Previous Page Table of Contents Next Page

Chapter I: The Issues

1. Rationale of the study and the issues raised
2. The scope of this paper
3. The countries in question

1. Rationale of the study and the issues raised

Survival conditions in dry tropical zones are often precarious. Over the past few decades, recurrent drought periods, together with population growth have thrown the ecosystems into turmoil. Gathering of fuelwood and extraction of other products from the forests have intensified around large towns. Traditional resource management systems are no longer able to effectively cope with these new situations. Fallow periods are increasingly being curtailed, soil is becoming ever less fertile, land clearance for agricultural purposes is being stepped up, overgrazing is increasing and fuelwood needs are constantly rising.

Wood is the main source of energy used by individuals in dry tropical zones as it accounts in most cases for over 85 percent of their energy sources. However, it is becoming increasingly difficult to acquire, particularly around large towns and therefore it has to be sought further away. Because supplies fail to meet the demand, the resource is becoming increasingly more scarce and is being overharvested. This is creating regular shortages, comparatively frequent in some towns. If population growth and current fuelwood consumption trends continue, this is likely to become a permanent feature that will lead to a substantial energy deficit. This is already the case in Africa, in the Sudano-Sahelian domain where there has been a decline in the consumption of wood products, from 1 to 0.74 m3 per person per year in recent years (Sharma et al., 1994). This decline is not attributable to the modernizing of homes and/or to a recourse to substitute energy sources. Beyond absolute and accurate figures, what matters most is being aware of this symptomatic downward trend.

This overharvesting of forests, together with land clearance for agriculture and sometimes, overgrazing reduces their numerous functions and the services they provided previously. These are being threatened not only by deforestation, but also by the reduction of biodiversity which affects the subsisting tree cover formations.

Lastly, we note that the disorder which is taking place as a result of the above, is leading to a fairly unproductive and dangerous use of the resource.

Table 1: Deforestation in the dry zones

Area of the zones

Area with forest cover


(million ha)

(million ha)

(percentage of zone)

Yearly average
(million ha)

Percentage of annual loss







Latin America













1 249.1





Source: FAO, 1993-b

The difficulties encountered by renewable resource management systems because of shortages in fuelwood resources, threats to food security, reduction of genetic diversity and deforestation have been identified in a number of national plans to combat desertification. These were debated at the United Nations Conference on Environment and Development in Rio de Janeiro, 3-14 June 1992. A number of principles and guidelines adopted at that conference, which are here used as references and benchmarks for this paper, are set out in the ‘Declaration of Forest Principles’ and in Agenda 21 and refer in particular to:

- recognition of the sovereign right of nations to manage their own forests based upon respect for sustainable national development;

- access by all to updated, reliable and accurate information on forest resources;

- participation of all the parties involved in framing and implementing forest policy; and

- importance of all types of forests in the maintenance of ecological processes.

Chapter 11 of Agenda 21 published at the Rio Earth Summit relating to forests stated that its specific objective was: “to prepare and implement, as appropriate, national forestry action programmes and/or plans for the management, conservation and sustainable development of forests.” One of the objectives is “to ensure sustainable management and, where appropriate, conservation of existing and future forest resources (...)”. More specifically, and with regard to tropical countries, Agenda 21 insists on “the importance of national policies and legislation and of strengthening of national institutions as a preliminary step in achieving sustainable development.” (CEE, 1994)

Furthermore, the International Convention to Combat Desertification was adopted on 17 June 1994 in Paris, signed by 114 countries and the European Union. It became effective in December 1996.

This realization has made it possible to focus the aspirations and interests of all the users of forest ecosystems around a commonly agreed objective, namely sustainable and integrated forest management. But the situation at the same time, continues to deteriorate. The effects of the many causes of deforestation and degradation of forests (climate, demography, politics, land tenure, agriculture) are worsening and many aspects of what is happening in these ecosystems evade us. These shortcomings reflect the limitations of our knowledge and of its dissemination. Yet over the past 10 to 15 years, much has been undertaken. Pilot projects have attempted to work out new management methods, and experimental designs have been established and monitored. Knowledge, know-how and their practical application have all improved, but they are still inadequately disseminated.

