ROOT SYSTEMS OF THREE ADJACENT, OLD GROWTH AMAZON FORESTS AND ASSOCIATED TRANSITION ZONES

Abstract

In the north central Amazon three distinct forest types frequently grow in association with only narrow transition zones between them. These forest types (tierra firme, caatinga and bana) grow on different soils and although these forests are readily distinguished above ground, below ground differences and distribution are less pronounced. Bio mass and vertical distribution of roots, with particular emphasis on fine roots are reported. Allometric equations are calculated on the basis of above ground stem basal area and stand volume. From 23 to 56% of the fine roots are concentrated above the mineral soil in a dense surface root mat. Fine root biomass ranges from 5.5 kg m^-2 ha^-1 in bana forest to 10.7 kg m^-2 h^-1 in tierra firme caatinga.