees, with Raphia palms and, in the eastern part, gregarious stands of Loesenera kalantha trees, very similar to those of Tetraberlinia tubmaniana. River borders are often characterized by typical riparian species such as leguminous trees (Cathormion altissimum, Monopetalanthus spp., Plagiosiphon emarginatus, Gluema ivorensis, a Sapotaceae, and Pandanus (monocotyledon species)).

More than half of the total land area is presently covered with forest fallow (NHCa), that is the complex of patches of the various reconstitution phases of high forest after clearing by shifting cultivation (mainly upland rice farming). They were termed “broken forest” (i.e. forest areas with “partial cuttings made for the purpose of clearing areas for agriculture”) and “low bush” (i.e. “areas which recently have been farmed and now are reoccupied by forest growth”) by Mayer in his assessment of vegetation cover, reported in (2). At that time (late 40's) these areas were already estimated at 4 100 000 ha or 42% of the total land area.

Open broadleaved forests (NHc/NHO)

Two types of savanna may be distinguished. The coastal savanna is from anthropic origin and can be considered as derived savanna. The savanna woodland of the north-west lies within the climatic limits of the semi-deciduous but the practice of burning and erosion degraded the original forest cover to savanna woodland with fire-resistant trees and scattered rock outcrops of barren granite boulders. Characteristic species are Cassia sieberiana and Acacia spp. (5).

Scrub formations (nH)

In densely populated areas of the coast with very short fallow periods and/or repeated burning young secondary forests have no time to develop. Part of the fallow forest areas remain permanently with shrubs (see section 2.1.1).

1.1.2 Present situation of the woody vegetation

Present areas

After a first estimation had been made in the late 40's by Mayer, using aerial photographs and extensive ground checking (2), the Bureau of Forest and Wildlife Conservation carried out an inventory of the National Forests in cooperation with the German Forestry Mission to Liberia (5). In the course of this study, the closed forest areas of the country was reassessed. The work was performed between late 1960 and early 1967. These area estimates were made by main region (southeast, northwest and north) and “timber areas”, and a separation was made between exploitable forests and unexploitable forests (mainly because of “rough terrain”). Since that time most documents have used the figures published by this national forest inventory without altering them to take into account the increased encroachment by agriculture in the forests (e.g. “Forest Resources of Africa” by R. Persson and documents (6) and (7). The following estimates are based on the above ones and past and present deforestation rates as indicated in section 2.1.1.

Areas of natural woody vegetation estimated at end 1980
(in thousand ha)

9054251 3306702 0005 500 404040100

- The relative areas of virgin (NHCf1uv) and logged-over forests (NHCf1uc) within the remaining productive forests (NHCf1) have been determined from the historical records of forest logging and assuming that practically all clearings for agriculture take place in already logged-over forests;

- the unproductive forests (NHCf2) include the mangrove and coastal forests (80 000 ha) and the areas of difficult topography (600 000 ha in the mid 60's) as indicated by the national forest inventory;

- the forest fallow areas (NHCa) have been determined from the historical series of clearings since they were first estimated by Mayer in the late 40's, and reconciling then the figures with those determined in the mid 60's. As for other countries these areas include inevitably patches of high forests mixed in the “check board” pattern of the areas affected by shifting cultivation;

- estimation of areas of open broadleaved forests (NHc/NHO) and shrub formations (nH) is very tentative at this stage; roughly speaking NHc/NHO2i corresponds to the woodland savannas in the north while NHc/NHOa includes those coastal tree savanna areas affected by cultivation. nH represents those shrub areas derived from previous repeated clearings and burning in the coastal area.


State ownership of the forest is clearly spelt out only for the National Forests (see below) through the 1953 Liberian Forest Conservation Act. There does not seem to be a significant area of private forests, if any.

Legal status and management

There has been over the last twenty years some slight changes in the total area, number and names of the National Forests originally demarcated (2) (3) (5) (7). In 1975 the 14 liberian National Forests covered a total area of 1 664 700 ha distributed as follows:

northwestern Liberia:Belle, Gola, Kpelle, Lorma, North Lorma, Yoma distrit, for a total area of approximately 606 500 ha;
northern Liberia:East Nimba, West Nimba, for a total area of approximately 42 000 ha;
southeastern Liberia:Gbi, Gio, Grebo, Krahn-Bassa, North-Gio, Sapo for a total area of approximately 1 016 200 ha.

They vary widely in size from 4 400 ha (North-Gio) to 514 000 ha (Krahn-Bassa) and have the following characteristics (5):

Part of the National Forestsis covered presently by concessions.

Three National Parks have been proposed but are not yet established. They are: Trempo National Park (13 000 ha), Bokumu National Park (2 950 ha) and Wologizi National Park (20 800 ha) (18). Therefore no forest area has been indicated in the table as unproductive for legal reasons (NHCf2r = 0).

Some standards of timbering, processing and silvicultural practices are specified in the Model Timber Concession Agreement which serves for the drafting of the concession contracts and includes a standard management plan. However the application of these standards does not correspond to the concept used in this study of intensive management and therefore NHCf1m = 0.

