• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.25 no.4
• /
• pp.1-13
• /
• 2022

This study was conducted to investigate the chlorophyll content, photosynthetic characteristics, and growth characteristics of Aster koraiensis and Dendranthema zawadskii var. latiloba according to shading treatment. A. koraiensis and D. zawadskii grew in four different shading treatment plots (0%, 50%, 75% and 95% of full sunlight) for experiments. It was found that as the shading level increased, the total chlorophyll content increased and dark respiration decreased in both A. koraiensis and D. zawadskii, indicating that A. koraiensis and D. zawadskii increase the utilization efficiency for photosynthesis under low light conditions. In addition, as the shading level increased, the net apparent quantum yield increased, resulting in the highest in the 95% shading plot, but the highest photosynthetic rate, water use efficiency, and leaf mass per area (LMA) were shown in the control group than in the shading treatments. The results showed that A. koraiensis and D. zawadskii are heliophytes showing plasticity to light, and if the light is restricted to continue to shade, it may be detrimental to growth. For healthy growth, it is considered suitable to grow A. koraiensis under full light conditions, and D. zawadskii under the light condition that blocks 0-50% of full sunlight.

• Korean Journal of Plant Resources
• /
• v.37 no.2
• /
• pp.203-213
• /
• 2024

In this study, we investigated the growth and physiological responses of Iris laevigata Fisch. to shading treatments in order to suggest optimal light conditions for ex-situ conservation of the northern lineage plants. For this purpose, a control plant receiving full sunlight and different shading treatments (50%, 75%, 95%) were installed, and leaf mass per area, chlorophyll content and fluorescence response, and photosynthetic characteristics were investigated. I. laevigata developed leaves with higher photosynthetic efficiency to adapt to lower light intensity as shading levels increased. Chlorophyll content increased with increasing shading levels, and leaf mass per area decreased with increasing leaf area. The chlorophyll fluorescence responses Fv/Fm and NPQ did not change with shading, and the activity of the carbon fixation system did not differ between treatments. I. laevigata exhibited a light-saturation point equivalent to that of sun plants and maintained photosynthetic capacity similar to that of controls up to 75% shading. The apparent quantum yield of I. laevigata decreased significantly at 95% shading, indicating adaptation to lower light conditions. It seems that the photosynthetic capacity of I. laevigata decreases when grown under 95% shading level compared to full sunlight, and it is judged that the longer the light is restricted by continuous shading, the more unfavorable the growth will be.

• Journal of Forest and Environmental Science
• /
• v.8 no.1
• /
• pp.35-49
• /
• 1992

Three theoretical growth equations, i.e., the Mitscherlich, the Gompertz, and the Logistic equation, were applied to the radical stem growth of 50 jack pines (Pinus banksiana Lamb.). For the determination of the parameters in these equations, NELDER-MEAD's method was used, which is one of the direct-search methods of optimization. It has been known to be very convenient in dealing with the issues related to optimization, specifically where the number of parameters are less than 6. It was found that although all the equations did not appropriately work as expected, the Mitscherlich equation revealed the least discrapancy from the obsered value among three. Using these equations and the first certain period data, i. e., 35, 55, 75 years, the predection of radius of age 95 was investigated. Comparing to the observed value, the most valid equation was the Mitscherlich, and the next were the Gompertz and the Logistic, in order.

• Journal of Korean Society for Atmospheric Environment
• /
• v.10 no.E
• /
• pp.371-386
• /
• 1994

Ecological examinations of the radial growth Patterns of pine trees(Pinus densiflora Sieb. et Zucc) growing on Mt. Namsan in central Seoul were made to test a Proposition that the pine trees decline due to the influence of air pollution and acid rain, which was proposed by some researchers in Korea, and the potential effects of current level of air pollutants to the growth of the Pine trees in central Seoul have been speculated. Tree-rings of 40 trees sampled at 3 sites of Mt. Namsan were prepared and examined using a Computer-aided Tree-Ring Measuring System at Kookmin University, Korea. Air Pollutant data collected by the Ministry of Environment( MOE ) and the Forestry Research Institute(FRI) were used to infer the general conditions of the environment. Correlation analysis was applied to the data set of tree growth and the other environmental factors. General information derived from the close examination of the tree-rings and the data on air pollution, drought and the other biological conditions suggested that the growth of the pine trees was severely affected by the occurrence of drought(climatic variation), the prevalence of the pine leaf gall midges(insects), and the suppression by the black locust trees(Robinia pseudo-acacia L.) (competition among trees). While the current condition of air pollution in Seoul cannot be categorized as good, the concentrations of air pollutants are not so high as to cause acute damages to the trees. In addition, while the data of rain acidity showed episodic low PHs of under 4.0, the average of them is far less acidic than those which were observed in either northeastern United States or central Europe, where the decline of trees were not solely attributed to any of the air pollutants. Considering the sequential facts that one of the most important environmental factors that affect the growth of trees is weather condition of the forest that the proposition of the decline of the pine trees was made without careful examination of the growth patterns and past growth history of them as well as the complex influences of many other factors including the weather conditions to the growth of trees, and that no objective explanation has been made on the causal relationships between the current condition of air pollution and the growth of the trees, such a proposition should be evaluated as invalid for the explanation of tree growth on Mt. Namsan in central Seoul, Korea. The author evaluates the factors of air pollution (including acid rain) as the predisposing factors, which may have the Potentials to chronically affect the tree growth at the forest ecosystem on Mt. Namsan for a long period of time. Ecosystem ecological studies should be further carried out to carefully explain both the functional and the structural aspects of the ecosystem processes, which include the biogeochemistry and the long-term changes of soil conditions as well as the growth of the other tree species on the mountain.

