Fig. 1
Methane generation potential and the distribution of methanogenic archaeal communities in paddy soils. a Richness (orange) of methanogenic archaeal communities and CH4 emission potential (purple) from 39 typical paddy fields (green) across northern to southern China. b α diversity (richness and Shannon index) of methanogens. The horizontal bars within boxes represent medians. The tops and bottoms of boxes represent 75th and 25th percentiles, respectively. c Canonical correspondence analysis (CCA) of methanogenic archaeal community structure. Black arrow indicates the vector of the explanatory variable, and points of different colors indicate paddy soil samples in 39 paddy fields (429 soil samples in total). MAT, mean annual temperature; MAP, mean annual precipitation; CEC, cation exchange capacity; TOC, total organic carbon; DOC, dissolved organic carbon; TN, total nitrogen; DTN, dissolved total nitrogen; DON, dissolved organic nitrogen; DAN, ammonium nitrogen; DNN, nitrate nitrogen; TP, total phosphorus; AP, available phosphorus; TK, total potassium; AK, available potassium. d Distance–decay relationships of methanogenic communities at three scales, local (1–100 m), meso (0.1–50 km), and regional (100–3500 km)