• Korean Journal of Environment and Ecology
• /
• v.37 no.2
• /
• pp.163-178
• /
• 2023

This study was conducted to understand the vegetation characteristics of Cheongwansan Provincial Park through the analysis of the plant community structure and to build data necessary for the continuous management and protection of Cheongwansan Provincial Park. The TWINSPAN and DCS analyses of the plant community structure of 63 survey districts in Cheongwansan Provincial Park identified eight colonies, including Cryptomeria japonica Community (I), Chamaecyparis obtusa-Pinus densiflora Commuity (II), P. rigida-P. densiflora Community (III), mixed coniferous and broad-leaved Community (IV), P. densiflora Community (V), deciduous broad-leaved such as Quercus spp. Community (VI), Q. mongolica-P. densiflora Community (VII) and P. thunbergii Community (VIII). The colonies can be grouped into afforestation communities (I, II, and III) dominated by C. obtusa, C. japonica, and P. rigida and natural forest communities (IV, V, VI, VII, and VIII) dominated by native species. Although Cheongwansan Provincial Park is a provincial park area that can represent natural ecosystems and landscapes, the rate of artificial forests is higher than that of other provincial parks. Most of the artificial forest communities are expected to maintain their current state, but since native species such as Machilus thunbergii, Neolitsea sericea, and deciduous broad-leaved, which are warm-temperate trees introduced through surrounding natural forests, appear in the lower layer, it is determined that it is possible to induce succession to natural forests suitable for climatic characteristics through management, and monitoring for continuous management is also necessary. Deciduous broad-leaved such as Quercus spp. Copete with P. densiflora in most natural forest communities. The vegetation series in the warm-temperate region of Korea appears to be in the early stages, and it is believed that the succession to Q. serrata or Q. mongolica, which appears next to coniferous in the series, is in progress. However, M. thunbergii and N. sericea, which appear in the middle stage of the succession in the warm-temperate region, have started to appear, and since Jangheung-gun belongs to the warm-temperate region considering the climate characteristics, the eventual succession to the warm-temperate forests dominated by evergreen broad-leaved is also expected. In this study, we built vegetation data from Cheongwansan Provincial Park, which lacks research on vegetation. However, since vegetation research in Cheongwansan Provincial Park is still insufficient, it is believed that further research should be continuously conducted to establish forest vegetation data and observe vegetation changes.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.34 no.1
• /
• pp.83-96
• /
• 2016

