|
|||||
|
|
Soil CO2 efflux along an elevation gradient in Qinghai spruce forests in the upper reaches of the Heihe River,northwest China |
|
| Authors: | Xianglin Zheng Chuanyan Zhao Shouzhang Peng Shengqi Jian Bei Liang Xiaoping Wang Shifei Yang Chao Wang Huanhua Peng Yao Wang |
| Institution: | 1. School of Life Sciences, Lanzhou University, Lanzhou, 730000, China 2. School of Forestry, Gansu Agricultural University, Lanzhou, 730000, China 3. Institute of Arid Meteorology, China Meteorological Administration, Lanzhou, 730000, China 5. Bureau of Qilian Mountains National Nature Reserve In Gansu, Zhangye, 734000, China 4. College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, China |
| Abstract: | This study was conducted in six plots along an elevation gradient in the Qinghai spruce (Picea crassifolia Kom.) forest ecosystem of the Qilian Mountains, northwest China. Soil CO2 efflux over bare soil (R s) and moss covered soil (R s+m) were investigated from June to September in 2010 and 2011 by means of an automated soil CO2 flux system (LI-8100). The results showed that R s ranged from 1.51 to 3.96 (mean 2.64 ± 0.72) μmol m?2 s?1 for 2010, and from 1.41 to 4.09 (mean 2.55 ± 0.70) μmol m?2 s?1 for 2011. The daily change trend of R s resembled that of air temperature (T a), and there was a hysteresis between R s and soil temperature (T s). The seasonal variations of R s at lowlands (i.e., Plot 1, Plot 2 and Plot 3) were driven by soil moisture and temperature (T a and T s), while that at highlands (i.e., Plot 4, Plot 5 and Plot 6) were obviously affected by temperature. There were higher values at Plot 2 and Plot 6, which were caused by the interaction between soil moisture and temperature. In addition, soil CO2 efflux over moss covered soil (R s+m) was 8.83 % less than that over bare soil (R s), indicating that moss was another factor affecting R s. It was concluded that R s had temporal and spatial variations and was mainly controlled by temperature and soil moisture; the main determinants differed at different elevations; moss could reduce R s. |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ | |