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Abstract

To study entering and exiting routes of male and female Hynobius leechii to a breeding site andstaying time of them within the breeding site, we monitored a breeding population located in the research forests of Kangwon National University. The breeding site was surrounded by a drift fence associated with nine pitfall males arrived earlier at the breeding pond than females did. The operational sex ratio (OSR), defined as the ratio of males to females which are ready to mate, over a breeding season was female-biased as 0.67 male vs 1 female (57 males vs 87 females), but daily OSRs, OSR in a particular day, within the breeding pond were male-biased with 1.36~7.5 male vs 1 female in six days out of seven investigated days. While breeding males stayed in the breeding pond for about 11 days, breeding females left the pond as soon as they completed oviposition. However, the females stayed at terrestrial areas near the pond for about seven days before completely leaving the breeding site. Entering and exiting routes to the breeding site were different between males and females, and betwen ovulated and oviposited females. Both males and females athe site. Males stayed longer within the breeding site lost more body weight.

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Abstract

This paper presents a paleoenvironmental study on Hoya Rincon de Parangueo, a maar lake in Valle de Santiago in Central Mexican Bajío. Maar lake sediments have been widely used for high-resolution reconstruction of paleoenvironment. Many different paleoenvironmental proxy data such as stable isotopes, pollen, sediment chemistry, and dung fungus spore were produced in this study. The pine-oak ratio, stable isotopes, and sediment chemistry help to reveal paleoenviromental changes throughout the whole period covered by sediment materials from this study site. The evidence I found indicates that during ca. 9,500 ~ ca. 8,300 cal yr B.P. there was dry climate; during ca. 8,300 ~ ca. 6,300 cal yr B.P. it was wetter; during ca. 6,300 ~ ca. 4,000 cal yr B.P. drier and cooler; during ca. 4,000 ~ ca. 1,100 cal yr B.P. milder and wetter. The presence of Chupicuaro culture between ca. 2,500 ~ 1,100 cal yr B.P. is implied by the high frequencies of Amaranthaceae and Zea mays. It seems that man left this lake around 1,100 cal yr B.P. due to a dry climate after 1,300 cal yr B.P. Spanish arrival around 400 cal yr B.P. is implied by the fact that Zea mays reappears and Sporormiella spp. become significant around 120 cm, whereas Poaceae drops sharply.

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Abstract

We investigated interventions by mother Jeju ponies on Jeju Island, Korea, to determine whethermothers assisted their offspring to attain higher status within the dominance hierarchy. Because dominance rank is important within each gender, we predicted that mothers would be more likely to intervene when their foals were play-fighting with foals of the same gender. A total of 173 play-fighting events were recorded from March to October 1998 and from April to October 1999. Of these, foals were more likely to play-fight with a foal of the same gender as with a foal of the opposite gender (120 versus 53 occurrences, respectively). A mother of one of the foals that were play-fighting intervened in 17 of these interactions. Contrary to the prediction, a mare was interactions between the opposite genders further, mothers were equally likely to intervene when a daughter was play-fighting with a male foal as when a son was play-fighting with a female foal. Hence, mothers were not more protective of daughters than sons. Mothers that were in the younger age class (2~11 years old) were as likely to intervene as those in the elder age class (17~25 years old). However, all foals that were harassed were offspring of mothers in the younger, more subordinate age class. Intervention directly maintains the dominance rank of the intervening mother, and may indirectly assist the intervening mothers foal to achieve a higher dominance rank. By discouraging their foals from play-fighting with the opposite genders, dominant mothers may rank.

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Abstract

In the current study, we examined the quality of surface water in ponds at two golf courses, locatedin southern (Country Club P) and eastern (Country Club B) areas of Korea respectively. Seasonal measurements ed oxygen, biological oxygen demand, chloride, alkalinity, hardness, and nitrogen compounds [NH3-N, NO2-N, NO3-N] and the concentrations of four heavy metals (Cd, Cu, Pb, and Zn) throughout the courses. The pH values were within the alkaline range (7.3 to 9.0), and the biological oxygen demand was generally between 0.5 and 3.1 mg/L. The alkalinity and hardness ranged from 19.1 to 68.5mg/L and 16.1 to 63.6 mg/L, respectively. Nitrogen as amonium (NH3-N) was detected in all samples, and the samples had low concentrations of NO2-N and NO3the highest Cd concentration was observed in the pond in Country Club P. Other metal concentrations were low compared to the Quebec guidelines.

