Study of distinguish root respiration from total soil respiration by root exclusion method in the temperate semi-arid grassland in Inner Mongolia, China

In order to determine the possibility of measuring the root respiration by using root exclusion method, we conducted field experiments to measured total soil respiration and net soil respiration in three temperate grassland communities including Leymus chinensis free-grazed steppe, stipa grandis free-grazed steppe and Leymus chinensis degenerated free-grazed steppe in the growing season, 2005. At the same time, the proportion of the root respiration to the total soil respiration was estimated in different steppes by this method separately. The results indicated that the root exclusion method was very operable in estimating the proportion of the root respiration to the total soil respiration in temperate grassland communities, and the proportion varied from 25%~45% with the mean value of 35.66%. The precision of this proportion was markedly improved compared with the correlation studies of both here and abroad, and it was provided with superior applied cost in the field of carbon cycle of grassland ecosystem.