Variation of soil respiration and its underlying mechanism in grasslands of northern China
Hou, J.-F.; Lü, X.-T.; Wang, C.; Wang, P.
Ying Yong Sheng Tai Xue Bao 25(10): 2840-2846
2014
ISSN/ISBN: 1001-9332 PMID: 25796890 Document Number: 675086
Soil respiration is one of the most important variables in terrestrial ecosystem progresses and global carbon cycle, and determines the CO2 flux from soil to atmosphere. Soil respiration also has great implications for predicting regional and even global carbon cycle changes under the background of global climate change. We measured respiration rates of soil samples collected from northern China grassland transect by short term incubation experiment in laboratory. Results showed that soil respiration rates increased with mean annual precipitation (MAP) from west sites to east sites, ranging from 0.35 to 2.09 μg CO2-C · g(-1) · h(-1). The variation range of soil respiration rates were 0.35-0.73 μg CO2-C · g(-1) · h(-1) with MAP < 100 mm, 0.57-0.98 μg CO2-C · g(-1) · h(-1) with MAP between 100 mm and 200 mm and 0.83-2.10 μg CO2-C · g(-1) · h(-1) with MAP > 300 mm, respectively. Soil respiration had a significant positive relationship with MAP, aboveground biomass, soil organic carbon and nitrogen content, while had a negative relationship with mean annual temperature and soil pH. Analysis of boosted regression tree showed that the predictors accounted for the explained variation included MAP (25.5%), aboveground biomass (23.6%), soil organic carbon content (18.3%) and soil organic nitrogen content (12.5%), and soil pH and mean annual tem- perature only explained 10.8% and 9.2% of the total variation, respectively.