• ALGAE
• /
• v.23 no.3
• /
• pp.201-207
• /
• 2008

Based on samplings during 2006-2007 on the intertidal zone of Playa Tampico, Eréndira and Punta Baja, Baja California, Ulva pertusa Kjellman (Ulvales, Chlorophyta) was recorded for the first time for the Pacific coast of Mexico. An alga native to Asia, U. pertusa has just recently been recorded in the southern coast of California (USA). The identification of U. pertusa was based on the observation of the morphology and reproductive characters of the collected specimens. Furthermore, the species identity was confirmed by molecular comparison between nuclearencoded ITS2 sequences of the Mexican samples and those of other Ulva species in GenBnak data. Habitat and distribution of U. pertusa along the Pacific coast of North America are also described. Considering our new report of its occurrence in Mexico, we conclude that U. pertusa is expanding its geographical distribution by trans-ocean introductions.

• Korean Journal of Environment and Ecology
• /
• v.29 no.3
• /
• pp.401-409
• /
• 2015

The fish community and introduced fish were surveyed at eight stations of Lake Soyang from March to October, 2013. A total of 41 species of twelve families were collected from the survey stations and among them, two species: Hemibarbus mylodon and Siniperca scherzeri (albino type) were identified as natural monument. There were fifteen Korean endemic species (36.6 %) including Acheilognathus yamatsutae. When compared with previous data (2003), A. yamatsutae, Pseudorasbora parva, Sarcocheilichthys nigripinnis morii, Sarcocheilichthys variegatus wakiyae, Orthrias nudus, Leiocassisuss ussuriensis, Oncorhynchus mykiss, and Micropterus salmoides appeared new in the lake. Dominant species were Hypomesus olidus (St. 1, 3, 6, 7, 8), Lepomis macrochirus (St. 2, 4) and Zacco platypus (St. 5). Of the 12 introduced species fishes in Lake Soyang, Anguilla japonica, Hemiculter eigenmanni, H. nipponensis, Rhinogobius giurinus and Tridentiger brevispinis were introduced and released from other native river water zones in Korea but Cyprinus carpio (Israeli type), Carassius cuvieri, O. mykiss, Ictalurus puntatus, L. macrochirus, and M. salmoides originated from foreign countries.

• Economic and Environmental Geology
• /
• v.20 no.2
• /
• pp.97-106
• /
• 1987

The geology of the Bupyeong mine area is consisted of Precambrian Gyeonggi gneiss complex and Mesozoic igneous rocks; i.e., pyroclastic rocks, intrusive breccia, granite and felsic porphyries which were formed during a Jurassic to early Cretaceous resurgent caldera evolution. Granites are not observed on the surface and in the underground of the mine. Bupyeong silver deposits occur as stockworks of base metal sulfides- minor silver minerals-quartz - carbonate veinlets, hosted by pyroclastic rocks and intrusive breccia at the southwestern margin of the caldera. Silver occurs mainly as native silver, and other silver minerals, minor in quantity, are argentite, tetrahedrite-freibergite, pyrargyrite, polybasite, canfieldite and dyscrasite. The average grade of silver ore is about 180g/t Ag. Discrimination of silver ore from the country rocks depends largely on the chemical analyses of rock samples taken every two meters from tunnels, diamond-drilling cores and mining stopes, because silver minerals are hardly observed in the ore by crude eye, and silver orebodies do not properly coincide with the concentrated zone of base metal sulfides which were precipitated at the earlier stage than the stage of precipitation of native silver. General characteristics of the loci of the silver orebodies are as follows; (1) The host rocks of orebodies are pyroclastic rocks and intrusive breccia. (2) Many of the orebodies are distributed around Gyeonggi gneiss complex. Especially where the paleotopography of gneiss complex shows a gradual slope, the basal stratigraphic horizon of the pyroclastic rocks unconformably overlying the gneiss complex offered a favorable loci of high grade ore. (3) $N5^{\circ}W$ to $N15^{\circ}$ E-striking faults played an important role in the localization of the orebodies. (4) Conduits of intrusive breccia within the gneiss complex, through which the intrusive breccia intruded into the upper pyroclastic rocks, exist beneath most of the main orebodies. This suggests that the conduits of intrusive breccia served as channelways for the migration of ore fluids.

