• The Korean Journal of Pesticide Science
• /
• v.14 no.2
• /
• pp.138-147
• /
• 2010

Nematicidal activity against pine wood nematode, Bursaphelenchus xylophilus, was tested in the pot and field by the treatment of microbial formulation after media optimization. The optimized media composition was glycerol 10 g, soybean meal 10 g, NaCl 1 g, $CaCO_3$ 2 g, $K_2HPO_4$ 0.125 g per liter and microbial complex formulation was made with liquid and powder type. Most effective antibiotics against symbiotic microorganism with nematode, kanamycin, was added to the formulation. The control effects against pine wood nematodes were checked by pot test and field test. In the result of treatment by trunk injection, five times treatment was more effective than one time and the treatment with the formulation of concentrated culture supernatant was the most effective in the nematicidal activity showing below 10% mortality in pine tree.

• The Korean Journal of Ecology
• /
• v.17 no.3
• /
• pp.261-275
• /
• 1994

The annual ring widths of tree and the vertical distribution of fine roots were investigated at 33 sites of pitch pine forests in Seoul, its vicinity and rural areas. The annual ring widths among 16 - 20 year-old pitch pines in urban areas were significantly lower than those in rural areas. The annual ring widths for the latest 5 years (1985-1989) for the age class of 11-20, 21-30 and 31-40 year old pines increased in the following order for all the age classes: urban areas< suburbs

• Journal of the Korean Association of Geographic Information Studies
• /
• v.13 no.1
• /
• pp.28-34
• /
• 2010

The spatial distribution characteristics of damaged trees by the pine wilt disease appear scattered spots spreading from single dead trees. That is the reason why it is difficult to early detect damage and to prevent from extensive damage. Thus, it is very important to forecast and analyze the damage occurrences, to establish strategies for prevention, and to supervise them. However, conventional survey which observes around roads or residential areas by naked eyes was impossible to investigate completely, missing target areas and dangerous areas. Therefore, aerial forecasting techniques on the damaged area were developed using GIS, GPS, and helicopters for an accurate observation of systematic and scientific approach in this study. Moreover, advantages of the techniques application were confirmed to survey 972 dead tree samples at 349 position-coordinates in 32 cities (about $28,810km^2$), 2005. This study is expected to apply widely to find dead trees and the causes, particularly by pine wilt disease.

• Asian-Australasian Journal of Animal Sciences
• /
• v.33 no.5
• /
• pp.856-865
• /
• 2020

Objective: This study was conducted to evaluate the physicochemical properties and changes in moisture concentrations of bedding materials under the conditions of rearing Korean Hanwoo cows. Methods: Two experiments were conducted to investigate the physicochemical characteristics (Exp. I) and usefulness as beddings for rearing cattle (Exp. II) by the type of beddings such as sawdust (SD), wood shavings (WS) and sawdust+wood shavings (S+W; 1:1 in volume), and the species of pine trees from different countries of origins (China, Pinus armandii, AR; Vietnam, Pinus kesiya, KE; USA, Pinus rigida, RI). Results: In Exp. I, SD-AR showed the largest proportion (78.3%) of fine particles (250 ㎛+below 250 ㎛) and the highest bulk density (208 kg/㎥) among treatments (p<0.05). The water absorption capacity at 24 h of both S+W-RI (713%) and -KE (701%) was the highest among treatments (p<0.05) and higher than those of SD or WS alone within each species of pine tree (p<0.05). Moisture evaporation rates (%) at 12 h were ranged from 52.3 to 60.8 for SD, 69.9 to 74.4 for WS, and 72.3 to 73.5 for S+W. Total amounts (mg/㎡) of ammonia emissions were the lowest (p<0.05) in KE species among the pine species within each type of bedding material, having higher ability of ammonia absorption. In Exp II, KE species in both side A and B had lower moisture concentrations (%) than other species. Regardless of types of beddings except SD-AR, moisture concentrations of beddings within a pen were higher (p<0.01) at side A than B. Conclusion: The KE species has better physical characteristics than other beddings and more useful for rearing Hanwoo cattle than other beddings, probably caused by the differences in the method and degree of wood processing rather than the species.

• Journal of Korean Society of Forest Science
• /
• v.84 no.2
• /
• pp.258-265
• /
• 1995

Regeneration process of edaphic pine(Pinus densiflora) climax forest in Bulyung-gyegog, Uljin-gun, Kyungsangbuk-do, was studied. The height of dominant trees in the stands are 12 15m. Upper layers are highly dominated by pine trees and are randomly distributed. Pine trees in lower layer grow in a patch type. In the upper layer, the age distribution is likely one model type with mode of 60 and 80 years. In the horizontal distribution of these trees, some of the even-aged cluster constituted of several tree were found. For the first 25 years, the stem diameter increment rates in upper layer are higher than those in the middle layer. It could be concluded that after the forest canopy had been broken out, the seedlings established densely in a patch in the gap with the decreasing density and some of them, distributed in random, would constitute the canopy.

