• Journal of Korean Society of Forest Science
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• v.84 no.4
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• pp.502-516
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• 1995

The objective of this study was to estimate throughfall, stemflow, interception loss and net rainfall in relation to rainfall interception, and to understand the factors affecting interception process at Pinus taeda stand and Pinus densiflora stand in the Research Forests of Seoul National University, located in Choosan, Kwangyang, Chollanamdo. 1. The gross rainfall during the period of field observation was 3,107.6mm(average 1,035.9mm/year). Most of the daily rainfall intensity was under 30mm, which was 90% in 1992, 81% in 1993 and 88% in 1994. 2. In this study the throughfall, stemflow, interception loss and net rainfall were expressed separately as a function of gross rainfall. The overall throughfall collected during the period of field observation was 2,432.5mm(78.3%) at Pinus taeda stand and 2,699.6mm at Pinus densiflora stand, out of total rainfall of 3107.6mm. The canopy storage capacity, which was determined by the prediction equation between gross rainfall and throughfall was 1.1mm at Pinus taeda stand and 1.3mm at Pinus densiflora stand. 3. The sums of stemflow from measurement of total rainfall at Pinus taeda stand and Pinus densiflora stand was 227.3mm(7.3%) and 62.7mm(2.0%), respectively. The minimum rainfall causing stemflow was estimated as 7.2mm at Pinus taeda stand and 1.9mm at Pinus densiflora stand. 4. Interception loss accounted for 447.8mm(14.4%) at Pinus taeda stand and 345.3mm(11.1%) at Pinus densiflorra stand. 5. Net rainfall was 2,659.8mm(85.6%) at Pinus taeda stand and 2,762.3mm(88.9%) at Pinus densiflora stand. 6. The rates of throughfall and stemflow increased with increasing the gross rainfall. However, the amounts of throughfall and the stemflow were constant above 30mm at Pinus taeda stand and 50mm at Pinus densiflora stand. The rates of interception loss decreased with increasing the gross rainfall. However, the amount of interception loss was constant above 50mm at Pinus taeda stand and Pinus densiflora stand.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2023.04a
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• pp.55-55
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• 2023

With the COVID-19 pandemic, there is increasing interest in anti-obesity strategies. According to the National Statistical Office, the obesity rate in Korea was 38.3% in 2020 and 37.1% in 2021. Obesity is a risk factor for several severe diseases, including stroke, heart disease, type 2 diabetes, and certain types of cancer. Pinus rigida × Pinus taeda is a hybrid of Pinus rigida Mill and Pinus taeda Linn, and its cones are considered a by-product. Although previous studies have investigated their pharmacological effects on antioxidant activity and protection against oxidative DNA damage, few researchers have explored their potential as functional natural materials. Therefore, we evaluated the anti-obesity effects of the cone of ethyl acetate fraction of P. rigida × P. taeda (ERT), specifically its ability to inhibit lipid accumulation. Our analysis showed that ERT contains phytochemicals (catechin and caffeic acid) which are known to improve immune function and inhibit cell damage. ERT inhibited lipid droplet accumulation at the cellular levels through Oil Red O staining. Furthermore, ERT suppressed the expression of adipogenic transcription factors (PPARγ and CEBP/α) as well as downstream lipogenic target genes (FAS and SREBP-1) thereby inhibiting adipogenesis. ERT also down-regulated key adipogenic markers, including aP2α, while inducing the phosphorylation of AMPK. It has been reported that PPARγ and CEBP/α are expressed in the early stages of adipose differentiation, while SREBP-1 is expressed in the late stage. Therefore, our findings suggest that ERT activates AMPK signaling pathways, which inhibits adipogenic transcription factors (PPARγ, C/EBPα, and SREBP1) and lipogenic genes (FAS and aP2α), thereby blocking lipid accumulation and preventing obesity and related disorders. ERT showed potential as a new resource for developing a functional material for anti-obesity agents.

