Soil carbon storage, litterfall and CO₂ efflux in fertilized and unfertilized larch (Larix leptolepis) plantations

• Published in: Ecological research 2008-07, Vol.23 (4), p.757-763
• Main Author: Kim, Choonsig
• Format: Article
• Language: English
• Subjects: Behavioral Sciences; Biomedical and Life Sciences; Carbon cycling; Carbon dioxide; Carbon dynamics; Carbon sequestration; Decomposition; Ecology; Evolutionary Biology; Fertilization; Fertilizers; Forest floor; Forestry; Larix; Larix leptolepis; Life Sciences; Moisture content; Organic carbon; Original Article; Plant Sciences; Plantations; Soil carbon; Soil depth; Soil fertility; Soil respiration; Soil sciences; Soil temperature; Soil water; Water content; Zoology
• ISSN: 0912-3814; 1440-1703
• DOI: 10.1007/s11284-007-0436-2

This study evaluated the effects of forest fertilization on the forest carbon (C) dynamics in a 36-year-old larch (Larix leptolepis) plantation in Korea. Above- and below-ground C storage, litterfall, root decomposition and soil CO₂ efflux rates after fertilization were measured for 2 years. Fertilizers were applied to the forest floor at rates of 112 kg N ha⁻¹ year⁻¹, 75 kg P ha⁻¹ year⁻¹ and 37 kg K ha⁻¹ year⁻¹ for 2 years (May 2002, 2003). There was no significant difference in the above-ground C storage between fertilized (41.20 Mg C ha⁻¹) and unfertilized (42.25 Mg C ha⁻¹) plots, and the C increment was similar between the fertilized (1.65 Mg C ha⁻¹ year⁻¹) and unfertilized (1.52 Mg C ha⁻¹ year⁻¹) plots. There was no significant difference in the soil C storage between the fertilized and unfertilized plots at each soil depth (0-15, 15-30 and 30-50 cm). The organic C inputs due to litterfall ranged from 1.57 Mg C ha⁻¹ year⁻¹ for fertilized to 1.68 Mg C ha⁻¹ year⁻¹ for unfertilized plots. There was no significant difference in the needle litter decomposition rates between the fertilized and unfertilized plots, while the decomposition of roots with 1-2 mm diameters increased significantly with the fertilization relative to the unfertilized plots. The mean annual soil CO₂ efflux rates for the 2 years were similar between the fertilized (0.38 g CO₂ m⁻² h⁻¹) and unfertilized (0.40 g CO₂ m⁻² h⁻¹) plots, which corresponded with the similar fluctuation in the organic carbon (litterfall, needle and root decomposition) and soil environmental parameters (soil temperature and soil water content). These results indicate that little effect on the C dynamics of the larch plantation could be attributed to the 2-year short-term fertilization trials and/or the soil fertility in the mature coniferous plantation used in this study.