• Korean Journal of Environmental Agriculture
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• v.42 no.1
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• pp.63-70
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• 2023

Golden apple snails (Pomacea canaliculat) (GAS) are widely used for weed control in rice cultivation. However, concerns on the ecological risk of invasive GAS species are increasing. This study aimed to evaluate the overall impacts of GAS on weed control, abundance of aquatic animals and insects, and rice yield, in comparison with that from other biocontrol agents such as loach (Misgurnus mizolepis) and catfish (Silurus asotus), which are alternatives for biological weed control in rice paddy cultivation. Field experiments included five treatments; control, herbicide, GAS, loach, and catfish. During the rice growth, weed appearance and biological abundance were monitored, and at harvest, the rice yield was determined. Weed control efficiency was the highest for GAS treatment (100%), followed by that for herbicide (95.8%), loach (57.5%), and catfish treatments (31.7%). Insect abundance was considerably decreased in GAS treatment due to heavy weed removal, which affects the habitat of aquatic animals and insects. The amount of rice yield (unit: kg 10 a^-1) was in the order of GAS (798.9) > loach (708.1) = herbicide (700.7) > catfish (629.4) > control (496.0). Therefore, considering the weed control efficiency, biological abudance, and rice yield, loach could be a potential alternative for biological weed control in organic rice farming. However, the activity of the biocontrol agents are susceptible to environmental conditions; therefore, further studies under different conditions are essential to confirm these findings.

• Korean Journal of Environmental Biology
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• v.36 no.1
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• pp.73-81
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• 2018

This study was conducted to understand the current status of the translocated species using a precede study and a model to evaluate the potential invasiveness that could adversely affect the aquatic ecosystem in the Gangneungnamdae Stream. A total of 12 translocated species were investigated and identified from 9 sites in a precede study, and steadily increased since 1982. For the study, which utilized research based on the total FISK (Fish Invasivenss Screening Kit) scores, all of the non-native fishes in Gangneungnamdae Stream were classified into two groups: namely as a high and a medium risk of becoming invasive. It was determined that there were two species (Zacco platypus and Pseudorasbora parva) that were determined to have posed the highest risk. The study determined that the mean scores were shown to have ranged from $3.06({\pm}0.16)-3.42({\pm}0.13)$. Consequently, the habitat analysis showed that the determined QHEI (Qualitative Habitat Evaluation Index) values in the stream averaged 146 (88-171), indicating that an optimal habitat condition did exist in that locale. It can be inferred that compared to land use in the surrounding watersheds, the QHEI values and frequency of translocated species showed the lower the altitude of stream, the QHEI values were decreased and in case of land use pattern, a noted decreased forest and grassland area, and gradually increased urbanized area was seen to exist in the region. The correlation between the fish assemblage, QHEI, land use pattern of surrounding watershed and number of translocated species was identified and analyzed when the stream altitude decreased, and the number of species was increased (r= - 0.782, p=0.0127), the number of species was decreased (r= - 0.737, p=0.0234), and finally when the QHEI values were decreased, it was noted that the urbanized area was increased (r=0.292, p=0.446). In the case of the number of translocated species, when the number of translocated species was increased, the associated urbanized area was increased.

• Journal of Wetlands Research
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• v.20 no.2
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• pp.161-172
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• 2018

A mixed farming system that includes organic rice production and freshwater fish farming is being called into attention in Korean agricultural industry and rural areas in order to improve farm management and environmental conservation. This study was conducted to evaluate the environmental and ecological value of such mixed farming practices. Expert assessment and rapid assessment method (RAM) of wetland evaluation were employed for this study. Experts have responded that biodiversity conservation including amphibian and reptile habitat (2.39), aquatic insect habitat (2.36), Fishery habitat (2.34), vegetation diversity (2.13), avian habitat (2.05), and experience and education were the most important function of mixed farming. The wetland function evaluation conducted using modified RAM indicated that rice-fish mixed system showed improvements in most of the evaluated functions, compared to the conventional rice paddies. The overall wetland function of rice paddies in rice-fish mixed system was greatly improved as compared with the conventional rice paddies. Rice paddies are known to play an important role in biodiversity maintenance, and provide ecosystem services such as climate modulation and carbon reduction. Rice-fish mixed system of farming may not only improve various ecosystem services of rice paddies, but may increase farm income through value added fish farming, as well as promotion of social services such as education and maintenance of tradition. Additional research is needed for quantitative analysis of the values gained from the most improved wetland function when mixed farming system is actually put into practice, and to utilize the results in advertising of the organic rice, and in various sectors such as food, education and direct payment policy.