Forest utilization

Log harvesting

Organized logging operations started mainly for the supply of the local market through processing in sawmills in the vicinity of Monrovia and of the ore mines (1), (2), (3), (5). The log production records and files show a production of 8 200 m3 in 1955 practically all for the local market (6). Production of export logs started really in 1963 with 11 000 m3 recorded this year and has been increasing at a rapid pace since, as can be seen from the following table:

SourcePeriodAverage annual production (in thousand m3)
1956–601961–651966–701971–75after 1975
Total production(6)2740173410 (71–74) 
FAO Yearbooks 50122448660 (76–78)
(16)  142 (67–70)414603 (76–77)
Log exports(6)ε1  9109314 (71–74) 
FAO Yearbooks 1376288250 (76–77)
(16)  97 (67–70)293304 (76–77)

1 The only record is for the year 1959 with 1 553 m3.

In spite of some discrepancies between the sources, the table shows a tenfold increase in total production of logs between the early 60's and the early 70's, a situation somewhat similar to that of Ivory Coast between the early 50's and early 60's (260 000 m3 in 1951–55 to 1 830 000 m3 in 1961–65 or a ratio of 1 to 7). These statistics do not take into account production from pitsawing which is probably insignificant compared to the total output of logging operations.

Concessions range in size from a few thousand ha to 200 000 ha or more (2 concessions of that magnitude in the late 70's). The total number of concessions is reported to have been 54 in 1973 (7) and 47 in the years 76–77 (15) with an average unit size of 59 000 ha and 81 000 ha respectively, the total area under concession having increased during that period from 3.19 to 3.82 million ha. The order of magnitude of these figures shows that little operable forest (NHCf1) is now outside the concessions even if account is taken of the proportion of the concession areas covered by unproductive vegetation.

The following table gives the breakdown by species for the year 1974 (6):

ClassCommercial nameLatin nameProduction
ISipoEntandrophragma utile64 47616.91
Sapele (sapelli)Entandrophragma cylindricum13 4183.52
TiamaEntandrophragma angolense12 6543.32
KosipoEntandophragma candollei10 8572.85
Acajou (khaya)Khaya spp.10 2672.69
Dibeton (lovoa)Lovoa trichilioides25 8146.77
Makore (douka)Tieghemella heckelii28 3437.43
NiangonTarrietia utilis70 91918.59
TetraberliniaTetraberlinia tubmaniana7 4611.96
Total class I species (above and other species class I)255 93367.12
IIWawa (obeche-samba)Tripochiton scleroxylon14 8173.89
Kusia (bilinga)Nauclea spp.8 6382.26
Abura (bahia)Mitragyna ciliata13 6933.58
AieleCanarium schweinfurthii6 3691.67
FramireTerminalia ivorensis11 5103.02
Red oakGilbertiodendron preussii4 1551.09
Total class II species (above and other species class II)60 98615.99
IIINagaBrachystegia leonensis22 8576.00
Ekki (azobe)Lophira alata18 5804.87
Dahoma (dabema)Piptadeniastrum africanum9 8712.59
TaliErythrophleum spp.3 1930.83
Total class III (above and other species) and other64 39716.89
 Total all species381 316100.00

Although two species of cabinet wood dominate markedly (sipo and niangon) representing more than 35% of the total production, the exploitation is not as selective as it is in some countries of Central Africa for instance. However, the first eight species of class I which are highly valued on the international market (Meliaceae plus makore and niangon) represented at that time nearly two thirds of the production and 70% of the volumes exported.

Average output per ha was estimated in 1974 at 7.5 m3 per ha (3 m3/acre) (6). Presently the area logged-over annually is about 80 000 ha.

Other forest products

Annual fuelwood production was estimated at 1.27 million m3 in the late 40's (Mayer quoted in (1)) and at 1.85 million m3 in 1978 by the FAO Yearbook of Forest Products. Annual domestic non-trade consumption (covering such items as lumber, poles, canoes, mortars and pestles, ustensils, agricultural implements and furniture) amounted roughly to 55 000 m3 in the late 40's according to the same source. “Other industrial roundwood” (mostly poles and posts) are estimated at 110 000 m3 in 1978 in the FAO Yearbook of Forest Products.

1.1.3 Present situation of the growing stock

The inventory of the National Forests provide detailed information on volumes over bark of the “faultless bole” of trees more than 40 cm DBH (5). An average estimate for the whole country, weighed by the respective areas of inventoried productive forests (NHCf1uv) is 98 m3/ha. If we take a ratio of 0.575 between this volume above 40 cm DBH and the volume VOB (gross volume over bark of stems more than 10 cm DBH), we arrive at an average VOB volume of 170 m3/ha.

The report on the inventory of 1 909 000 ha of forests in the south-west region of Ivory Coast (“Forestry Resources of the Southwest region” by Development and Resources Corporation - 1967) provides mean estimates of VOB volumes per ha for productive evergreen, transitional and semi-deciduous forests (respectively 153 m3, 194 m3 and 178 m3). If these estimates are weighed by the relative areas of these three main types as given in (1), an average VOB estimate is 168 m3/ha, an estimate very close to the one obtained in the preceding paragraph.

For logged-over productive forests (NHCf1uc), the average VOB volume is estimated at 155 m3 (VOB volume of undisturbed forests minus twice the extracted volume).

A weighed average of mean growing stock per ha for mangroves (estimated VOB: 30 m3) and forests on steep terrain (135 m3 in the North Lorma National Forest) is 125 m3 for unproductive forests (NHCf2).

These various estimates are summarized in the following table:

Growing stock estimated at end 1980
(total in millions m3)


No data have been found in the literature of volume increment in natural forests.

