• Korean Journal of Environmental Biology
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• v.40 no.3
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• pp.325-334
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• 2022

Paspalum distichum and P. distichum var. indutum are perennial weeds of the family Poaceae that prefer moist environments such as waterfronts and waterways. The origin of both species is North America. P. distichum is distributed all over the world. However, P. distichum var. indutum occurs only in the United States, Japan, and Korea. For this reason, in many countries, P. distichum and P. distichum var. indutum are classified as the same species. In other words, P. distichum var. indutum is a different ecological type of P. distichum. Both species can reproduce and spread mainly by rhizome fragments rather than seeds. This rhizome has a characteristic that it does not germinate if it is buried in the ground with depth of more than 3 cm. As a management method for P. distichum and P. distichum var. indutum in agricultural lands (paddy fields), it is effective to combine cultural control and chemical control methods. In other words, combining deep plowing and harrowing can suppress the budding of water sparrow that has invaded paddy fields or fallow paddy fields. After that, these two species that germinate can be controlled by spraying soil treatment herbicides such as butachlor and thiobencarb or foliar treatment herbicides such as cyhalofop-butyl and fenoxaprop-p-ethyl.

• Ecology and Resilient Infrastructure
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• v.2 no.3
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• pp.206-215
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• 2015

Predicting the changes in the potential distribution of invasive alien plants under climate change is an important and challenging task for the conservation of biodiversity and management of the ecosystems in streams and reservoirs. This study explored the effects of climate change on the potential future distribution of Paspalum distichum var. indutum in the Korean Peninsula. P. distichum var. indutum is an invasive grass species that has a profound economic and environmental impact in the waterfronts of freshwater ecosystems. The Maxent model was used to estimate the potential distribution of P. distichum var. indutum under current and future climates. A total of nineteen climatic variables of Worldclim 1.4 were used as current climatic data and future climatic data predicted by HadGEM2-AO with both RCP 2.6 and RCP 8.5 scenarios for 2050. The predicted current distribution of P. distichum var. indutum was almost matched with actual positioning data. Major environmental variables contributing to the potential distribution were precipitation of the warmest quarter, annual mean temperature and mean temperature of the coldest quarter. Our prediction results for 2050 showed an overall reduction in climatic suitability for P. distichum var. indutum in the current distribution area and its expansion to further inland and in a northerly direction. The predictive model used in this study appeared to be powerful for understanding the potential distribution, exploring the effects of climate change on the habitat changes and providing the effective management of the risk of biological invasion by alien plants.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.8 no.4
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• pp.52-67
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• 2005

The flora of the studied basin in the upper Keum River was listed as 237taxa; 63families, 162genera, 212species, 22varieties and 3forms. Based on the list of the ecosystem disturbance plants by the Ministry of Environment, 4taxa were recorded in the studied basin : Paspalum distichum(Gramineae), Paspalum distichum var. indutum(Gramineae), Ambrosia artemisiifolia var. elatior(Compositae), Ambrosia trifida(Compositae). Naturalized plants was listed as 54taxa; 16families, 41genera, 51species, 3varieties and naturalization index was 22.8percent of 1/4 the vascular plants. Upper Keum River was dominant floristic : indicator species were Salix gracilistyla community, Phragmites japonica community, native plants were Morus alba community, Spiraea prunifolia for. simpliciflora community, planting plants were Populus euramericana community, naturalized plants were Solidago serotina community, Helianthus tuberosus community.

• Ecology and Resilient Infrastructure
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• v.3 no.3
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• pp.189-200
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• 2016

The species distribution model would be a useful tool for understanding how invasive alien species spread over the country and what environmental variables contribute to their distributions. This study is focused on the potential distribution of two invasive alien species, the common ragweed (Ambrosia artemisiifolia) and knotgrass (Paspalum distichum) in the Korean Peninsula. The maximum entropy (Maxent) model was used for the prediction of their distribution by inferring their climatic environmental requirements from localities where they are currently known to occur. We obtained their presence data from the Global Biodiversity Information Facility and the Korean plant species databases and bioclimatic data from the WorldClim dataset. As a results of the modelling, the potential distribution predicted by global occurrence data was more accurate than that by native occurrence data. The variables determining the common ragweed distribution were precipitation of the driest month and annual mean temperature. Both annual and the coldest quarter mean temperatures were critical factors in determining the knotgrass distribution. The Maxent model could be a useful tool for the prediction of alien species invasion and the management of their expansion.

