terrestrial 208 soil 156 aquatic 141 lentic 80 paludal 78 wetland 78 very low temperature 59 permafrost 58 ice 44 forest 42 low temperature 33 anthropogenic 21 host-associated 21 plant host 18 rhizosphere 18 fresh water 16 low salinity 16 acidic 14 mine 12 contaminated 12 tundra 10 grassland 9 medium temperature 9 lotic 5 agriculture 5 cropland 3 spring 3 hot spring 3 animal host 3 insect host 3 fluvial 2 lacustrine 2 sediment 2 benthic 2 digestive tract 1 intestine 1 high temperature 1