1.2 Plantations

1.2.1 Introduction

Plantation forestry is a fairly recent activity in Liberia. (2) reports on pilot plantations carried out for observation purposes, in particular some based on the taungya system with hardwood species such as obeche (Triplochiton scleroxylon) and framire (Terminalia ivorensis). Introductions were conducted of many species at the University of Liberia Experiment Station from 1963 (Tarrietia utilis, teak, Cedrela, Gmelina, Pinus caribaea) (9). However, it is only in the early 70's that some planting started, by the loggers in 1971 in fulfilment of the reforestation obligations stipulated in the concession agreements, and by the government which started its own reforestation scheme with the World Food Programme and the assistance of Federal Republic of Germany in 1972. According to (7) there was approximately, at the end of 1973, 1 450 ha planted mainly with Gmelina arborea and Tectona grandis, of which 1 350 ha by concessions. At the end of 1975 the total planted area amounted to 2 800 ha (8). Although a large part of the planting took place in three zones (Bomi Hills, mainly, Yekepa in the Nimba county and Cavalla in Grand Gedeh county), this approach led to proliferation of small plantations (74 sites mentioned in (9)) with little or no maintenance (17).

Several industrial plantation projects have been initiated, still at an experimental or pilot scale, since 1975. With the assistance of the german technical assistance mission, 880 ha have been planted per year, 60% with Gmelina and 40% with Eucalyptus, Pinus, Albizia and Anthocephalus species. The Liberia Forestry Corporation (LFC), a joint venture with swedish pulp manufacturers, intends to plant tropical pines on a large scale south of Ylla along the Buchanan-Ganta railway. Until now, only trials of Pinus caribaea and P. occarpa have been carried out under this scheme which is to establish 100 000 ha of pulpwood plantations. The third main plantation project, financed jointly by the International Development Association (IDA), the African Development Bank (ADB) and the Government of Liberia aims at establishing between 1979 and 1983 a 1 600 ha commercial scale industrial trial plantation of fast-growing exotic and indigenous species in the National Reserve near Bomi Hills (Grand Cape Mount county) as a first phase of a proposed 70 000 ha programme which would be implemented over a 15-year period. Approximately 400–500 ha should have been planted by the end of 1980.

1.2.2 Areas of established plantations

The following table has been drawn from information gathered in the documents (7), (8), (9), (10), (12), (14), (15) and (17) and actualized at end 1980. An overall survival/success rate of 80% has been assumed for the plantations carried out under the National Reforestation Programme and the IDA/ADB/GOL and LFC programmes while it has been estimated at only 50% of the plantations established by the concessionaires, which are reported to be of an unsatisfactory quality (15) (17). At end 1980 the area of successfully established plantations has been estimated at 6 300 ha, of which 3 600 ha by the National Reforestation Programme, 800 ha by LFC, 400 ha by the IDA/ADB/GOL programme and 1 500 ha by concessionaires.

The need for maintenance of existing plantations has reduced slightly the amount of new plantation under the National Reforestation Programme from 1976 to 1978 as indicated in (17). This is another reason why the estimate of total successfully planted area at end 1980 appears smaller than the sum of targets indicated for the various plantation programmes.

Pines are planted essentially in the LFC and IDA/ADB/GOL programmes; teak, on one side, and fast-growing hardwood species (Gmelina, and to a lesser extent eucalypts, Albizia falcataria etc.), on the other side, are planted by concessionaires and within the National Reforestation Programme in the proportions 33%–67% (15) (17).

All existing plantations have been established with the main purpose of producing wood for industry.

Areas of established industrial plantations estimated at end 1980
(in thousand ha)

CategorySpeciesYears76–8071–7566–7061–6551–6041–50before 41Total
Age class0–56–1011–1516–2021–3031–40> 40 
PHL 1 = PHLTectona grandis11.10.5     1.6
PHH 1 = PHHGmelina arborea, eucalypts 2
and other fast-growing species 3
2.41.2     3.6
PH.1 = PHSubtotal hardwood species3.51.7     5.2
PS.1 = PSPines 41.1      1.1
P..1 = PTotal industrial plantations4.61.7     6.3

1 Terminalia ivorensis is also mentioned in (9)
2 (12) quotes as eucalyptus E. deglupta and E. tereticornis
3 Albizia falcataria, Anthocephalus sp.
4 Pinus caribaea and P. oocarpa

1.2.3 Plantation characteristics

There are few data on mean annual increments, production of thinnings and final cut since practically no stand has reached the rotation age and little mensuration work has yet been published. The information found has been summarized in the following table:

Final cut
Gmelina arborea8–1035(4 years)
200–2501200 stems/ha(9)
Pinus caribaea1513  (9)
1517  "
1520  "
1513(u.b.)195 (15)

2. Present trends

2.1 Natural woody vegetation

2.1.1 Deforestation

An interesting historical assessment is proposed by Voorhoeve in his book “Liberian high forest trees” (4). The author wrote the following in the early 60's:

“Primary forest probably existed in the distant past, when the forest zone of West Africa was still uninhabited or when only hunting pigmy tribes roamed the forests (stories about pigmies, ‘little men’, are still told in Liberia). Permanent human practice of shifting cultivation made the primary forest cover gradually vanish during the bygone ages, to be replaced by a secondary vegetation”.

“It is believed that as recently as 300 years ago Liberia was much more densely populated than at present. The area supporting high forest would have been much smaller than nowadays. If this view is correct, this could be compared with the present situation in Sierra Leone, where high forest stands are limited, and the major part of the country is covered by low bush and young secondary forest, included in the sequence of shifting cultivation”.

“However, diseases, tribal warfare, and slave trading are believed to have reduced the population of Liberia to its present level of about one million, and the low bush in the abandoned country might then have developed into the present high forest, which would be of a secondary character”.

“Evidence of this development is found in the forest: the occurrence of extensive single dominant forests (discussed later), the occurrence of forests where the secondary character becomes evident from the species composition, and the presence of relics of human occupation such as graves, ancient roads etc”.

