Amphibian and reptile biogeographic regions of Northern Eurasia,mapped separately

Distributions of amphibian and reptile faunas were separately delimited on a 1:20 000 000 vegetation map of Northern Eurasia divided into 245 10-degree-longitudinal segments of native subzone within the USSR borders as of 1990. All reptile and amphibian species recorded in every segment were listed, and the Jaccard indices were calculated, and the similarity matrix was studied with cluster analysis. Hierarchic classifications were made: the amphibian one consisting of 3 faunistic regions, divided into 4 subregions, 7 biologic provinces, and 23 districts. The reptile classification includes 4 faunistic regions, 7 subregions, 18 provinces, and 14 districts. The reptile classification has 1.5 times more provincial and district subdivisions than amphibian one. Environmental factors correlating with faunistic nonuniformity were revealed. Our amphibian and reptile schemes are 1.9 and 3.5 times more informative than those proposed earlier and account for 75 and 91% of variance in the faunal similarity coefficient of specific areas, respectively (multiple correlation coefficients 0.87 and 0.95). Environmental factors can explain 84 and 93% of faunistic nonuniformity (correlation coefficients 0.95 and 0.96).