In view of all these developments it became necessary to take stock and to try to publish a general document of direct utility for the main users in the countries concerned. That is the purpose of this paper. However, it only deals with natural forests, and will not address plantations or trees in agricultural systems.

2. The scope of this paper

This paper deals with the areas shown in Map 1, in which:

- annual rainfall over the past 10 to 15 years ranges between 300 and 1,200 mm; and
- there are between five and 10 dry months a year, namely, months with rainfall below 30 mm.
As far as Africa is concerned, excluding the extreme climates I and V (the Guinean forest and Saharan climates) this partly covers climates II, III and IV as defined by Aubréville (1949), namely:
- sub-humid tropical climates of the Sudano-Guinean type (in part);
- dry tropical climates of the Sahelian-Sudanian type (mainly); and
- dry tropical climates of the Sahelian-Saharan type.
Map 2 shows all the dry tropical woodlands in Africa (Menaut, 1983), while Map 3 shows only the forests in Africa south of the equator.

Main areas studied:

In Africa, in the Sahelian-Sudanian-Zambezian region (Map 4):

* the Sudanian and Sahelian domains in the centre and the west;
* part of the eastern domain to the east;
* the Zambezian domain (and the north-eastern part of the Kalahari);
* in Madagascar, the south and west coasts; and
* the southernmost tip of the Arabian Peninsula (Yemen).
In America (Map 5):
* zones of north-east Brazil (campos cerrados and caatingas);

* Chaco in Paraguay, Bolivia and Argentina;

* northern Venezuela;

* in Central America, the western half of Mexico (Mezquitales, Chapparales) and Yucatan and a common fringe area between Guatemala and El Salvador and the central area of Nicaragua; and

* in the Caribbean, Haiti and the Dominican Republic on the south and west coasts.

In Asia (Map 6):
* dry woodlands in the Indian Peninsula as far as the Thar Desert;

* Himalayan foothills in Pakistan; and

* centre of the Indo-China Peninsula, mainly Thailand, but also the southernmost part of Laos, the north of Cambodia and the centre of Myanmar.

Conversely, the following areas are not discussed in this paper:
- dry environments with a Mediterranean climate;
- dry zones of Australia and the Pacific;
- parks or savanna-parks and agro-forests;
- mangroves in the dry countries;
- irrigated perimeters in dry zones;
- savannas forming part of moist forests; and
- mountainous regions in all these zones.
Map 1 is based on the maps published in Répartition mondiale des zones arides (Unesco, 1977), the vegetation map of Africa (White, 1983), modified with the help of the climatological atlases of Central and South America and Asia (WHO/Unesco, 1975 and 1979) and of Africa (Jackson, 1961).


3. The countries in question

The main countries that make up the dry zones defined above are indicated in Table 2.

Table 2: Countries covered by this paper





Benin (north)

South Africa (north)

Argentina (north)


Burkina Faso


Bolivia (south)


Cameroon (north)


Brazil (north-east, central and south)

India (central and north)

Côte d’Ivoire (north)


Colombia (north)

Laos (south)



Costa Rica (east)


Ghana (north)

Madagascar (south and west)

El Salvador


Guinea-Bissau (north)


Guatemala (east)

Viet Nam (central and north)




Mauritania (south)

Namibia (east)

Mexico (east)



Nicaragua (central and east)

Nigeria (north)

Somalia (west)

Paraguay (north-east)

Central African Republic (north)


Dominican Republic



Venezuela (north)



Togo (north)

FAO’s records (1993) indicate that about 66 percent of the world’s dry and very dry ecological zones lie within the African continent. According to the tropical forest resources evaluation carried out by FAO in 1990, 52 percent of the dry deciduous forests are found in Africa, 23 percent in the Asia-Pacific region and 25 percent in Latin America. While the proportions may vary considerably according to definitions used, it remains obvious that the dry tropical woodlands are mainly in Africa.

International funding for dry tropical forest management at the present time is mainly directed to Africa. Few natural forest management projects exist in Asia or Latin America. Therefore, many of the references cited below refer to Africa.

Previous Page Top of Page Next Page