The present wave of deforestation is essentially due to shifting cultivation of upland rice by farmers intruding tracts of forests opened up by the network of logging roads which is spreading at the same rapid pace as logging itself (see section 1.1.2). Although no systematic comparative study of aerial photographs has been made, deforestation rates can be derived from fairly detailed and substantiated agricultural statistical records ((11), (13) and assessments made by Liberian experts (e.g. (15)).

According to (13) about 130 000 households were growing upland rice on 182 000 ha (individual fields of 1.4 ha) in the years 1975–76. Every year rice is planted on a new area, so that each family clear 1.4 ha annually. About 20% of the rice households cut “young bush” (less than 7 years old secondary growth), 50% cut “medium bush” (7–12 year old secondary growth) and 30% cut “high bush” (more than 12 year old). Approximately 60–65 000 ha of “high bush” is cleared every year, a figure corroborated by a detailed analysis of agriculture statistics per county. If we consider as a first approximation that half of this high bush is constituted by closed forests (NHCf) and half by secondary growth older than 12 years (NHCa) (15), we arrive at an area of 33 000 ha of closed forest cleared annually for upland rice cultivation. 5 000 additional hectares of low-lying forest land is cleared every year for swamp and irrigated rice farming and 3 000 ha for forest plantations and other reasons (permanent crops, urbanization etc.). These deforestation rates should increase slightly in the next 5-year period, with increasing agricultural population, incentives given to rice cultivation and increased forest planting.

Average annual deforestation
(in thousand ha)


1976–80 1981–85
ε3939241  4444246

It is assumed that almost all closed forests (NHCf) encroached are productive forests already logged-over (NHCf1uc), since these forests are those which are made accessible by the opening of logging roads. Annual deforestation was estimated already in the late forties at 20 000 ha of closed forests (2), and the doubling since that period corresponds approximately to the increase of the agricultural population.

The effect of the opening up of new forest lands (NHCf) with logging roads is somewhat mitigated by a larger fallow forest area (NHCa) at the disposal of the farmers. These areas which amounted to 4.1 million ha in the late forties (2) are estimated to have increased to 5.5 million ha in 1980 and could extend to 6.45 million ha in 1985, if, as it has been assumed, 90% of the areas cleared by shifting cultivation are supposed to revert to forest fallow (the remaining 10% being reduced to a permanent state of shrub vegetation).

2.1.2 Degradation

Apart from the evolution of forest fallow to shrub vegetation indicated above, degradation takes place in the open woodlands of the coast and in the north-west due mainly to repeated fires. However, no assessment either qualitative or quantitative has been found in the literature of this process which is minor compared to shifting cultivation in closed forests.

2.1.3 Trends in forest utilization

It is not unreasonable to think that the output per ha of extracted logs should increase slightly (say by 25% up to 10 m3 in 1985) with increasing processing facilities in the country, the reduction of forest areas available and the development of forest management and control procedures, as has happened in the neighbouring Ivory Coast. It may very well be that total annual production may level off at 600 000 m3 during the period 1981–85, a level already high compared to the total area of closed forest in the country. This would mean a total logged-over area during the next five years of 300 000 ha approximately.

2.1.4 Areas and growing stock at end 1985

The following tables summarize the situation as it is projected to the end of 1985 from the estimations made in the preceding sections.

Areas of natural woody vegetation estimated at end 1985
(in thousand ha)

6055051 1106601 7705 670 404040120

Growing stock estimated at end 1985
(totals in millions m3)


2.2 Plantations

Projections up to 1985 are difficult to make since it is not known yet in particular what will be the pace of the follow-up of the IDA/ADB/GOL Program (1979–83) and of the main phase of the LFC program. It has been estimated very tentatively that the successfully planted areas during the whole period 1981–85 will amount to 7 500 ha of pines (of which 5 000 ha by LFC), 900 ha of teak and 1 600 ha of Gmelina and other fast-growing hardwood species, or a total of 10 000 ha of new plantations or 2 000 ha per year.

Areas of established industrial plantations estimated at end 1985
(in thousand ha)

CategorySpeciesYears81–8576–8071–7566–7056–6546–55before 46Total
Age class0–55–1011–1516–2021–3031–40> 40 
PHL 1 = PHLTectona grandis and others0.91.10.5    2.5
PHH 1 = PHHGmelina arborea, eucalypts and other fast-growing hardwood species1.62.41.2    5.2
PH.1 = PHSubtotal hardwood species2.53.51.7    7.7
PS.1 = PSPines7.51.1     8.6
P..1 = PTotal industrial plantations10.0  4.61.7    16.3  

A concentration of the plantation effort on pines for pulpwood may be contemplated while the plantations of hardwood species should decrease. Results of various trials presently under way should lead to improved growth, the more so as the proportion of plantations carried out by concessionaires would be much more reduced that during the preceding decade.


