FIRE IN TROPICAL DRY FORESTS - CORTICOLOUS LICHENS AS INDICATORS OF RECENT ECOLOGICAL CHANGES IN THAILAND

The distribution of lichens in lowland deciduous and evergreen forests in Thailand is used to interpret recent changes in the distribution o f these forests. The role of fire in changing the forest structure, mi croclimate and species content is discussed. Characteristic corticolou s lichen communities of dry deciduous and moist evergreen forests are described, as well as changes in the composition of the flora followin g fire events. Where frequent fires have altered the forest rates of c hange in forest type are suggested using lichen data from randomly sel ected trees in forest plots, and growth rates of sampled species in qu adrats. The disjunct nature of the lichen floras in lowland deciduous and evergreen forests is discussed, their origin and use in interpreti ng changes in forest types in monsoon climates over long periods of ti me.