Through the research and analysis on the vegetation environment, flora of habitats through documentary and field studies over 14 habitats of Euryale ferox Salisbury within Jeollabukdo, with the objective of acquiring the basic data for forming an environment based on plantation of reservoirs that are composed with Euryale ferox, the following results were obtained. 1. The entire flora of the 14 habitats appeared to be 79 families, 211 genus, 298 species, two subspecies, 30 varieties and six forma, thus, a total of 336 taxa was confirmed. Among these, emergent water plants appeared to compose 17 taxa, floating-leaved plants to compose seven taxa including Euryale ferox floating plants to compose five taxa and submerged water plants to compose two taxa. As a result of analyzing the similarity only over the water plants. The lowest similarity rate appeared between Gamdong Reservoir and Aedang Reservoir, as the similarity rate between the two regions appeared to be 0% as a result of the analysis. Floating-leaved plants, lotuses and caltrops, appeared to be equally inhabiting in Hanseongji at Jeongeup and Seoknam Reservoir at Gochang, which showed the highest similarity rate, in addition to Euryale ferox. 2. When examining the appearance frequency of aquatic plants per growth type, Actinostemma lobatum and Phragmites communis, in addition to Euryale ferox each appeared 11 times, showing a high frequency of 78.6% and Trapa japonica, which is a floating-leaved water plant, appeared ten times(71.4%) and Zizania latifolia appeared eight times(57.1%). In addition, the appearance rate appeared to be high in the order of Persicaria thunbergii, Leersia sayanuka, Ceratophyllum demersum, Echinochloa crusgalli var. oryzicola, Scirpus maritimus, and Nelumbo nucifera. 3. The rare plants discovered in the Euryale ferox habitats pursuant to the IUCN evaluation standards was confirmed to be composed of five taxa, with three taxa including the least concerned species(LC), Melothria japonica at Yanggok Reservoir, Hydrocharis dubia at Myeongdeokji and Ottelia alismoides at Daewi Reservoir, in addition to vulnerable species(VU), Utricularia vulgaris at Sangpyeong Reservoir, along with Euryale ferox. 4. Most of the group or community types of the natural habitats of Euryale ferox appeared to be the Euryale ferix community' and the Daewi Reservoir of Gunsan was defined as caltrop + Euryale ferox + Nymphoides indica community. The green coverage ratio of Euryale ferox per natural habitats showed a considerably huge deviation from 0.03 to 36.50 and as the average green coverage ratio was appropriated as 9.8, it can be considered that maintaining the green coverage ratio of Euryale ferox in a 10% level would be advisable when forming a reservoir with Euryale ferox as the key composition species. 5. The vegetation community nearby the natural habitats of Euryale ferox per research subject area appeared to be composed of three Leersia japonica communities, two communities each for Zizania latifolia community and Trapa japonica community and one community each for Nelumbo nucifera community, Nymphoides peltata + Typha orientalis community, Trapa japonica + Nelumbo nucifera community, Hydrocharis dubia community, Leersia japnica + Paspalum distichum var. indutum community and Euryale ferox + Trapa japonica community, showing a slight difference depending on the location conditions of each reservoir. Thus, this result may be suggested as a guideline to apply when allocating the vegetation ratio and the types of floating-leaved plants upon planting plants in reservoirs with Euryale ferox as the main companion species.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.32 no.2
• /
• pp.68-81
• /
• 2014

This study was conducted to identify the spacialty, to illuminate the existence and values of Myeongwoldae(明月臺) and Forest Myeongwol, and to suggest the sustainable usage, preservation and management plans with the purpose of ecological and cultural landscaping characteristic and value identification. The result of the study is as follows. Castle Myeongwol and Port Myeongwol shows the status of Hallim-eup Myeongwol District which is the administrative center of western Jeju as well as is the fortress. Building Wolgyejeongsa and School Woohakdang, the head temple of education and culture, located in Myeongwol District represents the spaciality of Myeonwol-ri which was the center of education. Stand Myeongwol is one of the most representative Confucian cultural landscapes in Jeju Island and the field of communion with nature where scholars enjoy poetries, nature, changgi(Korean chess), and go in the Joseon Dynasty period. It was found that the current relics of Myeongwoldae was recovered through the maintenance project conducted by Youth Group Myeongwol composed with Hongjong-si(洪鍾時) as the center during the Japanese colonial era in 1931. It seems that the stonework of Myeongwoldae composed of three levels in the order of square, octagon, and circle based on the heaven-man unity theory of Confucianism and the octagon in the middle is the messenger of Cheonwonjibang(天圓地方), in other words, between the square-shaped earth and the circle-shaped sky. It is assumed that both Grand Bridge Myeongwol and Bridge Myeongwol were constructed as arched bridges in early days. Bridge Myeongwol is the only arched bridge remaining in Jeju Island now, which has the modern cultural heritage value. In Forest Myeongwol, 97 taxa of plants were confirmed and in accordance with 'Taxonomic Group and Class Criteria of Floristic Specific Plants', eight taxa were found; Arachniodes aristata of FD IV and Ilex cornuta, Piper kadsura, Litsea japonica, Melia azedarach, Xylosma congestum, Richosanthes kirilowii var. japonica, Dichondra repens, Viburnum odoratissimum var. awabuki of FD III. Otherwise, 14 taxa of naturalized plants including Apium leptophylihum which is imported to Jeju Island only were confirmed. In Forest Myeongwol, 77 trees including 41 Celtis sinensis, 30 Aphananthe aspera, two Wylosma congestum, a Pinus densiflora, a Camellia japonica, a Melia azedarach, and an Ilex cornuta form a colony. Based on the researched data, the preservation and plans of Myeongwoldae and Forest Myeongwol is suggested as follows. Myeongwoldae, Bridge Myeongwol, and Forest Myeongwol should be managed as one integrated division. Bridge Myeongwol, an arched bridge which is hard to be found in Jeju Island is a high-standard stonework requiring long-term preservation plans. Otherwise, Grand Bridge Myeongwol that is exposed to accident risks because of deterioration and needs safety diagnosis requires measures according to the result of precise safety diagnosis. It is desirable to restore it to a two-sluice arched bridge as its initial shape and to preserve and use it as a representative local landmark with Stand Myeongwol. In addition, considering the topophsis based on the analysis result, the current name of Jeju Special Self-Governing Province Monument No. 19 'Myoengwol Hackberry Colony' should change to 'Myeongwol Hackberry-Muku Tree Colony'. In addition, the serial number system which is composed without distinction of hackberry and muku tree should be improved and the regular monitoring of big and old trees, specific plants, and naturalized species is required.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.40 no.4
• /
• pp.1-17
• /
• 2012