• The Korean Journal of Ecology
• /
• v.24 no.6
• /
• pp.385-394
• /
• 2001

An attempt to clarify the landscape structure of urban areas was carried out in the greenbelt around Seoul, Korea's metropolis. By means of aerial photographs and a field survey, a vegetation map including land-use pattern was made. Landscape structure was described by analyzing this vegetation map and the results of phytosociological survey. Landscape element types identified were (1) secondary forest, (2) plantation, (3) cultivated field, (4) urbanized area, (5) graveyard, and (6) bare rock. Vegetation units, resulting from the phytosociological analysis, included Quercus mongolica, Q. variabilis, Q. acutissima, Pinus densiflora, Q. aliena, and Alnus japonica communities. Plantations were composed of Robinia pseudoacacia, Populus tomentiglandulosa, P. rigida, Larix leptolepis, P. koraiensis, and Castanea crenata stands. Patches near to human settlements in the lower zones of the mountains were fragmented and small but they became larger towards the higher mountain zones. On the other hand, the number of patches was fewer and their size was larger in Mt. Cheonggye more distant from the principal residential area, larger in size, and higher in elevation compared with the other 2 mountains, Mt. Daemo and Mt. Acha. Floristic composition of Mongolian oak(Q. mongolica) stand distributing in the upper part of each mountain, in which artificial interference is rare, showed a difference among those study areas different in parent rock and disturbance regime. But that of black locust(R. pseudoacacia) stand located in lowland of mountainous area, in which artificial interference is frequent was similar to each other. As the results of analyses on the frequency distribution of diameter classes of major species, dominant landscape elements, Mongolian oak forest showed different responses depending on artificial interference as continuous maintenance and retrogressive succession in the sites far from and near to the residential areas, respectively. On the other hand, black locust stands showed a probability to be restore to the native oak forest through progressive succession.

• Korean Journal of Soil Science and Fertilizer
• /
• v.26 no.2
• /
• pp.85-92
• /
• 1993

This study was investigated on the morphological characteristics of rice grain as affected by three fertilizer application treatments. Of no-nitrogen, optimum nitrogen, and heavy nitrogen without potassium in three regions of Suweon (Mid-West Plain Zone), Ichon(Mid-Inland Plain Zone), and Kyehwado(South-charyung Mts. Plain Zone) with four varieties, i.e., three Tonsil types(Geumgangbyeo, Milyang 23, and Chilseongbyeo) and one japonica type(Chucheongbyeo, Akibare in Japanese name). The results obtained were as follows: The increase of nitrogen application caused an increase of grain length in rough rice and grain width in milled rice, resulting in a decrease of the width/thickness ratio in milled rice. The width and thickness of rice grain produced in Kyehwado were smaller than those in the other regions. Therefore, the ratio of length/width and length/thickness in rice grain produced in Kyehwado was larger. The one thousand grain weight of rice was heavier at the optimum nitrogen level than at the no-nitrogen and heavy nitrogen without potassium treatment levels. The weight percentage of hull in rough rice grain decreased in accordance with the increase of nitrogen application, while the weight percentage of bran in brown rice was constant. This suggested that for the normal development of rice grain a constant ratio of bran is needed. The morphological change of rice grain by fertilizer treatments and the change of region cultivated could not be distinguished from the native characteristics of the variety. Other grain characteristics were discussed in view of treatment and regional effects.

• Journal of Plant Biology
• /
• v.14 no.4
• /
• pp.5-13
• /
• 1971

Pot and paddy field tests were conducted to study red discoloration of rice var. IR 667 leaves with reference to the leading Korean native variety Jinhung and Paldal, with the following results: 1. Minor elements such as Mn, Fe, B, Al, Ca and Si had no influence on the discoloration, but a supply of various soluble nitrogen compounds completely restricted it. The more prosperous the growth of IR 667 with nitrogen, the more severe the discoloration appears when nitrogen absorptin becomes limited. 2. Chlorotic pigments extracted from both IR 667 and Jinhung were compared spectrophotometrically, and found to have different spectral peaks. IR 667 had peak closer to red than Jinhung, indicating the characteristic of the variety. IR 667 was observed to be more sensitive to nitrogen deficiency than Jinhung or the other japonica variety. 3. It was concluded that all the factors limiting nitrogen supply for IR 667 growth, such as low nitrogen application, restriction of root respiration (low temperature, poor drainage, toxic gases or substances in the root zone, etc.) and pest injuries, would result in the appearance of the so-called red discoloration, because of the reduction in nitrogen uptake. Since, the discoloration of IR 667 is varietal characteristic when grown in Korea, control of it may be beneficial cultural practice in increasing grain yield, although the increased succeptibility to pests and a drop in the rate of maturity due to relatively high nitrogen level in the leaves may result in an unexpected drop in yield. It is anticipated that further exploration conducted from practical point of view will establish the relatioknships between the extent of red discoloration, nitrogen availability and grain yield in IR 667.

• Horticultural Science & Technology
• /
• v.17 no.2
• /
• pp.141-143
• /
• 1999

Genetic relationship of Calanthe discolor, C. sieboldii, and C. bicolor for elucidating the classification was investigated. Electrophoretic zymograms for either peroxidase or esterase isozymes indicated that bands of C. bicolor appear in the zone where those of C. discolor and C. sieboldii are located. Genetic relationship among the three Calanthe species using RAPD analysis showed that C. discolor and C. sieboldii are more distant each other than C. bicolor, demonstrating the genetic position of C. bicolor between the other two. It was assumed that C. bicolor is a natural hybrid between C. discolor and C. sieboldii.