• Korean Journal of Ichthyology
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• v.34 no.3
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• pp.160-171
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• 2022

This study investigated the characteristics of fish communities, habitat characteristics and the age of Lefua costata in the Jusucheon of Gangneung-si, Korea from January to December 2013. The survey collected 23 species belonging to ten families from 6 survey stations. The dominant and subdominant species were Zacco koreanus (relative abundance, 22.1%) and Rhynchocypris steindachneri (20.1%), respectively. The next most abundant species were Tridentiger brevispinis (10.7%), Orthrias nudus (9.7%), Zacco platypus (8.6%), Lefua costata (7.9%), Iksookimia koreensis (6.0%) and Pungitius sinensis (3.0%). Among the fish species collected, one species, P. sinensis, was class II endangered wildlife by the Ministry of Environment, and four species (Z. koreanus, I. koreensis, Silurus microdorsalis and Cottus koreanus), were endemic to Korea. Additionally, five migration fish species (Tribolodon hakonensis, Hypomesus nipponensis, Gasterosteus aculeatus, Oncorhynchus keta and Plecoglossus altivelis) were collected. The similarity index based on species composition and numbers separated fish communites in the Jusucheon according to main section, i.e., uppermost(St. 1), upper (St. 2~4), middle (St. 5), lower (St. 6). Ecosystem health of Jusucheon Stream (fish assessement index) evaluated using fish was assessed as very good (5 stations) and good (1 station). The main inhabit of L. costata was the middle-lower stream of aquatic plants habitats with mud bottoms, very slow water velocity and water depth 40~80 cm. The age groups for L. costata (female) estimated by the frequency distribution of total length in the spawning season (May) indicated that the 24~37 mm is 1-year old, the 38~51 mm group is 2-year old, the 52~63 mm is 3-year old, 64~77 mm is 4-year old and the 80~91 mm is more than 5-year old. Finally, characteristics of fish communities, habitat characteristics and the age of Lefua costata in the Jusucheon was discussed.

• Korean Journal of Environment and Ecology
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• v.18 no.1
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• pp.75-91
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• 2004