• Ecology and Resilient Infrastructure
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• v.2 no.3
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• pp.255-263
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• 2015

Biological invasion of alien plants is considered to be one of the most serious threats to biodiversity in riparian zones. The effects of two invasive alien plants, Sicyos angulatus and Paspalum distichum var. indutum, on the flora and community structure of the riparian vegetation were investigated at 22 sites at streams in Korea. Sicyos angulatus has invaded the central Korean Peninsula. This alien plant has caused problems to stream managers because of its aggressive vining growth. It had suppressed native vegetation such as trees, shrubs and tall grasses on bank slope and higher floodplains. Paspalum distichum var. indutum has become more widespread in the southern part of Korea. This invasive plant has shallow rhizomes and creeping, extensively branched stolons. It forms a dense mat over lotic or slowly-flowing water and threatens submerged and short emergent hydrophytes. In order to control the introduction and expansion of alien plants, limitation of artificial disturbances and appropriate alien plant management are needed in riparian areas.

• Korean Journal of Environmental Agriculture
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• v.26 no.1
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• pp.25-35
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• 2007

Excess runoff contaminated with N and P can impact the quality of downstream water. It has been known that aquatic plants improve the water quality through their intake of organic or inorganic nutrients. This study was conducted to select aquatic plants having high purification ability for nutrient N and P, and mineral nutrients related to EC such as K, Ca, Na, Cl, and $SO_4$ in raw sewage water in greenhouse. We assessed nutrient phytoremediation potential of alien hydrophyte and hydro-crop as well as native landscape hydrophyte to select suitable aquatic plant applied to artificial wetland and buffering site of stream-side. The amount of irrigation water during whole growing period of aquatic plane ranged from 225 L $m^{-2}$ to 444 L $m^{-2}$. Oryza sativa, Typha orientalis, Zizania latifolia, Aster subulatus, Coix lachryma-jobi var. mayuen, Paspalum disdichum var. indutum which had high biomass consumed the large amount of irrigation water over 350 L $m^{-2}$. As a result of analysis of water purification effect N and P content of shoot biomass, and media soil after experiment, Oryza sativa, Zizania latifolia, Aster subulatus, Coix lachryma-jobi var. mayuen, Paspalum distichum var. indutum showed high purification ability about eutrophication elements such as T-N and T-P. It is presented that Pistia stratiotes, Eichhornia crassipes, and Paspalum distichum var. indutum had excellent purification ability about K, Ca, Na, and Cl. Moreover, Paspalum distichum var. indutum greatly removed $SO_4$ in row sewage water.

• Korean Journal of Ecology and Environment
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• v.50 no.2
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• pp.195-206
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• 2017

We described a spatial distribution pattern and floral diversity on the Paspalum distichum community occurring at the ecological parks of Hwamyeong, Daejeo, Samnak, and Maekdo in the Nakdong river estuary. A total distribution area of P. distichum community was $303,462.6m^2$. Its largest area was found in Samnak eco-park ($185,910.1m^2$). The most richness of knotgrass patches in each ecological park was determined Maekdo eco-park (87). Cover class level-5 shows the largest area ($260,663.2m^2$). A total of 73 taxa (34 families, 55 genus, 65 species, and 8 varieties) were listed up on the P. distichum community. A welldeveloped population of knotgrass was found predominantly at sites linked into human impacts at the riverine floodplain, the stream courses flowing through the parks, and the man-made channels and wetlands. Finally we proposed an ecological management strategy for knotgrass population in the study area.

