Soil nitrogen mineralization in adjacent stands of larch, pine and oak in central Korea

To examine the effects of tree species on soil nitrogen (N) mineralization we monitored rates of soil nitrogen mineralization and nitrification using the buried bag incubation method in 37-year-old Japanese larch (Larix leptolepis Gordon), pitch pine (Pinus rigida Mill), and oak (Quercus serrata Thunb) stands on a similar soil in central Korea. Litter and mineral soil (0-15 cm) were incubated for 45 day intervals from 1 September 1994 to 31 August 1995. Mean daily N mineralization rates were significantly different among sampling dates and tree species. Annual net N mineralization and nitrification were also significantly different among the tree species; the annual N mineralization being 44 kg/ha/year for P. rigida, 92 for L leptolepis and 112 for Q serrata, and percent nitrification ranging from 45% for P rigida to 90% for L leptolepis. Litterfall N inputs seemed to influence soil N mineralization. This study indicates that under a similar environment and soil type, N mineralization may differ by several-fold under the influence of different species.