• Fisheries and Aquatic Sciences
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• v.24 no.12
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• pp.415-427
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• 2021

Wetland ecosystems act as natural freshwater purification systems, but their rich biodiversity is being threatened with the introduction of the non-native freshwater snail, Pomacea canaliculata. This study was conducted to measure the herbivory effects and growth rate of P. canaliculata on common macrophytes: Ipomoea aquatica, Ipomoea batatas, Pandanus amaryllifolius and Cucurma longa. In separate experiments, the macrophyte species were served as the snails' food as individual species and simultaneously. In the individual treatment, the growth pattern and rate were based on the snails' weight (mg/snail/day; n = 9) while the individual feeding consumption (mg/snail/day) was calculated from the leftover food. In the simultaneous treatment, the herbivory effects were evaluated as the feeding preference (%) from observations every two hours, while the total feeding consumption (mg) was calculated based on the food remaining after a 12-hour experiment (3 replicates: total n = 27). The results indicated that the growth pattern was significant for snails grazing on I. aquatica but not when other macrophyte species were eaten. The individual feeding consumption was higher when using I. aquatica than P. amaryllifolius but the growth rate for snails grazing on I. aquatica and P. amaryllifolius did not differ significantly. Meanwhile, the consumption of C. longa deterred the snails' growth rate. Although the snails consumed all the macrophytes in the individual experiment, when given the species simultaneously, the feeding preference and total feeding consumption were directed significantly more toward I. aquatica than P. amaryfollius and C. longa. We conclude that P. canaliculata is a generalist feeder given a limited choice of food but tends to show a strong feeding preference after being introduced to more food choices. These findings indicate that the introduction of P. canaliculata into wetland ecosystems may increase the herbivory effects on macrophytes, making these ecosystems vulnerable to the impact of eutrophication and biodiversity reduction.

• Korean Journal of Ecology and Environment
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• v.55 no.4
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• pp.259-273
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• 2022

Interactions between species in a community are very complex, and they are visualized and analyzed through a food web in simple way. Food web is a network of species connected by trophic links showing energy flow from prey to predator. Various models were developed to characterize the food web in ecosystems. In this study, we classified food web models to static models such as Ecopath and dynamic models such as AQUATOX. We presented characteristics of several different types of food web models in each category, and reviewed their applications used in aquatic ecosystems. Finally, we presented issues to be considered to develop food web models.

• The Korean Journal of Ecology
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• v.23 no.2
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• pp.135-140
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• 2000

The Government of Mongolia approved establishment of the Mongolian LTER network in December 1997. In June 1998, a seminar was organized by the Mongolian Academy of Sciences to initiate the program. Dr. James Gosz of the US LTER program keynoted the seminar. A Mongolian LTER Steering Committee was established to organize the network and to develop guidelines for its management. This Committee designated Hovsgol National Park in northern Mongolia as the first Mongolian LTER network site. Other potential sites are presently being considered. including study sites in steppe grassland and desert locations. The primary goals of the Mongolian LTER Network are to study human impacts on Mongolia's environment; with a focus on short-term impacts of nomadic grazing on terrestrial and aquatic ecosystems and long-term climate change impacts on more pristine environments in the protected areas. There are at least two additional goals: to provide information and advice on how best to protect Mongolia's pristine environments, and to train Mongolian students to work on environmental problems to encourage the growth of expertise for making sound environmental decisions.