• Journal of Korean Society of Forest Science
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• v.88 no.3
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• pp.285-291
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• 1999

Loblolly(Pinus taeda L.) and slash(Pinus elliottii Engelm.) pines are the most important timber producing species in the Southern United States. Site index equations to estimate site index curves(base age 25 years) for loblolly pine and slash pine plantations have been developed based on long-term repeated measurement data sets. To check magnitude of errors in estimating site index, each cumulative measurement cycle data sets and all combined data sets were used to recalculate site index values. The Chapman-Richards' growth function was selected for stand height prediction. Anamorphic base age invariant site index curves were presented based on this height prediction equation. Statistics used in the evaluation were mean of the differences and mean of the absolute differences. For plantation ages less than 5 years, site index values showed very sensitive fur both species based on the evaluation test.

• Journal of Korean Society of Forest Science
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• v.78 no.4
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• pp.401-411
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• 1989

The embryos of Pinus taeda, P. rigida, and P. taeda ${\times}$ rigida were cultured for adventitious shoot regeneration in vitro. Culture media were modified from Gresshoff and Doy (MGD), Murashige and Skoog (MMS), Lloyd and McCown (MLM), and Schenk and Hildebrandt (MSH). NAA was added to initiation media at a concentration of 0.1 or 0.01 mg/l. BAP was used at the concentrations of 0.1. 0.5, 1, 2, or 5mg/l. Each explant was induced for 3-4 weeks on solid medium. All explants were cultured up to 16 weeks. Illumination was about $1506{\pm}540lux$ at the level of the tissues in the growth room with a temperature of $25{\pm}2^{\circ}C$. A 16-hour photoperiod per 24 hours was used. Half-strength medium was used for all the subcultures. For shoot production by loblolly pine, MMS, MLM, or MSH is preferred with 5 mg/l BAP with either 0.1 or 0.01 mg/l NAA. For shoot production by pitch pine, MMS, MLM, or MSH is recommended with 2 or 5 mg/l BAP with 0.1 mg/l NAA. For shoot production by the hybrid pine, MMS or MLM is more effective with 1, 2 or 5 mg/l BAP with 0.1 mg/l NAA. There were no differences recognized among the species tried in the patterns of bud formation and shoot development. Different composition of media, in major and minor salts or possibly in vitamins, should be tested for the two developmental stages of adventitious shoots ; the induction of shoot buds and the elongation of them into shoots.

• Journal of Korean Society of Forest Science
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• v.94 no.6
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• pp.402-409
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• 2005

This study was undertaken to compare and estimate the severity of pitch canker of individual trees of Pinus rigida and Pinus rigida ${\times}$ P. taeda in two seed orchards in Jeju island, in which the orchards have been damaged by the pitch canker for seven years. Wind-pollinated two-year-old seedlings of P. rigida and P. rigida ${\times}$ P. taeda, in which the seedlings of P. rigida ${\times}$ P. taeda were from seeds of phenotypically selected, uninfected(but untested) trees, were inoculated with the pathogenic fungus, Fusarium circinatum, isolated from P. rigida and P. thunbergii. The virulence of the isolates was also identified. Statistically significant difference was found in 'stem cankers'(SC; ${\chi}^2=7.76$, P=0.05) among 4 plantations of P. rigida ${\times}$ P. taeda of two seed orchards. P. rigida was higher in 'top kill' (TK) and 'branch tip symptoms' (BT) than those of P. rigida ${\times}$ P. taeda. In artificial inoculation tests, mortality of the seedlings from the resistant candidates was 14% higher than that of the seedlings from the susceptible candidates. This result may becaused by unknown pollen trees and/or candidate tree selection based only on phenotype. Two of five fungal isolates, C-6-L(9) and C-6-L(19), showed significantly higher mortality (68% and 60%, respectively) than others, suggesting that these isolates can be used as virulent isolates for a mass artificial inoculation. Resistance candidate seedlings that were selected from this study can be utilized as useful materials for fundamental studies of genetics and biochemistry to breed resistance varieties to pitch canker.