This study was carried out to propose the improved method by analyzing the change of green space arrangement and planting structure of apartment complexes in Seoul. 12 survey sites, which have obvious differences, were selected by reflecting the change of floor area ratio, underground parking place, and green space ratio. We divided the survey sites into four types that high green ratio(over 40%) apartment on natural ground, low green ratio(under 40%) apartment on natural ground, low green ratio(under 40%) apartment on artificial ground, and high green ratio(over 40%) apartment on artificial ground each period based on green space ratio and ground structure, plant crown volume, planting density, and planting pattern. The main factors of change of green space arrangement were green space ratio and ground structure. The Green space ratio was changed by the floor area ratio with constructing underground parking place and floor area ratio was adjusted by government policy and economic status. Average width of front green area has been changed from 10.0m in high green ratio apartment on natural ground for 3.5m, 2.7m, and 4.5m each period. The average width of the buffer green area has been changed from 15.0m in high green ratio apartment on natural ground of 7.7m, and 2.7m by extending parking place in the low green ratio apartment of artificial ground, so buffer green areas have been reduced and disconnected. So buffer green area in apartment complexes has been extended that the average width of the buffer green area was 3.8m caused by growing recognition of green since 2001. The ratio of native plant in canopy layer was increased from 45.1 % in the case of the high green ratio apartment of natural ground in 1980~1983 to 55.6%. Average plant crown volume increased from $1.27m^3/m^2$ in high green ratio apartment on natural ground for $3.47m^3/m^2$ in a low green ratio apartment on natural ground. But average plant crown volume is $0.27m^3/m^2$ in the high green ratio apartment of the artificial ground plant density of canopy layer was changed from 5 individuals per $100m^2$ to 14.5 individuals per $100m^2$. We should construct the buffer green area with natural ground and get the function of ecological and beautiful environment regarding to garden concept in case of front green area, width 4.5m. We should get the function of increasing green volume by multi-layer planting with shade woody species and flower woody species in case of back-side green area, width over 5.0m. We should get the function of covering the wall and increasing green landscape by planting with high woody species in case of side green area. We should apply the ecological planting technique to buffer green area and connect buffer green area to inner green area in apartment complexes.

