Choonsig Kim

Fine Root Dynamics in Thinned and Limed Pitch Pine and Japanese Larch Plantations

ABSTRACT To investigate fine root dynamics after thinning (50% of standing tree) and liming calcium magnesium carbonate[CaMg(CO3)2] 2 Mg ha− 1, a 2-year study was performed in 40-year-old pitch pine (Pinus rigida Mill.) and 44-year-old Japanese larch (Larix leptolepis Gord.) plantations in central Korea. Mean total fine root mass (kg ha− 1± SE) in the control, thinned, and limed plots were 1234 ± 32, 1346 ± 67, and 1134 ± 40 for the pitch pine plantation and 1655 ± 48, 1953 ± 58, and 1868 ± 70 for the Japanese larch plantation, respectively. Live fine root mass of pitch pine at 0-10 cm soil depth decreased after thinning and liming. In addition, liming significantly increased dead fine root mass of Japanese larch. Fine root production (kg ha− 1 yr− 1± SE) in the control, thinned and limed plots was 1108 ± 148, 2077 ± 262, and 1686 ± 103 for the pitch pine plantation and 1762 ± 103, 1886 ± 277, and 2176 ± 271 for the Japanese larch plantation, respectively. Fine root turnover rates increased after liming for both plantations. Fine root nitrogen (N) and phosphorus (P) concentrations of Japanese larch (1.012% of N and 0.073% of P) were higher than those of pitch pine (0.809% of N and 0.046% of P) in the control. Also N and P inputs into soil through fine root turnover increased after treatments. Results indicated that comparing fine root dynamics among forest types and after forest management practices might influence differences in soil fertility and underground nutrient cycling.

Estimation of carbon storage based on individual tree detection in Pinus densiflora stands using a fusion of aerial photography and LiDAR data

The objective of this study was to estimate the carbon storage capacity of Pinus densiflora stands using remotely sensed data by combining digital aerial photography with light detection and ranging (LiDAR) data. A digital canopy model (DCM), generated from the LiDAR data, was combined with aerial photography for segmenting crowns of individual trees. To eliminate errors in over and under-segmentation, the combined image was smoothed using a Gaussian filtering method. The processed image was then segmented into individual trees using a marker-controlled watershed segmentation method. After measuring the crown area from the segmented individual trees, the individual tree diameter at breast height (DBH) was estimated using a regression function developed from the relationship observed between the field-measured DBH and crown area. The above ground biomass of individual trees could be calculated by an image-derived DBH using a regression function developed by the Korea Forest Research Institute. The carbon storage, based on individual trees, was estimated by simple multiplication using the carbon conversion index (0.5), as suggested in guidelines from the Intergovernmental Panel on Climate Change. The mean carbon storage per individual tree was estimated and then compared with the field-measured value. This study suggested that the biomass and carbon storage in a large forest area can be effectively estimated using aerial photographs and LiDAR data.

Soil properties of cultivation sites for mountain-cultivated ginseng at local level

Background Identifying suitable site for growing mountain-cultivated ginseng is a concern for ginseng producers. This study was conducted to evaluate the soil properties of cultivation sites for mountain-cultivated ginseng in Hamyang-gun, which is one of the most well-known areas for mountain-cultivated ginseng in Korea. Methods The sampling plots from 30 sites were randomly selected on or near the center of the ginseng growing sites in July and August 2009. Soil samples for the soil properties analysis were collected from the top 20 cm at five randomly selected points. Results Mountain-cultivated ginseng was grown in soils that varied greatly in soil properties on coniferous, mixed, and deciduous broad-leaved stand sites of elevations between > 200 m and < 1,000 m. The soil bulk density was higher in Pinus densiflora than in Larix leptolepis stand sites and higher in the < 700-m sites than in > 700-m sites. Soil pH was unaffected by the type of stand sites (pH 4.35–4.55), whereas the high-elevation sites of > 700 m were strongly acidified, with pH 4.19. The organic carbon and total nitrogen content were lower in the P. densiflora stand sites than in the deciduous broad-leaved stand sites. Available phosphorus was low in all of the stand sites. The exchangeable cation was generally higher in the mixed and low-elevation sites than in the P. densiflora and high-elevation sites, respectively. Conclusion These results indicate that mountain-cultivated ginseng in Korea is able to grow in very acidic, nutrient-depleted forest soils.

