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PART I - SITUATION AND PROSPECTS FOR FOREST CONSERVATION AND DEVELOPMENT

The status of forest resources

Information on the status of the world's forests - their extent, location, type and condition - is important for efforts to improve forest management worldwide and for assessments of forests' ability to provide the goods and services demanded of them. The following discussion focuses on two subjects: the area and condition of forest resources worldwide, and the status of the information base on global forest resources, particularly concentrating on information on forest area and forest-based biological diversity.

STATUS OF FOREST RESOURCES AND RECENT DEVELOPMENTS IN FOREST CONDITION

Forest cover1

The area of the world's forests, including natural forests and forest plantations, was estimated to be 3 454 million hectares in 1995, or about one-fourth of the land area of the Earth. About 55 percent of the world's forests are located in developing countries, with the remaining 45 percent in developed countries (Figure 1) (see Table 2 of Annex 3 for country data). The world's forests are almost equally divided between tropical/subtropical forests and temperate/boreal forests. Only about 3 percent of the world's forests are forest plantations. The remaining 97 percent are natural or semi-natural forests.

 

FIGURE 1
Forest areas by main regions in 1995

 

Change in forest cover

Data published in the State of the World's Forests 1997 (FAO, 1997d) provide a picture of the trends in forest cover over a 15-year interval (1980-1995) and allow a comparison between the 1980-1990 and 1990-1995 periods. Between 1980 and 1995, the extent of the world's forests (including both natural forests and forest plantations) decreased by some 180 million hectares. There was a net increase of 20 million hectares in developed countries, but a net loss of 200 million hectares in developing nations. The change in forest area by region between 1980 and 1995 is shown in Figure 2.

 

FIGURE 2
Forest area in 1995 as compared with 1980

Note: Data exclude the countries of the former Soviet Union.

 

Between 1990 and 1995, there was an estimated net loss of 56.3 million hectares of forests worldwide. This represented a decrease of 65.1 million hectares in developing countries and an increase of 8.8 million hectares in developed countries. Although the global loss of forests was still very high, the figures suggest that the rate of deforestation might be slowing. The estimate of forest cover change in natural forests of developing countries (which is where most deforestation is taking place) was an annual loss of 13.7 million hectares between 1990 and 1995, compared with 15.5 million hectares per year over the decade 1980-1990. It will be difficult to know if this is a trend, however, until a comparable global data set is available from the Global Forest Resources Assessment 2000 (see following discussion).

The major causes of change in forest cover in the tropics appear to be expansion of subsistence agriculture in Africa and Asia and large economic development programmes involving resettlement, agriculture and infrastructure in Latin America and Asia (FAO, 1996a). The net increase in forest area in developed countries is largely a result of afforestation and reforestation, including natural regrowth on land abandoned by agriculture. This increase has more than compensated for the clearing of some areas of forest in various developed countries, mainly for urban expansion and infrastructure development.

Forest condition: fire, ice and forest pests

The causes of forest degradation vary from place to place, and the magnitude and duration of the effects are often difficult to assess. The causes include insect pests and diseases, fire, overharvesting of industrial wood and fuelwood, poor harvesting practices, overgrazing, air pollution and extreme climatic events, such as storms. Particularly noteworthy causes of forest degradation in the 1997-1998 period were the dramatic wildfires that affected forests throughout the world, the 1998 ice storms in the United States and Canada and new insect pest and disease outbreaks.

Globally, 1997 and 1998 were the worst years for wildfires and forest fires in recent times. Although forest fires occur every year in the arid and semi-arid zones of the world, nearly all types of forests burned in 1997-1998, even some tropical rain forests which had not burned in recent memory. Droughts associated with the El Ni�o weather pattern (see Box 1) turned moist forests into drier habitats and increased the flammability of forest vegetation, thus increasing the number, frequency, size, intensity and duration of fires.