  1. FAO 1958 “Report to the Government of Liberia on the Timber Production Potential of Liberia” - by M.N. Gallant - FAO Report No. 952 - Rome

  2. International Cooperation Administration 1960 “Third Report on Forestry Progress in Liberia 1951–1959” - Washington

  3. FAO 1965 “Report to the Government of Liberia on Forest Land Use Policy and the College of Forestry in Liberia” - by J.H. Burgh and A.G. Friedrich - FAO Report No. 2051 - Rome

  4. Voorhoeve, A.G. 1965 “Liberian High Forest Trees - A Systematic Botanical Study of the 75 Most Important or Frequent High Forest Trees, with Reference to Numerous Related Species” - Wageningen (The Netherlands)

  5. German Forestry Mission to Liberia 1968 “General Report on National Forest Inventory in Liberia” - by M. Sachtler (and 11 other technical reports) - Reinbek (FRG)

  6. FAO 1975 “Liberia - Natural Resources Development: Establishment of a Concessions Secretariat - Forest Concessions” - by E. Jones - Report No. DP:LIR/71/515- Rome

  7. IBRD/IDA 1975 “Liberia- Growth with Development - A Basic Economic Report - Volume IV - Forestry and Forest Industries” - Washington

  8. Anonymous 1976 “African Forestry Commission - Fourth Session - Country Report of Liberia” - Monrovia

  9. FAO/IBRD 1976 Cooperative Programme “Report of consultant on Plantations” - by J. Burley - Rome

  10. Melvin Thornes, J. 1976 “Annual Report - Bureau of Forestry - Ministry of Agriculture - January 1–30 September 1976” - Monrovia

  11. Ministry of Agriculture 1976 “Statistical Handbook - Republic of Liberia” - Monrovia

  12. FAO/World Bank Cooperative Programme 1977 “Draft Report of the Liberia Forestry Project”- Report No. 26/77 LIB 4 - Rome

  13. Ministry of Agriculture 1977 “Production Estimates of Major Crops - 1976” - Monrovia

  14. Dow, L.E. 1978 “Progress Report - World Bank Project” (Memorandum of November 16, 1978 to FAO Headquarters) - Monrovia

  15. Forestry Development Authority 1978 “African Forestry Commission - Fifth Session - Liberia National Progress Report - Period 1976–1977” - Monrovia

  16. Forestry Development Authority 1978 “Eight World Forestry Congress - Jakarta (Indonesia) - 16–28 October 1978 - National Report on Forestry in Liberia” - Monrovia

  17. Woods, J.T. 1978 “Forestry Development Authority - First Annual Report for the Period May–June 1977 and July 1, 1977–June 30, 1978, submitted to the President of Liberia by the Board of Directors” - Monrovia

  18. Schmidt, G.W. 1979 “Comments on Dr. Verschuren's Draft Report on Liberia” - (Memorandum of October 5, 1977 to FAO Headquarters) - Monrovia


Madagascar s'étend sur 590 992 km2 (1 580 km du nord au sud sur une largeur de 450 à 570 km d'est en ouest) entre les 12° et 25°30' de latitude sud et les 43°15' et 50°30' de longitude est, à près de 400 km du continent africain dont elle est séparée par le canal de Mozambique.

L'île est un ensemble de hautes terres au relief tourmenté et dissymétrique, tombant à l'est sur l'Océan Indien par un escarpement abrupt, et s'inclinant à l'cuest par une longue pente vers le canal de Mozambique. Le point culminant atteint 2 876 m, au nord, dans le massif du Tsaratanana. Le relief forme un enchevêtrement complexe, morcelé, de massifs compacts, de sommets en pain de sucre, de collines, de plateaux et plaines élevées, de bassins, résultant d'un long travail d'érosion dans un très ancien plissement d'âge primaire. Sur le versant occidental allongé prennent appui des terrains sédimentaires (calcaires et grès) dans lesquels l'érosion a dégagé de grands bassins (Majunga, Morondava), ainsi qu'un relief de “côtes”, escarpements festonnés correspondant à la mise en saillie des couches dures, dépressions affouillées dans les formations tendres et plateaux. L'ensemble se termine à l'ouest par une côte découpée de baies et d'estuaires envasés et longée au nord-ouest, de bancs de coraux et d'îles (Nosy Bé). La plaine côtière orientale, étroite et rectiligne, est bordée de lagunes séparées par des seuils qui ont été creusés pour constituer une voie d'eau continue (canal des Pangalanes). Au nord, une région élevée qui juxtapose massifs cristallins, dômes volcaniques, plateaux calcaires et hauts bassins intérieurs, est d'accès peu aisé. Au sud, les plateaux calcaires du Mahafaly et de l'Androy dominent le rivage par des falaises escarpées.

Le climat est tropical et fondé sur l'alternance d'une saison sèche d'hiver (hiver austral, de Mai à Septembre), avec températures minimales en Juillet, et d'une saison humide d'été (été austral, d'Octobre à Avril), avec températures maximales en Janvier. La position en latitude d'une part, la configuration et le relief d'autre part, introduisent d'importantes nuances dans ce schéma général:

En outre, les côtes nord-ouest, nord et nord-est sont abordées en été par les cyclones tropicaux qui naissent sur l'Océan Indien ou sur le canal de Mozambique. Ils sont très dévastateurs et déversent des trombes d'eau sur les régions qu'ils touchent.

Le climat et la dissymétrie du relief donnent au réseau hydrographique ses traits particuliers: fleuves courts et torrentiels à l'est, cours d'eau plus longs et mieux hiérarichisés sur le versant occidental (Betsiboka, Tsizibihina, Mangoky, Onilahy). Ce sont encore les facteurs climatiques, ainsi que la nature cristalline du sous-sol, qui expliquent la large extension sur les plateaux des sols ferralitiques rouges.