• Journal of Korean Society of Forest Science
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• v.18 no.1
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• pp.23-33
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• 1973

The survivals of loblolly pine, Pinus taeda L. was gradually increased from southeast to northwest in the species range and the provenances from southeast of the species range showed fast growth rate. It is suggested that the loblolly pine from Arkansas and Texas will be good for inland of Korea, and the trees from Maryland and North Carolina Piedmont will be suitable for the west coastal and east coastal region of Korea, and trees from North Carolina Coastal Plain will be promising one for south coastal region of Korea.

• Journal of Korean Society of Forest Science
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• v.76 no.4
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• pp.330-337
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• 1987

Megagametophyte tissues from seeds of 45 loblolly pine clones were subjected to horizontal starch-gel electrophoresis. The resulting gels were tested for activity of five enzyme systems (GOT, SDH, PGM, MDH, and AP). Isozymes observed were under control of 11 loci. All 45 clones could be identified with unique genotypes at above 10 loci.

• Journal of Forest and Environmental Science
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• v.34 no.1
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• pp.82-86
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• 2018

Loblolly pine (Pinus taeda L.) is widely distributed in the southern part of the United States and it has been used as a major economic species in the region due to its excellent growth and stem straightness. The tree also grows only in the southern part of Korea because it is susceptible to cold. Recently climate changes have had widespread impacts on forest trees. Thus, the use of good quality seeds is prerequisite for assessing assisted migration adaptation trial. In this study, we conducted to investigate its cone and seed characteristics of each family, which is expected to improve seeds productivity for planting valuable timber trees. A total of 14 families were selected from the experimental forest in Boseong, Jeonnam province in 1981. The seed production capacity was estimated to range from 87.2 to 129.4 among families and the average was 111.3. The number of aborted ovules was investigated in the range of 11.4 to 29.5 for the first test and 7.4 to 22.2 for the second test. The average number of empty and filled seeds was 1.4 and 79.2 per cone, respectively. Based on the results, we can conclude that there is a strong correlation between the number of fertile scale and the seed production ability.

• Journal of Korean Society of Forest Science
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• v.59 no.1
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• pp.31-36
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• 1983

Flowering time of Pinus rigida Mill and Pinus taeda L, in an $F_1$-hybrid seed orchard was investigated for five years from 1971 through 1975. The two tree species flowered during late April to early May at the observation site, Flowering patterns of the two species of different sex of the same species changed yearly during the five observation years. Floral development of the two species appeared to depend largely on temperature factor during the period of the initiation of floral organs up to flowering provided that other environmental factors are normal. Six-days difference in flowing time between female inflorescence of pitch (flower later) and male inflorescence of loblolly (flower earlier) pines effectively isolated the two species reproductively on population levels. Not all of selected trees of the two species for their synchronized flowering appeared to be useful as parental trees for the establishment of $F_1$-hybrid seed orchards. With the result from this investigation the author suggested to use a modified simple recurrent selection method for pitch-loblolly hybrid pine breeding.

• Journal of Korean Society of Forest Science
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• v.90 no.2
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• pp.176-183
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• 2001

Loblolly pine (Pinus taeda L.) is the most economically important timber producing species in the southern United States. Much attention has been given to predicting diameter distributions for the solution of multiple-product yield estimates. The three-parameter Weibull diameter distribution yield prediction systems were developed for loblolly pine plantations. A parameter recovery procedure for the Weibull distribution function based on four percentile equations was applied to develop diameter distribution yield prediction models. Four percentiles (0th, 25th, 50th, 95th) of the cumulative diameter distribution were predicted as a function of quadratic mean diameter. Individual tree height prediction equations were developed for the calculation of yields by diameter class. By using individual tree content prediction equations, expected yield by diameter class can be computed. To reduce rounding-off errors, the Weibull cumulative upper bound limit difference procedure applied in this study shows slightly better results compared with upper and lower bound procedure applied in the past studies. To evaluate this system, the predicted diameter distributions were tested against the observed diameter distributions using the Kolmogorov-Smirnov two sample test at the ${\alpha}$=0.05 level to check if any significant differences existed. Statistically, no significant differences were detected based on the data from 516 evaluation data sets. This diameter distribution yield prediction system will be useful in loblolly pine stand structure modeling, in updating forest inventories, and in evaluating investment opportunities.