• Journal of the Korean Institute of Landscape Architecture
• /
• v.41 no.6
• /
• pp.1-19
• /
• 2013

This study tries to review 'Sakuteiki(作庭記)', the Book of Garden Making, compiled at the end of the 11th Century during the Heian Period of Japan, from the East-Asian perspective. 'Sakuteiki' is a Garden Theory Book, the oldest in the world as well as in Asia, and it contains the traditional knowledge of Japanese ancient garden culture, which originated from the continent(Korea and China). Traditional knowledge related to East-Asian garden culture reviewed in this paper is "Fungsu Theory"(風水, Asian traditional ecology: Fengshui in Chinese; Fusui in Japanese), stemmed from the culture to seek sound and blessed places to live in. Viewed from modern landscape architecture, the Fungsu Theory corresponds to ecology(science). The Fungsu Theory was established around the Han Dynasty of China together with the Yinyangwuxing(陰陽五行) Theory and widely used for making human residences including gardens. It was transmitted to Japan via Korea as well as through direct transaction between Japan and China. This study reinterprets garden design principles represented in Sakuteiki, which were selected in 5 key words according to the Fungsu Theory. The 5 key words for the Fungsu Theory are "the place in harmony of four guardian gods(四神相應地)", "planting trees in the four cardinal directions", "flow of Chi(氣)", "curved line and asymmetry", and "mountain is the king, water is the people". Garden design principles of "the place in harmony of four guardian gods(四神相應地)" and "planting trees in the four cardinal directions" are corresponding to "Myeongdang-ron(明堂論, Theory of propitious site)". The place in harmony of four guardian gods mentioned in Sakuteiki is a landform surrounded by the flow of water to the east, the great path to the west, the pond to the south, and the hill to the north. And the Theory originated from Zhaijing(宅經, Classic of dwelling Sites) of China. According to this principle, the city was planned and as a miniature model, the residence of the aristocrat during the Heian period was made. At the residence the location of the garden surrounded by the four gods(the flow of water, the great path, the pond, and the hill) is the Myeongdang(明堂, the propitious site: Mingtang in Chinese; Meido in Japanese). Sakuteiki explains how to substitute for the four gods by planting trees in the four cardinal directions when they were not given by nature. This way of planting originated from Zhaijing(宅經) and also goes back to Qiminyaoshu (齊民要術), compiled in the 6th Century of China. In this way of planting, the number of trees suggested in Sakuteiki is related to Hetu(河圖) and Luoshu(洛書), which are iconography of Yi(易), the philosophy of change, in ancient China. Such way of planting corresponds to that of Yongdoseo(龍圖墅, the villa based on the principle of Hetu) presented in Sanrimgyeongje (山林經濟), an encyclopedia on agriculture and living in the 17th Century of Korea. And garden design principles of "the flow of Chi(氣)", "curved line and asymmetry" is connected to "Saenggi Theory(生氣論, Theory of vitality)". Sakuteiki explains the right flow of Chi(氣) through the proper flow and the reverse flow of the garden stream and also suggests the curved line of the garden stream, asymmetric arrangement of bridges and stones in the garden, and indented shape of pond edges, which are ways of accumulating Chi(氣) and therefore lead to "Saenggi Theory" of the Fungsu Theory. The last design principle, "mountain is the king, water is the people", is related to "Hyeongguk Theory(形局論, Theory of form)" of the Fungsu Theory. Sakuteiki explains the meaning of garden through a metaphor, which views mountain as king, water as the people, and stones as king's retainers. It compares the situation in which the king governs the people with the help of his retainers to the ecological phenomena in which mountain(earth) controls water with the help of stones. This principle befits "Hyeongguk Theory(形局論, Theory of form)" of the Fungsu Theory which explains landform on the analogy of social systems, people, animals and things. As above, major garden design principles represented in Sakuteiki can be interpreted in the context of the Fungsu Theory, the traditional knowledge system in East Asia. Therefore, we can find the significance of Sakuteiki in that the wisdom of ancient garden culture in East-Asia was integrated in it, although it described the knowhow of a specific garden style in a specific period of Japan.

