Myong Jong Yi

Biomass, production and nutrient distribution of a natural oak forest in central Korea

Biomass, production, and nutrient distribution of a pure Quercus variabilis Bl. stand (stand 1) and two mixed Q. variabilis–Q. mongolica Fisch. stands (stand 2 and 3) were investigated in central Korea. Stand 1 naturally occurred on a site with a southern aspect while stand 2 and stand 3 occurred on sites with a northern aspect. Total (overstory + understory vegetation) biomass (t ha-1) and annual production (t ha–1 year–1) were 137.8 and 11.1 for stand 1, 216.2 and 16.6 for stand 2, and 253.3 and 19.7 for stand 3. Nutrient contents (kg ha–1) in the vegetation were distributed as follows: K, 478–860; N, 471–839; Ca, 428–791; Mg, 72–125; Na, 77–141; and P, 37–71, and were greatest in stand 3 followed by stand 2, and stand 1. Stand density influenced the differences in biomass, annual production and nutrient contents in the vegetation. Forest floor dry mass and N content (kg ha–1) were 13 400 and 169 for stand 1, 10 400 and 133 for stand 2, and 11 200 and 127 for stand 3. Total amounts of N, P and Na in the ecosystem were greatest in the upper 40 cm of mineral soil followed by the vegetation and forest floor. However, the vegetation contained a greater amount of K than the mineral soil. It appeared that microenvironments, such as, aspect influenced the distribution of natural oak species within a relatively small area and resulted in differences in biomass, production and nutrient distribution among the stands.

Carbon and nitrogen storage in an age-sequence of Pinus densiflora stands in Korea

The carbon (C) and nitrogen (N) storage capabilities of Pinus densiflora in six different stand ages (10, 27, 30, 32, 44, and 71 years old) were investigated in Korea. Thirty sample trees were destructively harvested and 12 were excavated. Samples from the above and belowground tree components, coarse woody debris (CWD), forest floor, and mineral soil (0–30 cm) were collected. Tree biomass was highest in the 71-year-old stand (202.8 t ha−1) and lowest in the 10-year-old stand (18.4 t ha−1). C and N storage in the mineral soil was higher in the 71-year-old stand than in the other stands, mainly due to higher soil C and N concentrations. Consequently, the total ecosystem C and N storage (tree+forest floor+CWD+soil) was positively correlated with stand age: increasing from a minimum in the 10 year old stand (18.8 t C ha−1 and 1.3 t N ha−1) to a maximum in the 71-year-old stand (201.4 t C ha−1 and 8.5 t N ha−1). The total ecosystem C storage showed a similar sigmoidal pattern to that of tree C storage as a function of the age-sequence, while N storage in the CWD, forest floor and mineral soil showed no significant temporal trends. Our results provide important insights that will increase our understanding of C and N storage in P. densiflora stands and our ability to predict changes according to stand age in the region.

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.

Physiological and chemical characteristics of field-and mountain-cultivated ginseng roots

Demand is increasing for mountain-cultivatedPanax ginseng (MCG) because its quality is considered superior to that of field-cultivated ginseng (FCG). However, MCG grows very slowly, and the factors that might affect this are unknown. In addition, little information is available about the physiological characteristics of its roots. Here, we investigated local soil environments and compared the histological and chemical properties of MCG and FCG roots. Average diameters, lengths, and fresh weights were much smaller in the former. Photosynthesis rates and root cambial activity also were reduced in the MCG tissues. Our analysis of soil from the mountain site revealed an extremely low phosphorus content, although those samples were richer in total nitrogen and organic matter than were the field soils. MCG roots also contained higher amounts of ginsenosides, and total accumulations increased with age. Moreover, ginsenoside Rh2, a red ginseng-specific compound, accumulated in the MCG roots but not in those from FCG plants. Interestingly, numerous calcium oxalate crystals were found in MCG roots, particularly in their rhizomes (i.e., short stems). Therefore, we can conclude from these results that low levels of the essential mineral phosphorus in mountain soils are a critical factor that retards the growth of mountain ginseng. Likewise, the high accumulation of calcium oxalate crystals in MCG roots might be an adaptation mechanism for survival in such a harsh local environment.

Forest biomass carbon accumulation in Korea from 1954 to 2007

Abstract Estimating the level of forest biomass accumulation in Korea is a challenging task because of historical reasons and the later reforestation implemented at the national level. Nevertheless, systematic national forest inventories and direct field measurements make it possible to estimate the carbon (C) sinks as well as their distribution. Simple linear relationships between the stand biomass and stand volume were developed for each forest type (coniferous, deciduous and mixed forests) in Korea based on direct field measurements. These relationships were used to estimate the changes in C accumulation of the above-ground and total biomass from 1954 to 2007 based on the national forest inventories. The mean C density and C stock of the above-ground biomass for all forest types increased from 3.49 Mg C ha−1 and 16.71 Tg C in 1954 to 31.46 Mg C ha−1 and 196.45 Tg C in 2007, respectively, and the total biomass for all forest types increased from 4.29 Mg C ha−1 and 20.57 Tg C in 1954 to 38.58 Mg C ha−1 and 239.85 Tg C in 2007, respectively. Such a large C uptake in Korea is due mainly to the successfully implemented reforestation and subsequent forest management practices.

