TROPICAL MOIST FORESTS - DESTRUCTION AND SPECIES EXTINCTION

Tropical moist forests are currently being altered or destroyed at a rapid rate. A 1980 assessment by the Food and Agricultural Organisation (FAO) for all tropical countries has now been superseded for some by new assessments based largely on more recent satellite imagery. Comparison of different estimates are complex because of different definitions of 'forest', 'alteration', 'degradation' and 'destruction'. Making allowance for these problems, the new estimates show that rate of deforestation has, in general, increased. A recent assessment by Myers for 1989 is more pessimistic than earlier surveys, estimating that remaining forest areas are less and rates of destruction higher, but Myers includes logging as forest destruction and excludes degraded forest from his measurements. The total number of species in tropical moist forests are poorly known. The pattern of likely species extinctions depends on the proportion of forest altered and destroyed, and its spatial pattern, and can be used to help set priorities for conservation.