• Journal of Forest and Environmental Science
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• v.30 no.4
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• pp.383-392
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• 2014

In this study, we investigated the Fukiage sand dunes of southern Kyushu, Japan. We surveyed the status of recovery of coastal Japanese black pine forests damaged by pine wilt disease and their disaster prevention capability. We placed two transects: Transect 1, in an area that was severely damaged (80-90% damage rate) by pine wilt disease, and Transect 2, in an area that was mostly undamaged (<10% damage rate). Then, we installed survey lines, carried out vegetation surveys, and measured the depth and pH of humus soil. The survey lines were placed perpendicular to the coastline from the top of the fore-dune to the inland area, and divided into five 50 m sections. Before the point 100 m inland from the top of the fore-dune, the number of invasive hardwoods and of Japanese black pines were small because of the poor growth environment in both transects. Past the 100 m point, the species and number of Japanese black pines and broad-leaved trees increased further inland because the growth environment improved. In addition, the recovery metrics of tree height, diameter at breast height, age, and number in Transect 1 were much lower than those in Transect 2, and the basal area of broad-leaved trees and the depth of humus soil in Transect 1 were lower than in Transect 2, and the soil pH of humus soil in Transect 1 was higher than that of Transect 2. The shape ratio of the Japanese black pine forests indicated that they were insufficient for disaster prevention. Therefore, in order to fully promote the disaster prevention capability of coastal Japanese black pine forests, we should not only focus on prevention of pine wilt disease but also undertake continuous control efforts taking into consideration the sound growth environment such as appropriate density and soil management and removal of invasive broad-leaved trees.

• Journal of Life Science
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• v.25 no.12
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• pp.1445-1449
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• 2015

The pinewood nematode Bursaphelenchus xylophilus (Nematoda: Parasitaphelenchidae) poses a serious threat to pine forests in Europe and East Asia, leading to a debilitating pine wilt disease. Infected pine trees in Korea are generally fumigated or crushed to small wood chips after felling. Although pine wilt disease often recurs in pest management sites, there are no adequate means to monitor the effectiveness of pest control measures in those sites. Recently, a male-produced aggregation pheromone, 2-(undecyloxy)ethanol, was shown to be useful for attracting several Monochamus species, which are vectors for the pinewood nematodes. In this study, we investigated the abilities of 2-(undecyloxy)ethanol at three different doses (175, 350, and 700 mg), as well as host plant volatiles (α-pinene and ethanol), to attract M. alternatus (Coleoptera: Cerambycidae) at a pine forest in Pohang, Korea where infected pine trees had been cut down and fumigated. Twenty-seven M. alternatus were captured in cross-vane panel traps made of polyethylene terephthalate bottles and acrylic sheets. The results indicate that a high dose of 2-(undecyloxy)ethanol (700 mg per trap) is the most effective for attracting M. alternatus. The aggregation pheromone could be used to monitor the effectiveness of pest control measures as well as M. alternatus populations.

• Journal of the Korean Wood Science and Technology
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• v.40 no.1
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• pp.53-59
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• 2012

This study used pine wilt disease damaged trees as raw materials. The damaged woods were subjected to soaking treatment using wood vinegar, nematicide and sea water, fumigated treatment using fumigation, and the bending strength and hardness of the timber were measured at different points of time after the treatment. In soaking treatment, the highest bending strength was obtained from wood vinegar (100 fold dilution)-soaked specimens of Pinus densiflora and the nematicide-soaked specimens of Pinus thunbergii. The highest hardness in cross section was gained from the nematicide-soaked specimens of Pinus densiflora and Pinus thunbergii, the highest hardness in radial section was obtained from the nematicide-soaked specimens of Pinus densiflora and wood vinegar (100 fold dilution)-soaked specimens of Pinus thunbergii, and the highest hardness in tangential section was obtained from the nematicide-soaked specimens of Pinus densiflora and Pinus thunbergii, and there were not significantly different among the treatments. When fumigated treatment was applied, bending strength, hardness was somewhat lower in the control but were not significantly different between the treatments.