Nitrogen Fixation, Soil Nitrogen Availability, and Biomass in Pure and Mixed Plantations of Alder and Pine in Central Korea

ABSTRACT Rates of nitrogen (N) fixation, soil N availability, and aboveground biomass were measured in 27-year-old pure and mixed Alnus hirsuta and Pinus koraiensis plantations in central Korea. Nodule biomass and N fixation were 179.3 kg ha− 1 and 46.6 kg ha− 1yr− 1 for the pure A. hirsuta plantation (PA) and 95.2 kg ha− 1 and 41.1 kg ha− 1yr− 1 for the mixed A. hirsuta + P. koraiensis plantation (MAP), respectively. A. hirsuta seemed to provide more than two thirds of annual N requirement for P. koraiensis.Rates of acetylene reduction were significantly related to soil temperature (R2 = 0.51, P < 0.001), but not to soil moisture content. Total inorganic N [ammonium (NH4 +)plus nitrate (NO3 −)] availability measured using ion exchange bags were significantly higher under PA (27.91 μ g-N bag− 1) and MAP (31.34 μ g-N bag− 1) than under the pure P. koraiensis plantation (PP) (14.31 μ g-N bag− 1). Especially soils under the influence of A. hirsuta showed at least 2 fold increase in resin total inorganic N concentrations. Total aboveground biomass (Mg ha− 1) was 147.3 for PA, 145.8 for MAP, and 174.8 for PP, respectively, and was not significantly different among plantations. A. hirsuta significantly increased soil N availability; however, the influence of N fixation on aboveground biomass was not significant for the study plantations.

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.

Biomass and carbon storage in an age-sequence of Japanese red pine (Pinus densiflora) forests in central Korea

The biomass and carbon (C) storage of the main ecosystem components were examined in an age-sequence of six Japanese red pine forest stands in central Korea. The tree biomass was determined by the destructive method, and the C storage of the tree biomass, forest floor and mineral soil was estimated by analyzing the C concentration of each component. The above-ground and total tree biomass increased from 21.76 and 28.82 Mg ha−1 in the 17-year-old stand to 308.83 and 385.74 Mg ha−1 in the 73-year-old stand. The comparisons of above-ground tree and tree root biomass in replicate stands indicated that stand density has an effect on tree biomass partitioning for Japanese red pine, especially on the biomass allocation of above-ground tree and tree roots. The C concentrations were lowest in the tree roots while the highest concentrations were found in the foliage across the six Japanese red pine forest stands. The C storage in the forest floor and mineral soil were age-independent. The above-ground and total ecosystem C stocks increased from 19.40 and 43.49 Mg ha−1 in the 17-year-old stand to 162.72 and 247.39 Mg ha−1 in the 73-year-old stand. Although the total tree biomass C showed considerable accumulation with stand age, the relative contribution of the below-ground ecosystem to the total ecosystem C storage demonstrated large variation. The results of this study assist in understanding C storage and its change with stand development in Japanese red pine forests, which makes this species a large sink for atmospheric C at the regional scale.

Biomass and nutrient distribution of pinus koraiensis seedlings invading a mixed forest dominated by quercus mongolica

This study was conducted to estimate the biomass and nutrient distribution in understory P. koraiensis seedlings invading a mixed forest dominated by Quercus mongolica in central Korea. Total above and belowground biomass for the three overstory and understory dominant tree species were 2.70 t/ha for P. koraiensis, 210.56 t/ha for Q. mongolica, and 28.39 t/ha for Q. variabilis. P. koraiensis seedlings seemed to allocate more biomass to foliage (31.0% of total biomass) than overstory Quercus spp. (0.9%), so as to exploit the low light flux found in the shady conditions. Furthermore, the high specific leaf area of P. koraiensis seedlings indicated morphological characteristics of shade leaves in low light conditions. Total nitrogen (N) and phosphorus (P) contents for P. koraiensis seedlings and Quercus spp. were 19.6 and 1.9 kg/ha, and 94.7–626.5 and 9.4–137.6 kg/ha, respectively. Our results suggested that understory P. koraiensis seedlings exerted only a minor influence on the biomass and nutrient distribution for the study forest.

Estimating the Changes in Forest Carbon Dynamics of Pinus densiflora and Quercus variabilis Forests in South Korea under the RCP 8.5 Climate Change Scenario

Forests contain a huge amount of carbon (C) and climate change could affect forest C dynamics. This study was conducted to predict the C dynamics of Pinus densiflora and Quercus variabilis forests, which are the most dominant needleleaf and broadleaf forests in Korea, using the Korean Forest Soil Carbon (KFSC) model under the two climate change scenarios (2012−2100; Constant Temperature (CT) scenario and Representative Concentration Pathway (RCP) 8.5 scenario). To construct simulation unit, the forest land areas for those two species in the 5th National Forest Inventory (NFI) data were sorted by administrative district and stand age class. The C pools were initialized at 2012, and any disturbance was not considered during the simulation period. Although the forest C stocks of two species generally increased over time, the forest C stocks under the RCP 8.5 scenario were less than those stocks under the CT scenario. The C stocks of P. densiflora forests increased from 260.4 Tg C in 2012 to 395.3 (CT scenario) or 384.1 Tg C (RCP 8.5 scenario) in 2100. For Q. variabilis forests, the C stocks increased from 124.4 Tg C in 2012 to 219.5 (CT scenario) or 204.7 (RCP 8.5 scenario) Tg C in 2100. Compared to 5th NFI data, the initial value of C stocks in dead organic matter C pools seemed valid. Accordingly, the annual C sequestration rates of the two species over the simulation period under the RCP 8.5 scenario (65.8 and 164.2 g C m yr for P. densiflora and Q. variabilis) were lower than those values under the CT scenario (71.1 and 193.5 g C m yr for P. densiflora and Q. variabilis). We concluded that the C sequestration potential of P. densiflora and Q. variabilis forests could be decreased by climate change. Although there were uncertainties from parameters and model structure, this study could contribute to elucidating the C dynamics of South Korean forests in future.