• The Korean Journal of Ecology
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• v.23 no.2
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• pp.83-88
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• 2000

When interpreting change over time in forest ecosystems, distinguishing the effects of forest succession from the effects of environmental stress can be difficult. The result may be a simplistic interpretation. citing a specific successional or environmental cause of forest change when both types may be occurring. We present two case studies of changes in the forest floor in northern hardwoods. First, the belief that 50% of soil organic matter is lost in the first 20 years after logging was based on a study comparing northern hardwood stands of different ages. We resampled a series of 13 such stands after an interval of 15 years, and found that the young stands were not, in fact. losing organic matter as rapidly as predicted from the original chronosequence study. The pattern of higher organic matter content in the forest floors of older stands compared to young stands could be equally well explained by changes in logging practices over the last century as by the aging of the stand. The observed pattern of forest floor organic matter as a function of stand age was previously interpreted as a successional pattern, ignoring changes in treatment history. In the second case study, observed losses of base cations from the forest floor were attributed to cation depletion caused by acid rain and declining calcium deposition. We found that young stands were gaining base cations in the forest floor; losses of base cations were restricted to older stands. Differences in litter chemistry in stands of different ages may explain some of the pattern in cation gains and losses. In this case, the contribution of successional processes to cation loss had been overlooked in favor of environmental stress as the dominant mechanism behind the observed changes. Studies of environmental stress use repeated measures over time. but often don't consider stand age as a factor. Studies of successional change often assume that environmental factors remain constant. We were able to consider both forest succession and external factors because we repeatedly sampled stands of different ages.

• Journal of Forest and Environmental Science
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• v.15 no.1
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• pp.71-76
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• 1999

This study compared soil characteristics and carbon storage between urban and natural lands in Chunchon. Soil pH was lower in natural lands (5.0) than in urban lands (6.6), and therefore exchangeable cation was a little lower in natural lands. Organic matter and cation exchange capacity were respectively, 1.4 and 1.7 times higher in natural lands than in urban lands, while available $P_2O_5$ was about 3.2 times higher in urban lands. Organic carbon storage in soils averaged $24.8{\pm}1.6$ (standard error) t/ha in urban lands and $31.6{\pm}1.6t/ha$ in natural lands, 1.3 times greater than in urban lands. Annual carbon accumulation in soils of natural lands was 1.3 t/ha/yr (litterfall minus decomposition). The carbon storage in Chunchon' s soils equaled about 31% of annual carbon emission (245,590 t/yr).

• The Korean Journal of Ecology
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• v.15 no.1
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• pp.35-46
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• 1992

To elucidate nutrient cyclings such as nitrogen, phosphorus and potassium in mongolian oak(quercus mongolica) forest, nutrient elements of precipitation, throughfall, outflow, soil, various plant organ and litter were determined at mt.nambyeongsan, pyeongchang-gun, gangwon province in central part of korean peninsula. Annual precipitation input, throughfall and outflow of nutrientswere 10.3, 8.6 and 4.2 kg/ha for the N, 0.11, 0.24 and 0.02 kg/ha for the Pand 1.3, 10.9 and 1.2 kg/ha for the K, respectively. Inseasonal changes of nutrient concentrations, N, P and Kconcentrations which were rich in young leaves decreased steadily until autumn and decreased abruptly during autumnal yellowing. The standing N, P and K concent were 565, 37 and 257 kg/ha for standing phytomass of overstory, 33, 3 and 18 kg/ha for understory, 132, 3.6 and 14 kg/ha for litter on ground including deadwood and 20, 752, 14 and 420 kg/ha for the soil, respectively. The amounts of annual uptake, reture and retain were 174.2, 57.2, 117.2 kg/ha for the N, 9.9, 3.5, 6.4 kg/ha for the P and 73.2, 30.3, 42.9 kg/ha for the K, respectively. Reabsorption efficiency, ratio of the nutrient amount reabsorbed into woody organs to that in the mature leaves before shedding, was 71%(or 99.8 kg/ha in the amount), 69%(or 5.1 kg/ha) and 57%(or 33.1% kg/ha) and recycling coeffciently made with which the large amount of nutrients is absorbed through roots during growing season(UPTAKE) and reasorbed from the leaves before shedding(RETAIN) but the small amount of nutrients is returned through litterfall(RETURN).

