Abstract
Soil respiration was measured with the enclosed chamber method in an ungrazed Leymus chinensis steppe during the growing seasons of 2001 and 2002. Soil respiration rate ( R S) was significantly influenced by air temperature ( T) at the diurnal scale, and could be described by Van't Hoff's equation ( R S = R 10 exp( β( T − 10))). At the seasonal scale, the normalized soil respiration rate at 10 °C ( R 10) was mainly controlled by soil water content ( R 2 = 0.717, P < 0.001), while the sensitivity of soil respiration to temperature ( Q 10) was partially affected by absolute growth rate ( R 2 = 0.482, P = 0.004). Thus, soil respiration could be described as R S = (20.015 W − 84.085) (0.103AGR + 1.786) ( T−10)/10 during the growing seasons, integrating soil water content ( W) and absolute growth rate (AGR) into the temperature-dependent soil respiration equation. It was validated by the observed soil respiration rates in this study ( R 2 = 0.890, P < 0.001) and observations from near-field experiment ( R 2 = 0.687, P = 0.011). It implied that accurately evaluating annual soil respiration should include the effects of plant biomass production and other abiotic factors besides air temperature.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have