Production  structure  of  main  commercial  tree  species  was  studied  in  a  mangrove  forest  in  East 
Sumatera, Indonesia. This research was carried out in January 1991 using the estimation of standing biomass 
with stratified clipping method in order to know the production structure of the main commercial tree species in 
this mangrove forest, i.e. Rhizophora apiculata, Bruguieraparviflora and B. sexangula. 
The results obtained show that R. apiculata tended to have a sparser foliage of thicker leaves along the stem 
than B. parviflora or B. sexangula; therefore, R. apiculata is regarded as a shade-intolerant tree species. In 
contrast, either B. parviflora or B. sexangula tended to have a larger proportion of leaves and branches along the 
stem; consequently, those species are recognized as shade-tolerant tree species.