Biodiversity and seasonal community composition of benthic macroinvertebrates were studied from Upo wetlands in Gyeongsangnam-do, Korea, comprising Upo (4 sites), Mokpo (2 sites), Sajipo (1 site), Jjokjibeol (1 site), Yeobeol (1 site), and Topyeongcheon (2 sites) areas from October 2002 to August 2003. As a result, it was known that Upo wetlands retained relatively well-preserved littoral zones which may provide good habitats for benthic macroinvertebrates; however, frequent disturbances of littoral zones caused by flood were the major factor affecting on the survival and distribution of benthic macroinvertebrates in the areas. During the study period, a total of 135 species of benthic macroinvertebrates in 10 genera, 59 families, 16 orders, 7 classes, and 3 phyla were collected those of which are the highest degree of diversity of the taxa ever known in Korean wetlands: aquatic insects 103 spp. (Diptera 27 spp., Odonata 24 spp., Coleoptera 19 spp., Hemiptera 16 spp., Ephemeroptera 9 spp., Trichoptera 7 spp., and Collembola 1 sp.), Crustacea 2 spp., Mollusca 19 spp. (Gastropoda 12 spp. and Bivalvia 7 spp.), and Annelids 11 spp. (Oligocaeta 1 sp. and Hirudinea 10 spp.). Sajipo (St.G) and Jjokjibeol (St.H) areas yielded relatively larger numbers of species, 54 spp. and 53 spp., respectively, while more than 40 species occurred at most other sites. Based on quantitative sampling (0.5m${\times}$2m), aquatic insects (88.0％), particularly chironomids in Diptera (61.0％), occupied major proportion of the total individuals of benthic macroinvertebrates, while Mollusca (5.3％), Annelida (3.5％), and Crustacea (3.2％) occupied minor proportions. In standing water areas, diverse groups of benthic macroinvertebrates such as chironomids, demselflies, aquatic bugs, aquatic beetles, crustaceans, and gastropods were dominant in terms of individual number; in the running water areas, on the other hand, chironomids and baetid mayflies were dominant. However, gastropods, i.e. viviparids, were the dominant group of benthic macroinvertebrates in most study areas in terms of biomass. Dominance indices were 0.22-0.51 (mean$\pm$sd 0.42$\pm$0.09) in autumn, 0.31-0.96 (0.02$\pm$0.23) in winter, and 0.30-0.89 (0.57$\pm$0.18) in summer; diversity indices were 3.50-4.26 (3.80$\pm$0.24) in autumn,1.55-4.50 (3.10$\pm$1.01) in winter, and 1.35-3.77 (2.55$\pm$0.09) in summer. Highly movable or true aquatic benthic macroinvertebyates such as aquatic bugs, aquatic beetles, and gastropods recovered earlier after flood. In the study sites of Upo wetlands, Upo and Sajipo areas showed relatively higher values of average diversity index which may indicate a good habitat condition for benthic macroinvertebrates.

• Korean Journal of Environment and Ecology
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• v.11 no.1
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• pp.100-110
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• 1997

To clarify the structure and function of ecosystem and establish the method for the conservation of biodiversity and community analysis at Soksacheon and Gyebangcheon, the authors surveyed the aquatic environment and freshwater fish fauna at 13 stations from July, 1995 to June, 1996. Collected 1,908 individuals were belong to 20 Species, 4 Oredr, 1 Suborder, 6 family, 7 Subfamily. The detail results are as follows. 1. It was confirmed that most of the surveyed stations were mountain valley of river type Aa, Ab. River structures were mixed with pebble, sand, rock and water quality of Soksacheon were pH(7.41), [COND.(0.051), TURB.(10.00), DO(8.66), W.T.(15.4)] and Gyebangcheon were pH(7.44), [COND.(0.097), TURB.(21.59), DO(9.35), W.T.(15.4)]. 2. Among them, 18 species were primary freshwater fishes(99.98%) and 2 species of pheripheral freshwater fishes(0.02%). 12 species(60%) of them were endemic species of Korea and they were Moroco kumgangenesis, Microphysogovio longidorsalis, Cobitis rotundicaudata, Misgurnus anguillicaudatus, Coreoleucisus splendidus, Cobitis longicorpus, Oncorhynchus masou ishikawai, Brachymystax lenok, Hemibarbus longirostris, Silurus microdorsalis, Cobitis koreensis koreensis and Hemibarbus mylodon. 3. Dominant species were Moroco kumgangenesis(46.85%) and Zacco temmincki(27.35%).

• Korean Journal of Environment and Ecology
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• v.31 no.4
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• pp.365-380
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• 2017

Rapid changes in the flora of exotic species are ecological problems that cause the alteration of national and regional biota. The purpose of this study is to identify the reality of neophyte flora currently inhabiting in Korea. Having analyzed a total of 151 studies published up until 2016, we found the qualitative and quantitative gaps among the preceding studies due to the lack of rigorousness on the application of the spatial and temporal level of exotic species and academic terminology. In this study, the neophyte is defined as the flora introduced temporarily after the Enlightenment in Korea (late 19th century) and spatially in the Eastern Asiatic Province of the Takhtajan's floral region instead of a country boundary. A total of 326 taxa of 184 genera of 39 families were identified and analyzed for their distributional origin and habitat characteristics. Approximately 87% (285 taxa) was a component of the single-layered herb vegetation, and a total of 211 taxa originated from Europe and North America which are the same temperate biome as Korea. The wetland vegetation components were much fewer with 21 taxa, but they included a large number of invasive alien species that caused critical deterioration in the habitat structure and function of aquatic ecosystems. Ecological approaches to exotic species categories such as Ephemerophyten and Apophyten have emerged.