• Journal of Forest and Environmental Science
• /
• v.14 no.1
• /
• pp.112-127
• /
• 1998

A meeting for Japan Society of Erosion Control Engineering took place, from May 20-21 in Sapporo, Japan, with the presentations of 21 special topics and 185 general papers. Special topics consists of 6 copies on volcanic disaster prevention, 6 copies on the activity report of Earthquake Erosion Control Engineering Society, 5 copies on the management and guidelines of riparian zone and 4 copies on debris disaster occurred in 1997. General papers consists of 10 copies on slope stability, 10 copies on slope failure, 9 copies on earthquake, 41 copies on environmental erosion control, 25 copies on debris flow, 11 copies on warning and refuge, 10 copies on erosion control plan, 11 copies on erosion control project, 10 copies on erosion control facility, 12 copies on volcanic erosion control, 4 copies on revegetation technology, 4 copies on forest hydrology, 4 copies on avalanche, 4 copies on landslide, 18 copies on debris flow and 2 other copies presented by international student. Among the special topics, 5 papers with the titles of the function and structure of riparian zone, the interactive relation of flood and riparian zone, the management method of channel and river forest for controlling debris flow, the forest restoration efforts by native population, the law and social issue for building river riparian zone were presented in the subsection of "The Management and Guidelines of Riparian Zone". Thus, this article summarize and introduce the presented contents which are very important and can be referred to keep environmentally sound-river in the erosion control field.

• Journal of Species Research
• /
• v.6 no.1
• /
• pp.59-67
• /
• 2017

Southwest Primorye is located in the southern most part of the Russian Far East. The flora of this area is one of the most thoroughly studied and contains 1,530 species of vascular plants, belonging to 622 genera and 154 families, representing 55.6% of the flora of the Primorsky Territory. The flora native to Southwest Primorye encompasses 1,356 species from 547 genera and 148 families. Adventitious plants are represented by 174 species from 127 genera and 37 families. Among other areas of the Russian Far East, only Southwest Primorye has flora in common with the Korean Peninsula, which contains plant species in the subtropical and tropical latitudes: Mitrasacme indica Wight, Halosciastrum melanotilingia [Boissieu] M. Pimen. et V. Tichomirov, Streptolirion volubile Edgew., Lipocarpha microcephala [R. Br.] Kunth, Pueraria lobata [Willd.] Ohwi, Belamcanda chinensis [L.] DC., Zoysia japonica Steud., Deinostema violacea [Maxim.] Yamazaki and Parthenocissus tricuspidata [Siebold et Zucc.] Planch. Most of the flora is represented by the species restricted to Southwest Primorye (seven endemic species) or the Korean Peninsula (seven hemiendemic species). A total of 50.2% of the 10 largest families are nemoral (preboreal) floras, located in the transitional zone of the boreal and nemoral floras. In terms of the structure of the ranked taxonomic spectrum of the largest families, the flora of Southwest Primorye is more similar to that of Northeast China with influence of the Korean flora.

• Korean Journal of Environment and Ecology
• /
• v.29 no.5
• /
• pp.718-728
• /
• 2015

The fish community and inhabiting status of introduced fish were surveyed at nine stations of Gangeungnamdae stream from September 2013 to May 2014. A total of 36 species of fourteen families were collected from the survey stations and among them, Pungitius sinensis was identified as endangered species. There were nine Korean endemic species (25%) including Coreoleuciscus splendidus. Dominant species were Rhynchocypris steindachneri (St. 1), Zacco koreanus (St. 2, 4, 5, 6), Ladislabia taczanowskii (St. 3)), Zacco platypus (St. 7, 8) and Tribolodon hakonensis (St. 9). Of the 11 introduced species fishes in Gangeungnamdae stream, L. taczanowskii, Pungtungia herzi, Coreoleuciscus splendidus, Squalidus gracilis majimae, Pseudogobio esocinus, Rhynchocypris kumgangensis, Z. platypus, Z. koreanus, Koreocobitis rotundicaudata, Liobagrus andersoni and Coreoperca herzi were released from Han river water zone in Korean. Rapidly expanded population and distribution of introduces fishes were Z. platypus, Z. koreanus, P. herzi and S. gracilis majimae, but L. taczanowskii, C. splendidus, R. kumgangensis were not rapidly expanded population. Settlement but very small population fishes were C. herzi and L. andersoni. When reduced 3% fishes of relative abundance with previous data (1973), R. steindachneri, Orthrias toni, Iksookimia pacifica, Plecoglossus altivelis, P. sinensis and Gymnogobius urotaenia, and R. steindachneri was most reduced from 56.1% to 12.9%.