• Journal of the Korean Institute of Traditional Landscape Architecture
• /
• v.31 no.2
• /
• pp.1-19
• /
• 2013

This study was carried out to analyze distribution situation of alien plants and to propose management plan in the 3 Folk village in Gyeongsangbuk-do which is Cultural property designated by the State; Hahoe, Yangdong and Hangae. This research is for improve of sincerity of historical site and provide basic information which use about administration of preservation. The results are as follows. 1. Overall flora and alien plants appearance The total flora in the 3 folk villages were listed total 752 taxa including 127 families, 430 genera, 614 species, 5 subspecies, 100 varieties and 33 forms. Among them, woody plants take 263 taxa(35.0%) and herbaceous plants take 489 taxa (65.0%). Flora in the Hahoe, Yangdong and Hangae village were total 534, 479 taxa and 408 taxa and exotic plant index was 30.1%, 38.2% and 37.0% respectively. In types of exotic plants, ornamental exotic plants were 135 taxa, deciduous exotic plants were 21 taxa, cultivating exotic plants were 64 taxa, and naturalized exotic plants were 80 taxa and those result lead that the ornamental exotic plants is the highest ratio. According to the villages, Hahoe village had 161 taxa(30.1%), Yangdong Village had 183 taxa(38.2%), and Hangae village had 151 taxa(37.0%) that Yangdong village showed the most number of exotic plants. 2. Planting of landscape exotic plants in the unit cultural assets Meanwhile, Ornamental exotic plants in old house's gardens in Andong Hahoe village which is designated as a unit assets, those are total 30 taxa; followed by the Okyeon house(8 taxa) is highest and the Yangjindang(7), the Hadong house(6) and the Chunghyodang(5). Magnolia denudata appears the most as for 4 times and Campsis grandiflora etc. each took 2 times. Based on the Yangdong village, Gyeongju, that are found total 51 taxa; followed by the Dugok house(16 taxa) the Sujoldang(14), the Mucheondang(13), and the Sangchunheon (12). High appearance rate of ornamental exotic plants were Viburnum opulus for. hydrangeoides, Lycoris squamigera, Caragagna sinica and Magnolia denudata etc. Based on the Hangae village, Seongju, that are designated total 62 taxa; followed by the Jinsa house(35 taxa), the Gyori house(25), the Hanju head family house(20), and the Hahoe house(16). Taxa with high appearance rates were Caragana sinica, Juniperus chinensis var. horizontalis, Magnolia denudata, Viburnum opulus for. hydrangeoides, Chaenomeles speciosa etc. 3. Problems of exotic plant landscapes in the outer spaces of the folk villages Problems of exotic plant landscapes in the outer spaces of the Hahoe village are as follows. In lower of the Mansongjeong forest, Ambrosia artemisifolia, which are ecosystem disturbance plants designated by the Ministry of Environment, live with high dominance value. This should be have a remove with Sicyos angulatus immediately. In the Nakdong river bed around the Mansongjeong forest is covered with a riparian vegetation forest belt of Robinia pseudoacacia L. forest, Populus nigra var. italic community, and Populus x tomentiglandulosa community colony. Based on the Yangdong village, the planted or naturally distributed Ailanthus altissima colony, sporadically distributed Robinia pseudoacacia as well as Amorpha fruticosa are detected all over the village and ecotones. Based on the Hangae village, Ailanthus altissima and Robinia pseudoacacia are sporadically distributed around the village and there is a sign of spreading. similarity of exotic plantsis 47.0% to 48.6% and a reason why this happened is all of research site in Gyeongsanbuk-do and that is why growth norm of plant is similar, exotic plant which is sales for ornamental and it infer to require related countermeasure of each villages and joint related countermeasure.

