Study on Dynamics of Calorific Value,Biomass and Energy in Calamagrostis epigejos Population in Songnen Grassland (in English)

There were two peaks of seasonal changes of the calorific value in shoot and leaves of Calamagrostis epigejos in middle June and in the early August respectively. The calorific value in stem presented a single peak curve which appeared in the early August. The calorific values in inflorescence and dead standing showed a fluctuation and the peak value of inflorescence was in the early September and that of dead standing was in middle June. The seasonal changes of energy standing crop on the above-ground part synchronized with that of the biomass, which presented a single peak curve. The energy allocated to each organ in different seasons was in the order as leaves >stem >inflorescence in middle June, leaves >stem >dead standing >inflorescence in early July, leaves >stem >inflorescence >dead standing in middle July, and leaves >stem >dead standing >inflorescence from August to September. The vertical allocation of energy in the parts of above-ground was that the energy value gradually increased from the surface to the 20 cm high level and the maximum value at the 10-20 cm high level which made up 26.91% of energy on the above-ground partion, and then it was decreased. In the under-ground portion, the energy value progressively decreased with depth and the maximum value was at 0-10 cm depth layer which made up 69.01% of energy of the under-ground portion.