• Korean Journal of Environment and Ecology
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• v.25 no.4
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• pp.516-525
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• 2011

We studied the influence certain environmental factors (proximity of roosting site, roads, and residential areas) have on the spatial distribution of cranes in the Cheorwon, Korea. Using a range finder and GPS, data were collected from January to February 2007 and were subsequently evaluated with ArcGIS. The size of the cranes' wintering habitat was estimated to be 7$76.9km^2$. Five hundred and fifty-five flocks of cranes were observed and detailed distributions were collected. Feeding distribution of the cranes showed clustered distribution, however, no tendencies of spatial autocorrelation were apparent. Adjacent regions with paved roads and residences showed lower densities than other areas. Distances at which paved roads and residential areas induced changes in feeding flock densities were 1500m and 1750m, respectively. Feeding flock density decreased with increased distance from roosting site. Feeding flock density of the two crane species did not increase as distance from roads increased, however, the density of individuals showed a significant increasing tendency with increased distance from roads. In both species, density of feeding flocks and individuals significantly increased with increasing distance from residential areas. In Red-crowned Cranes, the density of feeding flocks and individuals significantly decreased with increasing distance from roosting site, however, in the case of White-naped Cranes, there was an even distribution in density of feeding flocks and individuals.

• Korean Journal of Environment and Ecology
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• v.22 no.6
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• pp.632-639
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• 2008

This paper deals with feeding site distribution aspect and seasonal distribution change of the wintering geese in Cheonsu bay and reclaimed area from October 2006 to March 2007. Geese were distributed mostly in agricultural land(rice field) during day time. According to the distribution map by maximum counts, observed geese of agricultural land were frequently distributed in large agricultural land. Especially, Geese were more used agricultural land near the reservoir where used as roosting site than the other sites. Diurnal feeding site of the geese were agricultural land near the reservoir with huge flock during early wintering season(October), but geese were used the agricultural land far from reservoir after mid wintering season(after January). The feeding flock size of Geese were decreased and feeding site was more far from the reservoir than in mid wintering season during late wintering season(March). Habitat use rate of the quadrat area where below 1km from the reservoir was most high in early wintering season. Contrary, habitat use rate where 2km far from the reservoir was shown lowest habitat use rate in early wintering season, but it was increased during mid wintering season(January) and decreased after mid wintering season. Habitat use rate of the agricultural land where 2km below and 1 km far from reservoir was shown middle rate, but it was increased until November and decreased after November. This result shown that feeding site preference of the wintering geese was affected by distance from roosting site(reservoir), and feeding site was changed as a food sources decreasing by stay time of geese flock.

• Korean Journal of Environment and Ecology
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• v.23 no.1
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• pp.41-49
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• 2009

This research conducted a survey on the feeding crane's size, formation and distribution distance subsequent to road pattern and feeding flock's size during the wintering season eight times at the Cheolwon basin in Korea from December 2005 until February 2006. The survey results are as follows: First, the feeding flocks of the Red-crowned and White-naped Crane were found to mainly consist of two to four individuals. Mono-specific feeding flocks were more identified than hetero-specific feeding flocks in both Red-crowned and White-naped Cranes. There existed a significant difference in the ratio by size between the feeding Red-crowned and White-naped Cranes. The crane's average distribution distance from the paved road was much farther than from the unpaved road, paved farm road and unpaved farm road. In case of the white-naped crane, there was a difference in its distance length from between the road and farm road and there existed a significant difference only in the paved road in the distance length by road pattern between these two bird species[Red-crowned and White-naped Crane]. Such a result indicates that crane species don't prefer the road with frequent vehicular traffic to the road with low vehicular traffic. 5 or more individuals of feeding flocks of the Red-crowned Crane were located at a farther distance length from the paved road comparing to less than 5 individuals of the whole feeding flocks and less than 5 individual feeding flocks. 5 or more individuals of feeding flocks of the White-naped Crane were located at a farther distance length from the paved road, paved farm road and unpaved farm road than less than 5 individuals of feeding flocks of the White-naped Crane; however, there existed no difference in distance length subsequent to their group size. Conclusively, it was found out that the flocks with a larger size were more greatly affected by interrupting factors. Considering such results, there seems to be a more relation to the fact that larger size feeding flocks of crane species have a higher efficiency in the lookout for their surroundings.