La population, estimée à 9 329 000 en 1980 croît au taux élevé de 3,13% (UN/ESA Population Studies No. 60). La densité est en moyenne de 16 habitants au km2 mais est très variable suivant les régions. L'ouest et le sud n'ont de peuplement dense que dans quelques secteurs côtiers: les régions intérieures, vouées à l'élevage extensif, ont moins de 2 habitants au kilomètre carré. L'est, en revanche, surtout la plaine côtière, abrite plus de 100 habitants au kilomètre carré. Ce sont toutefois les Hautes Terres du centre, domaine d'une riziculture intensive et où se trouvent les plus grands centres urbains, qui ont les plus fortes concentrations humaines. La densité de la population y dépend surtout de l'existence de terres irriguées et est étroitement associée aux conditions topographiques et aux caractéristiques des sols.

La plus grande partie des terres, dans l'ouest et dans le sud, est le domaine de l'élevage des bovins (zébus). Ce dernier est partout extensif, livré aux pratiques traditionnelles des feux de brousse allumés en fin de saison sèche pour ranimer les pâturages. L'agriculture fournit au pays l'essentiel de ses revenus et constitue l'activité de base d'une population à 85% rurale. La riziculture s'implante de plue en plus, partout où il pleut suffisamment pour permettre soit la culture pluviale, soit la culture inondée.

1. Situation actuelle

1.1 Végétation ligneuse naturelle

La végétation forestière primaire a disparu de la majeure partie du territoire. La grande forêt ombrophile ne se rencontre plus que dans des secteurs réduits à l'est et au nord-ouest, dans le Sambirano. Détruite partout ailleurs par les incendies et les défrichements, elle a fait place à une formation dégradée, le “savoka”, forêt d'arbustes, riche en espèces ubiquistes et en bambous. Défrichée et incendiée à son tour, le savoka, à l'est et au centre, se dégrade peu à peu en savane. Les savanes couvrent de vastes étendues au centre et à l'ouest avec, à l'ouest, des espèces comme le baobab et les euphorbes, adaptées à une longue saison sèche. Dans le sud et le sud-ouest domine le “bush”, végétation buissonnante des régions semi-désertiques, avec un grand nombre d'espèces charnues et épineuses.

1.1.1 Description des types de végétation

La description suivante de la végétation ligneuse de Madagascar est essentiellement un résumé de celle faite dans le document (2), avec des détails supplémentaires extraits des documents (1),(6),(7) et (9).

Formations forestières feuillues denses (NHC)

(a) La forêt ombrophile orientale représente plus de la moitié de toutes les forêts denses du pays. Elle s'étend de façon plus ou moins continue du nord au sud et s'étage depuis la côte jusqu'aux plateaux et montagnes du centre. Dans l'ensemble, c'est une forêt très hétérogène, sans essences dominantes, d'environ 25 à 30 m de hauteur. Plus de 150 espèces y sont en mélange. Les gros arbres poussent rarement très droit, ont beaucoup de branches et sont couverts d'épiphytes, de mousses et de lichens. On n'y distingue pas de strates bien définies, mais le tout forme une association très dense, complexe et intimement mêlée. Les essences intermédiaires poussent plus droit et sont de meilleure forme que les essences dominantes. Le sous-étage est excessivement dense et contient souvent beaucoup de lianes et de bambous-lianes. D'une manière générale, la forêt est plus humide et plus riche vers le nord et vers le littoral. Sa vigueur et sa qualité diminuent du nord au sud et surtout d'est en ouest. La pluviométrie et la température y sont pour beaucoup. Les pluies qui atteignent 3 000 mm, ou même davantage, au nord, sont très inférieures à 2 000 mm au sud, et une différence du même ordre est observée d'est en ouest sur le versant oriental jusqu'à l'altitude de 1 000 mètres. On peut distinguer quatre types principaux de forêt orientale selon l'altitude:

(b) La forêt base sclérophylle des pentes occidentales de la chaîne orientale a presque tout à fait disparu par suite de l'action des feux périodiques. Les rares témoins, en voie de régression, de cette forêt sempervirente, ont une strate supérieure de faible hauteur (10–12 mètres), constituée principalement par un assez grand nombre d'espèces arborescentes telles que Uapaca bojeri, Leptolaena pauciflora, Sarcolaena oblongifolia, Asteropeia densiflora, Agauria salicifolia, Dodonaea madagascariensis, Faurea forficuliflora, Dicoma incana, Rhus taratana, Protorhus buxifolia et Cussonia bojeri. Les arbustes du sous-bois sont surtout des Philippia spp. Vaccinium spp., Helichrysum spp. etc. Les lianes sont assez nombreuses mais peu puissantes, les épiphytes assez rares, les bambous manquent. Il n'y a pas de strate muscinale, mais seulement des plantes basses vivaces éparses.

(c) La forêt tropophile occidentale est composée de quelques grands massifs (Bara, Manasamody, Bongolava, Ankarafantsika, entre Analalava et Ambato-Boeni et entre Antsalova et le Mangoky, ainsi que le long de ce fleuve) et de nombreux petits massifs entourés d'une savane en expansion. Les feux de brousse et l'exploitation forestière incontrôlée et parfois abusive gri gnotent systématiquement cette forêt qui est en voie de disparition assez rapide presque partout. La pluviométrie est d'environ 1 500 mm dans le nord-est et baisse progressivement jusqu'à 600 mm dans le sud-ouest, mais ce qui caractérise cette zone “sèche” de basse altitude, c'est surtout la longue période de sécheresse, qui dure de 5 à 7 mois. La caducité du feuillage pendant cette période oppose les formations ligneuses denses à celles de la zone orientale. Une des essences les plus typiques, fréquente surtout sur des terrains calcaires, mais non exclusivement, est Hildegardia erythrosiphon, grand arbre facilement reconnaissable par son port, à branches étalées, presque horizontales. Comme dans la forêt orientale, la futaie est en général dense, hétérogène et riche en essences, quoiqu'à un degré moindre. Les arbres dominants ne dépassent pas 20 à 25 mètres vers le nord et 15 à 20 mètres plus au sud, mais peuvent être assez gros. Néanmoins leur nombre et leur volume à l'hectare sont plus faibles que dans les forêts du nord-est. Le sous-bois est très dense, mais la végétation herbacée est plutôt pauvre. Les épiphytes sont rares. On a groupé les forêts de l'ouest en quatre catégories en relation avec la grande diversité des terrains:

(d) Sur les sols salés limoneux, exposés directement aux alternances des marées, la mangrove est présente dans l'extrême nord près de Diégo-Suarez et se retrouve jusqu'au sud du Morombe, presque exclusivement sur la côte occidentale. Les espèces qui la constituent sont: Rhizophora mucronata, Bruguiera gymnorhiza, Ceriops boiviniana, Avicennia officinalis et Sonneratia alba. A ces espèces se mêlent fréquemment Heritiera littoralis, Terminalia catappa, Thespesia populnea, Derris uliginosa et sur les bords de ces peuplements Casuarina equisetifolia ainsi qu'une grande fougère Acrostichum aureum. Le plus important massif borde l'estuaire de la Betsiboka. D'intérêt économique considérable, la mangrove est largement exploitée (écorces à tanin des Rhizophora, Ceriops et Bruguiera et bois de feu) et se régénère facilement dans des conditions normales.

(e) Certaines parties marécageuses dans la zone occidentale se trouvent parfois occupées par des formations assez homogènes, telles que les raphiales sur des dépressions à fond argileux. Le palmier Raphia ruffia y forme des peuplements presque purs, avec deux fougères, Nephrodium unitum et N. cucullatum. Sur les terrains cristallins, où les marécages sont temporaires, on trouve Ficus sakalavanum avec des Phragmites. Par contre, sur les terrains calcaires, Typha angustifolia ainsi que la fougère Acrostichum aureum, sont abondantes.

(f) Des vestiges de galeries forestières différant peu de celles qui bordent les fleuves de l'ouest, existent le long des cours d'eau dans la zone semi-aride méridionale. Parmi les essences les plus puissantes, on trouve Colvillea racemosa, Eugenia sakalavarum, Protorhus grandidieri, Ficus spp., Tamarindus indica etc…, la plupart à feuilles persistantes

(g) Le terme malgache “savoka” désigne des formations secondaires, d'aspect et de composition très divers qui succèdent directement à la forêt dense détruite par la culture itinérante (abattis suivis de l'incinération de ce qui a été abattu) (voir aussi paragraphe 2.1.1). Les espèces aptes à occuper le terrain immédiatement après l'abandon de la culture temporaire sont peu nombreuses. Elles forment des peuplements souvent presque impénétrables et généralement à peu près purs. Dans l'est, ce sont principalement des bambous (Ochlandra capitata, Arundo madagascariensis), Afromomum angustifolium, Daniellia ensifolia, Psiadia altissima, Philippia sp., Solanum auriculatum et Harungana madagascariensis. Ce dernier est un petit arbre qui forme sur des surfaces étendues des peuplements secondaires simulant une forêt à peu près pure avec sous-bois de Pteridium aquilinum et Lycopodium clavatum, auxquels se mêle un petit nombre d'espèces autochtones, comme Tristemma virusanum, ou naturalisées: Psidium guyava, divers Citrus etc. Plus au centre, les savoka de moyenne altitude (800 à 1 300 m) comprennent notamment: Solanum auriculatum, Harungana madagascariensis, Ravenala madagascariensis, Trema orientalis, Dombeya spp. et des bambous. Les savokas feraient retour à la forêt si le paysan ne les détruisait à leur tour, lorsque la forêt primairs commence à manquer, pour y établir de nouvelles cultures, ou lorsqu'il veut augmenter la surface de la savane pour l'élevage des bovins. Ces formations secondaires sont très étendues dans la zone orientale du pays.

Formations forestières feuillues ouvertes (NHc/NHO)

Dans la zone orientale, après culture prolongée, le savoka est envahi par des graminées qui transmettent les incendies et amènent la régression de la végétation ligneuse secondaire. Les savanes qui en résultent, sont donc d'origine anthrophique, pas climatique. Elles sont recouvertes de hautes graminées, Hyparrhenia rufa dominant sur les bons sols, et Eleusina indica et Pennisetum sp. sur les terrains plus dégradés. Leur hauteur atteint suivant les cas de 1,5 à 3 mètres. Peu nombreuses sont les espèces qui résistent aux incendies répétés; c'est le cas du Ravenala madagascariensis qui supporte le passage des feux et se retrouve ainsi piqueté dans le paysage. Quelques espèces de la futaie de la forêt basse sclérophylle des pentes occidentales, dont le Uapaca bojeri, se sont répandues dans la savane secondaire relativement récente, mais finissent par disparaître devant la répétition des incendies qui détruisent les jeunes individus. Ce sont surtout Dicoma incana, Stereospermum euphorioides et Acidocarpus excelsus. Cependant des individus âgés et très dissemines d'autres espèces ont résisté aux feux grâce à leur écorce pratiquement incombustible et à l'absence de graminées sous le couvert de leur feuillage. Tel est le cas de Brachylaena ramiflora, d'un Nuxia et d'un Ficus.

