• 한국물환경학회지
• /
• 제30권4호
• /
• pp.377-385
• /
• 2014

To study the fluctuations and relationship in climate change, environmental factors and cyanobacteria communities, we investigated Chudong station of the Daechung reservoir. The average annual temperature showed the maximum value ($13.9^{\circ}C$) from 1994, showed a gradually increasing pattern from 1969 to 2010 in the Daechung reservoir. The number of days with temperatures over $20^{\circ}C$, minimum temperature of the year and average temperature of the winter season patterns also showed a significant increase. The long-time changed in the annual precipitation were not showed a significant variation. The water temperature record comparatively high value in summer, declined in winter. At all period, the phytoplankton were highest biomass in July 2000, and then, showed comparative higher biomass in the summer months. Cyanobacteria taxa were also showed more than 50%. Emergence of cyanobacteria also appeared in November 2007, were prolonged emergence. The dominant genera of taxa were the dominant sphere (Microcystis spp.) until early 2000. After that, the dominant species were the dominant linear (Aphanizomenon spp., Anabaena spp.). Cyanobacteria were the most correlated with water temperature (r = 0.341, p<0.01) and phosphate concentration (r = 0.355, p<0.01).

• 생태와환경
• /
• 제33권3호통권91호
• /
• pp.267-273
• /
• 2000

온도와 연관된 줄날도래 (Hydropsyche kozhantschikovi)의 우화 양상을 연구하기 위하여 경기도 왕숙천에서 1999년 4월${\sim}$6월 동안 조사를 실시하였다. 우화하는 성충의 정량채집은 피라미드형 우화트랩을 이용하였다. 수온은 1999년에 1시간 간격으로 모니터링하였다. 우화는 일일 평균 수온이 약 10$^{\circ}C$에 도달한 4월 15일에 시작되었고, 그 이후 빠르게 증가하여 약 10일만에 우화의 정점에 도달하였으며, 5월 25일까지 40일간 지속되었다. 우화된 성충의 평균개체수는 35.8 inds./m$^{2}$였고, 암수의 성비는 수컷 : 암컷 = 1 : 2.04였다. 수컷이 암컷보다 2일 정도 우화가 빨랐다. 일일 우화 양상은 일몰 직후(19 :00${\sim}$21 : 00)에 제1정점(66.7%)이 나타나고, 일출 직전(05:00${\sim}$07:00)에 제2정점 (11.1%)이 나타나는 쌍생형 양상이었다. 본 연구의 적산온도 회귀모형에 따르면 우화의 시점, 정점, 그리고 완료에 도달하기 위한 누적적산 온도는 각각 453.89 DD (수컷 440.48 DD, 암컷 473.97DD), 615.71DD(수컷 610.18 DD, 암컷 622.09 DD), 그리고 820.24DD (수컷 828.25 DD, 암컷 804.71 DD)였다.

• The Korean Journal of Ecology
• /
• 제21권6호
• /
• pp.805-808
• /
• 1998

The methanolic crude leaf extract of Acacia melanoxylon shows inhibitory effects on seed germination, shoot growth, root growth and biomass of black gram (Phaseolus mungo L. Co 1) and weeds (Cassia occidentalis L. and Cyperus rotundus L.). The post emergence treatment was given on the 8th day after sowing and 4-6 days after seedling emergence. After postemergence treatment with 20% extract concentration, wilting symptoms appeared in P. mungo and C. occidentalis while necrosis occurred in C. rotundus. The seedling growth was inhibitory at all concentrations (5%, 10%, 20%) as compared to control plants. This inhibitory effect may be due to the presence of allelochemicals like phenolics in the A. melanoxylon leaves. Different types of phenolic acids were identified.

• The Korean Journal of Ecology
• /
• 제27권1호
• /
• pp.1-7
• /
• 2004

With the emergence and development of ecological engineering in China, and also the research and demonstration of Chinese Ecological Agriculture (CEA), in recent 10 years many types of ecological engineering have been appeared in Southern China, they could be classified into 4 typical patterns. These typical patterns are; 1. Ecological Building (EB), such as ecological public toilet, ecological garden, ecological integrated building, farmers' ecological household, the combine of ecological building and CEA; 2. Ecological Engineering in Paddy Field (EEPF), like rice-fish system, water caltrop-wild ricestem-fish system, mulberry-silkworm-pig-fish system; 3. Ecological Engineering of Agroforestry Systems (EEAF), as tea-food crops intercropping system, rubber-tea-chicken system, bamboo-chicken system, fruit tree-chicken system, metasequoia-fish-duck system; 4. Ecological Engineering Linked with Biogas (EELB), such as animal (pig)-biogas-fish system, animal (pig)-biogas-fruit tree system, animal-biogas-food crops system. Some case studies were presented in the paper. It is showed that these typical patterns have better ecological, social and economic benefits, now they are deeply been extending in southern China.

