US EPA

1541782 

Journal Article 

Influencing factors and partitioning of respiration in a Leymus chinensis steppe in Xilin River Basin, Inner Mongolia, China 

Geng Yuanbo; Luo Guangqiang 

2011 

Yes 

Journal of Geographical Sciences
ISSN: 1009-637X
EISSN: 1861-9568 

21 

1 

163-175 

10.1007/s11442-011-0836-7 

WOS:000285985800012 

Based on the static opaque chamber method, the respiration
rates of soil microbial respiration, soil respiration, and ecosystem respiration were measured
through continuous in-situ experiments during rapid growth season in semiarid Leymus chinensis
steppe in the Xilin River Basin of Inner Mongolia, China. Soil temperature and moisture were the
main factor affecting respiration rates. Soil temperature can explain most CO(2) efflux
variations (R(2)=0.376-0.655) excluding data of low soil water conditions. Soil moisture can also
effectively explain most of the variations of soil and ecosystem respiration (R(2)=0.314-0.583),
but it can not explain much of the variation of microbial respiration (R(2)=0.063). Low soil
water content (<= 5%) inhibited CO(2) efflux though the soil temperature was high. Rewetting the
soil after a long drought resulted in substantial increases in CO(2) flux at high temperature.
Bi-variable models based on soil temperature at 5 cm depth and soil moisture at 0-10 cm depth can
explain about 70% of the variations of CO(2) effluxes. The contribution of soil respiration to
ecosystem respiration averaged 59.4%, ranging from 47.3% to 72.4%; the contribution of root
respiration to soil respiration averaged 20.5%, ranging from 11.7% to 51.7%. The contribution of
soil to ecosystem respiration was a little overestimated and root to soil respiration little
underestimated because of the increased soil water content that occurred as a result of plant
removal. 

Leymus chinensis steppe; ecosystem respiration; soil respiration; microbial respiration; temperature; moisture