Spatial Variation in Bird Community Composition in Relation to Topographic Gradient and Forest Heterogeneity in a Central Amazonian Rainforest

Figure 2

Results from Principal Coordinate Analysis (PCoA) used to generate a simple ordination of 72 areas at the Reserva Florestal Adolpho Ducke (RFAD), Manaus, Brazil, based on the similarity matrix of distances generated by the Sorensen index for the qualitative matrix (presence and absence data) for the entire bird community. Letters represent the 72 areas in which the bird species were sampled using 240 m mist-net lines placed throughout the RFAD (p = plateau; s = slopes; v = valleys). The closer the points are to one another in the graph, the more similar are their bird species community composition. Note that the species composition, with a group of p in the upper part, a group of s in the middle, and a group of v in the lower part, changes significantly along the topographical gradient from plateau to valleys.