Fig. 8

Arsenic resistance and metabolism gene biogeography. a Relative abundance of arsenic resistance genes in soil metagenomes. b Rank rplB-normalized abundance of arsenic-related genes in soil metagenomes. Sites are ordered by rank mean abundance. Note the differences in y-axes. c Abundance-occurrence plots of arsenic-related gene sequences clustered at 90% amino acid identity. Number of samples included are as follows: Brazilian forest n = 3, California grassland n = 2, Centralia active n = 7, Centralia recovered n = 5, Centralia reference n = 1, Disney preserve n = 2, Illinois soybean n = 2, Illinois switchgrass n = 1, Iowa agricultural n = 2, Iowa corn n = 2, Iowa prairie n = 3, Mangrove n = 2, Minnesota grassland n = 2, Permafrost Canada n = 2, Permafrost Russia n = 1, and Wyoming soil n = 1