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- P-ISSN2765-2203
- E-ISSN2765-2211
- KCI Candidate
Abstract
The oriental stork (Ciconia boyciana) is listed as an endangered species internationally. Its resident population has been extirpated in South Korea since 1971. Its predicted historical habitat included forests (54%), rice paddy fields (28%), grasslands (17%), river-streams (less than 1%), and villages (less than 1%) based on pre-extirpation records in a previous study. However, habitat attributes of recently reintroduced oriental storks since 2015 remain unknown. To examine habitat use patterns and home ranges of recently reintroduced oriental storks, 2015-2017 tracking data of 17 individuals were used to analyze their spatial attributes with a Kernel Density Estimate method and breeding status. Their habitat use patterns from peripheral to core areas were highly associated with increasing rice paddy fields (26%) and decreasing forested areas (55%). Scale-dependent home ranges were 51% smaller for breeders than for non-breeders on average. Our study results highlight that the habitat use pattern of reintroduced oriental storks seems to be comparable to the historical pattern where the used area is likely to be more centralized for breeders than for non-breeders in South Korea. Furthermore, the direction of habitat management for oriental storks should focus on biodiversity improvement of rice paddy fields with chemical free cultivation and irrigation.
Abstract
We investigated habitat use and home range of a rescued and released white-naped crane using GPS tracking technology in Cheorwon, South Korea, from October 2016 to March 2017. Four types of roosting sites were identified: frozen reservoirs, paddy fields, rivers, and wetlands. Upon arrival, the white-naped crane preferred wetlands in the Demilitarized Zone (DMZ). In late wintering season, it showed a tendency to change main roosting sites in the following order: rice paddies, rivers, and frozen reservoirs. Among 14 sleeping places, Civilian Control Zone (CCZ) with various type of available habitats was more preferred than the DMZ. Places outside of CCZ were rarely used due to anthropogenic disturbances during the night. The tracked white-naped crane widely chose daytime feeding sites while moving around all over rice paddies in the CCZ. Mean diurnal movement distance was 10.5 km with a maximum of 24.8 km. Its home range measured with Minimum Convex Polygon (MCP) and Kernel Density Estimation (KDE) was 172.30 km2 with MCP, 159.60 km2 with KDE 95%, 132.48 km2 with KDE 90%, and 42.45 km2 with KDE 50%. All estimated values of home ranges were higher in the early and later winter than those in the middle period.
Abstract
This study investigated the impact of baseflow on fish community in the Ungcheon stream (16.5 km long) located downstream of the Boryeong Dam, Korea. Based on field monitoring, there were five dominant fish species in the Ungcheon Stream accounting for 75% of the total fish community: Zacco platypus, Zacco koreanus, Tridentiger brevispinis, Rhinogobius brunneus, and Pungtungia herzi. These five fish species were selected as target species. HydroGeoSphere (HGS) and River2D models were used for hydrologic and hydraulic simulations, respectively. A habitat suitability index model was used to simulate fish habitat. To assess the impact of baseflow, each representative discharge was examined with or without baseflow. The HGS model was used to calculate baseflow within the study reach. This baseflow was observed to increase gradually with longitudinal distance. Validation of the hydraulic model demonstrated that computed water surface elevated when baseflow was included, which was in good agreement with measured data, as opposed to the result when baseflow was excluded. Composite suitability index distributions and weighted usable area in the study reach were presented for target species. Simulations indicated that the baseflow significantly increased habitat suitability for the entire fish community. These results demonstrate that there should be a substantial focus on the baseflow for physical habitat simulation.
Abstract
Areas (WPA) were classified based on their habitat characteristics and on the analysis of their emergent fish communities, as estuarine (n=2), coastal dune (n=1), marsh (n=2), stream (n=2), and stream-marsh (n=1) types. The environmental factors revealed to have the greatest influence on the species diversity of emergent fish were maintenance and repair, installation of reservoirs, and construction of artificial wetlands around them. The present study offers basic information on the diversity of fish species in different Wetland Protected Area types that can be used to inform conservation and management decisions for WPA.
