Chin J Plan Ecolo ›› 2000, Vol. 24 ›› Issue (6): 687-692.

• Research Articles • Previous Articles     Next Articles

Field Experimental Studies on the Effects of Climate Change on Nitrogen Mineralization of Meadow Steppe Soil

WANG Qi-Bing, LI Ling-Hao and BAI Yong-Fei   

  • Published:2000-06-10
  • Contact: WANG Yan-Fen

Abstract:

We assessed the potential impact of global warming on rates of net ammonification, net nitrification and net mineralization of soil nitrogen by transferring intact soil cores (0-15 cm) from 1469 m higher-elevation meadow steppe to 1187 m and 960 m lower-elevation sites respectively in the Xilin River Basin of Inner Mongolia. After incubation for one growing season, ammonium nitrogen and nitrate nitrogen (including nitrite nitrogen) of the soil samples were determined. The annual mean air temperature at the three selected study sites during the field study was, from higher-to lower-elevation, -0.5℃, 2.2℃ and 4.4℃ respectively. Affected by these different air temperature regimes, the net ammonification rate was 0.05 mgN·kg-1·m-1, 0.13 mgN·kg-1·m-1, 1.09mgN·kg-1·m-1. Correspondingly,the net nitrification rate was respectively 0.05mgN·kg-1·m-1, 0.76 mgN·kg-1·m-1 and 0.26mgN·kg-1·m-1,and the net mineralization rate was 0.10mgN·kg-1·m-1, 0.89mgN ·kg-1·m-1 and 1.35 mg N·kg-1·m-1 in the soil transferred to the three sites. Hence we conclude that increasing air temperature will enhance soil N mineralization.