Forests cover 30 percent of the world’s land area and provide habitats for countless species. These complex ecosystems are also vital to livelihoods and to economic and social development, providing food and raw materials for construction, energy and manufacturing. They are also vital to environmental protection and to the conservation of natural resources. Forests contain more carbon than the atmosphere. In a world facing climate change, forests – with their dual roles as producers and absorbers of carbon – take on a new importance.
Genetic diversity provides the basis for the evolution of forest tree species. It has enabled forests and trees to adapt to adverse and changing conditions, a process that has given rise to a unique and irreplaceable portfolio of forest genetic resources.
The vast majority of forest genetic resources remain unknown, especially those in tropical forests. Estimates of the number of tree species vary from 80 000 to 100 000. Yet fewer than 500 have been studied in any depth for their present and future potential. Until recently, studies concentrated on those few species deemed most suitable for wood, fibre and fuel production in plantations and agroforestry systems. However, there is increasing awareness of the critical value of forest genetic diversity, both per se and as a basis for confronting global challenges such as climate change.
As a result of pressures on forest lands and unsustainable use of resources, the great potential of forest genetic diversity is at risk of being lost forever – before it has been identified, let alone utilized. The loss and degradation of forests remain major global concerns despite the enormous efforts that have been put into promoting sustainable forest management.
Threats to forest genetic diversity
Each year, 13 million ha of forests are lost, mainly through conversion to other land uses. While this loss is somewhat offset by 5.7 million ha of forest restoration and afforestation annually, the Earth is still losing some 200 km2 of forest each day. Given our general lack of knowledge of forest genetic resources, it is impossible to estimate the precise extent of the genetic loss that is resulting from deforestation and forest degradation. However, there is little doubt that genetic erosion is occurring in many places.
Changing weather patterns are altering the growing conditions of forest trees, as well as the population dynamics of the pests and diseases that attack them. In Canada, cold winters used to hinder the spread of the borer beetle. Now, because winters have become warmer, this insect is expanding its range into new areas and attacking pine trees that have no resistance to it. As this example illustrates, improving knowledge of forest genetic diversity, including knowledge of genetic resistance to pests, is becoming increasingly important in forest management.
Sustainable forest management
Focus on forest genetic resources
Understanding and managing forest tree genetic diversity is important in all types of forests. Monitoring the diversity of tree populations in primary forests can improve our knowledge of how forest goods and ecosystem services are delivered. In plantation and agroforestry systems, tree populations are subject to intensive genetic selection and breeding.
Sustainable management of forests requires better understanding of the specific features of forest trees and their genetic diversity. Forest tree species are generally long lived and extremely diverse. A given species can occur naturally in a broad range of ecological conditions. Moreover, forest species have evolved through several periods of climatic change; their genetic variability provides them with the capability to adapt to emerging climatic conditions. Trees also have various mechanisms for natural seed dispersal that allow them to migrate over long distances. However, for many species, even this capacity may not be sufficient to enable them to survive in today’s rapidly shifting climatic zones.
Forest trees are generally managed with long rotation periods (the time between regeneration and harvesting): 5–10 years for fast-growing species and up to 150–200 years for slower-growing species. With climate change, it can no longer be assumed that growing conditions in 100 years time will be the same as those present today. The need to adapt to changes that occur over lengthy rotation periods will therefore become an increasingly important consideration in forest management.
Forest genetic diversity has provided the potential for adaptation in the past and will be needed to do so again as we face the challenge of mitigating, or adapting to, further climatic changes. Maintaining evolutionary processes and genetic diversity within forest tree populations requires a “dynamic gene conservation” approach. Such an approach can be based on managing tree populations within the environment to which they are adapted (in situ) or on dynamically using tree populations that have been removed from their natural habitats (ex situ).
In recent decades, countries have established conservation areas, such as forest gene conservation areas. However, the selection, management and monitoring of such areas would generally benefit from better planning and coordination that would enable them more effectively to conserve the genetic diversity of species whose distributions span several countries or regions. Exchange of information, methodologies and experiences, and coordination of efforts will be crucial in this respect.
The sustainable use of forest genetic resources, including appropriate selection of forest seeds and management of germplasm, is fundamental to the management of forest plantations. Correctly matching species and seed sources to site conditions, combined with proper silviculture, can improve productivity by well over 20 percent. Forest genetic resources provide traits that increase productivity, enhance the quality of outputs and enable adaptation to biotic and abiotic stressors.
The Commission on Genetic Resources for Food and Agriculture
Integrating the potential of forest genetic resources
The field of forest genetic resources management is undergoing significant changes. Traditionally concerned with the technical aspects of genetic conservation, tree improvement and seed supply, it is expanding to include the provision of ecosystem services. Scientific advances in biotechnology and legal developments concerning the exchange of genetic resources are creating new opportunities and challenges that give rise to the need for an enabling policy environment.
The Commission is well positioned to link the management of forest genetic resources to relevant global policy issues and to integrate it into cross-sectoral strategies. As part of its Multi-Year Programme of Work, the Commission guided the preparation of The State of the World’s Forest Genetic Resources.
The State of the World’s Forest Genetic Resources recognizes that forest genetic resources make an important contribution to sustainable development through the provision of timber, food, fuel and various environmental services. The report assesses the status and trends of forest genetic resources at global level, based on country reports and regional syntheses. The themes covered in the report include the state of the conservation and management of forest genetic resources, trends affecting the forest sector and their implications for genetic resources, institutional and policy frameworks for the conservation and management of forest genetic resources, the state of knowledge of current and emerging technologies, and future needs and required responses. The preparation of the report assisted in the identification of the priorities reflected in the Global Plan of Action for the Conservation, Sustainable Use and Development of Forest Genetic Resources.