• Korean Journal of Environmental Biology
• /
• v.36 no.2
• /
• pp.117-123
• /
• 2018

In this study, the efficiency of photosynthetic electron transfer according to LED color temperature was verified in order to find a way to efficiently grow trees under night illumination. The experiment was carried out with White treatment, Warmwhite treatment, and non-treatment with donarium cherry. The study uses to a method for analyzing and evaluating the color temperature of an LED light source by photochemical analysis. We found that all treatments 115 DAT of maximum fluorescence amount(P) had the lowest. In the treatment using white light and the Warm-white light, the T amount of florescence of the late stage during the transition of the J-I level was increased, and the photosystem I electron transfer efficiency was decreased. Therefore, the electron transport efficiency of $RE1_O/CS$ and RE1o/RC were reduced. Especially, compared to Warmwhite, the light intensity increased greatly in the white-light treatment, The $PI_{TOTALABS}$ of 7 DAT was the highest value, but it was decreased to the lowest value on 115 DAT. This study has shown that the white treatment was low in electron transfer efficiency and soundness. Warmwhite-light treatments showed lower stress.

• Journal of Korean Society of Forest Science
• /
• v.97 no.3
• /
• pp.266-273
• /
• 2008

The effects of soil acidification on the seedling growth and nutrition of Pinus densiflora and Quercus acutissima were investigated. The relationship between the seedling growth and molar (Ca+Mg+K)/Al ratio of in soil solution was examined. The results suggested that growth inhibition of seedling Pinus densiflora and Quercus acutissima was due to the low pH of soil solution, which was followed by leach of Al into soil solution, and decrease of essential elements, such as Ca in aerial pant of the seeding caused by the increase of Al concentration in subterranean pant of the seedlings. The level of growth inhibition was determined not only by Al concentration, but also by the balance of inorganic elements, Al, Ca, Mg and K. The growths of two species in total dry weight were clearly inhibited when molar (Ca+Mg+K)/Al ratio of the soil was lower than 6.0. The growth in dry weight, in the condition of the molar ratio was 0.8, was decreased 60% or 50% for the seedling of Pinus densiflora or Quercus acutissima respectively. It was concluded that the molar (Ca+Mg+K)/ Al ratio could be an important index for evaluation of the effects of soil acidification, due to acid deposition such as acid rain, on growth of trees and nutrition. And it might be a more useful indicator for evaluation of critical load of acid deposition on forest ecosystems.

• Journal of Korean Society of Forest Science
• /
• v.90 no.1
• /
• pp.74-82
• /
• 2001

The effects of Al and Mn concentration on dry weight growth, nutrient status and gas exchange rates of 2-Year-old Japanese red pine(Pinus densiflora) seedlings grown in a nutrient culture solution were investigated. Al was added as aluminum chloride at 0, 10, 30 or 60ppm, and Mn was added as manganese chloride at 0, 30 or 60ppm to the nutrient culture solution. The pH of the solution was maintained at 4.0 by adding HCl or NaOH solution. The seedlings were transplanted into the nutrient culture solution, then they were grown in a greenhouse for 90 days. The interactive effects of Al and Mn on the dry weight growth of the seedlings were not significant. There were a main effect of Al or Mn on the dry weight growth and element concentrations of the seedlings. The treatment with Al of ${\geq}10ppm$ or that with Mn of 60ppm induced a significant reduction in the dry weight growth, which indicates that the effect of Al is stronger than that of Mn. The chlorophyll content of needles was not affected by Al treatment, but was significantly reduced by treatment with Mn of 60ppm. Furthermore, the treatment with Al of 60ppm or that with Mn of ${\geq}30ppm$ caused a significant reduction in the dark respiration rate of the roots. The net photosynthetic rate of the seedlings reduced with increasing the concentration of Al or Mn in the nutrient culture solution, which suggests that Al or Mn induced reductions in the relative growth rate(RGR) and net assimilation rate(NAR) of the seedlings were mainly due to the decrease of net photosynthesis.

