• The Korean Journal of Ecology
• /
• v.14 no.4
• /
• pp.399-413
• /
• 1991

Benthic macroinvertebrate communities and environments at the upper and lower sites of levees in the middle reaches of paenae stream, a tributary of the naktong river,were investigated in four seasons from August 1989 to may 1990. Current velocities were significantly fast at the loer sites than the upper sites of levees. Substratum compositions were also different between these two sites. Abundances of major species of benthic macroinvertebrates occurring in four seasons were primarily dtermined by temperature. in each location of levees, however, current velocities and substratum particle sizrs were important in determining species were generally higher than upper sites of levees. Biological indices were also high at the lower sites of levees. diversity, evenness and dominance indices were positively correlated with the quantity of the middle-sized large pebbles(3∼5cm in diameter) in stream bed.

• Journal of Ecology and Environment
• /
• v.36 no.1
• /
• pp.101-112
• /
• 2013

To quantitatively analyze the effects of burning, we conducted a vegetation survey in the grasslands in Kirigamine, central Japan. We classified each species into stages of succession based on the life-history traits of the species and defined the score of the species in each stand based on the classification. We weighted the scores with a v-value, the product of coverage and height in the quadrat, and summed them to calculate the index of dynamic status. With these indices, we were able to quantitatively compare the stands in the study area and discern minute differences between the stands with different lengths of restoration periods since the disturbance of burning. These indices correlated with the v-value of trees, suggesting that the disturbance of burning seemed to affect the trees in the stand. We then calculated the growth of the tree species Pinus densiflora to evaluate its contribution to the index of dynamic status.

• Journal of Ecology and Environment
• /
• v.36 no.1
• /
• pp.95-100
• /
• 2013

Many countries have adopted a single, well-described approach to the use of phototrophs for monitoring river water quality, which involves the use of indices related to diatom composition at a site. Increasingly these indices have focussed on assessing ambient phosphate concentration. However, there is a wide range of other methods which can provide additional information to make up for any weaknesses in the standard method. Some of these methods are reviewed briefly here. They can be useful, for instance, when considering temporal and spatial variability in phosphate concentration at a particular site and providing much more insight on heavy metal or pesticide pollution than revealed by routine water analysis.

• Journal of Ecology and Environment
• /
• v.33 no.4
• /
• pp.363-376
• /
• 2010

Vegetative communities of created wetlands often display lower species richness, less cover, higher occurrence of non-native or invasive species, and fewer obligate wetlands species than those in natural wetlands, thus failing to meet basic success criteria for wetland mitigation. This study examined the effects of two design elements, disking-induced microtopography and hydrologic regime, on the first year vegetation development pattern of a mitigation wetland newly created in the Virginia piedmont. Elevation and species cover were measured along replicate multiscale circular transects in two adjacent wetland sites that are different in their hydrologic regime. Two microtopographic indices, tortuosity (T) and limiting elevation difference (LD), were calculated from the elevation measurements. Both indices were higher in disked plots than non-disked plots, showing the effect of disking on microtopography. Out of forty-one vegetation taxa observed in the wetland, 29 taxa were naturally colonized and 12 taxa were seeded. All plots except one non-disked plot were dominated by wetland vegetation. Species richness and diversity were higher in disked than in non-disked plots. Vegetation community development seemed also influenced significantly by hydrologic regime of the site. The effect of microtopography on species richness and diversity was more pronounced in a relatively dry site compared to a wet site. In addition, percent cover, species richness and diversity of vegetation were positively correlated with microtopographic indices such as T and LD. Two design elements, microtopography and hydrologic regime, should be considered and incorporated in wetland creation to enhance plant community development.

• Journal of Ecology and Environment
• /
• v.33 no.2
• /
• pp.105-114
• /
• 2010

The principal objective of this study was to characterize the relationships between geographical conditions (e.g., island area, distance to mainland) and landscape structures of uninhabited islands, and to evaluate the effects of islands and their landscape structures on species richness. One hundred randomly selected islands and 5,000 m buffered areas derived from the boundaries of each island were used to summarize the number of observed bird species, and landscape pattern indices, particularly patch density, edge density, shape index, and mean nearest neighboring distance. Spatial arrangements of individual patch type at the class level, which are markedly affected by the distance from an island to the mainland, have a superior ability to explain the variances in species richness, as compared to the geographical conditions and landscape pattern indices at the landscape level. The results demonstrate that the patch type landscape structure is the primary factor affecting species richness, as well as the distance to the mainland. In particular, landscape pattern indices of cropland/pasture and woody cover are statistically significant in terms of explaining species richness, which suggests that food resources and appropriate conditions in landscape structures of habitat types are assumed as important elements in attracting bird species. This study also proposes the importance of evaluation on the landscape structure of each island, in order to designate protected areas and to establish a management plan for species conservation in uninhabited islands.

• STI Policy Review
• /
• v.1 no.2
• /
• pp.51-68
• /
• 2010

This paper compares OECD nations by developing a comprehensive evaluation index that examines the efforts and achievements of countries toward Low-Carbon Green Growth. The input-process-output of a Low-Carbon Society system is in dynamic competition with that of a High-Carbon Society system. The model used in this study of the comprehensive evaluation index for Low-Carbon Green Growth was comprised of Large indices such as Input, Process, and Output. The Input and Output consisted of 'Social-economic' and 'Physical-ecological' Middle indices while the Process was made up of 'Stimulation mechanisms' and 'Participation of stakeholders and Knowledge flow' Middle indices. In order to calculate the comprehensive evaluation index, our model gave a weight to each indicator/index and applied a weighted arithmetic mean. Korea ranked $15^{th}$ out of 30 OECD nations in the comprehensive evaluation that analyzed Input ($14^{th}$), Process ($18^{th}$), and Output ($17^{th}$). The top five nations were Switzerland, Sweden, Denmark, Germany, and France; while Japan was $8^{th}$ and the USA $26^{th}$.