• Journal of Korean Society of Forest Science
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• v.103 no.3
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• pp.313-320
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• 2014

The purpose of this study was to provide basic data for preserving forest ecosystem with understanding forest wetland condition of Mt. Cheongok. It was found from this research that vascular plants of surveyed area were composed of 72 families, 167 genera, 209 species, and 2 subspecies, 27 varieties, 5 formae. totaling 243 taxa. Among the investigated vascular plants, Korea endemic plants were 9 species, rare plants 15 species, and naturalized plants 8 species, respectively. According to the occurrence frequency within the wetland investigated, obligate upland plants (OBU) accounted for 75.72% (184) among the total species investigated, wherea obligate wetland plant (OBW) were four species (4.65%). There were 26 of hygrophyte plants and 2 of emergent plants in the research area according to wet degree. According to habitat category, the most frequently occurred habitat was forest (136 species, 55.97%), and the others were in the order of meadow and shrubland (70 species, 28.81%), wet meadow (35 species, 14.40%), and aquatic environment (2 species, 0.82%), respectively. In the result of analysis of important value, Fraxinus rhynchophylla and Carex pseudosinensis was the highest as 22.17% and 10.40%. It was confirmed that the species diversity was relatively high. Shannon-Wiener's species diversity index was calculated as 2.507. Based on these results, long-term monitoring survey should be urgently needed for ecological restoration and recovery.

• Journal of Wetlands Research
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• v.18 no.2
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• pp.173-182
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• 2016

Although the ecosystem extends numerous functions for the benefit of humankind, construction of horticultural facilities can potentially lead to the degeneration of some of these functions owing to the expansion of impervious regions and loss of habitats. Thus, this study aimed to examine the effect of construction of horticultural facilities on plant biodiversity. Analysis of the vegetation distribution characteristics showed that horticultural facilities had significantly lower plant diversity than did rice paddies. Hence, the proposed approach involved low-impact development, arrangement of habitat space, plant preservation, restricted use of chemical fertilizer, habitat creation, and reduced preservation cost. Lifestyle analysis suggested the importance of developing favorable environments for the growth of annual plants and aquatic plants. In all, 20 species of naturalized plants belonging to 10 families were identified. Furthermore, the proportion of these naturalized plants was higher in glass greenhouses and multi-span greenhouses, suggesting the advantages of employing natural soil mulching while avoiding concrete mulching. Statistical analysis was performed to validate the results, which suggested that impervious regions be converted to natural soils. Collectively, the findings of this study are expected to be used for establishing policies for the construction of eco-friendly and ecological horticultural facilities; this may aid the maintenance of sustainable agricultural landscapes and large-scale development of the reclaimed lands.

• Journal of the Korean Institute of Landscape Architecture
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• v.42 no.3
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• pp.35-49
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• 2014

In this study, the faunae before and after creating the Solbangjuk Wetland Ecological Park located in Jecheon-city were compared. As a result, the change of the fauna according to the creation of the park showed the phenomenon that the species having the strong wilderness are reduced and the rate of general species become higher. In addition, the species which receive the restrictions for moving such as mammals, amphibians and reptiles are being gradually decreased by the increased visitors owing to the creation of the park. Moreover because there was the case where group of fishes have died caused by discharging and working the water in the reservoir during the creation process of the park, the supplementation work for this is required. However, it showed that the insects sucking the honey from flowers in the composed flower garden after creating the park, and the aquatic insects which live in this park that the stable water system for the growth of wetland plants is maintained, are increased, respectively. As a result of this survey, because the reservoir for agriculture adjacent to the residential area is generally small, the securing of the habitat space for the wild animals living in this park when creating the ecological parks seems to be necessary. The countermeasure should be considered so that some areas of the reservoir can be maintained in their natural state by adjusting the visitors' trails and the position of facilities for in order to secure the habitat of the wild animals.