Abstract
The objective of this study was to analyze the genotype of black-spotted pond frog (Pelophylax nigromaculatus) using seven microsatellite loci to quantify its genetic diversity and population structure throughout the spatial scale of basins of Han, Geum, Yeongsan, and Nakdong Rivers in South Korea. Genetic diversities in these four areas were compared using diversity index and inbreeding coefficient obtained from the number and frequency of alleles as well as heterozygosity. Additionally, the population structure was confirmed with population differentiation, Nei’s genetic distance, multivariate analysis, and Bayesian clustering analysis. Interestingly, a negative genetic diversity pattern was observed in the Han River basin, indicating possible recent habitat disturbances or population declines. In contrast, a positive genetic diversity pattern was found for the population in the Nakdong River basin that had remained the most stable. Results of population structure suggested that populations of black-spotted pond frogs distributed in these four river basins were genetically independent. In particular, the population of the Nakdong River basin had the greatest genetic distance, indicating that it might have originated from an independent population. These results support the use of genetics in addition to designations strictly based on geographic stream areas to define the spatial scale of populations for management and conservation practices.
Abstract
To understand restoration and conservation projects conducted in Korea for endangered freshwater fishes and amphibians/reptiles, information about Request for Protocols-related studies on restoration, breeding, and release were collected. Trends of studies were visualized via word clouds and VOSviewer program using a text mining technique. Analysis of restoration projects for endangered freshwater fishes elucidated that most research studies conducted to date were focused on genetics and release through captive breeding that could be classified into captive breeding and habitat environments. As for research projects related to amphibians/reptiles, monitoring projects had the highest number, followed by genetic, translocation, and monitoring studies. In addition, restoration projects for amphibians/reptiles included a large number of post-capture translocation projects. Thus, many projects were confirmed by public institutions rather than by the Ministry of Environment. Network analysis revealed that it was largely classified into capture, translocation, and Kaloula borealis. Based on these results, limitations, achievements, and challenges associated with projects conducted thus far are highlighted. Research directions for future restoration and conservation of endangered freshwater fishes and amphibians/reptiles in South Korea are also suggested.
Abstract
Distribution of fish community depends largely on environmental disturbance such as habitat change. In this study, we evaluated the impact of environmental variables and microhabitat patch types on fish distribution in Yudeung Stream at 15 sites between early May and late June 2019. We used non-metric multidimensional scaling to examine the distribution patterns of fish in each site. Gnathopogon strigatus, Squalidus gracilis majimae, Zacco koreanus, and Zacco platypus were associated with riffle and boulder areas, whereas Iksookimia koreensis, Acheilognathus koreensis, Coreoleuciscus splendidus, Sarcocheilichthys nigripinnis morii, and Odontobutis interrupta were associated with large shallow areas. In contrast, Cyprinus carpio, Carassius auratus, Lepomis macrochirus, and Micropterus salmoides were found at downstream sites associated with large pool areas, sandy/clay-bottomed areas, and vegetated areas. On the basis of these results, we suggest that microhabitat patch types are important in determining the diversity and abundance of fish communities, since a mosaic of different microhabitats supports diverse fish species. As such, microhabitat patches are key components of freshwater stream ecosystem heterogeneity, and a suitable patch composition in stream construction or restoration schemes will support ecologically healthy food webs.
Abstract
Iris dichotoma Pall. found on Daechung Island in Korea has been designated as an endangered species. To aid in conservation efforts of this species, this study investigated its germination characteristics and seed dormancy type. Four sets of seeds were incubated at different temperatures (4/1°C, 15/6°C, 20/10°C, and 25/15°C). One set of seeds was cold stratified (4 weeks at 4/1°C). The final germination rate and mean germination time showed that the optimal germination temperature was 25/15°C. Final germination rates were ~70%, showing no significant difference among temperature treatments. However, mean germination time were significantly different among all temperature treatments except for 4/1°C. Mean germination time for seeds with temperature treatments of 15/6°C, 20/10°C, and 25/15°C were 3.2, 2.1, and 1.5 weeks, respectively. At 25/15°C, the mean germination time was half of that at 15/6°C. Seeds of I. dichotoma had fully developed embryos at the time of dispersal. No additional growth of the embryo was observed. Cold stratification did not affect the final germination rate or the mean germination time. This study shows that seeds of I. dichotoma have no physiological or morphological dormancy, unlike other members of the Iris genus known to have seed dormancy that needs a relatively high incubation temperature (≥25/15°C) for mass propagation to occur. These results will be useful for understanding ecophysiological mechanisms related to the species’ habitat. They are also useful for mass propagation of I. dichotoma for the purpose of conserving this endangered species.