• Journal of Environmental Policy
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• v.7 no.3
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• pp.141-160
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• 2008

The effects of disturbance on bird community were studied in Ssanggok Valley and Beopju Temple area, Songni Mt. National Park in $2006{\sim}2008$. We divided three sites by habitat condition such as traffic road(strong disturbance), trail(medium) and control(weak) site. During breeding and non-breeding seasons(n=12), number of species, number of individuals, species diversity and density did not differ among three sites, but in breeding season(n=9), number of species(Kruskal Wallis, $x^2$=10.32, p=0.006), number of individuals(Kruskal Wallis, $x^2$=7.118, p=0.028) and species diversity of birds(Kruskal Wallis, $x^2$=9.847, p=0.007) were significantly higher in trail site with medium disturbance than in other sites. In breeding season, nesting and foraging guild rate were not different among three sites. In guild analysis, hole was the highest nesting guild and canopy was the highest foraging guild in three sites.

• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2003.04a
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• pp.199-202
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• 2003

우리나라 전체 시설원예 면적 52,135ha(2001년) 중 난방을 하고 있는 시설원예 면적은 12,710ha로서 약 24%정도를 차지하고 있다. 시설재배면적의 지역분포를 비교해 보면, 시설채소의 경우 중부 이북지역에 44%, 남부에 56%의 비율로 분포해 있으며, 시설화훼의 경우 중부 이북 58%, 남부 42%로서 난방비가 많이 소요되는 지역이라도 수도권을 중심으로 유통이나 지리적 면에서 유리한 지역에 시설재배면적이 많이 분포해 있다. (중략)

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.452-460
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• 2017

Rice fields are important stopover sites for the conservation of shorebirds during long-distance migration. These fields serve as food sources providing energy for the next leg of the journey. Shorebirds are able to change their preferred food source at stopover sites. However, the type and distribution of food resources remain unknown for the shorebirds in the Republic of Korea. Therefore, we studied the type and distribution pattern of food resource (macroinvertebrates, remaining rice, and other seeds) for shorebirds in the rice fields. We have identified potential and actual food sources for shorebirds in the rice fields. The potential food sources were collected by using a core-sampling method and the actual food source was ascertained by observational analysis. As a result, a total 19 species of benthic macroinvertebrates in 15 families were recorded as potential food sources. A total of 9 families in 9 orders of benthic macroinvertebrates known to be actual food sources were also recorded during the study period, including loaches, and a tuber of sea club rush. Also, the distribution of the food source depended on soil conditions generated by cultivation such as plowing, harrowing, and the use of pesticides. In the present study, we identified the type and distribution of food sources for shorebirds. This information can be used as essential primary baseline data for conservation of shorebirds using the rice fields of the Republic of Korea.

• Journal of the Korean association of regional geographers
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• v.12 no.4
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• pp.437-448
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• 2006

Bare-topped thufur is called as frost scars, implying the rupturing stage of vegetated mounds, Field observations and measurements provide empirical information on the process and factors of thufur disintegration in Mt. Halla, Initial bare patches on mound apexes are scaled up by continuous removal of soil and vegetation, resulting in the formation of crater-like thufur, Frost action plays a primary role in thufur disintegration, In particular, pipkrake loosens soil particles within the bare patches and subsequently accelerates the degradation of vegetated mounds during periods with frequent diurnal freeze-thaw cycle and high soil moisture, Deflation also has an impact on thufur breakup in that the bare patches usually lack upper dark brown soil and are covered with granules, Withered shrubs such as Juniperus chinensis var. sargentii are frequently observed in frost scars and disrupted mounds, indicating that thufur disintegration has been probably influenced by global warming.