• Journal of Forest and Environmental Science
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• v.25 no.1
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• pp.49-55
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• 2009

The present study analyses the effect of land use on the vegetation of some desert ecosystems in Abu Dhabi, United Arab Emirates (UAE). Three sites were selected to represent different types of land use, inside Umm Al-Banadeq forest, outside the forest and along Abu Dhabi-Al Ain Trucks Road. In total, fifty-two stands were examined; including a matrix of 14 species ${\times}$ 52 stands. Based on species cover data, stands were classified using TWINSPAN and ordinated using DCA. Four vegetation groups were generated at level three of classification. Zygophyllum mandavillei was dominant in most vegetation groups; Heliotropium bacciferum dominated vegetation groups inhabited the forest. Species richness, species turnover, relative evenness and relative concentration of dominance of forest vegetation groups were 2.8, 5.7, 0.7, and 2.0, respectively. The differences were attributed to both natural variability and forestry-induced changes, including change in land use, drainage and ploughing and shading by trees. Vegetation group inhabited Abu Dhabi-Al Ain Trucks Road, that were dominated by Haloxylon salicornicum and Zygophyllum mandavillei have high total cover (8.8 m per $m^{-1}$). Most community and vegetation attributes were significantly higher inside the forest than outside. Human interventions and environmental factors affected species diversity and abundance of these communities.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.198-203
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• 2003

The effects of salmon carcasses on forest and stream ecosystems were determined by nitrogen stable isotope analysis in natural streams in Hokkaido, Northern Japan, where numerous chum salmon (Oncoryhncus keta) were migrated upstream ITom ocean to spawn in autumn. The leaves and soils surrounding riparian forest and stream dwelling invertebrates were collected before and after migration. The nitrogen stable isotope ratio $({\delta}^{15}N)$ of riparian vegetation (Salix spp.) were different depending on the presence of salmon and distance from the stream. The $({\delta}^{15}N)$ of stream dwelling invertebrates were different between salmon present and absent stream. This difference was tested using the experiment channel by implanting salmon carcasses. The nitrogen stable isotope ratio of epilithic algae and leaf shredding animals were nearly 3 higher in the salmon implanted treatment suggesting that around 20％ of salmon derived nitrogen was uptake either in algae and leaf shredding invertebrates. These results suggest that the salmon carcasses effects not only on stream primary production but also on primary consumers, which decompose leaves fertilized with nitrogen from carcasses.

• Korean Journal of Ecology and Environment
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• v.43 no.4
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• pp.453-458
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• 2010

DOC (Dissolved Organic Carbon) is an operational terminology for organic carbon molecules dissolved in natural waters. DOC has been studied by ecologists extensively, because it plays a key role in various ecological functions such as substrates for secondary production and the carbon cycle. DOC also represents a substrate for microbial growth within potable water distribution systems, and can react with disinfectants (e.g., chloride) to form harmful disinfection by-products. In addition, residual DOC may carry with it organically bound toxic heavy metals. DOC in aquatic ecosystems may ultimately be transported to the oceans, or released back to the atmosphere by heterotrophic respiration, which can accelerate global climate change. There is evidence that DOC concentrations in aquatic ecosystems are increasing in many regions of the world including Europe, North America, and even in Korea. Land use changes, elevated temperature, elevated $CO_2$, recovery from acidification, and nitrogen deposition have been proposed as mechanisms for the trend. However, the key driving mechanism is yet to be conclusively determined. We propose that more extensive and longer-term observations, research of chemical properties of DOC, impacts of elevated DOC on environmental issues and interdisciplinary approaches are warranted as future studies to fill the gaps in our knowledge about DOC dynamics.

• Mycobiology
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• v.41 no.3
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• pp.121-125
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• 2013

Arbuscular mycorrhizal fungi (AMF) have mutualistic relationships with more than 80% of terrestrial plant species. This symbiotic relationship is ancient and would have had important roles in establishment of plants on land. Despite their abundance and wide range of relationship with plant species, AMF have shown low species diversity. However, molecular studies have suggested that diversity of these fungi may be much higher, and genetic variation of AMF is very high within a species and even within a single spore. Despite low diversity and lack of host specificity, various functions have been associated with plant growth responses to arbuscular mycorrhizal fungal colonization. In addition, different community composition of AMF affects plants differently, and plays a potential role in ecosystem variability and productivity. AMF have high functional diversity because different combinations of host plants and AMF have different effects on the various aspects of symbiosis. Consequently, recent studies have focused on the different functions of AMF according to their genetic resource and their roles in ecosystem functioning. This review summarizes taxonomic, genetic, and functional diversities of AMF and their roles in natural ecosystems.