• Journal of the Korean Wood Science and Technology
• /
• v.33 no.6 s.134
• /
• pp.8-16
• /
• 2005

Fire-killed trees of Korean red pine are valuable resources for industrial uses. It is common only believed that fire-killed trees are too weak and brittle to use in construction purposes. The misunderstandings of fire-killed trees lead these valuable resources abandonment. The purposes of this research are focused on scrutinization of material properties of fire-killed trees to facilitate industrial uses of these resources. The sample logs were collected from the forest fire site of the eastern coast area in which the most catastrophic wild fire had taken place in 2000. Fire-killed Korean red pines were classified into 3 levels by the degree of fire damage so called light, medium and heavy, then their physical, mechanical and chemical properties were compared with sound trees. No significant difference in physical appearances were found in the cross sections by degree of damage compared to sound tree but bark char. Investigation on mechanical and chemical properties indicates that forest fire did not impact significantly in lowering the strength of damaged trees. It was concluded that there was any limitation of forest fire-killed trees of Korean red pine in industrial utilization.

• Journal of Forest and Environmental Science
• /
• v.32 no.2
• /
• pp.120-128
• /
• 2016

Forest sequesters large terrestrial carbon which is stored in the biomass of tree and plays a key role in reducing atmospheric carbon. Thus, the objectives of the present study were to assess the growing stock, above ground biomass and carbon in trees of Ponda watershed of Rajouri district (J&K). IRS-P6 LISS-III satellite data of October 2010 was used for preparation of land use/land cover map and forest density map of the study area by visual interpretation. The growing stock estimation was done for the study area as well as for the sample plots laid in forest and agriculture fields. The growing stock and biomass of trees were estimated using species specific volume equations and using specific gravity of wood, respectively. The total growing stock in the study area was estimated to be $0.25million\;m^3$ which varied between $85.94m^3/ha$ in open pine to $11.58m^3/ha$ in degraded pine forest. However in agriculture area, growing stock volume density of $14.85m^3/ha$ was recorded. Similarly, out of the total biomass (0.012 million tons) and carbon (0.056 million tons) in the study area, open pine forest accounted for the highest values of 43.74 t/ha and 19.68 t/ha and lowest values of 5.68 t/ha and 2.55 t/ha, respectively for the degraded pine forest. The biomass and carbon density in agriculture area obtained was 5.49 t/ha and 2.47 t/ha, respectively. In all the three forest classes Pinus roxburghii showed highest average values of growing stock volume density, biomass and carbon.

• The Plant Pathology Journal
• /
• v.39 no.3
• /
• pp.290-302
• /
• 2023

Abamectin offers great protection against Bursaphelenchus xylophilus, a well-known devastating pathogen of pine tree stands. Trunk injection of nematicides is currently the most preferred method of control. This study aimed to evaluate the potency of the commonly used formulations of abamectin against B. xylophilus. Twenty-one formulations of abamectin were evaluated by comparing their sublethal toxicities and reproduction inhibition potentials against B. xylophilus. Nematodes were treated with diluted formulation concentrations in multi-well culture plates. And, populations preexposed to pre-determined concentrations of the formulations were inoculated onto Botrytis cinerea culture, and in pine twig cuttings. Potency was contrastingly different among formulations, with LC₉₅ of 0.00285 and 0.39462 mg/ml for the most, and the least potent formulation, respectively. Paralysis generally occurred at an application dose of 0.06 ㎍/ml or higher, and formulations with high sublethal toxicities caused significant paralysis levels at the tested doses, albeit the variations. Nematode reproduction was evident at lower doses of 0.00053-0.0006 ㎍/ml both on Botrytis cinerea and pine twigs, with significant variations among formulations. Thus, the study highlighted the inconsistencies in the potency of similar product formulations with the same active ingredient concentration against the target organism, and the need to analyze the potential antagonistic effects of the additives used in formulations.

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

• Korean journal of applied entomology
• /
• v.53 no.2
• /
• pp.141-147
• /
• 2014

Pinewood nematode (PWN: Bursaphelenchus xylophilus) is known to kill pine tree species that are indigenous to countries where the pest was inadvertently imported, but some cultures from the extraction of dead pines do not damage trees. Experiments were conducted to examine the effect of pre-inoculation of these low-pathogenic pinewood nematode on resistance of pine trees against the pest species. The pre-inoculated pine saplings showed induced resistance which lasted for a year, and repeated inoculation of these low-pathogenic nematodes enhanced tree resistance. All nematode samples extracted from dying or dead pines that had been killed not more than three months before the extraction were pathogenic, and most of those extracted from pines that had been killed 2-3 years before were low-pathogenic. When inoculated in pine saplings, number of low-pathogenic nematodes settled, as studied two days after inoculation, was not different from that of pathogenic ones. However, as studied after 30 days of inoculation, rate of reproduction in low-pathogenic nematodes was far lower than that of pathogenic nematodes. The rate of reproduction of several nematode isolates growing on fungal mat media of Botrytis cinerea varied, but three of four low-pathogenic isolates showed same level of reproduction rates as pathogenic ones.