• Journal of Korean Society of Forest Science
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• v.102 no.4
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• pp.499-505
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• 2013

Pine wilt disease has known as a serious forest disease in East Asia such as Japan, Korea and China. Fumigation and burning are considered as best way to treat infected tree at early detection. For investigate spectral reflectance characteristics of infected trees, periodic measurement has been done in both infected and non-infected trees. Infected and non-infected trees' reflectance (400 nm~2,500 nm wavelength) are detected from June to October with GER3700 spectrometer. Noise of reflectance data was corrected using cubic spline interpolation method. Reflectance was changed in most of infected trees with ranges Red (600 nm~700 nm) and Middle Infrared (1,400 nm~1,500 nm) within two months after injected by Pine Wood nematode (PWN), but there was no differences in non-infected trees. Infected and non-infected trees were compared statistically in each period. As a result, we found that a statistically significant difference was occurred at Red and Middle Infrared (MIR) 2 months after injection (p<0.05), however, no significant difference in near infrared (p>0.05). Therefore, the early detection of infested pine trees by PWN may possible through detecting the change of spectral reflectance at red and MIR.

• Journal of Cadastre & Land InformatiX
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• v.50 no.1
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• pp.201-214
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• 2020

This study aimed to early detect damaged trees by pine wilt disease using the vegetation indices of UAV images. The location data of 193 pine wilt disease trees were constructed through field surveys and vegetation index analyses of NDVI, GNDVI, NDRE and SAVI were performed using multi-spectral UAV images at the same time. K-Means algorithm was adopted to classify damaged trees and confusion matrix was used to compare and analyze the classification accuracy. The results of the study are summarized as follows. First, the overall accuracy of the classification was analyzed in order of NDVI (88.04%, Kappa coefficient 0.76) > GNDVI (86.01%, Kappa coefficient 0.72) > NDRE (77.35%, Kappa coefficient 0.55) > SAVI (76.84%, Kappa coefficient 0.54) and showed the highest accuracy of NDVI. Second, K-Means unsupervised classification method using NDVI or GNDVI is possible to some extent to find out the damaged trees. In particular, this technique is to help early detection of damaged trees due to its intensive operation, low user intervention and relatively simple analysis process. In the future, it is expected that the utilization of time series images or the application of deep learning techniques will increase the accuracy of classification.

• Journal of agriculture & life science
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• v.43 no.2
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• pp.9-15
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• 2009

The objectives of this study was to obtain the basic information for reasonable management of soil ecosystem damaged by pine wilt disease. Soil temperature and moisture content were $15.3{^{\circ}C}$ and 11.5% at whole-cut site, $14.4{^{\circ}C}$ and 13.5% at partial-cut site, and $13.7{^{\circ}C}$ and 14.8% at control site, respectively. The content of soil organic matter throughout the study period ranged from 2.11 to 2.64% at whole-cut site, 2.26 to 3.33% at partial-cut site, and 2.27 to 3.10% at control. Soil respiration rates showed seasonal fluctuations increasing in summer, which showed positive correlations between soil respiration and soil temperature. Average soil respiration were 0.24, 0.36 and $0.32gCO_{2}/m^{2}/hr$ at whole-cut site, partial-cut site, and control, respectively. $Q_{10}$ values ranged from 2.39 to 2.68 at Pinus densiflora stands damaged by pine wilt disease. Annual soil respiration rate at whole-cut site, partial-cut site and control were 8.1, 15.6 and $14.6tCO_{2}/ha/yr$, respectively.

• Journal of Korean Society of Forest Science
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• v.113 no.2
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• pp.259-270
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• 2024

Since 2013, Korea has allocated significant budgets and manpower nationwide to prevent the spread of pine wilt disease and to reduce damage. As a result, the number of damaged trees decreased from 2.18 million in 2014 to 310,000 in 2021. However, the damage has increased again since then. Despite the overall decrease in the number of damaged trees, the scope of the damage continues to expand every year. Previous studies have develope In order to judge the control performance, a quantitative control performance analysis method to objectively evaluate control performance. This method takes into consideration two factors-quantity change and the change in the damage area, which is an area factor. This approach provides a more comprehensive assessment than the control guidelines that only suggest changes in damage grade based on the volume of damaged trees. The expansion of the damage range is also an important factor in analyzing control performance, but previous studies have not reflected this. Therefore, this study calculates the change in the distance of the pine wilt disease boundary area for Gyeongsangbuk-do, where changes in the damage range can easily be observed from year to year. The study then creates application criteria and coefficients and uses them to improves control performance index calculation formula. As a result, it was possible to calculate a quantitative analysis of the control performance, taking into account the changes in the damage range. When the improved formula was applied to 26 cities, counties, and districts in Gyeongsangbuk-do, it slightly decreased or increased compared to the existing calculation formula. This confirmed that the control performance index can change from a positive value (+), indicating increased damage, to a negative value (-), indicating reduced damage.