• Journal of Environmental Science International
• /
• v.11 no.3
• /
• pp.149-154
• /
• 2002

This study was conducted to find the structure of phytoplankton community in the Hoeya river(Ulsan) from March 2000 to February 2001. The taxa of phytoplankton identified included 135 species, 5 divisions, 33 families and 82 genera. Among them, chrysophyta(diatoms) were 63 species(46.7%), chlorophyta(green algae) 47 species(34.8%), pyrrophyta(dinoflagellates) 13 species(9.6%), cyanophyta (cyanobacteria) 8 species(5.9%) and euglenophyta(euglenoids) 4 species(3.0%) respectively. Ecological important species is called frequently appearing species, red tide causative species, seawater species and pollution indicator. 22 species including Aulacoseira granulate were recorded frequently appearing species. 19 species including Ceratium furca were recorded as red tide causing species. And the pollution indicators were 33 species including Actinastrum hantzschii var. fluviatile. The highest standing crops were 3,103,441 cells/$\ell$ in August at the RW-1 and the lowest 1,245 cells/ $\ell$ in January at the RW-5. In the community analysis, the dominanance indices ranged from 0.34(October, RW-2) to 0.94(January, RW-1) and the diversity indices from 0.50(May, RW-2) to 2.57(September, RW-2). The saprobic indices were 2.43 in RW-1, 2.41 in RW-2, 2.375 in RW-3, 2.40 in RW-4, 2.43, in RW-5. Therefore, these areas were investigated "$\beta$-mesosaprobic". According to the similarity index among the stations, these areas were defined as residential district areas(RW-2 and RW-3), lower part of the dam (RW-1) and seawater areas(RW-4 and RW-5).

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.21 no.1
• /
• pp.119-132
• /
• 2018

This study was conducted to suggest an assessment indices to evaluate the ecosystem services of the unique functions of wetlands as well as economic value provided by the village wetlands. The assessment indicators applied in this study were used by the RAM indices. The results of RAM assessment on the village wetlands in Cheonan city were analyzed by item and critical functions of the village wetland. They were derived by assessment indicators of ecosystem services, and the village wetland ecosystem were presented by Focus Group Interview (FGI). The 20 critical indices were selected from 52 different indices by analyzing the wetland function assessment items. 13 indicators excluding duplicate indexes by function, were selected as ecological service impact indicators. Finally, ecosystem services were evaluated by using AHP analysis to calculate the weight of each assessment indices and apply it to the 9 village wetlands. The results of this study confirmed that the functions of the village wetlands are compliant with the ecosystem services. Based on this assessment of the unique functions of wetlands, it will serve as a methodology for assessing ecosystem services. The study was also conducted on 49 wetlands in Cheonan. The detailed assessment of wetland ecosystem services based on the wetland ecosystem function proposed by this study, was further developed as a follow-up study. It suggested that the wetland areas should be compared and be used as a general standard. In addition to the assessment of the economic value of ecosystem services provided by the village wetlands, it would be useful to assess the unique features and convert them into value.

• Journal of Forest and Environmental Science
• /
• v.31 no.2
• /
• pp.126-135
• /
• 2015

This study was conducted to evaluate the ecological characteristics of forest cover types which were classified by cluster analysis in the natural forest of Sobaeksan on the basis of the vegetation data from the point-quarter sampling method. Recognized forest cover types were 1) Mixed mesophytic forest, 2) Taxus cuspidata forest, 3) Fraxinus rhynchophylla-Quercus mongolica forest, 4) Betula ermanii forest, 5) Pinus densiflora forest, 6) Quercus mongolica mixed forest, and 7) Quercus mongolica pure forest. For those of classified types, the species composition was expressed by importance value (IV) to describe the community floristically. The species diversity was quantified using the Shannon's diversity index. The results showed that the forest cover types were characteristically different from one another in growing species and compositional rates, depending upon the type which was formed by a number of similar vegetational sample points. Species diversity indices (H') of total and overstory both were the highest in the mixed mesophytic forest (3.530 and 2.880, respectively), and lowest in the Q. mongolica pure forest (2.122 and 0.000, respectively) with only one canopy species. The highest species diversity in the mixed mesophytic forest may due to the relatively high species richness and evenness in the forest cover types. The description on ecological characteristics were suggested to understand the formation and development of forest cover types in this study area.

• Korean Journal of Environmental Biology
• /
• v.42 no.2
• /
• pp.207-218
• /
• 2024

Food webs have received global attention as next-generation biomonitoring tools; however, it remains challenging because revealing trophic links between species is costly and laborious. Although a link-extrapolation method utilizing published trophic link data can address this difficulty, it has limitations when applied to construct food webs in domestic streams due to the lack of information on endemic species in global literature. Therefore, this study aimed to develop a link extrapolation-based food web model adapted to Korean stream ecosystems. We considered taxonomic similarity of predation and dominance of generalists in aquatic ecosystems, designing taxonomically higher-level matching methods: family matching for all fish (Family), endemic fish (Family-E), endemic fish playing the role of consumers (Family-EC), and resources (Family-ER). By adding the commonly used genus matching method (Genus) to these four matching methods, a total of five matching methods were used to construct 103 domestic food webs. Predictive power of both individual links and food web indices were evaluated by comparing constructed food webs with corresponding empirical food webs. Results showed that, in both evaluations, proposed methods tended to perform better than Genus in a data-poor environment. In particular, Family-E and Family-EC were the most effective matching methods. Our model addressed domestic data scarcity problems when using a link-extrapolation method. It offers opportunities to understand stream ecosystem food webs and may provide novel insights into biomonitoring.