Carbon isotope ratios of plants and occurrences of C4 species under different soil moisture regimes in arid region of Northwest China |
| |
| Authors: | Guoan Wang Jiamao Han Liping Zhou Xiaogang Xiong Zhenhai Wu |
| |
| Institution: | Department of Plant Nutrition, College of Resources and Environment, China Agricultural University, Beijing 100094, China; Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China; College of Environmental Sciences, MOE Laboratory for Earth Surface Processes, Peking University, Beijing 100871, China; Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; Northwest Sci-Tech University of Agriculture and Forestry, Yangling 712100, China |
| |
| Abstract: | Carbon isotope ratio of leaf dry matter, δ 13C, was measured on species occurring within Baiyin desert community, consisting of valley, slope and ridge microhabitats, and within Shandan desert community, consisting of Gobi desert and seasonal flooded creek microhabitats, in Northwest China. δ 13C of C3 species increased with a decrease in soil water availability, suggesting that water-use efficiency (WUE) increased with decreasing soil moisture, whereas for all C4 species, δ 13C tended to decrease with decreasing soil water availability, suggesting that WUE also increased with decreasing soil moisture. Above results indicated that water-use pattern was conservative under drought for C4 and C3 plants. In this present study, C4 species' occurrences within different microhabitats were investigated and C4 plants were observed to be absent and/or scarce within relatively lower soil moisture microhabitats, whereas they occurred and/or even had a high abundance within relatively higher soil moisture microhabitats, suggesting limited moisture available was a key factor of limiting C4 distribution in arid region of Northwest China. |
| |
| Keywords: | |
|
|
