Soil Nitrogen Mineralization In Response To Different Of Avenues Carbon Input In Secondary Forest Southern Of Daxinganling

Forest ecosystems in the global carbon and nitrogen cycle plays an important role.The soil is the basis of forest. So the study of soil carbon and nitrogen cycle, for understanding of forest ecosystem carbon and nitrogen cycle, and the relationship between forest ecosystem and the global warming has important significance. We selected a typical populus davidiana secondary forest to conduct a set carbon input change treatments of removing litter, two-fold litter, removing root, control (one-fold litter).They were conducted to investigate effects of carbon input on soil nitrogen mineralization. To explore soil nitrogen supplying capacity for further research.And revealing the forest ecosystem productive forces, forest soil nutrient circulation and nitrogen cycling mechanism to provide theoretical support. We can summarize the above points as following:(1)Seasonal changes of available nitrogen content and soil mineralization rate in populus davidiana secondary forest was not different trend. Ammonia nitrogen was the major form of inorganic nitrogen, and the proportion of ammonium nitrogen to the total inorganic was 72%-84%.(2) Different carbon input to the available nitrogen content have a significant impact. After removing the root soil available nitrogen content increased 19% compared with the control treatment, indicating available nitrogen content of affect of roots showed the removal of roots> controls;and two-fold litter treatment on soil available nitrogen content than one-fold litter average processing a 58% increase, removing litter treatment on soil nitrogen content reduced by an average of 27% compared to one-fold litter treatment, litter inputs influence of soil available nitrogen content is 2 times the litter>1 times the litter> removal of litter. During the growing season, treatments of soil available nitrogen content were significantly differences (P<0.001), there was a significant interaction between the months and C treatments (P<0.001).(3) Different carbon inputs to soil nitrogen mineralization has clear implications. After removing the root soil nitrogen mineralization rate increased 22% compared with the control treatment, soil nitrogen mineralization rate of removing the root control treatment was significantly (P= 0.015).There was no significant interaction between the months and C treatments;and and two-fold litter treatment on soil nitrogen mineralization than one-fold litter average increase of 273%, removing litter treatment on soil nitrogen mineralization reduced treated by an average of 103% compared to one-fold litter treatment. During the growing season, soil nitrogen mineralization differences in treatment were significantly (P<0.001), there was a significant interaction between the months and C treatments CP<0.001).