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.128-128
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• 2021

Most of the studies about stormwater low impact development technologies used generalized observations without fully understanding the mechanisms affecting the whole performance of the systems from catchment to the facility itself. At present, these LID technologies have been treated as black box due to fluctuating flow and environmental conditions affecting its operation and treatment performance. As such, the implications of microbial community to the overall performance of the tree-box filter were investigated in this study. Summer season was found to be the most suitable season for microorganism growth since more microorganism were found during this season. Least microorganism count was found in spring because of the plant growth during this season since plant penology influences the seasonal dynamics of soil microorganisms. Litterfall during fall season might have affected the microorganism count during winter since, during this season, the compositional variety of soil organic matter changes affecting growth of soil microbial communities. Microbial analyses of sediment samples collected in the system revealed that the most dominant microorganism phylum is Proteobacteria in all the seasons in both inlet and outlet comprising 37% to 47% of the total microorganism count. Proteobacteria was followed by Acidobacteria, Actinobacteria and Chloroflexi which comprises 6% to 20%, 9% to 20% and 2% to 27%, respectively of the total microorganism count for each season. These findings were useful in optimizing the design and performance of tree box filters considering physical, chemical and biological pollutant removal mechanisms.

• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.1
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• pp.1-15
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• 2016

Annual litterfall production and leaf area index (LAI, $m^2/m^2$) were estimated using litter traps in Gwangneung, Mt. Taewha and Mt. Gariwang. Annual total litter fall production including branch, bark, others was the highest in Gwangneung($7497.3{\pm}326.5kg/ha/yr$), which had the highest basal area at late successional stage, and followed by Mt. Taewha($5929.1{\pm}225.8kg/ha/yr$) and Mt. Gariwang($3,210.1{\pm}220.1kg/ha/yr$). Mt. Gariwang had the lowest litterfall production due to high elevation and short growing season even with the higher stand density and basal area than Mt. Taewha. Similarly, LAI, which was calculated by multiplying the mass of leaf litter with specific leaf area, was the highest in Gwangneung($5.99{\pm}0.69$) and followed by Mt. Taewha($5.20{\pm}0.24$) and Mt. Gariwang($4.06{\pm}0.42$) and the upper canopy species had the highest leaf area index in every sites (Gwangneung : 4.72, Mt. Taewha : 3.08, Mt. Gariwang : 2.19). However, species specific LAI estimation based on the relationship between basal area and leaf area was limited due to upper canopy species non-proportionality of basal area with LAI. In addition, the comparison between direct and indirect LAI measurement showed the importance of canopy clumping, especially at high density. Our study emphasized the necessity of direct LAI measurement using litter fall traps especially at temperate deciduous forest with diverse species.

• Journal of Korean Society of Forest Science
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• v.85 no.3
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• pp.496-505
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• 1996

Soil respiration was measured every two weeks from May through November 1995 using the soda lime method in 40-Year-old Pinus rigida and Larix leptolepis plantations on a similar soil in Yangpyeong, Kyonggi Province. Treatments included control and no-roots(plots trenched and root regrowth into plots prevented). Root respiration was evaluated by comparing no-roots sub-plots to control plots. Mean soil respiration showed highly significant species effects(p<0.01) and was highest at the Pinus rigida control plot($0.38g/m^2/hr$) and lowest at the Larix leptolepis no-roots plot($0.31g/m^2/hr$). High soil respiration in Pinus rigida may be related to aboveground litter production. The annual $CO_2$ fluxes ranged from 23 to 27t/ha/yr. We found significant correlations between temperatures(air : $R^2$=0.53, soil : $R^2$=0.55) and soil respiration(p<0.01), but no significant correlations between soil moisture and soil respiration(p>0.1). Root respiration was 3% of total soil respiration. We might underestimate rapt respiration because of shallow trenches and $CO_2$measurements right after trenching. Factors controlling soil respiration including belowground litterfall(especially fine roots) inputs, litter quality should be well understood to predict soil carbon fluxes and relative contributions to total soil respiration in forest ecosystems.

• Korean Journal of Medicinal Crop Science
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• v.6 no.1
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• pp.51-56
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• 1998

This study was carried out to evaluate environmental and ecological characteristics of natural habitat for cultivation of Epimedium koreanum. Habitat of E. koreanum was the slope foot of mountain descending gradually toward mostly northwest from top of mountain with slope of $2{\sim}20%$ and the altitude ranged from 60 to 400m above the sea level. Some physiochemical characteristics of habitat soil were as follows: pH, $4.1{\sim}5.8$, organic matters content, $4.9{\sim}6.6%$ and cation exchange capacity, $14.8{\sim}34.3\;me/100g$ soil, respectively. Habitats were shaded by deciduous broad-leaved tree mainly, and compared with those of naked area, relative photon flux density was $3.5{\sim}13.1%$ and relative luminance was $3.3{\sim}11.9%$ due to shading. Air temperature of habitat under shade was $4.3{\sim}6.5^{\circ}C$ lower than that of naked area. Habitat soil temperature was lower than that of naked area but temperature range was smaller than that of naked area. E. koreanum plants were growing with semishading plants under shade of tree leaf. From investigation of natural characteristics of habitat, it was concluded that E. koreanum plant would grow at place with a little change in temperature and moisture of soil which was caused by shading and mulching with litterfall of broad-leaved tree.

