Abstract:

The CO2 concentration (370, 550 and 700 μmol/mol) was controlled with open-top chambers, and different contents of NH4NO3 were supplied to control nitrogen levels [0、4、8 g/(m2?a)]. This paper studied the effects of elevated atmospheric CO2 concentration and nitrogen deposition on biomass accumulation and allocation in Deyeuxia angustifolia communities in Sanjiang Plain. The results showed that the aboveground biomass of Deyeuxia angustifolia communities decreased with atmospheric CO2 concentration increasing, under different nitrogen supply levels. While belowground increased began and decreased afterwards. The total biomass of Deyeuxia angustifolia communities decreased with atmospheric CO2 concentration increasing, under different nitrogen supply levels. The changed trends of the biomass in roots, stems and leaves of Deyeuxia angustifolia communities in varied treatments were different. The elevated atmospheric CO2 concentration and nitrogen deposition could affect the roots biomass significantly, but could not affect biomass allocation of Deyeuxia angustifolia communities significantly.