 

BOX 1
The 1997-1998 El Ni�o southern oscillation:
El Ni�o and La Ni�a


The El Ni�o Southern Oscillation (ENSO) is a periodically occurring oceanic-atmospheric phenomenon. It consists of El Ni�o, a "warm phase" or a large-scale warming in the equatorial Pacific Ocean, and La Ni�a, a "cool phase" in which surface waters of the central Pacific Ocean are colder than normal. These phases are closely associated with changes in atmospheric conditions (Southern Oscillation). ENSO events occur on average every four years and typically last 14 to 22 months. They exhibit certain characteristic rainfall and temperature anomalies. The El Ni�o that began in March 1997 and continued until mid-1998 is believed to have been one of the most severe in recorded history. It had a pronounced impact on weather and climate around the globe. While some parts of the world received more rain than normal, abnormally dry conditions occurred across northern Australia, Indonesia and the Philippines in both seasons and in southeastern Africa and northern Brazil during the northern winter season, and Indian monsoon rainfall was lower in the northern summer season. The record-high global temperatures in 1998 were also believed to be linked to El Ni�o. La Ni�a started to develop in mid-1998. Climatic anomalies in 1998 which may be associated with La Ni�a include dry conditions in parts of South America; wetter than normal conditions in northern Australia and the Philippines; above-normal rainfall during the southwest monsoon in India; increased hurricane activity in the Caribbean and Central America; dry spells in parts of Argentina and Chile; above-normal rainfall in southern Africa, with the exception of Zimbabwe; and possibly drier than normal conditions in the Horn of Africa.

 

In 1997, wildfires raged in Indonesia, Papua New Guinea, Australia, Mongolia, the Russian Federation, Colombia, Peru, Kenya, Rwanda and other parts of Africa. By mid-1998, fires were reported in Indonesia, the Amazon, Mexico and Central America, the United States, western Canada, far-eastern Russia and parts of Europe. National disasters were declared in many of these places and national and international resources were mobilized to fight the fires. Neighbouring countries and international and non-governmental organizations (NGOs) all responded. In March 1998, the Secretary-General of the United Nations requested the United Nations Environment Programme (UNEP) to coordinate the UN system's response to the situation arising from the outbreak of forest fires in Indonesia.

Few global figures are available on the extent of the 1997-1998 fires and associated loss of life, economic damage and environmental impacts.

The largest areas of forests burned in Brazil and Indonesia. Low rainfall in much of the Amazon attributed to the El Ni�o weather pattern contributed to a prolonged fire season (beyond the usual July to early October period) and an unusually high number of fires. In 1997, over 2 million hectares of rain forest in Brazil burned (Schemo, 1998). Analysis of satellite data from the United States National Oceanic and Atmospheric Administration showed an increase of over 50 percent in the number of fires from July to November 1997 compared with the same period in 1996, and an 86 percent increase in a 100-day period (June to early September) in 1998 compared with the same period in 1997 (Schwartzman, 1998). Most of the fires occurred in Mato Grosso and Par� states.

Some Brazilian forests of particular ecological or cultural significance were affected. In March 1998, fires burned over 600 000 ha of rain forest in Roraima, including parts of the Yanomami Indian reserve, near the border with Venezuela (Schemo, 1998). In late September 1998, raging fires destroyed a large area of Brasilia National Park - a sanctuary for rare species from Brazil's central savannah region - killing wildlife and smothering the Brazilian capital with smoke. Earlier in the month, fire in the state of Mato Grosso threatened to move into Xingu National Park, home to 17 indigenous groups, until rains extinguished the fire.

In Indonesia the fires of 1997-1998 burned millions of hectares in Sumatra and Kalimantan. The exact area is still unknown. One estimate is that about 2 million hectares (including savannah with grassland) burned in 1997 alone. Several organizations have begun the lengthy and complex task of interpreting satellite images to determine the total area burned (Schweithelm, 1998). Large quantities of smoke generated by ground fires fed by slow burning fuels affected neighbouring countries, influencing human health, interfering with transportation systems and disrupting the multi-million-dollar tourist industry, all of which contributed significantly to the economic and social cost of the fires. Many underground fires continued to burn into mid-1998 in natural peat and coal beds, threatening new outbreaks of fire.

