Kyeong Hak Lee

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.

Biomass accumulations and the distribution of nitrogen and phosphorus within threeQuercus acutissima stands in central Korea

Above- and belowground biomass and nitrogen (N) and phosphorus (P) distribution within threeQuercus acutissima stands were investigated in central Korea. The average age (year) and diameter at breast height (DBH, cm) were 10.8 and 7.9 for Stand 1, 38.2 and 17.1 for Stand 2, and 44.0 and 20.7 for Stand 3, respectively. Fifteen trees were destructively harvested for dimension analysis of component biomass (stem wood, stem bark, foliage, branches, and roots) plus N and P concentrations. Total biomass (t ha-1) was 88.7 for Stand 1, 154.9 for Stand 2, and 278.1 for Stand 3 while N and P contents in all tree components (kg ha-1) were 483.3 and 52.2, 697.1 and 55.0, and 1113.9 and 83.7. Nitrogen concentrations were highest in the foliage, followed by the stem bark, branches or roots, and stem wood. In contrast, P concentrations were greatest in the roots, then foliage, branches, stem bark, and stem wood. In general, N and P concentrations in these components significantly decreased with tree age and DBH, while N and P contents significantly increased with age and size. These relationships were stronger for size than for age. Our current data could be utilized to estimate N and P budgets for silvicultural practices, including fertilization, thinning, and harvesting.

Geostatistical analysis of regional differences in stem taper form of Pinus densiflora in central Korea

This study verified regional differences in the stem form of Pinus densiflora Sieb. et Zucc. (red pine) and identified the relationship between stem form and climatic factors in the central region of the Korean peninsula. Regional differences in stem form index at tree base (butt) and top stem section were found. Compared to the stem form in the eastern uplands, the stem form in the western lowlands could be characterized by a more conical butt section and more cylindrical middle and upper section. Through geostatistical analysis of kriging and spatial regression, several climatic factors proved to exert a meaningful influence on stem taper form. On the stem form at the butt section, the precipitation during the late growing season exerts statistically significant effects. High precipitation during the growing season in the western lowland and coastal region causes the stem form at the butt section to be more tapered. On the stem form at the middle and upper section, temperature and precipitation during the growing season, and wind during the late growing season have statistically meaningful influences. High temperature, precipitation, and wind during the growing season in the western lowland and coastal region jointly influence the stem form at the middle and upper sections which result in more cylindrical profiles. This study can be considered an initial investigation into the factors controlling stem form variability in the central region of the Korean peninsula. The results can be used to develop more accurate regional stem taper models needed for reasonable management of red pine stands in different regions.

Influence of stand age class on biomass expansion factor and allometric equations for Pinus rigida plantations in South Korea

Abstract The objective of this study was to examine the influence of stand age class (I:<20 years old; II: 21–40 years old; III: 41–60 years old) on BEF and stem density and to develop allometric equations for the three stand age classes in order to estimate the biomass of pitch pine (Pinus rigida Mill.) plantations in South Korea. BEFs (g g−1) were observed to decrease in the three stand age classes with 1.983 for stand I, 1.201 for stand II and 1.131 for stand III. Results showed that there was a significant statistical difference in BEFs (p < 0.05) among the stand age classes. The stem densities (g cm−3) of the three stands were 0.430, 0.451 and 0.481, respectively, and there was no significant statistical difference (p > 0.05) among stand age classes. Both model 1 (DBH as predictor variable) and model 2 (DBH and total height as predictor variables) showed good results based on the model evaluation criteria (R 2 , RMSE and FI). The stem wood had the highest biomass distribution percentage of the three age classes with 52%, 67% and 69% determined for classes I, II and III, respectively. Stand age-dependent BEFs and allometric equations will help forest managers to accurately estimate the biomass and carbon stocks of the different pitch pine plantations in South Korea, which is essential in climate change mitigation.

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.

