A comparison of fine-scale distribution patterns of four plant groups in an Amazonian rainforest

We carried out a comparison among the floristic patterns of four different plant groups (palms, trees, melastomes and pteridophytes) in a lowland rain forest site in Peruvian Amazonia. The study site consisted of a mosaic of e daphic patches reflecting the different geological formations that can be f ound on the surface. We collected the data along a linear transect (500 m l ong, divided into 20 x 20 m or 5 x 20 m subplots), and recorded of the four plant groups all individuals that exceeded a minimum size limit predefined for each plant group. We also recorded the drainage conditions and soil ty pe classes in each subplot of the transect. The results indicated that diff erent plant groups can produce similar floristic patterns in local spatial scales, and that these patterns reflect similarities in edaphic conditions. All matrix correlations calculated between pairs of the four plant groups were positive and statistically significant. Floristic composition in all p lant groups correlated with soil class, and to a somewhat lesser degree wit h drainage. These results imply that any one of the four plant groups could serve as a rough indicator of more general floristic patterns, and that ev en the inventory of a limited part of the flora can shed light on the flori stic variation found in Amazonian forests.