A representative sample of forest fires elsewhere in the world includes the following:

Active media coverage of the unusually large fires in Indonesia, the Amazon and Mexico increased public awareness of these predominantly man-made environmental disasters. The smoke from the fires, which endangered public health and economies beyond national borders, also helped focus public attention on the fires and the need to deal with policy issues related to fire outbreaks.

The use of fire is an integral part of land management in both agriculture and forestry. Some forests are ecologically adapted to fire, and prescribed burning is an important component of forest management practices in some places. However, there is ample evidence that a large proportion of the wildfires that occur each year are caused by human intervention. A seven-year field study of fire in the Amazon carried out by the Woods Hole Research Center, United States, shows that about half of the wildfires in the region were caused by fires set by farmers and ranchers to clear old cattle pasture and to burn newly cut forest which subsequently burned out of control. The effects of drought in 1997-1998 were aggravated by shifting cultivation (particularly slash-and-burn agricultural practices), pasture management, improperly executed timber harvesting operations and large-scale land clearance under agricultural conversion schemes. A considerable number of fires that burned around the world in 1997-1998 (as in other times) were cases of arson. The fires of 1997-1998 clearly highlight the need to improve planning and management of agricultural land use practices to reduce the risk of wildfires; to address deficiencies in forest management systems; and to examine policies and regulations related both to conversion of forest land to agriculture and to improvement of forest stewardship.

The fires of 1997 and 1998 have stimulated various international efforts related to fires. A global system of early warning to indicate the potential fire risk related to climatic conditions is being investigated by several international organizations, including the World Health Organization (WHO), the World Conservation Union (IUCN), UNEP and FAO. A national system for advance warning by radio linked to meteorological forecasts from satellite imagery has been successfully tried in Burkina Faso. WHO has produced guidelines for forest fire emergencies. Many national and international meetings were organized in 1998 for fire-fighting and health experts, potential donors and, perhaps more significant, policy-makers to address the control, effects and underlying causes of fires. UN agencies that organized fire meetings in 1998 include UNEP and the United Nations Office for the Coordination of Humanitarian Affairs (Geneva, Switzerland, April 1998), WHO and the Pan-American Health Organization (Lima, Peru, August 1998) and FAO (Rome, October 1998, on public policies affecting forest fires).

Apart from the fires, 1998 was notable for another type of disaster which severely affected forests: ice. A series of ice storms in January 1998 resulted in extensive damage to forests in the northeastern United States and eastern Canada (see Box 2). An estimated 10 million hectares of forests and trees were affected, extending from Ontario to Quebec and New Brunswick in Canada and across northern New England in the United States (Irland, 1998).

 

BOX 2
Effects of the ice storm in the northeastern
United States in January 1998


In January 1998, in what meteorologists called a "100-year event", a series of ice storms blanketed northern New England and New York with up to 7.5 cm of ice. Nearly 7 million hectares of rural forests and urban trees across the states of Maine, New Hampshire, Vermont and New York were affected. Some 2 million hectares were severely damaged. Hardwood species suffered most. Estimates for natural resource losses exceeded US$1 000 million. The effects of the storm remain: thousands of kilometres of forest roads and trails are littered with debris; many rural landowners will lose forest income; management plans may be obsolete and need costly revision; and debris increases the risk of insect pest outbreaks and fire.

Source: USDA Forest Service, 1998.

While less visible than the wildfires and ice storms within the last two years, recent outbreaks of insect pests and diseases in forests may result in substantial economic loss and environmental damage. Although insect pests and diseases are often integral components of forest dynamics, severe outbreaks can be damaging and require costly control efforts. Their incidence and economic impact may be highest on plantations established for the purpose of wood production. Some new pest outbreaks reported in the last few years are noted in Box 3.