• Journal of Ecology and Environment
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• v.41 no.6
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• pp.173-181
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• 2017

Background: This study was undertaken to analyze the distribution and ecological characteristics of invasive alien plant species on Jeju Island, and to provide basic data for their management and control. Results: A field research was conducted at 436 locations on Jeju Island. The field research identified nine species of invasive alien species growing on Jeju Island. Based on the distribution pattern, Hypochaeris radicata L., Rumex acetosella, and Ambrosia artemisiifolia L. were found to be distributed horizontally throughout Jeju Island, with vertical growth in two or more vegetation zones, from warm temperate to the subalpine zone. Widely distributed species penetrate various habitats, such as grasslands, ranches, roadsides, farmlands, and empty lots, and have an immensely negative impact on the ecosystem, including declining biodiversity on Jeju Island. Paspalum distichum var. indutum Shinners, Paspalum distichum L., Solanum carolinense L., and Aster pilosus Willd. were distributed in some areas as a biased distribution species, whereas Lactuca scariola L. and Solidago altissima L. were found only in certain areas as centralized distribution species. Conclusions: The centralized distribution species and biased distribution species of the invasive plants in the ecosystem of Jeju Island should be physically eliminated, keeping in mind the short- and mid-term perspectives and monitoring, and by considering expansion of additional distribution areas. Due to limitations of physical/chemical elimination, time, and cost, widely distributed species require to be eliminated and managed, mainly to restore the integrity of the ecosystem, by planting native species to reestablish the habitat.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.14 no.2
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• pp.59-81
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• 2011

The flora of the Sinpyeong and Churyeong stream were listed 324 taxa; 87 families, 227 genera, 289 species, 1 subspecies, 31 varieties and 3 forms. The Sinpyeong stream were 249 taxa and Churyeong stream were 221 taxa. Based on the rare plants (IUCN) by the Korea Forest Service and Korea National Arboretum were recorded; Penthorum chinense (Crassulaceae), etc. and endemic plants, 6 taxa; Weigela subsessilis (Caprifoliaceae), Lycoris flavescens (Amarylidaceae), etc. Based on the specific plants by floral region were total 12 taxa (3.7% of all 324 taxa of flora); Monochoria korsakowi (Pontederiaceae), etc. in class III. 10 taxa (Salix glandulosa (Salicaceae), Ulmus parvifolia (Ulmaceae), Impatiens noli-tangere (Balsaminaceae), Grewia biloba var. parviflora (Tiliaceae), Nymphoides peltata (Gentianaceae), Actinostemma lobatum (Cucurbitaceae), Cirsium pendulum (Compositae), Microstegium japonicum (Gramineae), etc.) in class I. Based on the naturalized plants, 51 taxa and ecosystem disturbing wild plants, 6 taxa (Rumex acetosella, Sicyos angulatus, Aster pilosus, Ambrosia artemisiaefolia, Hypochaeris radicata, Paspalum distichum var. distichum) and naturalization rate was 15.7% of all 324 taxa of flora, urbanization index was 18.8% of all 271 taxa of naturalized plants. Based on the hydrophytes, 23 taxa and emergent hydrophytes were 17 taxa, floating-leaved hydrophytes were 3 taxa, submergent hydrophytes were 2 taxa, free-floating hydrophytes was Spirodela polyrhiza.

• Journal of Environmental Science International
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• v.27 no.11
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• pp.1105-1115
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• 2018

The aim of this study was to collect crucial data for the improvement of water quality and ecosystem conservation by analyzing water samples, sediments, benthic macroinvertebrates, and fish in the Seosan reservoir. The average values of water quality parameters from 2001 to 2016 were a chemical oxygen demand of 10 mg/L, total nitrogen of 1.22 mg/L, and total phosphorus of 0.074 mg/L. Cadmium was detected in the range of 0.531-0.748 mg/kg in the reservoir sediment. Fish belonging to 6 families and 9 species were identified in the reservoir. The dominant species were Carassius auratus and Micropterus salmoides. Benthic macroinvertebrates belonging to 22 families and 28 species were identified. The ecological score of the benthic macroinvertebrate community was 15 inside the reservoir (St. 2). Micropterus salmoides, an invasive alien species, was determined to be the subdominant fish species based on the number of captures, and the presence of the invasive species, Sicyos angulatus L. and Paspalum distichum L. was confirmed among the land flora.