Mitigation options for the Bangladesh forestry sector: implications of the CDM

The Clean Development Mechanism (CDM) under the Kyoto Protocol has expedited various global warming mitigation opportunities that allow Bangladesh to receive investments from those Annex I countries wishing to offset their emissions of greenhouse gases. Bangladesh has a special interest in strategies for combating global warming because its large areas that need to be planted represent a potentially large carbon sink, and at the same time its high rate of deforestation represents a huge carbon source. To properly assign carbon credits within the forestry sector of Bangladesh, a number of important issues and uncertainties need to be examined and resolved. Afforestation and reforestation (A/R) offers opportunities for carbon credits, which is subject to the end-use of the forest products. A/R may be the best option, as well as conserving the existing carbon sink offered by Bangladesh for mitigating global warming. This article discusses the legal issues raised in combating global warming; the potential of the Bangladesh forestry sector to combat global warming; implications of the forestry options for different land uses; and issues to be settled regarding carbon credits. Future policy and governance issues are considered which will enable the Bangladesh forestry sector to mitigate global warming and to obtain carbon credits.

DBH-height modeling and validation for Acacia mangium and Eucalyptus pellita in Korintiga Hutani Plantation, Kalimantan, Indonesia

Diameter at breast height (DBH)-height models were developed and validated for Acacia mangium and Eucalyptus pellita species in the tree plantation of Pangkalan Bun, central Kalimantan, Indonesia, using the six commonly used nonlinear growth models. A total of 2992 and 4511 total height and DBH measurements were used for A. mangium and E. pellita species, respectively. These data were randomly split into two datasets. The majority of the data (80%) were used for the initial model development and the remaining data (20%) were applied for model validation. The combined data (100%) were used for the final model development. For model validation, the bias () for each DBH class (5 cm interval) and the overall bias were determined. The performance of the developed models were evaluated and ranked using the coefficient of determination (R2), root mean square error (RMSE), bias, absolute mean difference (AMD) and Furnival index (FI). The Weibull model had the best performance followed by the Chapman-Richards model in predicting the total height of A. mangium species and for E. pellita, the Korf/Lundqvist and Chapman-Richards models were the best models based on the evaluation statistics and rank analysis.

Comparison of Kalman filters in combining panel data from the annual inventory system of the South Korea National Forest Inventory

National Forest Inventories (NFIs) serve a primary purpose of providing crucial information for formulating national forest policy, environmental planning and reporting to international processes (Tomppo and others 2010). Pressure for timely and reliable forestry statistics urges countries to put a NFI in place or to consider alternative designs. Some countries, for example, USA and Finland, moved from a periodic inventory design to an annual inventory design (Lawrence and others 2010) with the Swedish NFI being one of the earliest examples of the transition (Matern 1960, Ranneby and others 1987). An annual inventory systematically subdivides a plot network, with equal proportion, into a number of panels equal to the length of measurement cycle (Reams and others 2005). A measurement cycle is typically five or ten years. Panels are measured successively on an annual basis. Remeasurement starts in the next cycle once all panels are visited. Thus, an annual inventory is expected to meet the demand for continually updated information.

Notes on the biomass expansion factors of Quercus mongolica and Quercus variabilis forests in Korea

Biomass expansion factors, which convert timber volume (or dry weight) to biomass, are used for estimating the forest biomass and accounting for the carbon budget at a regional or national scale. We estimated the biomass conversion and expansion factors (BCEF), biomass expansion factors (BEF), root to shoot ratio (R), and ecosystem biomass expansion factor (EBEF) for Quercus mongolica Fisch. and Quercus variabilis Bl. forests based on publications in Korea. The mean BCEF, BEF, and R for Q. mongolica was 1.0383 Mg/m 3 (N = 27; standard deviation [SD], 0.5515), 1.3572 (N = 27; SD, 0.1355), and 0.2017 (N = 32; SD, 0.0447), respectively. The mean BCEF, BEF, and R for Q. variabilis was 0.7164 Mg/m 3 (N = 17; SD, 0.3232), 1.2464 (N = 17; SD, 0.0823), and 0.1660 (N = 8; SD, 0.0632), respectively. The mean EBEF, as a simple method for estimating the ground vegetation biomass, was 1.0216 (N = 7; SD, 0.0232) for Q. mongolica forest ecosystems, and 1.0496 (N = 8; SD, 0.0725) for Q. variabilis forest ecosystems. The biomass expansion factor values in this study may be better estimates of forest biomass in Q. mongolica or Q. variabilis forests of Korea compared with the default values given by the Intergovernmental Panel on Climate Change (IPCC).