• Korean journal of applied entomology
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• v.49 no.2
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• pp.115-121
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• 2010

The bean bug, Riptortus clavatus Thunberg (Hemiptera: Alydidae), is a pest of soybeans and tree fruits. It enters reproductive diapause during winter. We studied the effect of different combinations of temperature, day length, and treatment period on the termination of diapause in R. clavatus using adult females collected in October and November 2006. Ovarian development was used to determine diapause termination. The treatments were: (1) HTLD; $25^{\circ}C$, 14L:10D treatment for 1, 2, 3 weeks and 30 days, (2) HTSD; $25^{\circ}C$, 10L:14D treatment for 1, 2, and 3 weeks, (3) LTLD; $8^{\circ}C$, 14L:10D treatment for 1, 2, and 3 weeks followed by HTLD for 3 weeks, and (4) LTSD; $8^{\circ}C$, 10L:14D treatment for 1, 2, and 3 weeks followed by HTLD for 3 weeks. The HTSD treatments did not affect ovarian development, and resulted in no significant difference in the number of mature eggs in ovaries or the percentage of diapause-terminated females compared to the control females before treatment. The percentage of females that terminated diapause was significantly higher in the HTLD treatment than in the HTSD treatment. The HTLD treatment for more than 14 days increased the percentage of diapause-terminated females, accelerated the development of the ovaries, and increased the number of mature eggs in ovaries. Compared with the HTLD or HTSD treatments, the LTLD or LTSD treatments followed by the HTLD treatment accelerated ovarian development and increased the number of ovipositing females. The pre-LTSD treatment for 1 week was enough to increase the number of eggs oviposited.

• Korean Journal of Environment and Ecology
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• v.29 no.5
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• pp.693-702
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• 2015

In order to identify the species and to reveal the phylogenetic relationship of rook populations found in Jeju-do Province in winter seasons, we determined the sequences of mitochondrial cytochrome c oxidase I (COI) gene and analyzed the genetic structure of maternal lineages and phylogenetic relationship. The rook DNAs were isolated from the post-mortem specimens and plumages collected from agricultural farms in Jeju-do Province including U-do Island. The obtained COI sequences (n=41) showed over 97.0% identities with those previously reported from Corvus frugeligus. Three COI haplotypes (J01-J03) were detected from COI sequences of the rooks obtained in Jeju-do Province but those did not show the site-specific patterns, showing that they might be derived from a common maternal origin. Eight maternal haplotypes were detected from all COI sequences obtained. Among those three haplotypes contained the COI sequences from Northeast Asia including eastern Russia, Mongolia and South Korea. On the other hand, the other five haplotypes contained the COI sequences reported from Central Asia, Middle East, western Russia and European countries. The COI sequences from Jeju-do Province were located on three haplotypes (CF01-CF03) belonging to Northeast Asian rook lineages. The NJ tree showed the distinct branch patterns suggesting two different maternal lineages of C. frugilegus, which proposed as two parapatric subspecies, C. f. frugilegus (Western) and C. f. pastinator (Eastern). These findings using DNA barcoding approaches will be contributed to provide the information about avian fauna for understanding the genetic structure of maternal lineage, phylogenetic relationship and their molecular ecology.

• Journal of Korean Society for Geospatial Information Science
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• v.23 no.1
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• pp.101-111
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• 2015

Stream restoration projects have become threats to riparian ecosystem in Rep. of korea. Riparian wildlife becomes isolated and the animals are often experience difficulties in crossing riparian corridors. The purposes of this study is to select suitable wildlife passages for wild animals crossing riparian corridors. Maximum entropy model and snow tracking data on embankment in winter seasons were used to develop species distribution models to select suitable wildlife passages for water deer. The analysis suggests the following. Firstly, most significant factors for water deer's habitat in area nearby riparian area are shown to distance to water, age-class, land cover, slope, aspect, digital elevation model, tree density, and distance to road. For the riparian area, significant factors are shown to be land cover, size of riparian area, distance to tributary, and distance to built-up. Secondly, the suitable wildlife passages are recommended to reflect areas of high suitability with Maximum Entropy model in riparian areas and the surrounding areas and moving passages. The selected suitable areas are shown to be areas with low connectivity due to roads and vertical levee although typical habitats for water deer are forest, grassland, and farmland. In addition, the analysis of traces on snow suggests that the water deer make a detour around the artificial structures. In addition, the water deer are shown to make a detour around the fences of roads and embankment around farmland. Lastly, the water deer prefer habitats around riparian areas following tributaries. The method used in this study is expected to provide cost-efficient and functional analysis in selecting suitable areas.