• Korean Journal of Environment and Ecology
• /
• v.32 no.6
• /
• pp.698-708
• /
• 2018

The purpose of this study was to investigate differences in the breeding call characteristics of cicada species found in urban and forest areas in the central region of Korea by examining the interspecific effects and environmental factors affecting the breeding calls and breeding call patterns. The selected research sites were Gyungnam Apartment in Bangbae-dong, Seoul for the urban area and Chiak Mountain National Park in Wonju for the forest area. The research method for both sites was to record cicada breeding calls for 24 hours with a recorder installed at the site and analyze the results. Data from the Korea Meteorological Administration were used for environmental factors. The research period was from June 19, 2017 to September 30, 2017. As a result of the study, there were differences in the emergence of species between the two research sites: while Platypleura kaempferi, Hyalessa fuscata, Meimuna opalifera, Graptopsaltria nigrofuscata, and Suisha coreana were observed at both sites, Cryptotympana atrata was observed in the urban area and Leptosemia takanonis in the forest area only. The emergence periods of cicadas at the two sites were also different. The activities of P. kaempferi and L. takanonis were noticeable in the forest area. In the urban area, however, L. takanonis was not observed and the duration of activity of P. kaempferi was short. In the urban area, C. atrata appeared and sang for a long period; H. fuscata, M. opalifera, and G. nigrofuscata appeared earlier than in the forest area. S. coreana appeared earlier in the forest area than in the urban area. According to the daily call cycle analysis, even cospecific cicada showed a wide variation in their daily cycle depending on the region and the interspecific effects between different cicadas, and the environmental differences between the urban and forest areas affected the calls of cicadas. The results of correlation analysis between each cicada breeding calls and environmental factors of each site showed positive correlation with average temperature of most cicadas except P. kaempferi and C. atrata. The same species of each site showed positive correlations with more diverse weather factors such as solar irradiance. Logistic regression analysis showed that cicadas with overlapping calling times had significant effects on each other's breeding calls. C. atrata, which appeared only in the urban area, had a positive effect on the calling frequency of H. fuscata, M. opalifera, and G. nigrofuscata, which called in the same period. Additionally, L. takanonis, which appeared only in the forest area, and P. kaempferi had a positive effect on each other, and M. opalifera had a positive effect on the calling frequency of H. fuscata and G. nigrofuscata in the forest area. For the environmental factors, the calling frequency of cicadas was affected by the average temperatures of the urban and forest areas, and cicadas that appeared in the forest area were also affected by the amount of solar radiation. According to the results of statistical analysis, urban cicadas with similar activity periods are influenced by species, especially with respect to urban dominant species, C. atrata. Forest cicadas were influenced by species, mainly M. opalifera, which is a forest dominant species. The results of the meteorological impact analysis were similar to those of the correlation analysis, and were influenced mainly by the temperature, and the influence of the insolation was more increased in the forests.

• Korean Journal of Ecology and Environment
• /
• v.39 no.1 s.115
• /
• pp.119-130
• /
• 2006

As unialgal cultures to examine the growth kinetics of an algal species, Microcystis aeruginosa was grown in chemostats with nitrogen and phosphorus limitation. The nutrient concentrations of $NH_4\;^+\;and\;PO_4\;^{3-}$ to limit the growth of M, aeruginosa were approximately 200 ${\mu}M$ and 7 ${\mu}M$, respectively. Cell size of the algae decreased towards the $NH_4$-nitrogen limitation under a constant dilution rate, while it increased in the $PO_4$-limitaion. The cell quota of nitrogen under nitrogen-limited conditions was 6.1 ${\mu}mol$ mg $C^{-1}$ and, under nitrogen sufficient conditions, ranged from 9.5 ${\mu}mol$ mg $C^{-1}$ to 12.4 ${\mu}mol$ mg $C^{-1}$. In addition to the cell quota, the half-saturation constants for nitrogen uptake ($K_s$) and the growth rate (${\mu}_m$) was 36 ${\sim}$ 61 ${\mu}M$ and 0.28 ${\sim}$ 0.35 ${\mu}mol$ cell ${\cdot}$ $hr^{-1}$ to show high values in comparison with other algal species. As the limiting concentration, cell quota and uptake rate of M. aeruginosa were higher than those of any other species, the its nitrogen requirement would be great. In the other side, as the half saturation constant ($K_s$) for nitrogen uptake was higher, and the ratios ofmaximum uptake rate ($V_m$) and $K_s$ was relatively low, the species would have the low competitive ability in the low nitrogen concentration in the ambient water. However, the low concentration of nitrogen in the Nakdong River during the Microcystis outbreak would be the inevitable results of the algal blooms. In the lower Parts of the Nakdong River, the nutrient status was coupled with the growth kinetics of the blooming algae to have clear seasonal variations through a year.

