Carbon and nitrogen inputs by litter fall in fertilized and unfertilized larch plantations

Abstract

This study was carried out to evaluate the effects of fertilization on carbon and nitrogen dynamics by litter fall of a 36-year-old larch (Larix leptolepis) plantation in the Sambong Exhibition Forests, Gyeongsangnam-do, Korea. Litter was collected monthly between April 2003 and May 2006. Seasonal inputs of litter fall components such as needle, broad leaf, branch, bark and total litter inputs followed a similar pattern between fertilized and unfertilized plots. The annual amounts of the litter components were not significantly different (P > 0.05) between fertilized and unfertilized plots. Mean needle litter fall was similar between the fertilized (2564 kg ha−1 yr−1) and unfertilized plots (2501 kg ha−1 yr−1) and total annual litter fall averaged 3552 kg ha−1 yr−1 in the fertilized and 3541 kg ha−1 yr−1 in the unfertilized plots during the sampling period. Proportion of needle litter fall was slightly higher in the fertilized (72.2%) than in the unfertilized (70.8%) plots. Carbon concentrations of needle litter were not significantly affected by fertilization (P > 0.05), while there was a significant fertilization effect on nitrogen concentrations with high nitrogen concentrations of needle litter in the fertilized (7.7 g kg−1) compared with the unfertilized (6.8 g kg−1) plots. There was no significant difference (P > 0.05) in the organic carbon inputs by needle litter between the fertilized and unfertilized plots, whereas annual nitrogen inputs were significantly higher in the fertilized (17.7 kg N ha−1 yr−1) than in the unfertilized (15.6 kg N ha−1 yr−1) plots. The results indicated that nitrogen dynamics by litter fall could be affected by fertilization, but a minimal impact to carbon dynamics by litter fall in the larch plantation.