Abstract: A total of 130 specimens from twoRana chensinensispopulations were collected in this study, with the Zhengzhou population (Henan Province) being the southern part of the range and the Zhalantun population (Inner Mongolia) being the northern part of the range. Female fecundity and 26 morphological characters in males and females were measured to examine geographical variation of different populations. The results showed that females were significantly larger than males. The body size of Zhalantun population was significantly larger than that of Zhengzhoupopulation, which is in accordance with Bergman’s rule. However, the length of the limbs was also larger in the cold climate that does not conform to Allen’s rule. Sexual size dimorphism inR. chensinensis did not obey Rensch’s rule. Females should be more sensitive to environmental changes because they could grow faster than males in snout-vent length and weight which ensures their greater reproductive success. The different variation trends in body sizes between females and males across different environment imply the substantial differences in their adaptationstrategies, which should be the main reason for geographic variation in morphologicalcharacteristics and female fecundity across different populations.

Key words: dummy variables, stand carbon storage, simultaneous equations, larch plantation