• Journal of the Korean Wood Science and Technology
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• v.37 no.3
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• pp.200-207
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• 2009

As an effort to utilize the pine woods damaged by pine wilt disease, this study analyzed the density of pine wood nematode and compressive strength of damaged trees treated through soaking and fumigating. The density of nematode in Pinus densiflora and Pinus thunbergii woods soaked in wood vinegar and nematicide, and in seawater reduced greatly in 21 days and in 30 days, respectively. When reextracted nematode was injected artificially into healthy trees, infection was not observed after the lapse of six months, and the mean density of Pinus densiflora and Pinus thunbergii was $0.47g/cm^3$ and $0.54g/cm^3$, respectively, and their compressive strengths were $304kgf/cm^2$ and $363kgf/cm^2$, respectively. As to change in the density of pine wood nematode after fumigating, pine wood nematode was detected until the third month in both species, and those detected afterwards were found to be similar nematodes. After 24 months, the mean densities of Pinus densiflora and Pinus thunbergii were $0.54g/cm^3$ and $0.52g/cm^3$, respectively, and their compressive strengths were $353kgf/cm^2$ and $370kgf/cm^2$, respectively.

• Korean Journal of Remote Sensing
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• v.31 no.5
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• pp.385-394
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• 2015

Pine wilt disease has greatly damaged pine forests not only in East Asia including South Korea and China, but also in European region. The damage caused by pine wood nematode (Bursaphelenchus xylophilus) is expressed in bundles within stands and rapidly spreading, however, present field survey methods have limitations to detecting damaged trees at regional level. This study extracted the damaged trees by pine wilt disease using time series hyperspectral aerial photographs, and analyzed their distribution characteristics. Hyperspectral aerial photographs of 1 meter spatial resolution were obtained in June, September, and October. Damaged trees by pine wilt disease were extracted using Normalized Difference Vegetation Index (NDVI) and Vegetation Index green (VIgreen) of the September photograph. Among extracted damaged trees, dead trees with leaves and without leaves were classified, and the spectral reflectance values from the photographs obtained in June, September, and October were compared to extract new outbreaks in September and October. Based on the time series dispersion of extracted damaged trees, nearest neighbor analysis was conducted to analyze distribution characteristics of the damaged trees within the region where hyperspectral aerial photographs were acquired. As a result, 2,262 damaged trees were extracted in the study area, and 604 dead trees (dead trees in last year) with leaves in relation to the damaged time and 300 and 101 newly damaged trees in September and October were classified. The result of nearest neighbor analysis using the data shows that aggregated distribution was the dominant pattern both previous and current year in the study area. Also, 80% of the damaged trees in current year were found within 60 m of dead trees in previous year.

• Korean journal of applied entomology
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• v.55 no.4
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• pp.501-511
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• 2016

Predicting potential spatial distribution of Monochamus alternatus, a major insect vector of the pine wilt disease, is essential to the spread of the pine wilt disease. The purpose of this study was to predict future domestic spatial distribution of M. alternatus by using the CLIMEX model considering the temperature condition of the vector's life history. To predict current distribution of M. alternatus, the administrative divisions data where the pine wilt spots caused by M. alternatus were found from 2006 to 2014 and the 10-year mean climate observed data in 68 meteorological stations from 2006 to 2015 were used. Eight parameter sets were chosen based on growth temperature range of M. alternatus reported in preceding researches. Error matrix method was utilized to select and simulate the parameter sets showing the highest correlation with the actual distribution. Regarding the future distribution of M. alternatus, two periods of 2050s(2046-2055) and 2090s(2091-2100) were predicted using the projected climate data of RCP 8.5 Scenario generated from Korea Meteorological Administration. Overall results of M. alternatus distribution simulation were fit in the actual distribution; however, overestimation in Seoul Metropolitan area and Chungnam Region were shown. Gradual expansion of M. alternatus would be expected to nationwide from western and southern coastal areas of Korea peninsula.