• Korean Journal of Environment and Ecology
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• v.17 no.3
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• pp.295-303
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• 2003

The tidal flat area of south and west coast consists of 2.4% of total land area of Korea. About 83% of tidal flat is located at the west coast, and the remaining tidal flat is located at the south coast. This tidal flat is also divided for administrative regions which are Gyeonggi Province(35.1%), Chungnam Province(12.7%) Jeonbuk Province(4.7%), Jeonnam Province(44.0%) and Gyeongnam Province(3.5%). The tidal flat of west coast of Korea is one of the most important stopover site for shorebirds on the East Asia-Australia Flyway. The tidal flat is used for feeding and resting place by migratory shorebirds. Generally, waterbirds including migratory shorebirds are considered as key species to show the superiority of wetland. By the criteria of Lamsar Convention in the basis of waterbird, at least 14 coastal wetlands in Korea have to be internationally important wetlands. The factors to affect the distribution of shorebirds at the certain tidal flat are closely related with 1) the distribution of benthic invertebrates, potential prey of shorebirds 2) the availability of roosting site 3) the size of tidal flat 4) the intensity of human disturbance. In this paper, we summarized the regional status of tidal flat of Korea and its conservation methods related with migratory waterbirds.

• Korean Journal of Environment and Ecology
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• v.16 no.1
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• pp.34-45
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• 2002

Of the four tidal flat areas(Yeocha-ri, Dongmak-ri, Sundu-ri and Donggum-ri) on Southern Ganghwa Island, the distribution of migratory waterbirds showed a difference in the numbers of individuals and species. Higher numbers of individuals and species were observed on the Yeocha-ri tidal flat. The dominant waterbirds species at the four areas was the Dentin(Calidris alpina). This species showed an occupancy rate(42.0-79.1%) on the Yeocha-ri tidal flat, which was much higher relative to the other areas. The Yeocha-ri tidal flats were higher relative to MSL than the other tidal flats. When the Dongmak-ri tidal flat was covered by sea water, the Yeocha-ri tidal flat was 0.0317$\textrm{km}^2$ in area and on this space we observed many resting waterbirds. The biomass of the waterbirds' potential prey on the Yeocha-ri tidal flat was higher(1.6~2.5$\times$) than other tidal flats. Twenty-three species and 266 individuals were found on the Yeocha-ri tidal flat, which was higher than the tidal flats. The food of Dunlin, which was the dominant species in these four areas, was mainly Reticunassa festiva and Umbonium thomasi(Gastropoda) and Perinereis aibuitensis(Polychaeta). A Dunlin(38.11g) used to eat 1,295 individuals of these food items for daily basal energy. Gastropod, its density was highest on Yeocha-ri tidal flats. The distribution of waterbirds seemed to be closely related with the distribution of the benthos, space and safety of resting site. We suggest that the environments of tidal flats, which are rich foraging habitats, are important factors for conservation of waterbirds.

• Korean Journal of Environmental Agriculture
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• v.32 no.4
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• pp.294-303
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• 2013

BACKGROUND: It is well known that rice-fields can provide excellent foraging places for birds including seasonal migrants, wintering, and breeding and hence the high biodiversity of rice-fields may be expected. However, how environmental change including climate-changes on life-history and population dynamics in birds on rice-fields has not been fully understood. In order to investigate how climate-change affects population migratory patterns and migration timing, I modeled a population dynamics of birds in rice-fields over a whole year. METHODS AND RESULTS: I applied the Lotka-Volterra equation to model the population dynamics of birds that have been foraging/visiting rice-fields in Korea. The simple model involves the number of interspecific individuals and temperature, and the model parameters are periodic in time as the biological activities related to the migration, wintering and reproduction are seasonal. As results, firstly there was a positive relationship between the variation of seasonal population sizes and temperature change. Secondly, the reduced lengths of season were negatively related to the population size. Overall, the effects of the difference of lengths of season on seasonal population dynamics were higher than the effects of seasonal temperature change. CONCLUSION(S): Climate change can alter population dynamics of birds in rice-fields and hence the variation may affect the fitness, such as reproduction, survival and migration. The unstable balances of population dynamics in birds using paddy rice field as affected by climate change can reduce the population growth and species diversity in rice fields. The results suggest that the agricultural production is partly affected by the unstable balance of population in birds using rice-fields.