• Current Research on Agriculture and Life Sciences
• /
• 제26권
• /
• pp.17-22
• /
• 2008

This research put most emphasis on setting the guidelines for improvement through character analysis of landscape ecology to cope with ecological malfunction of the woodland surrounded in cultivated areas. The results are as follows. 1) As a result of character analysis of the woodland in cultivated area in point of landscape ecology in five case sites, the size of case site 3 is the largest as $3,000m^2$ and it is shown that a colony of pine trees which is valuable in terms of ecological, scientific, historic and cultural senses. 2) As a result of analysis on expansibility of woodland in cultivated area, case site 1 is 0.25, the lowest, flexibility is 4, the highest. In order to improve ecological function in woodland, it is regarded that maintaining curve form rather than straight one. 3) As a result of analysis of morphological diversity, case site 5 shows 1.3, the highest. However, the condition of vegetation and emergence frequency of species indicates low value degree. 4) Based on the result of analysis of landscape ecological character like above, the number of guidelines for the woodland in cultivated area is three and vegetation is four.

• Proceedings of the National Institute of Ecology of the Republic of Korea
• /
• 제3권3호
• /
• pp.149-153
• /
• 2022

The degree distribution of the plant-pollinator network was identified by analyzing the data in the ecosystem and reproduced by a model of the growing bipartite mutualistic networks. The degree distribution of pollinator shows power law or stretched exponential distribution, while plant usually shows stretched exponential distribution. In the growth model, the plant and the pollinator are selected with probability P_p and P_A=1-P_p, respectively. The number of incoming links for the plant and the pollinator is l_p and l_A, respectively. The probability that the link of the plant selects the pollinator of the existing network given as $A_{k_i}=k^{{\lambda}_A}_i/{\sum}_i\;k^{{\lambda}_A}_i$, and the probability that the pollinator selects the plant is $P_{k_i}=k^{{\lambda}_p}_i/{\sum}_i\;k^{{\lambda}_p}_i$. When the nonlinear growth index is 𝛌_X=1 (X=A or P), the degree distribution follows a power law, and if 0≤𝛌_X<1, the degree distribution follows a stretched exponential distribution. The cumulative degree distributions of plants and pollinators of 14 empirical plant-pollinators included in Interaction Web Database were calculated. A set of parameters (P_A,P_P,l_A,l_P) that reproduces these cumulative degree distributions and a growth index 𝛌_X (X=A or P) were obtained. We found that animal takes very heterogenous connections, whereas plant takes a more flexible connection network.

• 생태와환경
• /
• 제54권4호
• /
• pp.334-345
• /
• 2021

우리나라 산림 생태계의 주요 우점종인 낙엽성 참나무 6종의 지구온난화에 의한 초기 생장의 영향을 파악하기 위하여, 야외 (대조구)와 대조구보다 온도 (3.0℃ 상승)와 CO₂ 농도 (2배 상승)를 증가시킨 기후변화처리구에 종자를 파종하고 2주 간격으로 발아 및 초기 생장을 측정하였다. 그 결과 6종 참나무 유식물들의 지상부와 지하부 출현시기는 대조구보다 기후변화처리구에서 모든 종이 더 빨랐다. 잎 출현시기는 기후변화처리구에서 굴참나무, 신갈나무 그리고 졸참나무가 빨랐다. 지하부 길이는 기후변화 처리구에서 굴참나무, 신갈나무 그리고 떡갈나무가 길었고 상수리나무는 구배 간 차이가 없었으며 갈참나무와 졸참나무는 짧았다. 지상부 길이는 기후변화처리구에서 졸참나무가 길었고, 상수리나무, 신갈나무 그리고 떡갈나무는 차이가 없었으며 갈참나무는 짧았다. 이상의 결과는 지구온난화 환경에서 지상부와 잎의 출현시기가 빠르고 지하부 생장이 좋은 신갈나무의 초기 생장이 가장 유리함을 나타내었다. 반면, 기후변화처리환경에서 지상부와 지하부의 생장이 가장 낮은 갈참나무는 다른 참나무에 비하여 생육이 불리하였다. 또한 상수리나무는 지구온난화 환경에 따른 초기 생장의 차이가 적어 가장 영향이 적은 나무로 판단된다.