Carbon storage and soil CO2 efflux rates at varying degrees of damage from pine wilt disease in red pine stands.

We evaluated the carbon (C) storage and soil CO2 efflux rates of red pine (Pinus densiflora S. et Z.) stands damaged by pine wilt disease (PWD) in Korea. Ten red pine plots at varying degrees of damage from PWD were established and grouped into five categories (very slightly, slightly, moderately, severely, and very severely damaged plots) based on differences in the tree density. The incidence of PWD was a major cause of C loss from forest ecosystems, but the magnitude of loss depended on the severity of disease damage. An exponential regression of the CO2 efflux rates against the corresponding soil temperature was highly significant (R(2)=0.82-0.95, P<0.01) for the varying degrees of damage from PWD. The rates of change in the CO2 efflux rates with temperature, as defined by the Q10 values, were generally lower in the slightly (2.94) versus the moderately (3.60) or severely (4.26) PWD-damaged stands. The cumulative soil CO2-C efflux rates for two years were significantly higher in the slightly (10.8 Mg Cha(-1) yr(-1)) or moderately (10.9 Mg Cha(-1) yr(-1)) versus the very severely (7.9 Mg Cha(-1) yr(-1)) PWD-damaged stands. The results indicate that the C storage and soil CO2 efflux rates in red pine stands can be impacted by the incidence of PWD, with a significant C reduction in the severely damaged stands.

Short-term Effects of Fire on Soil Properties in Pinus densiflora Stands

This study was performed to investigate a short time change (one week after fire) on soil properties due to the fire inPinus densiflora Sieb. et Zucc stands of the Kosung area in Kangwon Province in Korea. Twenty seven sampling plots [16 burned (8 low intensity fire, 8 high intensity fire) and 11 unburned plots] were chosen. Mineral soil samples from three depths (0–5, 5–15, and 15–25 cm) under the forest floor were collected. Forest fire in the area affected soil chemical properties. Soil pH, total nitrogen, available phosphorus, potassium, calcium, and magnesium in the surface soil (0–5 cm) of the burned area compared with the unburned area increased, but there was no marked change in the subsurface soil (5–25 cm). Organic matter, total nitrogen, available phosphorus, and exchangeable cations in the surface soil were generally lower in the high than in the low intensity fire areas. This indicates that these nutrients on the high intensity fire may be volatilized. The results suggest that change in soil chemical properties in the area was restricted mainly to the surface soil and was different between the high and the low intensity fire types.

Initial effects of thinning on soil carbon storage and base cations in a naturally regenerated Quercus spp. forest in Hongcheon, Korea

Thinning can affect soil carbon (C) and base cation balances by reducing tree density and altering microclimate and organic matter budget; however, the subsequent changes in soil C and base cation contents after thinning are not well elucidated. Thus, this study investigated the effects of thinning on C storages in soil (at 0–10 cm, 10–20 cm, and 20–30 cm depths) and forest floor and concentrations of soil exchangeable base cations (Ca2+, Mg2+, K+, and Na+). Thinning treatments of different intensities based on the removed basal area (no thinning: control, 15% thinning: T15, and 30% thinning: T30) were applied to a naturally regenerated 31 to 40-year-old Quercus spp. forest. Soil C concentrations at 10–20 cm and 20–30 cm depths were significantly higher in T15 and T30 than in the control after 39 months, but not after 4 months. T15 and T30 treatments seemed to increase soil C storage at 0–30 cm after 39 months, but did not significantly change forest floor C storage after 4 and 39 months. Concentrations of exchangeable K+ of T15 and exchangeable base cations except for Ca2+ of T30 depth were significantly lower than those of the control at 0–10 cm after 4 months, but not after 39 months. This study shows that thinning treatments on a naturally regenerated Quercus spp. forest could increase soil C concentration after a few years but temporally decrease concentrations of soil exchangeable base cations.

