Variations in carbon isotopic ratios (δ 13C) of C3 plants and distribution of C4 plants were investigated along an altitudinal transect on the eastern slope of Mount Gongga, and the environmental effects on them were...Variations in carbon isotopic ratios (δ 13C) of C3 plants and distribution of C4 plants were investigated along an altitudinal transect on the eastern slope of Mount Gongga, and the environmental effects on them were discussed. It is shown that plants with C4 photosynthetic pathway mainly occur at altitudes below 2100 m a.s.l., suggesting that the low summer temperature is responsible for the distributional pattern. In addition, δ 13C of C3 plants increases with elevation at the region above 2000 m a.s.l. with the characteristics of humid climate, and the increase rate in δ 13C for C3 plants is about 1.3‰ per kilometer. Temperature determines the altitudinal trend of δ 13C.展开更多
Carbon isotope ratios (δ 13C) of plants, litter and soil organic matter (0–5 cm, 5–10 cm and 10–20 cm) on the eastern slope of Mount Gongga were measured. The results show that δ 13C values of plants, litter and ...Carbon isotope ratios (δ 13C) of plants, litter and soil organic matter (0–5 cm, 5–10 cm and 10–20 cm) on the eastern slope of Mount Gongga were measured. The results show that δ 13C values of plants, litter and soil organic matter all decrease first and then increase with altitude, i.e. δ 13C values gradually decrease from 1200 to 2100 m a.s.l., and increase from 2100 to 4500 m a.s.l. The δ 13C altitudinal variations are related to the distribution of C3 and C4 plants on the eastern slope of Mount Gongga, because C4 plants are observed to grow only below 2100 m, while C3 plants occur at all altitudes. There are significantly positive correlations among δ 13C of vegetation, δ 13C of litter and δ 13C of soil organic matter, and litter, 0–5 cm, 5–10 cm and 10–20 cm soil organic matter are 0.56‰, 2.87‰, 3.04‰ and 3.49‰ greater in δ 13C than vegetation, respectively. Considering the influences of rising concentration of atmospheric CO2 and decreasing δ 13C of atmospheric CO2 since the industry revolution on δ 13C of plants, 1.57‰ is proposed to be the smallest correction value for reconstruction of paleovegetation using δ 13C of soil organic matter.展开更多
基金Supported by National Natural Science Foundation of China (Grant No. 40673017)
文摘Variations in carbon isotopic ratios (δ 13C) of C3 plants and distribution of C4 plants were investigated along an altitudinal transect on the eastern slope of Mount Gongga, and the environmental effects on them were discussed. It is shown that plants with C4 photosynthetic pathway mainly occur at altitudes below 2100 m a.s.l., suggesting that the low summer temperature is responsible for the distributional pattern. In addition, δ 13C of C3 plants increases with elevation at the region above 2000 m a.s.l. with the characteristics of humid climate, and the increase rate in δ 13C for C3 plants is about 1.3‰ per kilometer. Temperature determines the altitudinal trend of δ 13C.
基金supported by the National Natural Science Founda-tion of China (Grant No. 40673017)
文摘Carbon isotope ratios (δ 13C) of plants, litter and soil organic matter (0–5 cm, 5–10 cm and 10–20 cm) on the eastern slope of Mount Gongga were measured. The results show that δ 13C values of plants, litter and soil organic matter all decrease first and then increase with altitude, i.e. δ 13C values gradually decrease from 1200 to 2100 m a.s.l., and increase from 2100 to 4500 m a.s.l. The δ 13C altitudinal variations are related to the distribution of C3 and C4 plants on the eastern slope of Mount Gongga, because C4 plants are observed to grow only below 2100 m, while C3 plants occur at all altitudes. There are significantly positive correlations among δ 13C of vegetation, δ 13C of litter and δ 13C of soil organic matter, and litter, 0–5 cm, 5–10 cm and 10–20 cm soil organic matter are 0.56‰, 2.87‰, 3.04‰ and 3.49‰ greater in δ 13C than vegetation, respectively. Considering the influences of rising concentration of atmospheric CO2 and decreasing δ 13C of atmospheric CO2 since the industry revolution on δ 13C of plants, 1.57‰ is proposed to be the smallest correction value for reconstruction of paleovegetation using δ 13C of soil organic matter.