• Korean Journal of Environment and Ecology
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• v.34 no.6
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• pp.503-514
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• 2020

Climate change leads to changes in phenological response and movement of plant habitats. Korea's evergreen broad-leaved forest has widened its distribution area compared for the past 20 years, and the range of its native habitats is moving northward. We analyzed climate indices such as the warmth index, the cold index, the lowest temperature in the coldest month, and the annual average temperature, which are closely related to vegetation distribution, to predict the change in the native habitat of Lauraceae evergreen broad-leaved trees. We also analyzed the change and spatial distribution to identify the habitat climate characteristics of 8 species of Lauraceae evergreen broad-leaved trees distributed in the warm temperate zone in Korea. Moreover, we predicted the natural habitat change in the 21st century according to the climate change scenario (RCP 4.5/8.5), applying the MaxEnt species distribution model. The monthly average climate index of the 8 species of Lauraceae evergreen broad-leaved trees was 116.9±10.8℃ for the temperate index, the cold index 3.9±3.8℃, 1495.7±455.4mm for the annual precipitation, 11.7±3.5 for the humidity index, 14.4±1.1℃ for the annual average temperature, and 1.0±2.1℃ for the lowest temperature of winter. Based on the climate change scenario RCP 4.5, the distribution of the Lauraceae evergreen broad-leaved trees was analyzed to expand to islands of Jeollanam-do and Gyeongsangnam-do, adjacent areas of the west and south coasts, and Goseong, Gangwon-do on the east coast. In the case of the distribution based on the climate change scenario RCP 8.5, it was analyzed that the distribution would expand to all of Jeollanam-do and Gyeongsangnam-do, and most regions except for some parts of Jeollabuk-do, Chungcheongnam-do, Gyeongsangbuk-do, and the capital region. For the conservation of Lauraceae evergreen broad-leaved trees to prepare for climate change, it is necessary to establish standards for conservation plans such as in-situ and ex-situ conservation and analyze various physical and chemical characteristics of native habitats. Moreover, it is necessary to preemptively detect changes such as distribution, migration, and decline of Lauraceae evergreen broad-leaved trees following climate change based on phenological response data based on climate indicators and establish conservation management plans.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.1
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• pp.1-9
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• 2006

Regardless of the recent observed warmer winters in Korea, more freeze injuries and associated economic losses are reported in fruit industry than ever before. Existing freeze-frost forecasting systems employ only daily minimum temperature for judging the potential damage on dormant flowering buds but cannot accommodate potential biological responses such as short-term acclimation of plants to severe weather episodes as well as annual variation in climate. We introduce 'dormancy depth', in addition to daily minimum temperature, as a complementary criterion for judging the potential damage of freezing temperatures on dormant flowering buds of grape vines. Dormancy depth can be estimated by a phonology model driven by daily maximum and minimum temperature and is expected to make a reasonable proxy for physiological tolerance of buds to low temperature. Dormancy depth at a selected site was estimated for a climatological normal year by this model, and we found a close similarity in time course change pattern between the estimated dormancy depth and the known cold tolerance of fruit trees. Inter-annual and spatial variation in dormancy depth were identified by this method, showing the feasibility of using dormancy depth as a proxy indicator for tolerance to low temperature during the winter season. The model was applied to 10 vineyards which were recently damaged by a cold spell, and a temperature-dormancy depth-freeze injury relationship was formulated into an exponential-saturation model which can be used for judging freeze risk under a given set of temperature and dormancy depth. Based on this model and the expected lowest temperature with a 10-year recurrence interval, a freeze risk probability map was produced for Hwaseong County, Korea. The results seemed to explain why the vineyards in the warmer part of Hwaseong County have been hit by more freeBe damage than those in the cooler part of the county. A dormancy depth-minimum temperature dual engine freeze warning system was designed for vineyards in major production counties in Korea by combining the site-specific dormancy depth and minimum temperature forecasts with the freeze risk model. In this system, daily accumulation of thermal time since last fall leads to the dormancy state (depth) for today. The regional minimum temperature forecast for tomorrow by the Korea Meteorological Administration is converted to the site specific forecast at a 30m resolution. These data are input to the freeze risk model and the percent damage probability is calculated for each grid cell and mapped for the entire county. Similar approaches may be used to develop freeze warning systems for other deciduous fruit trees.