 

BOX 3
Recent insect pest and disease outbreaks


In the Philippines, new insect pest outbreaks include the moths Nyctalemon spp. on Endospermum peltatum and Xyleutes spp. on Gmelina arborea, which are affecting plantations, and the scolytid beetle Dryocoetiops laevis on Dipterocarpus grandiflorus in secondary forests. The giant wood moth (Endoxyla spp.) and the cerambycid beetle (Phoracantha spp.) are becoming significant new threats to eucalyptus plantations in Queensland, Australia. The Asian long-horned beetle, Anoplophora glabripennis, is affecting urban hardwoods in New York and Chicago, United States. The gypsy moth (Lymantria dispar) is affecting thousands of hectares in eastern Europe and Turkey. New disease problems include Phythopthora spp. on Elmerrillia seedlings in Indonesia and root rot of Acacia mangium in the Philippines caused by Phellinus noxius.

Climatic extremes associated with El Ni�o in 1997-1998 (see Box 1) are thought to be linked to some of the current severe pest outbreaks affecting forests and trees. For example, a serious outbreak of gypsy moth (Lymantria dispar) which is posing a risk to northern European forests is believed to have been exacerbated by increased temperatures and prolonged drought conditions over the last two years. The outbreak, which started in 1996 and was still ongoing in mid-1998, is affecting thousands of hectares of valuable hardwoods (particularly oaks) in Bulgaria, Croatia, Romania and Serbia.

 

STATUS OF EFFORTS TO ASSESS GLOBAL FOREST RESOURCES

Forest resources assessment

Forest resources assessments generally provide information on forest extent and location, types, condition, wood volume, and/or biomass. They may be done on a subnational, national, regional or global level. Global assessments are done in one of two ways: using a bottom-up approach which harmonizes and sums national statistics, or using a top-down approach in which data are generated at the regional, continental or global level. National forest inventories are fundamental to bottom-up approaches to forest resources assessment (see Box 4).

 

BOX 4
Importance of forest inventories as a basis
for sustainable forest management


Forest inventories and statistical systems serve as the foundation of sound policies to support sustainable forest management. Integrating social, economic and environmental concerns into forest-sector planning requires a great deal of information on forests, across the landscape and through time. Studies repeatedly come to the same conclusion: much better information is needed on the quantity, quality and use of forests. Despite growing demands for better information, investments in even basic forest inventories are declining. Many countries have not conducted a comprehensive and statistically sound forest inventory since the 1970s or early 1980s. In other countries, physical inventories are declining in frequency and intensity and are being replaced by modelling. New methods, such as remote sensing, are expanding the ability to observe large changes in land cover. Still, without reasonably current forest inventories, it is increasingly difficult to assess change in forest quality and function and to draw useful conclusions about the sustainability of use.

 

The major global forest cover assessment efforts are being carried out by FAO, the International Geosphere-Biosphere Programme (IGBP), the European Commission's Joint Research Centre (JRC) and the World Conservation Monitoring Centre (WCMC). FAO and WCMC mainly use a bottom-up approach, which provides the most detail at the country level. IGBP and JRC use a top-down method, which provides spatial information on forest cover over broad areas. The FAO, JRC and IGBP assessments are ongoing, long-term programmes.

Currently available information. FAO, in collaboration with other partners, has been conducting global forest resources assessments about every ten years since 1947. The latest Forest Resources Assessment (FRA), which was done for 1990, was carried out jointly by FAO, the United Nations Economic Commission for Europe (ECE) and their member countries (FAO, 1995).2 FRA 1990 was divided into two parts: one for the industrialized countries (the temperate and boreal forests) and the other for developing countries (mainly tropical and subtropical, but also some temperate forests). ECE and FAO conducted the temperate/boreal forest resources assessment (TBFRA) through the use of a questionnaire. The tropical assessment was based on existing reliable information and a remote-sensing-based sampling design for study of land cover changes. The assessment for developing countries produced information primarily about the area of forest in 1990 and the change since 1980, with data from different years adjusted to these reference points. This information is available by country and by ecofloristic zone. TBFRA includes data on state and change of forest area (which have not been adjusted to a given reference year) and gives additional information on ownership and management status, growing stock, annual growth and fellings. FRA 1990 is currently the most comprehensive source of global-, regional- and national-level information on forest state and change available. It does not, however, show the spatial distribution of forests.