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Abstract

In order to investigate the organic carbon distribution, net primary production, annual litterproduction, organic carbon in litter layer, soil organic carbon and soil respiration were studied in an oak forest, Kongju, Chungnam Province in Korea. Net primary production was estimated to 15.84 ton Cha－1yr－1. The amount of carbon allocated to leaf and reproductive organ, branch, stem and root was 1.71, 4.03, 7.34, 2.76 ton Cha－1yr－1, respectively. Anual litter production was 5.21 tonha－1yr－1, which amounted to 2.35 ton Cha－1 yr－1. Average amount of organic carbon in litter layer (L+F) was 6.06 ton C/ha, and that of L layer decreased carbon in this oak forest was 165.19 ton C/ha. The amount of carbon evolved through soil respiration was 11.24 ton Cha－1yr－1. Net amount of 4.60 ton Cha－1yr－1was absorbed from the atmosphere by this oak forest.

초록

서울시 생태계 보전지역인 진관내동 습지, 방이동 습지와 밤섬에서 2004년 3월 토양을 채취한 후 5월부터 10월까지 유묘출현법(seedling emergence method)으로 토양 종자은행을 관찰하였다. 그 결과 진관내동에서는 총 42종, 5,190개체가 출현하였고,방이동에서는 총 39종, 2,265개체, 밤섬에서는 총 39종, 1,047개체가 발아하였으며 가장 개체수가 많았던 곳은 진관내동 버드나무군락이었다. 진관내동 습지와 밤섬에서 가장 많은 개체수를 보인 것은 밭뚝외풀이었고 방이동 습지에서는 부들속 식물들이었다. 진관내동과 방이동에서 실시한 군락별 토양 종자은행 조사 결과 갈대군락, 버드나무군락, 고마리군락, 달뿌리풀군락, 은사시나무군락 등에서 지상부 우점종과 지하부 우점종이서로 다른 반면 애기부들군락과 부들군락에서는 일치하였다.습윤조건에서 56종, 침수조건에서 25종이 출현하였고, 두 조건에서 다 출현한 종은 18종이었다. 개구리밥등의 부유식물과 물닭개비등의 일부 정수식물은 침수조건에서만 발아하였다. 부들속 식물, 돌피 골풀 등의 정수식물은 습윤과 침수 조건 모두에서발아하였다. 밤섬에서 채취한 수변으로부터의 거리별 토양 종자은행에서는 수위의 유동성이 큰 수변 3(식생대로부터 거리300~350m)에서 가장 많은 수의 종자가 관찰되었다.

Abstract

Soil seed banks at ecological preservation areas in Seoul, Jinkwannae-dong, Bangi-dong andBam-sum, were studied by seedling emergence method from May to October 2004. Total number of species and individuals in seed banks were 42 and 5,190 at Jinkwannae-dong, 39 and 2,290 at Bangi-dong, and 39 and 1,047 at Bamsum. Salix koreensis comunity at Jinkwannae-dong has the highest number of seedlings among all sites. The most abundant species were Lindernia procumbens in Jinkwannae-dong and Bam-sum and Typha re different from that of plant comunities such as Phragmites comunis community, Salix koreensis comunity, Persicaria thunbergii community, Phragmites japonica community, and Populus tomentiglandulosa community. However the dominant species of seed banks in Typha comunity was Typha spp. Total 63 species emerged in either the wet or submerged conditions. Fifty six species appeared in the wet condition and 25 in the submerged condition. Eighteen species appeared in both conditions. Numbers of species and individuals were much less in the submerged condition than in the wet condition but free-floating hydrophytes including Rorippa islandicaMonochoria vaginalis appeared only in the submerged condition. In the investigation of soil seed bank by distance from water edge (Bamsum), water side 3 (300~350m from water) edge, where water level is fluctuating frequently, has the highest number of seedlings.

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Abstract

The ripe unfertilized eggs of Acheilognathus signifer were elliptical shape and baggily swollenaxis and oil globe were not observed. The zona radiata of A. signifer had the structure of regular fibrilar net and the diameter of outer opening micropyle was about 2.5 μm and that of inner opening micropyle was about 1.5~2.0 μm. Development of fertilized eggs in A. signifer was proceeded in inclining position of animal pole and hatched in 49 hours under 20 1 ℃. The yolk sac was absolutely absorbed in 21 days after hatching.

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This study was conducted to evaluate the effect of the conventional pesticide application systemon the rice spider community based on the quantitative inin Baran area, Hwasung-si, Kyeonggi-do from 1996 to 1998. Spiders were the highest dominant group comprising over 90% of all natural enemies in their density, and showed very stable yearly ocurrence. In these fields the mean density of spiders was about 10 individuals/0.25m2during the rice growing season, and thre families including Lycosidae, Tetragnathidae and Linyphiidae were very abundant. The colonization of spiders occurred in early season and they showed rapid density increase in mid-season. They maintained the highest density to the late season and their density decreased at harvest season. In the years of the low rice pest occurrence, the disturbance effect on spider community by pesticides were less. Two dominant species, Pirata subpiraticus and Pachygnatha clerki, had different population dynamics; Pirata subpiraticus showed the rapid density increase in the mid-July, and most of them remained immature stages, however, in the case of Pachygnatha clerki population, they rapidly increased in the late August and most of them remained adult stage during the late growing season.

