The Global Forest Resources Assessment 1990 provides comprehensive information on the current state of global forests and recent changes including area, growing stock, management and conservation. Some information related to the environmental functions of forests is also given.
The FAO 1990 survey was implemented by following similar institutional arrangements, as those used in the previous studies. FAO/ECE, Geneva, was responsible for assessment in developed countries whilst FAO, Rome, conducted the assessment in developing countries as well as the global synthesis.
The objectives of the assessment were to: (i) provide reliable and globally consistent information on the state of forest resources at the end of 1990 and on the extent of changes between 1980 and 1990; and (ii) undertake special studies related to environmental functions of forests.
An overview of main results of global forest resources assessment is given in Table 1.
The global assessment included 179 countries with a total land area of 12 900 million ha. Forests constituted slightly over 3,400 million ha or 27 percent of the land area. The total growing stock was 384,000 million m3 and growing stock per ha 114 m3.
Forests of the developed regions represent about 41 percent of the global forest area and 43 percent of the total growing stock. In most of the developed countries, net annual increment has been higher than fellings for several decades and consequently there has been a rise in growing stock, despite an overall increasing trend in fellings. The area of forest in the developed regions remained more or less unchanged over the decade 1980 to 1990.
Forests of the developing region represent about 59 percent of the total forest area of the world and 57 percent of the total growing stock. For several decades deforestation and forest degradation have been occurring on an accelerated scale. The loss of forest area during 1980-90 amounts to 163 million ha,of which 154 million ha in the tropics.
During 1980-90 global forests were a net source of 0.9 ± 0.4 Petagrams (Pg) (= 900 ± 400 million tons) of carbon to the atmosphere. Tropical forests served as a source of 1.65 ± 0.4 Pg (1650 ± 400 million tons) of carbon and temperate forests as a sink of 0.74 ± 0.1 Pg of carbon.
The significant reduction in biodiversity coupled with the continuing process of deforestation in developing countries remain major concerns, as does the protection of the environment and nature conservation in the developed regions.
Mainly as a result of population growth and shrinking forest area in the developing regions, per caput forest area fell globally from an average of nearly 1.2 ha in 1960 to 0.6 ha in 1990 and it is projected to be less than 0.2 ha by 2020.
If the population of the world grows as projected by the UN during 1990-2020, deforestation and forest degradation trends are expected to continue and even to worsen, unless policies are set and implemented to conserve the world's forest resources. The problems of local wood shortage, land degradation, global warming, and biodiversity loss are expected to be exacerbated.
At the local level there is emergence of forest management practices with participation of local communities in the developing countries, and the valuation of environmental functions of the forest in the developed countries.
The recognition of environmental functions of forests is increasing both in developed and developing countries as evidenced by the adoption of international conventions on change and biological diversity and of a statement of forestry principles at UNCED 1992. There is a rapidly rising demand for reliable forest resources information at global, regional and national levels, in particular, related to environmental function of forests such as biomass and biological diversity. The 1990 assessment indicates a lack of adequate institutional capacity in both the developing and developed countries to cope with this demand. A concerted effort is required at the national as well as international level to build the needed capacity, as recommended in chapter 11 of UNCED Agenda 21, in order to understand and solve the pressing problems of the world's forests.