Since FRA 1990, new information requirements have emerged, including location-specific or spatial data which support efforts in sustainable forest management and assessment of forests' environmental functions (e.g. conservation of biological diversity, mitigation of global climate change). As a consequence, several groups, including IGBP, JRC and WCMC, have embarked upon additional global assessments of forest cover and deforestation. All are assessing various aspects of the spatial distribution of forest cover, although none are as comprehensive as the FRA programme or present the same information.

IGBP, an international consortium of scientific organizations, developed a global low-resolution satellite image-mapping project. The work is based on interpretation and classification of advanced very-high-resolution radiometer (AVHRR) satellite imagery which has a 1-km resolution. The IGBP land cover data set and maps and a related Global Land Cover Characterization database are being validated. While the main objective of these projects is not to provide information on forest area per se, estimates of forest area may be generated from the database and biomass estimates may be derived from modelling.

The JRC TREES (Tropical Resources and Environment monitoring by Satellites) project, established in 1991, develops forest cover assessment techniques for the tropical belt. The project includes:

A multiyear set of AVHRR data was acquired over the whole tropical belt during the period 1991-1994. This global assessment has been further calibrated using high-resolution image maps for selected sites. The main outputs of this effort include a global tropical forest cover base map at 1-km resolution (the first such forest map at this resolution) and related figures at the regional to national levels.

The second phase (1996-1999) of the TREES project is directed at developing a prototype that can regularly produce relevant and accurate information on the state of tropical forest ecosystems. A panel of international experts has identified "hot spots" where deforestation is the most active. JRC is developing more automatic methods of forest monitoring using a range of remote-sensing and other spatial data and has developed a new sampling scheme to measure changes using different types of high-resolution satellite imagery.

TFIS organizes the data (remote-sensing or cartographic) and current knowledge (reports, field observations, etc.) in a systematic manner. Work is being done to allow an interface between TFIS and information systems of the European Commission and other regional and international organizations.

In 1996, WCMC, in collaboration with the World Wide Fund for Nature (WWF), compiled a World Forest Map showing forest extent and protected areas with forested land. The map is the product of a global geographic information system (GIS) containing more detailed maps and digital files from the best available national and international sources, compiled mainly between the early 1980s and early 1990s by WCMC in collaboration with IUCN. WCMC used a nominal scale of 1:1 million, adjusting input data of varying scales (ranging from 1:100 000 to 1:5 million).

The digital information was used to estimate the area of each major forest type in the world under protection and to provide a baseline for future monitoring of forests. The spatial data have formed the basis for a major statistical analysis of forest protection in the world, carried out by WCMC in conjunction with the Center for International Forestry Research (CIFOR), and have been published on CD-ROM. The digital map is maintained at WCMC.

WCMC recently produced a new set of national-level forest statistics derived from the land cover maps overlaid with the political boundaries of countries. This could provide area estimates at the national level.

WCMC has also developed a GIS database showing an estimate of forest cover some 8 000 years ago for the World Resources Institute (WRI) and WWF. Using the data from WCMC, WRI, under its Frontier Forests Initiative,3 developed another global map comparing the large tracts of forest lands remaining today with those existing 8 000 years ago. The Frontier Forests Initiative assessed three attributes: historic forest lost, forest condition (the amount of the world's current forest cover remaining in large tracts of intact natural forest) and threats to frontier areas. The WRI/WCMC map may be considered a global assessment of natural forest change over a large time span.

As a follow-up, WRI has launched the major Global Forest Watch project to monitor forest development globally. Currently WRI is working with some 20 NGO partners in Cameroon, Gabon, Canada and Indonesia to map concessions, roads and other developments. The goal is to carry out a similar effort in all major forested countries within the next five years.