• Korean Journal of Environmental Biology
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• v.26 no.3
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• pp.170-176
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• 2008

Organic carbon distribution and carbon budget of a Quercus variabilis forest in the Youngha valley of Mt. Worak National Park were investigated. Carbon in above and below ground standing biomass, litter layer, and soil organic carbon were measured from 2005 through 2006. For the estimation of carbon budget, soil respiration was measured. The amount of carbon allocated to above- and below-ground biomass was 56.22 and 13.90 ton C ha$^{-1}$. Amount of organic carbon in annual litterfall was 2.33 ton C ha$^{-1}$ yr$^{-1}$. Amount of soil organic carbon within 50 cm soil depth was 119.14 ton C ha$^{-1}$ 50 cm-depth$^{-1}$. Total amount of organic carbon in this Q. variabilis forest was 193.96 ton C ha$^{-1}$. Of these, 61.43% of organic carbon was allocated in the soil. Net increase of organic carbon in above- and below-ground biomass in this Q. variabilis forest was estimated to 7.68 ton C ha$^{-1}$ yr$^{-1}$. The amount of carbon evolved through soil respiration was 6.21 ton C ha$^{-1}$ yr$^{-1}$. Net amount of 1.47 ton C ha$^{-1}$ yr$^{-1}$ was absorbed from the atmosphere by this Q. variabilis forest.

• Journal of Korean Society of Forest Science
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• v.98 no.2
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• pp.183-188
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• 2009

It is necessary to determine the amount of carbon dioxide ($CO_2$) absorbed by plants and released from forest floor into atmosphere, to gain a better understanding how forests participate in the global carbon cycle. Soil $CO_2$ efflux, litter production, and decomposition were investigated in Q. variabilis and P. densiflora stands in the vicinity of Gwangju, Chonnam province. Soil $CO_2$ efflux was measured using Infrared Gas Analyzer (IRGA) at midday of the 10th day at every month over 12-month period, to quantify seasonal and annual budgets of soil $CO_2$ efflux. Soil temperature and soil moisture were measured at the same time. Seasonal soil $CO_2$ efflux in Q. variabilis and P. densiflora were the highest in summer season. In August, maximum soil $CO_2$ efflux in Q. variabilis and P. densiflora was 7.49, $4.61CO_2{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. Annual $CO_2$ efflux in each stand was 1.77, $1.67CO_2kg{\cdot}m^{-2}$ respectively. Soil $CO_2$ efflux increased exponentially with soil temperature and related strongly in Q. variabilis ($r^2$=0.96), and in P. densiflora ($r^2$=0.91). Litter production continued throughout the year, but showed a peak on November and December. Annual litter production in the Q. variabilis and P. densiflora stands were $613.7gdw{\cdot}m^{-2}{\cdot}yr^{-1}$ and $550.5gdw{\cdot}m^{-2}{\cdot}yr^{-1}$.$yr^{-1}$, respectively. After 1 year, % remaining mass of Q. variabilis and P. densiflora litter was 48.2, 57.1%, respectively. The soil $CO_2$ efflux rates in this study showed clear seasonal variations. In addition, the temporal variation in the $CO_2$ efflux rates was closely related to the soil temperature fluctuation rather than to variations in the soil moisture content. The range of fluctuation of soil $CO_2$ efflux and litter decomposition rate showed similar seasonal changes. The range of fluctuation of soil $CO_2$ efflux and litter decomposition rate was higher during summer and autumn than spring and winter.

• Korean Journal of Environmental Agriculture
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• v.19 no.1
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• pp.75-79
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• 2000

To investigate seasonal variations of soil solution chemistry, samples were collected from zero tension lysimeters in O, A, and B horizons of 26-year-old Larix leptolepis. Pinus koraiensis and Quercus mongolica stands in Kwangju, Kyunggi Province from September, 1996 through June. 1999. Potassium, $Mg^{2+}$, $Cl^-$, and $No_3\;^-$ concentrations increased in October and November concurrent with inputs of fresh litterfall and twigs. Sodium, $Ca^{2+}$, $K^+$, and $Mg^{2+}$ concentrations increased in March and April concurrent with the yellow sand effect. Potassium concentration showed the highest variation among ions, and $Cl^-$ concentration showed positive correlations with $K^+$ and $Mg^{2+}$ concentrations. Soil solution pH decreased while $Al^{3+}$ and $K^+$ concentrations increased during the study period. If our data reflects long term trends. then $Al^{3+}$ concentration in the O horizon will reach the toxic level (0.180 meq/l) within 10-20 years depending on species.