Patterns and trends in tropical forest cover

In the 2005 edition of the Global Forest Resources Assessment of the Food and Agriculture Organization of the United Nations, a moderate negative trend was reported regarding the change of tropical forests: the net annual change was estimated at –11.8 million ha for the period 2000–2005, while the rate was –11.65 for the previous decade. Tropical Asia showed the highest rate and most negative trend, passing from –0.8% to –0.96% per year. The remote sensing survey done for previous Forest Resource Assessment editions covering the period 1980–2000 revealed distinct change processes in the three tropical regions. Survey results indicated that socio-economic and cultural aspects that characterise and differentiate the geographic regions determine the nature of the change processes and underlying cause–effect mechanisms, while the ecological setting determines the intensity of change and reveals its environmental implications. A comparison of deforestation processes of the two decades indicated an on-going process of “radicalisation” of the dynamics determined by an increasing frequency of high-gradient changes (e.g. total clearing rather than fragmentation and degradation) and by a shift of deforestation fronts towards wetter zones, with a consequent higher per-hectare carbon emission associated with deforested areas.