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Abstract

The sexual dimorphism and intra sexual dimorphism in males of Rhinogobius brunneus wereinvestigated at Jiam stream, a tributary of the Bukhan river from May, 2005. The frequency distributions in standard length were similar for the females and maleLs, but maleSs were smaller than the females and maleLs. The ratio of MaleL (N= 79) to maleS (N= 79) was 1 : 0.46. The comparison between female (N= 79) and maleL (N= 79) gave significant differences (P<0.05) in 18 morphometric characteristics (SNL, AHD, PHD, ML, DL, MW, AHW, IFW, PHW, ED, HL, FDFL, SDFB, CFL, AFB, VFL, PFL, PFB) and 12 characteristics (SNL, AHD, ML, DL, MW, AHW, IFW, PHW, HL, FDFL, CFL, PFB) (PMW, HL, CFL, VFL, PFL) in female (N= 36) and maleS (N= 36) had significant differences (P<0.05) and three characteristics (ML, DL, HL) had very significant differences (P<0.001). Eleven characteristics (SNL, AHD, PHD, ML, DL. MW, AHW, IFW, PHW, HL, FDFL) were significantly different in maleL (N=36) and maleS (N=36) (P<0.05) and six (ML, DL, MW, AHW, HL, FDFL) were very significantly different (P<0.001).

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Abstract

We investigated the effects of pollutants on two pine species (Pinus koraiensis and Pinus rigida) in an industrial region, using a physiological approach. We measured the growth and physiological parameters (photosynthetic activity and chemical contents) of the pine trees in relation to environmental pollutants. The concentrations of manganese (Mn), fluorine (F) and chlorine (Cl) in needles of two pine species at the damaged site were significantly higher than those at the control site, and concentrations of essential elements (P) and chlorophyll in needles at the damaged site were significantly lower than at the control site. The light-saturated net photosynthesis (Psat), apparent quantum yield (Φ), carboxylation efficiency (CE) of both pines at the damaged site were significantly lower than those at the control site. The length of shoots and survivorship of needles of two pines at the damaged site were significantly lower than those at the control site. Especially, at damaged site, growth of shoots and needle longevity of P. koraiensis are larger than those of P. rigida.

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Abstract

For the first time in Korea, plant size, distribution pattern and root growth form of Tamarix chinensiswere surveyed at natural stand in Shiwha Lake, from June to July in 2005. T. chinensis grew in the range of 350 m towards north-south and 270 m in east-west direction. The mean number of stems germinated from same root system was 1.9. On the stem base, the numbers of living and dead plants were 1,398 and 114, respectively. Mean perimeter and height of 1,398 plants were 5.93.2 cm and 15951 cm, respectively. By dividing into 10 classes based on the perimeter size, the largest number of plants were included in the second smallest class category. However, by dividing into 10 classes on the baalong the height showed normal distribution curve. The heights of dead plants were small in perimeter but diverse in height. On the root base, the number of plants was the greatest in the smallest size class, and conspicuously decreased with size increment. Distribution of T. chinensis was clumped pattern. Age of the largest plant was 8-year. T. chinensis had two types of root growth. One was horizontal growth in the periphery of soil surface, and the other vertical growth.

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Abstract

A study on changes on the distribution of vascular hydrophytes and the growth pattern ofSchenoplectus triqueter (Scirpus triqueter) was undertaken at the Nakdong River estuary from 2002 to 2004. The change was due to physical alteration of the estuary for the past 25 years. These plant species are the major food sources for winter waterfowl. A total of 32 species of vascular hydrophytes from 17 families were found Estuary (brackish water). After the construction of the barage on the estuary in 1987, the number of hydrophytes has remarkably increased to 17 species (5 species in 1985) in the main channel of the River. In particular, a comunity of Eurale ferox was found at the backwater wetland of the Daejeo side of the main channel. The introduced species of Eichhornia crassipes and Pistia stratiotes that were epidemic in 2001 at West Nakdong River was not found any more. The other species such as Nymphoides indica , Myriophyllum spicatum, Ruppia spp. were rediscovered. The large area (about 1,300ha) of Zostera sp. was the main sources of food for swans, but disappeared because of direct and indirect impacts of reclamation in the River estuary. Curently, there remains a small patch of Zostera spp. and about 250ha of S. triqueter. Schenoplectus triqueter grew mostly between April-September and tuber formed, between September~October. The growth of S. triqueter up to 60~80cm in length was observed in 5 sites out of the 7 sites in brackish area. Tubers of S. triqueter were eaten by waterfowls such as swans as winter food. In five sites, tubers took 44~57% of total biomass in October. Tubers were found in deep layers; 5~15cm (9%), 15~25cm (28%), 25~40cm (55%), below 40cm (6~7%). The reclamation of the area. In order to determine the extent of changes of the distribution of these plants and the carrying capacity of the area for waterfowl, an intensive research is urgently needed.