Simulating the soil carbon dynamics of Pinus densiflora forests in central Korea

Abstract We developed a simple forest soil carbon model (Korean Forest Soil Carbon model, KFSC) requiring a small number of parameters to evaluate the forest soil carbon stocks and dynamics. The KFSC was composed of live biomass (BIO), primary dead organic matter (DOM) (AWD: aboveground woody debris; BWD: belowground woody debris; ALT: aboveground litter; and BLT: belowground litter), and secondary DOM (HUM: humus and SOC: soil organic carbon). The KFSC was validated against six Pinus densiflora forests at Gyeonggi province in central Korea and validation results showed that the model predicted the AWD, ALT, and SOC stocks with high precision (r 2=0.90–0.98, slope = 0.95–0.98). We simulated 160 years of carbon dynamics of the P. densiflora forests in Gyeonggi province (11,607 ha) under alternative clear-cut intervals that had been taking place in the past (30, 50, and 80 years). Simulated total SOC stock ranged from 298.7 to 520.5 Gg C depending on the scenario and increased with time in all scenarios. The estimated total SOC stock was higher in the scenario of less frequent clear-cut, while its annual increment was higher in the scenario of more frequent clear-cut in the past. The KFSC will be useful, especially for simulating soil carbon dynamics in forests with scarce information, and has the potential to estimate soil carbon dynamics at a national scale by incorporating with geographical information system.

Effects of container volumes and fertilization on red (Pinus densiflora) and black pine (Pinus thunbergii) seedlings growth

The growth, carbon and nitrogen responses of container grown 2–0 red (Pinus densiflora) and black pine (Pinus thunbergii) seedlings were examined at three types of container volume (250 cm3, 350 cm3, 500 cm3) with or without foliar fertilization. There were significant main and interaction effects of seedling growth on container volume and foliar fertilization. Root collar diameter, height, and dry mass of both pine seedlings decreased significantly (P < 0.05) with decreasing of container volume with fertilization, while no effect of container volumes without fertilization. Carbon and nitrogen concentrations of foliage were significantly different (P < 0.05) among container volumes, while other seedling components were not significantly different (P > 0.05) among the container volumes or between seedling types. The results indicate that growth characteristics and nitrogen status on container grown red and black pine seedlings were enhanced by increased container volumes with fertilization.

Effect of thinning on carbon storage in soil, forest floor and coarse woody debris of Pinus densiflora stands with different stand ages in Gangwon-do, central Korea

This study was conducted to investigate effects of thinning on carbon (C) storage of soil, forest floor and coarse woody debris (CWD) in Pinus densiflora stands, central Korea. Two study stands (25- and 55-year-old stands) were located in P. densiflora forests of Gangwon-do and thinned in 2008. Each stand was divided into three plots by different thinning intensities based on stand density: no thinning (control, 0%), moderate thinning (M, 30%), and heavy thinning (H, 50%) in the 25-year-old stand and no thinning (control, 0%), light thinning (L, 20%), and moderate thinning (M, 30%) in the 55-year-old stand. We measured C storage of 0–30 cm depth soil, forest floor and CWD in 2009. Total C storage (t C ha−1) of soil, forest floor and CWD in two thinned plots was significantly higher than that in the control plot only in the 55-year-old stand: 66.4 for control, <84.2 for L, <117.9 for M. On the other hand, total C storage in the 25-year-old stand did not show a consistent tendency among thinning intensities. We speculated that 1 year was too short to detect any consistent changes in total C storage of soil, forest floor and CWD by thinning, and long-term observation would be needed.

Quantitative Comparisons of Soil Carbon and Nutrient Storage in Larix leptolepis, Pinus densiflora and Pinus rigitaeda Plantations

This study was carried out to evaluate soil carbon and nutrient storage of three adjacent coniferous plantations (Larix leptolepis, Pinus densiflora and Pinus rigitaeda) growing on a similar site with a same planting age (42-year old) in the Sambong Exhibition Forests, Hamyang-gun, Gyungsangnam-do. The soil carbon concentration among three plantations was not significantly different in 0∼10cm soil depth, but other two depths (10∼20cm and 20∼30cm) showed higher carbon concentration in P. densiflora plantation than the other two plantations. The exchangeable cation concentrations (Ca and Mg) in 0∼10cm depth were significantly lower in L. leptolepis plantation than in the other two plantations, while nitrogen and phosphorus concentrations were not significantly different among three plantations except for nitrogen at 10∼20cm depth in P. rigitaeda plantation. Soil carbon storage in 0∼20cm depth of three plantations was unaffected by the stand types. Soil nutrient storage was not significantly different at each depth except for nitrogen storage at 10∼20cm depth in P. rigitaeda plantation because of the variation of bulk density and coarse fragment. This result demonstrates that soil carbon and nutrient concentrations among the plantations on a similar soil condition can be altered significantly by tree species effects over 40 years after plantation establishment.