Abstract: There are the congnitive differences in the response and mechanism of plant δ¹³C to altitude. Furthermore,it is difficult to find a plant species growing at different altitudes to reduce carbon isotope fractionation difference between species. Bryophytes are the good bioindicator plants with their relative simple structure,high sensitivity to environmental change,and wide distribution with altitude gradient. However,the effect of altitude change and environmental change on carbon isotope of bryophytes was discussed in few researches only. In this paper,carbon isotope composition (δ¹³C) of epilithic mosses at different altitudes in the north and south slopes of the Mount Taibai was analyzed. The effect of environmental factors on the relationship between carbon isotope of epilithic mosses and altitude was also discussed. A significant linear correlation between δ¹³C of epilithic mosses and altitude in the north and south slopes of the Mount Taibai was found (south slope:R²= 0.45 and P<0.01; north slope:R²=0.31 and P<0.01). The δ¹³C of epilithic mosses in the north and south slopes of the Mount Taibai increased by 2.0‰ and 1.1‰ when the altitude increased by 1 000 m. Moreover,the effect of atmospheric CO₂ concentration and its carbon isotope composition,atmosphere pressure,precipitation,biomass,etc. on the response of carbon isotope composition of epilithic mosses to altitude was low. Temperature may be the main factor affecting δ¹³C of epilithic mosses in the Mount Taibai.

Key words: epilithic moss, environmental significance, stable carbon isotope, altitude, Mount Taibai