Each of the above-mentioned efforts uses different definitions, sources and methods for classifying the vegetation. Their estimates of forest cover are thus not directly comparable. The quality of information from any assessment depends largely on the quality of the basic input data. The maps from WCMC and WRI were compiled from existing data sources, which could reflect land cover, land use and/or land potential. Consequently, they suffer from the same problems of harmonization as do most bottom-up approaches.

The Global Observation of Forest Cover (GOFC), a new effort of an international partnership of institutions including FAO, will build on previous global forest assessments using earth satellites. GOFC has a goal of stimulating the production of globally consistent products derived from satellite data, supplemented by in situ data, by 2002. This will be achieved by facilitating the provision of forestry information and satellite data to organizations such as FAO and UNEP, the Global Climate Observing System (GCOS) and the Global Terrestrial Observing System (GTOS), NGOs and national forest ministries through partnership arrangements with space agencies.

Information to be available through FRA 2000. The FAO Global Forest Resources Assessment 2000 (FRA 2000) will be the most comprehensive and complete assessment yet. As envisioned, FRA 2000 will consist of:

As the data will be spatially registered, researchers may be able to measure changes in land cover over time; thus a base may be established for improved comparisons for beyond 2010.

FRA 2000 will make further improvements on the data-gathering techniques used in 1990 and will also make use of the data and technologies of other organizations. FAO will use some of the imagery and GIS data sets of IGBP, JRC, the Earth Resources Observation Systems (EROS) Data Center of the United States Geological Survey and others to develop the global forest cover map and database for FRA 2000.

EROS Data Center, FAO and WCMC are developing the Global Forest Map, which will be the first globally consistent small-scale map showing forest cover distribution. The map is being generated through refinement and modelling of IGBP's Global Land Cover Characterization database using advanced image processing and GIS techniques, combined with validation by national experts and existing reliable information.

In the past, an update on global forest resources was possible only every ten years. Institutional development and communication technologies may eventually make it possible to have much more frequent updates and much better quality of data. While technological gains have improved the precision of the estimates and the range of information that can be collected, many countries still need assistance in the planning, execution and financing of their own national forest inventories.

These assessment efforts will continue to provide vital information on the location and extent of forests at the global level. Even more valuable will be the information on net change in extent and condition of forests over time, which addresses the heart of the problem - what is happening to the world's forests and consequently to forests' ability to provide the range of goods and services demanded of them.

Assessments of forest-based biological diversity

Natural forests are arguably the single most important repository of terrestrial biological diversity (diversity of ecosystems, species and genetic resources). Diversity is an essential factor in maintaining forest function. Conservation and management of biological diversity are, therefore, important issues in forest planning. Global, regional and national planning, priority-setting and decision-making related to the conservation of biological diversity all depend on an understanding of the distribution of species and ecosystems, their protection status and the threats to them, and on information on the status of the conservation and use of forest genetic resources.

Species diversity. Knowledge of the world's diversity of species, their distribution and status is very incomplete. Some groups of organisms (e.g. birds) and some parts of the world have been studied more than others. Furthermore, total species diversity is better understood than the diversity of species associated only with forests (see Table 1), as the latter requires an assessment of habitat occurrence or dependence. Evaluation of forest species diversity is meaningful only for the better-known taxonomic groups. Efforts to classify birds, mammals and some plant groups according to forest occurrence are part of FRA 2000.

