FIG 4.

Maximum likelihood phylogenetic tree based on translated amino acid sequences of the nifH gene from three different land use systems in the Amazon rainforest: black, primary forest (F); white, pasture (P); gray, secondary forest (SF). Only operational protein units (OPU) representing ≥5 sequences were used. The size of the circle is proportionate to the number of sequences within an OPU. Numbers at the nodes reflect bootstrap support values above 70% with branches within clusters being collapsed. The percent contribution of sequences from different land uses and percent similarities of translated nifH gene sequences to closely related NifH protein sequences are provided.