Changes in planted forests and future global implications

International audience

英语. This paper focuses on an analysis of planted forests data from the 2015 Forests Resources Assessment of the U.N. Food and Agriculture Organisation (FRA 2015). It forms one of a series of papers in the FRA 2015 special issue of this journal. While total forest area decreased from 4.28 billion hectares to 3.99 billion hectares from 1990 to 2015, with percent global forest cover dropping from 31.85% to 30.85%, the area of planted forests increased from 167.5 to 277.9 million hectares or 4.06% to 6.95% of total forest area. Increase was most rapid in the temperate zone, and regionally in East Asia, followed by Europe, North America, and Southern and Southeast Asia. However the annualised rate of increase in area of planted forests slowed in the 2010-2015 period to 1.2%, below the 2.4% rate suggested is needed to supply all of the world's timber and fibre needs. The majority of planted forests comprised native species with only 18-19% of the total area being of introduced species. Introduced species were dominant in the southern hemisphere countries of South America, Oceania and Eastern and Southern Africa where industrial forestry is dominant. Twenty countries accounted for 85% of planted forest area and a different 20 countries for 87% of planted forest roundwood supply. As with forest area, roundwood supply from planted forests also showed an increasing trend although this was based on minimal data. There was a mismatch in composition and rankings of the top 20 countries with top forest area and roundwood production suggesting that there are substantial opportunities to increase roundwood production in the future, especially in China which has the largest area but is currently ranked 3rd in roundwood production. Outlook statements were developed for the FAO sub regions based on past changes in planted forest area, population growth, and climate and forest health risks to identify key issues for the future. The overall view from this study suggests that climate impacts, especially from extreme climatic events will affect planted forests in the future and that forest health impacts can also be expected to increase. Outlooks vary regionally. Europe and North America are likely to be most concerned with climate and health risks; Asia will experience population pressure that will impact on land availability for new forests and risks from extreme weather events, and will need to make the most of its existing forests; Africa will need to increase planted forest area to offset continuing deforestation and rapid population growth; and Oceania, the Caribbean, Central and South America are likely to be most concerned with climate impacts. To ensure the continued contribution of planted forests, a number of responses will be required to both maintain existing and also to develop new forests. Intensification of production in existing forests will lessen the need for greater forest areas and offset any land use conflicts related to food security; climate adaptation strategies will need to be developed as a matter of urgency, and forest health focus must remain a priority for research. Establishment of new forests will be eased through greater community and stakeholder engagement. Application of models such as WWF's New Generation Plantations, which recognises the importance of society and the need to consider the full range of forest products and services within the wider landscape and spectrum of land uses, will be important. We recommend that to enable deeper analysis related to planted forests future FRA Assessments consider ways to better gather data specific to planted forests such as productivity so that this important component of global forests can be better understood.