• Korean Journal of Ecology and Environment
• /
• v.36 no.3 s.104
• /
• pp.322-335
• /
• 2003

Nutrient fluxes and sediment oxygen demands (SOD) were measured with intact sediment cores collected from three stations in the downstream of Nagdong River. The sediments were subjected to controlled oxic and hypoxic conditions and temperature gradients (from $10^{\circ}C$ to $30^{\circ}C$) of the overlying waters in laboratory batch system. The effect of temperature and labile layer thickness of the sediment on SOD were examined. $PO_4\;^{3-}$ and $NH_4\;^+$ fluxes were elevated above $20^{\circ}C$ and large mobilities were observed when they were coupled with a hypoxic and high-temperature condition. In the well oxygenated conditions, $PO_4\;^{3-}$ fluxes were negative or negligible but $NH_4\;^+$ fluxes ranged from 1.3 mg N $m^{-2}\;hr^{-1}$ to 2.3 $m^{-2}\;hr^{-1}$. Temperature quotients($Q_{10}$) of $PO_4\;^{3-}$ fluxes were 3.7 ${\sim}$ 7.3 ranges to have the most high values. $PO_4\;^{3-}$ and $NH_4\;^+$ fluxes had the logarithmic increase with temperature, while $NO_3\;^-$ was negatively absorbed to the sediment and linearly correlated with the temperature. $SiO_2$ fluxes showed no difference among oxic and hypoxic conditions and sediment texture. The nutrient fluxes would be closely correlated with pore water chemistry of sediments and activated by the top sediment layer composition such as labile organic matters or algal detritus. The ecological implications of the nutrient fluxes were discussed in terms of sources and sinks of nutrients coupled to algal productions in the Nagdong River.

• Korean Journal of Ecology and Environment
• /
• v.36 no.1 s.102
• /
• pp.38-47
• /
• 2003

The water quality of the Pyeongtaek Reservoir and its main streams has been eval uated far water pollution state in March, June, September and December,2000. The following are the findings: $NH_4$ accounts for the majority of TN in the inflow streams. In the reservoir, TN and $NH_4$ are the more present in the winter season and less in the summer season, with $1.6{\sim}2.4$ times of $NO_3$ and $5.3{\sim}11.4$ times of $NO_2$ found in December and June compared with other seasons. The concentration of each component is different between streams: $NH_4$ among inorganic nitrogen has the highest concentration in the upstream, and $NO_3$ is more prevalent in the downstream. SRP accounts for $25{\sim}69%$ of TP in the stream. Unlike N component, P component in the reservoir rapidly decreases from upstream toward downstream, except in the summer. Average SRSi slightly increases in the fall, i.e., immediately after rainfall. In the streams, the average concentration of chlorophyll-a ranges from 9 to $33{\mu}g/l$, and is relatively high in the downstream. In contrast, in the reservoir, it is the highest in the upstream where $NH_4$ and SRP are frequently found. In particular, diatom and cryptomonad algae are bloomed in March, and blue-green algae in September; their maximum values are $108{\mu}g/l$ and $130{\mu}g/l$, respectively. Considering the concentration of N and P nutrients, pollution loads can affect the Pyeongtaek Reservoir in the downstream in this order: Ansong Stream