• Journal of Ecology and Environment
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• v.45 no.4
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• pp.228-236
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• 2021

Background: A review of the literature was carried out to study dust and sandstorm (DSS) in terms of its ecosystem processes and relationship to other dryland disasters in Northeast Asia. Drylands are ecosystems that include grasslands, semi-deserts, and deserts, and these types of ecosystems are vulnerable due to their low primary productivity that depends on a small amount of precipitation. Results: Drought, dust, desertification, and winter livestock disasters (called dzud) are unique natural disasters that affect the region. These disasters are related in that they share major causes, such as dryness and low vegetation cover that combine with other conditions, wind, cold waves, livestock, and land-surface energy, to dramatically impact the ecosystem. Conclusions: The literature review in this study illustrates the macroscopic context of the spatial and temporal patterns of DSS according to geography, climate, and vegetation growth in the drylands of Northeast Asia. The effects of ocean climates and human activities were discussed to infer a possible teleconnection effect of DSS and its relations to desertification and dzud.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.27 no.2
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• pp.29-42
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• 2024

As a global response to climate and biodiversity challenges, there is an emphasis on the conservation and restoration of ecosystems that can simultaneously reduce carbon emissions and enhance biodiversity. This study comprised a text analysis and keyword extraction of 1,100 research papers addressing nature restoration in Korea, aiming to provide a quantative and systematic evaluation of domestic research trends in this field. To discern the major research topics of these papers, topic modeling was applied and correlations were established through network analysis. Research on nature restoration exhibited a mainly upward trend in 2002-2022 but with a slight recent decline. The most common keywords were "species," "forest," and "water". Research topics were broadly classified into (1) predictions of habitat size and species distribution, (2) the conservation and utilization of natural resources in urban areas, (3) ecosystems and landscape managements in protected areas, (4) the planting and growth of vegetation, and (5) habitat formation methods. The number of studies on nature restoration are increasing across various domains in Korea, with each domain experiencing professional development.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.20 no.4
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• pp.15-28
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• 2017

A protected area means a space designated and protected by law from development pressure and environmental pressure. It is mainly designated to protect specific ecosystems, natural landscapes, and cultural resources from irrational development (or damage), and involves policies of the public sector such as central and local governments. The United Nations Educational, Scientific and Cultural Organization (UNESCO) has conducted conservation and restoration projects for preserving natural ecosystems and genetic resources. In order to conserve the ecosystem in the protected area, national and public organizations purchase private land and use it ecologically; in addition, ecological restoration project is carried out for the purpose of creating waterside ecological belt or preserving ecosystem. Land acquisition refers to the land where highly influenced by the water quality and need to restore, and purchased by negotiating with the landlord. Although the nation and public institution carried out ecosystem restoration project for partial purchase land in order to conserve ecosystem, it is below the expected effect due to lack of comprehensive management system and have some problems in restoration project and unification of management institutions. Land acquisition in Donggang River Basin Ecological Conservation area is initiated in 2005 for creating income of local residents and ecological restoration. However, the lack of overall management and awareness resulted in poor vegetation growth and poor response by local residents due to terrain exposure. As such, there is insufficient research on the current situation and systematic integrated management although the number of land acquisition is increasing year after year. Futhermore, overall recognition and follow-up monitoring of eco-restoration are still inadequate. Therefore, the survey on the awareness of the purchase land ecosystem restoration project is necessary for the efficient restoration project and establishment of the management strategy for land acquisition in the future. Therefore, in this study, we provide fundamental materials on further research projects by carrying out research on the awareness of ecological restoration projects in the Donggang River basin ecological preservation area.