Plant communities of a savanna in northern Bolivia I. Seasonally flooded grassland and gallery forest
Seasonally flooded savanna in northern Bolivia was studied to present a phytosociological classification of the vegetation using the Braun-Blanquet approach. However, syntaxa were not named according to the Braun-Blanquet nomenclature, because the method has been applied too rarely on savanna vegetation in South America. Five community clusters, syntaxa of the highest level of a hierarchical system, were distinguished. 1. The Eleocharis peruviana community cluster comprises communities of mostly aquatic vascular plants colonizing small ponds and streams. 2. The Rhynchospora-Aeschynornene pratensis community cluster represents the vegetation of floodplains of whitewater rivers. 3. Other floodplain communities that grow on mudflats of small clearwater streams are found in the Eleocharis-Rhynchospora coryrnbosa community cluster. 4. The Echinodorus grisebachii-Cyperus luzulae community cluster was divided into two subdivisions which either include communities of swamps and backwaters (4.1 Eichhornia-Elodea granatensis subdivision) or communities of a pasture covering most of the clearwater river floodplains (4.2 Paratheria prostrata subdivision). 5. Some examples of low gallery forest communities that fringe the clearwater rivers were combined to the Licania-Vochysia divergens community cluster. Several of the 24 communities which form the five community clusters were further divided into two or more subtypes. The differences in floristic composition of the syntaxa can be related to soil types and to the depth and duration of the flooding.