 

TABLE 1
Data availability for the major taxonomic groups

Taxonomic group

Total species

Number of forest-occurring species

Total endemic and/or restricted-range species

Number of forest-occurring endemic species

Total threatened species

Number of threatened forest species

Birds

����a

+++

����a

+++

����b

+++

Mammals

����a

+++

����a

+++

����b

+++

Reptiles

��a

+

���

+

��

+

Amphibians

��a

+

����

+

��

+

Invertebratesc

+

d

+

Trees

��

+++

+++

��e

+++

Palms

���f

+++

���

+++

��f

+++

Ferns

���f

+++

���

+++

��f

+++

Other plants

��f

+

+

��f

+

Notes: ���� data available for all countries; ��� data almost complete; �� data incomplete; � data very incomplete; +++ division into forest/non-forest species needed, being done for FRA 2000; + division into forest/non-forest species needed.
a WCMC, 1994.
b WCMC, 1996b.
c The large number of invertebrates makes them unsuitable for attempting numerical analyses.
d Data available for a small number of groups (dragonflies, swallowtail butterflies).
e WCMC, 1998a.
f WCMC, 1998b.

 

A detailed understanding of the distribution of species richness within forests requires mapping of species distributions or richness contours. This work has been undertaken several times on a national scale. On a regional scale, progress has been made in mapping total species richness in many groups (e.g. the Mapping African Biodiversity Patterns project of the Danish Centre for Tropical Biodiversity), but as yet these efforts do not incorporate separate analysis of forest species.

Other approaches for evaluating forest species diversity and/or identifying priority areas for its conservation depend on the overlay of different estimates of "biodiversity hot spots"4 with forest cover data. Such hot spot data sets have been compiled, for example, for endemic bird areas (EBAs), i.e. areas containing at least two restricted-range bird species (those whose distribution covers less than 50 000 km2) (Bibby et al., 1992). These have been quite accurately mapped, and in the absence of similar data for other taxonomic groups, the EBA data provide a useful measure of the importance of biological diversity for particular geographic areas. Other hot spot data sets include WCMC and IUCN's Centres of plant diversity (WWF/IUCN, 1994), WWF-US's Global 200 ecoregions5 and Conservation International's Hotspots.6

Mapping could also be used to identify areas where threatened and endangered forest species are concentrated. This would require categorization of species according to their forest occurrence and, ideally, relatively detailed data on their distributions. Nonetheless, some advances could be gained simply from addressing presence/absence data at the national or provincial level.

A country may have high forest species diversity either because it has a wide range of different forest types each with its own distinct biota (e.g. the United States) or because individual forest types are highly diverse in species (e.g. some lowland tropical moist forest). The former characteristic is generally related to the size of the country, the latter not necessarily so. Countries with very high forest diversity usually combine the two characteristics.

Forest ecosystem diversity. Ecosystem diversity in forests is important not only in its own right but also as a predictor of species diversity. However, assessing ecosystem diversity requires meaningful systems of classification of forests, and these are increasingly difficult to generate as the geographical scale increases. Scientists may develop schemes that are useful in local or national contexts for expressing differences between forest ecosystems, based on combinations of physiognomy, phenology and floristics. However, harmonizing several different schemes to produce overviews on a continental or global scale is a difficult task which may entail so much simplification as to eliminate any real utility in expressing ecosystem diversity.

For example, the harmonization of forest cover data from 70 different sources to produce the first global map of closed forest distribution, The WWF world forest map (WCMC, 1996a), resulted in a simplistic classification with only five classes (temperate needleleaf, temperate broadleaf and mixed, tropical moist, tropical dry and mangrove forests), reflecting the difficulty of combining the many much more detailed classification systems used throughout the world. A more detailed classification involving 25 classes which was used by WCMC and CIFOR in the production of a subsequent digital data set on global forest cover (Iremonger, Ravilious and Quinton, 1997) is more meaningful in biodiversity terms but is still very simplistic.

Remote sensing data are potentially a powerful source of information on forest ecosystem distribution and diversity. However, many regionally focused programmes, such as TREES and Pathfinder,7 have been forced to use simplified classification schemes because of the analytical complexity of extracting more detail from satellite data. Global satellite-derived land cover data are available from the EROS Data Center in preliminary form. This data set helps to provide a consistent global view of forests' location and information about their diversity according to a number of classification schemes ranging from the simple to the complex, based on phenology as well as spectral response. The greatest advance in examining forest ecosystem diversity on a broad geographic scale is likely to come through the combination of remote sensing data with ecoregional classifications as envisaged in FRA 2000.

