Table 1 Information summary of sampling sites

ED

Erdaoqiao

30°05′14″ N

101°56′55″ E

Constructed rectangular pool with length 100–110 cm, width ~ 60 cm, and depth ~ 35 cm. The pool is paved with tiles and connected to the spring outflow. Clear water and sulfur smell. Green mats on the edge of pond. Sample type includes mats and water.

ZG-1

Zhonggu village

30°15′57″ N

101°52′24″ E

Walled rectangular cement pool with length ~ 500 cm, width ~ 320 cm and depth ~ 100 cm. Five outflows at the bottom of the pool. Green mats on entire bottom of the pond. A pipe outlet. Sample type includes mats and water.

ZG-2

Zhonggu village

3 m away from ZG-1

Shallow small natural circular mud pool with slow outflow. Roughly rounded with diameter ~ 60 cm, depth ~ 10 cm. Clear water. Green mats on the edge of pond. Sample type includes mats, sediment and water.

ZG-3

Zhonggu village

50 m away from ZG-1

Round natural pool with diameter ~ 150 cm, depth 45 cm. Slow outflow at the bottom of the pool. Floating mats. Sample type includes mats and water.

ZG-4

Zhonggu village

500 m away from ZG-1

Shallow round natural pool with diameter ~ 110 cm, depth ~ 10.5 cm. A vertical pipe was connected to the outflow, with a bucket at the top. Lots of sinter on the pipe and bucket. Green mats on the edge of pool, Yellow mats floating on the pool. Sample types include mats, sediment, sinter and water.

DB

Danba

30°36′39″ N 101°41′9″ E

A small pool with outflow from the rock wall. Green mats on the rock. Clear sulfur water. Sample type includes mats and water.

MN

Maoniugu

30°36′9″ N 101°43′46 E″

A shallow pond with small outlet, irregular shaped with length ~ 65 cm, width ~ 45 cm, and depth ~ 5 cm. Clear water. Reddish and green mats on the edge of pond. Sample type includes sediment and water.

LL-1

Lotus lake

29°25′4″ N 101°18′1″ E

Small natural source pool with slow outflow. Roughly shaped with length ~ 65 cm, width ~ 55 cm, and depth ~ 35 cm. Clear water and fine stone bottom. Sample type includes sediment and water.

LL-2

Lotus lake

Near LL-1

Shallow small pool with spouting outlet. Length ~ 65 cm, width ~ 55 cm, and depth ~ 15 cm. Lots of reddish brown mats on the edge of spring. Many black fine stone at bottom. Sample type includes mats, sediment, and water.

LL-3

Lotus lake

Close to LL-1

Shallow water flow channel (~ 55 cm width, ~ 5 cm depth) downstream of LL-1. Clear water. Many blue-green biofilm on rocks. Sample type includes biofilm and water.

LL-4

Lotus lake

Close to LL-2

Shallow water flow channel (~ 85 cm width, ~ 5 cm depth) downstream of LL-2. Many green filaments. Clear water and rocky bottom. Sample type includes sediment, water and filaments.

LL-5

Lotus lake

Near LL-1

Spring pool with jet outflow. Length ~ 4 m, width ~ 3 m, and depth ~ 800 cm. Black sands and fine stone at the bottom. Some yellowish-white filament on the bank of pool. Brown mats at spring outlet. Sample type includes water, sediment, filament and mats.

LL-6

Lotus lake

Near LL-1

The spring outflow from cracks in stone. Irregularly shaped with length ~ 80 cm, width ~ 45 cm, and depth ~ 35 cm. Clear water. Silvery and yellow rocks at bottom. Blue-green biofilms on the edge of spring. Sample type includes biofilm, sediment and water.

LL-7

Lotus lake

Near LL-1

A sulfate pool with slow outflow. Roughly rounded with diameter ~ 4 m, depth ~ 4 cm. Yellowish-white filaments and brown mats in center of pool. Black-green filament on bank of spring. Sample type includes filament, mats and water.