Les savanes de la zone occidentale sont essentiellement formées de hautes graminées (Hyparrhenia spp.) plus hautes et en général plus denses que celles de l'est ou le centre. Sur les sols fertiles, où les formations graminéennes sont plus puissantes et où par la suite les incendies sont les plus violents, les arbres et les arbustes manquent. Sur les sols plus ou moins arides, sablonneux ou rocailleux, où les graminées sont moins denses, la savane est parsemée d'arbres ou d'arbustes. De nouveau elle est d'origine anthropique (voir 2.1.1.). Cependant, la forêt occidentale présente un certain nombre d'espèces ligneuses aptes à supporter le passage des incendies et même à se multiplier dans les formations graminéennes, au début de leur extension. Parmi celles-ci plusieurs espèces de palmiers sont particulièrement résistantes aux feux. La plus remarquable à cet égard et la plus fréquente dans la plus grande partie de la zone est Medemia nobilis. Un autre palmier, abondant surtout sur les terrains sableux, est Hyphaene shatan. Beaucoup moins étendue est l'aire du Borassus madagascariensis. Qutre ces palmiers les autres arbres les plus fréquents dans les savanes de l'ouest sont, par ordre d'abondance décroissante: Sclerocarya caffra, Acridocarpus excelsus, Stereospermum euphorioides et Incoma incana, auxquelles se joignent quelques arbustes qui, pour la plupart, sont éliminés par l'attaque trop fréquente des incendies: Strychnos spinosa, Gymnosperia linearis, Bridelia pervilleana, Terminalia seyrigii et Grewia triflora.

Formations (essentiellement) arbustives (nH)

Le fourré dense des hautes montagnes (aux altitudes supérieures à 2 000 m) forme des peuplements d'étendue variable dispersés du nord au sud de l'île, présentant toutefois en commun des caractères qui confèrent à l'ensemble une certaine unité quant à la physionomie de la végétation et quant à sa composition floristique. Cette végétation est constituée principalement par de nombreuses espèces de bruyères (Ericacées) arborescentes (Philippia) et de Composées (Psiadia, Senecio, Vernonia). Certaines espèces sont communes à plusieurs massifs, tandis que quelques genres présentent dans les divers massifs des espèces endémiques presque à chaque massif montagneux. Tel est le cas de Heteromorpha sp., Helichrysum sp. etc. Les genres Syncephalum, Vaccinium, Kosteletzkia, Dialypetalum, Nicodemia, Gentianothamnus, Radamaea, Terminalia, Aristea et Arthropodium sont représentés chacun par une ou deux espèces endémiques. De loin en loin, quelques arbres dépassent de peu l'ensemble: Agauria salicifolia (Ericacée), Ilex mitis, Cussonia bojeri, Alberta minor, Dodonaea madagascariensis, Tambourissa gracilis, Podocarpus rostratus, Vitex humbertii, Pittosporum chysophyllum, Faures forficuliflora, Weinmannia spp. etc. Les lianes manquent presque totalement et les épiphytes sont très peu nombreux. La strate muscinale et lichénique est disjointe et les plantes herbacées sont plutôt rares.

La fréquence des défrichements et le passage répété des feux ont dégradé la forêt originale en brousse éricoïde à Helichrysum, Philippia, Agauria et Pteridium. De la dégradation de la forêt tropophile, d'autre part, résulte le “bois-fourré” avec une strate arborée discontinue dominante et une strate buissonnante plus ou moins dense.

Une végetation xérophile riche en espèces occupe la zone semi-aride sud où la pluviométrie annuelle est comprise entre 300 et 500 mm. La plus grande partie est formée de plaines et de plateaux de faible altitude comprise entre 200 et 400 m. Deux groupes de végétation caractérisent le paysage du point de vue physionomique: d'une part la famille endémique des Didiéréacées (Didierea madagascariensis, D. trollii, Alluaudia procea, Decaryia madagascariensis et Alluaudiopsis sp.), d'autre part le genre Euphorbia (Euphorbia stenoclada et E. laroo). Ces arbres, peu élevés, atteignant au plus 10 à 12 mètres ne constituent pas des forêts, mais, avec quelques autres bien plus clairesemés, Adansonia za, A. fony, Tetrapterocarpon geayi, Dicoma incana, D. carbonaria, Gyrocarpus americanus, Maerua filiformis et Ficus marmorata, ils dominent plus ou moins lächement des fourrés assez clairs sur les sols rocailleux, plus denses et difficilement pénétrables ailleurs. Les espèces ligneuses constituant ces fourrés appartiennent aux genres Acacia, Chadsia, Commiphora, Grewia, Solanum, Dichrostachys, Iphiona, Uncarina, Jatropha, Gardenia, Rhigozum, Cadaba, Megistostegium, Sclerocarya et bien d'autres. Les lianes, de faible dimensions, sont assez abondantes. Les arbres, les arbustes et les lianes sont en partie aphylles ou à feuillage réduit persistant ou caduque. Les plantes épineuses sont en forte proportion, ainsi que les espèces à feuilles épaisses, succulentes. Les plantes plus ou moins basses sont éparses sur le sol, y compris les graminées, des Abutilon, de petits Aloe, Senecio etc. Un curieux palmier à feuilles tristiques, Neodypsis decaryi, est propre à la partie orientale de la zone sud, sur les pentes inférieures des premières montagnes qui la bordent.

Dans les marécages salés, la flore comprend un nombre de genres caractéristiques de ces conditions écologiques particulières, représentés ici par des arbustes ou des herbacées: Erblichia, Turnera, Flumbago, Salicornia sp., Salvadora angustifolia, Cryptostegia pluchea etc. Scaevola koenigii, S. plumieri et Lumnitzera racemosa sont des arbustes communs sur les dunes qu'ils contribuent à fixer.

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