• Journal of Ecology and Environment
• /
• 제35권4호
• /
• pp.343-349
• /
• 2012

The use of growth medium is often recommended milkweed seedlings to grow and develop after emergence, and it is affected by growth medium and local habitat conditions. The effects of growth medium and partial shade on early growth of milkweed under drought stress (Calotropis procera L.) were studied in a field experiment. A split-split plot experimental design with three replications was carried out in the nursery. The main treatment plot was divided into two levels of shade; (no shading and partial shading). Sub treatment plot1 included growth medium at four levels (G1 = clay [suitable for milkweed growth], G2 = clay + sand, G3 = clay + perlite, G4 = clay + perlite + sand) and sub treatment plot2 included drought (irrigation intervals) at six levels (D1 = 2 [control], D2 = 4, D3 = 6, D4 = 8, D5 = 10, and D6 = 12 days per for three month). The results showed that drought stress significantly decreased emergence percentage, shoot length, shoot dry weight (SDW1), root dry weight (RDW), seedling dry weight (SDW2) and vigor index (VI). The use of growth medium increased all seedling characteristics. The G3 (clay + perlite) growth medium showed the highest performance, especially in terms of emergence percentage and seedling dry weight. Partial shade improved shoot length, shoot dry weight, and vigor index. Our results showed that the best treatment for high-vigor milkweed seedlings under drought stress was G3 (clay + perlite) growth medium and partial shade.

• Journal of Ecology and Environment
• /
• 제33권4호
• /
• pp.299-306
• /
• 2010

The use of local seed provenance is often recommended in forest restoration. Early vigor is a combination of the performance of seed germination and emergence after planting. The ability of young Brant's oak plants to grow and develop after emergence and its dependence on local habitat conditions was investigated in this study. The effects of seed source and shade on early growing seedlings of Brant's oak (Quercus brantii L.) were determined in field measurements. Seeds of Quercus brantii L. were collected from 4 forest areas (seed sources) in southern Zagros (Provinces of Kohkilouyeh-Bouyer Ahmad and Fars) at altitudes of 850, 1,100, 1,500, 2,100 m a.s.l., and planted in a nursery constructed in southwestern Iran. According to a split-plot design consisting of four blocks, each containing two main treatment plots (no shading, partial shading), each main plot was sub-divided into four sub-plots (for elevations of 850, 1,100, 1,500 and 2,100 m). Results showed that shade treatments had significant effects on emergence percentage and rate, shoot length, shoot dry weight (SDW), root dry weight (RDW), leaf area (LA), and chlorophyll content. Ecological factors also had an effect on seed performance. Altitude of seed source had a very significant effect on root length, LA, SDW, and RDW. The seeds collected from 850 m a.s.l. elevation showed the highest performance, especially in leaf area, root length, shoot dry weight, and root dry weight. Our results showed that the altitude of 850 m a.s.l. was the best for collecting Brant's oak seeds.

• 한국생활과학회지
• /
• 제19권5호
• /
• pp.857-872
• /
• 2010

Recently, interest in fair tourism and demand for this service has been steadily increasing. This study examined the tourists' perceptions of their fair tourism experiences. Phenomenological method was adopted as a qualitative research approach. Participants were nine adults who were interviewed in depth on their experiences of fair tourism. Data analysis led to the emergence of seven categories (sharing and volunteerism, environment and animal protection, tourism created together, communication and relationship, from consumption to experience, ethicality and fairness, contemplating life) and 21 subcategories. This research was a significant step in providing options to explore the improvement of ethical-tourism and may have implications for the future development of tourism. This study also has various implications for tour operators, consumers, and government. In future all stakeholders should make efforts to establish the tour culture which encourages consumers to consider the ethicality and fairness of their choices as tourists.