Specific study which highlights the future work which needs to be done in order to properly survey the vast botanical wealth to be found here, and also in other tropical regions.
1: Methodology. I. Critical review of the main methods used for vegetation mapping and vegetation studies in the tropics. II. Method used for vegetation classification and analysis during the present survey. 2: Physical environment and physiographic classification of the vegetation. I. Geomorphology, geology and pedology. II. Bioclimates. III. Physiographic classification of the vegetation. 3: History of the vegetation and phytogeography. I. History of the vegetation. II. Phytogeography of Malesia. III. Phytogeography of Sumatra. 4: Vegetation and forest types. I. A short cartographical analysis of the main plant formations of Sumatra. II. Plant formations in lowland swamp areas. III. Plant formations of the plains and piedmonts (alt. 150 m). IV. Plant formations of the low hills (150--500 m). V. Plant formations of the upper hills (500--1000 m). VI. Plant formations of limestone hills. VII. Montane plant formations. VIII. Agroforestry systems. 5: Conclusions and perspectives.