Forest genetic resources. FAO, the International Plant Genetic Resources Institute (IPGRI) and the International Centre for Research in Agroforestry (ICRAF) are facilitating regional initiatives to assess the status of genetic resources of forest trees at species and provenance levels; to identify gaps or overlaps in protection and development efforts; and to elaborate action plans for the conservation, management, sustainable utilization and enhancement of genetic resources of priority species. Regional syntheses will be prepared from data provided by the countries.

At the global level, FAO is developing the Global Information System on Forest Genetic Resources (REFORGEN) for monitoring the status of genetic resources of woody species at the national level (see Box 5). This is the only global effort that specifically targets forest genetic resources.

 

BOX 5
REFORGEN: the FAO database on forest
genetic resources


Forest genetic resources, including the diversity present in the thousands of useful tree species, constitute a resource of tremendous social, economic and environmental importance. Efforts to conserve and use forest genetic resources wisely are assisted by the Global Information System on Forest Genetic Resources (REFORGEN), which provides reliable and up-to-date information on the status of these resources and on related activities and programmes. FAO's Forestry Department, in close collaboration with governments and national institutes of many countries, has been working since 1993 on the development of the system, which now covers more than 1 600 species from 144 countries. It includes information on:

� institutions dealing with conservation and utilization of forest genetic resources in a given country;
� the main native and introduced tree species in the country and their major uses;
� tree species endangered at the species and/or population level;
� tree species managed for in situ conservation;
ex situ conservation activities in vivo and in vitro;
� tree improvement programmes;
� availability of forest reproductive materials for conservation and research purposes.

Linkages to complementary data systems of other organizations are being developed. REFORGEN will soon be accessible through the Internet and on CD-ROM.

 

A global perspective on biological diversity. Assembling a global perspective on biological diversity is a slow and complex task. Major advances have been made in compiling global data sets on current and original forest cover, but a global vegetation classification is still lacking. Other advances at the global level have come from the identification of areas important for species diversity in key groups, but congruence of diversity patterns between groups has been addressed only at the regional level, and even then not thoroughly.

The increasing volumes of data involved in the analysis and management of global forest biological diversity require new approaches to data management. National capacities to gather and manage data to generate useful information - both for national use and to contribute to understanding of the global picture - will need to be built. Recent experiences show that the greatest challenges are organizational, not technological. By focusing on the processes involved in creating environmental information, rather than concentrating on data, international efforts such as the Biodiversity Data Management Project (UNEP/WCMC, 1996) are making useful contributions.

In addition to information from national sources, international research and other efforts can make a useful contribution to improvement of the global biological diversity information base. Likely sources of such improvement in the near future include:

Combining these and other initiatives should produce a more coherent global view of biological diversity in forests. However, the crucial step in maintaining biological diversity in forests is the translation of this knowledge into improved forest management and conservation practices throughout the world.

1 The State of the World's Forests 1997 provided the most recent data available on global forest cover. As no new global data set on forest resources will be available until the results of the Forest Resources Assessment 2000 study are published, a summary of the 1995 figures published in SOFO 1997 is provided in this section.
2 A partial, interim assessment using modelling was done for forest cover and forest cover change for the reference year 1995; the results were published in SOFO 1997.
3 The Frontier Forests Initiative is a five-year, multidisciplinary effort to promote stewardship in and around the world's last major frontier forests by investment, policy and public opinion.
4 Ecosystems which have a high level of biological diversity and are under threat of destruction.
5 See WWF-US's Web site: http://www.worldwildlife.org.
6 For more information, see Conservation International's Web site: http://www.conservation.org.
7 Pathfinder is the Humid Tropical Forest Inventory Project, a collaborative research effort of the University of New Hampshire, the University of Maryland and the National Aeronautics and Space Administration, United States.

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