• Korean Journal of Soil Science and Fertilizer
• /
• v.31 no.1
• /
• pp.39-45
• /
• 1998

As a basic research for developing a sludge application technique in forestry, this study was conducted to investigage a reasonable amount and period of sludge to be applied onto forest nursery of Acer palmatum Thunb. The paper mill sludge was used for the study, and ammonium nitrate was treated to some of them to reduce the C/N ratio lower than 40. The maximum amount of applied sludge was 7ton/ha/year, and they were spread on spring and on late summer. The sludge application did not stimulate early growth of the trees during a year. Since there was no significant changes in soil chemical properties, the amount of applied sludge was thought to be too little to result in a significant role for tree growth. However, the soil water showed significant increase of Cu when the activated sludges were applied during late summer. Thus, the time of application need to be determined cautiously with considering the risk of ground water contamination. In conclusion, if we set a goal from the view point of long-term concept such as forest productivity rather than to get a short-term product, the uncomposted sludge in small amount during growing season might be considered to be applied on forest nursery.

• Korean Journal of Agricultural and Forest Meteorology
• /
• v.26 no.2
• /
• pp.89-102
• /
• 2024

Land Surface Phenology (LSP) plays a crucial role in understanding vegetation dynamics. The near-infrared reflectance of vegetation (NIRv) has been increasingly adopted in LSP studies, being recognized as a robust proxy for gross primary production (GPP). However, NIR v is sensitive to the terrain effects in mountainous areas due to artifacts in NIR reflectance cannot be canceled out. Because of this, estimating phenological metrics in mountainous regions have a substantial uncertainty, especially in the end of season (EOS). The topographically corrected NIRv (TCNIRv) employs the path length correction (PLC) method, which was deduced from the simplification of the radiative transfer equation, to alleviate limitations related to the terrain effects. TCNIRv has been demonstrated to estimate phenology metrics more accurately than NIRv, especially exhibiting improved estimation of EOS. As the topographic effect is significantly influenced by terrain properties such as slope and aspect, our study compared phenology metrics estimations between south-facing slopes (SFS) and north-facing slopes (NFS) using NIRv and TCNIRv in two distinct mountainous regions: Gwangneung Forest (GF) and Odaesan National Park (ONP), representing relatively flat and rugged areas, respectively. The results indicated that TCNIR v-derived EOS at NFS occurred later than that at SFS for both study sites (GF : DOY 266.8/268.3 at SFS/NFS; ONP : DOY 262.0/264.8 at SFS/NFS), in contrast to the results obtained with NIRv (GF : DOY 270.3/265.5 at SFS/NFS; ONP : DOY 265.0/261.8 at SFS/NFS). Additionally, the gap between SFS and NFS diminished after topographic correction (GF : DOY 270.3/265.5 at SFS/NFS; ONP : DOY 265.0/261.8 at SFS/NFS). We conclude that TCNIRv exhibits discrepancy with NIR v in EOS detection considering slope orientation. Our findings underscore the necessity of topographic correction in estimating photosynthetic phenology, considering slope orientation, especially in diverse terrain conditions.

• Journal of Korean Society of Forest Science
• /
• v.77 no.2
• /
• pp.229-234
• /
• 1988

To evaluate potential of VA mycorrhizal fungi for promoting growth of nitrogen-fixing trees and efficiency of fungal inoculation in relation to soil fertility and dual inoculation with bacteria, Alnus firma was grown for six months in pots with steam-sterilized soil after inoculation with Glomus mosseae, and Robinia pseudoacacia was grown in the fumigated field after inoculation with native Glomus sp. and Gigaspora sp. In unfertilized Alnus plants, 27% increase in dry weight(or 18% in height) was observed by Glomus inoculation, while plants inoculated with both VA mycorrhiza and actinomycete(crushed nodule inoculum) showed synergistic effect of 83% dry weight increase over uninoculated plants. In fertilized Alnus plants, mycorrhizal inoculation alone or dual inoculation with actinomycete resulted in depression of height and dry weight of plants. In case of Robinia, dual inoculation stimulated height growth by 23% (or dry weight by 25%) over the control in unfertilized field, while 13% more height growth(or 21% more dry weight) was observed in fertilized field. It is concluded that VA mycorrhizae, especially Glomus mosseae, have a potential for growth enhancement in Alnus, that synergistic effect of dual inoculation(mycorrhiza + actinomycete) exists in both Alnus and Robinia, and that responses of these plants to VA mycorrhiza are more pronounced in unfertilized soil.