• The Korean Journal of Applied Statistics
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• v.28 no.1
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• pp.49-60
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• 2015

Various kinds of ordination methods such as correspondence analysis and canonical correspondence analysis are used in community ecology to visualize relationships among species, sites, and environmental variables. Ter Braak (1986), Jackson and Somers (1991), Parmer (1993), compared the ordination methods using eigenvalue and distance graph. However, these methods did not show the relationship between population and biplot because they are only based on surveyed data. In this paper, a method that measures the extent to show population information to biplot was introduced to compare ordination methods objectively.

• The Korean Journal of Ecology
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• v.15 no.2
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• pp.117-125
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• 1992

TWINSPAN(two-way indicator species analysis), DCCA(detrended canonical correspondence analysis) and polar ordination method wee used so as to analyze the the relation between forest vegetation and hibitat of mudungsan(1, 187m) located in kwangju area. Vegetationsurvey consulted 1:25, 000 topographical map, set up 41 quadrats and analyzed from April, 1990 to August, 1991. Forest vegetation of mudungsan was classifild to quercus acutissima community, fraxinus mandshurica community, quercus mongolica community, quercus serrata community, quercus dentata community, quercus variabilis community, and pinus densiflora community by TWINSPANmethod, and this almost coincide with the result of plar ordination. according to DCCA analysis, P. densiflora community was formed in xeric and low altitude region which soil nutrient was poor, compared with other communities. q. variabilis and q. acutissima community wee distributed in the region that low altitude and organic matter content was comparatively low, but q. acutissima community was formed in a damp region while q. variabilis community in a xeric region. q. mongolica and f. mandshurica formed the communities in a high altitude region, especially f. mandshurica cmmunity was distributed in a high humidity region. According to polar ordination analysis, the forest vegetation was classified to 7 communities by means of environmental gradient such as humidity, organic matter, ph, temperature, c.e.c and P2O5.

• The Korean Journal of Ecology
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• v.9 no.3
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• pp.135-147
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• 1986

The simplification and the searching trends of complex data which assumed relationship between predictor variables and object variables are one of primary objective of ecological research. This study was aimed to apply cononical analysis consisting of canonical correlation analysis and canonical variate analysis related to lichen vegetation and several environmental variables which are elevation, height on grond, exposure side and cover values. Data collected from the Duckyoo National Park in August 1985. Lichen species was ranked by eqivocation information theory with cover values. Canonical correlation analysis was applied to one data set both set both environmental variables and lichem family. In order to make two sets of data matrix the scale of position vector ordination was calculated from the vector scalar product for lichen species. Canonical variate analysis was applied to rearranged data which was made by interval class code for environmental variables. The sharpness values was calculated in frequency of cotingency tables and the dispersion profiles of each species in classes of environmental variables was designed to extract component values based on the decomposition of expected frequencies in contingency table. The results of canonical correlation analysis revealed canonical first correlation value 0.815(89%), and second correlation value 0.083(11%). Significance test showed that the hypothesis of joint mutuallity of canonical correlation is accepted (P>0.05). The relation between canonical score of vegetation variables and that of environmental variable indicated linear tendency.

• The Korean Journal of Ecology
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• v.20 no.2
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• pp.125-132
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• 1997

A study of forest vegetation in Mt. $T\v{o}kyu$ National Park was investigated by ordination technique. By TWINSPAN(Two-Way Indicator Species Analysis) method, 10 groups were recognized as follows: pinus densiflora, Quercus variabilis, Quercus serrata, Quercus mongolica-Rhododendron schlippenbachii, Quercus mongolica-Abies koreana, Quercus mongolica-Acer pseudo-sieboldi-amum, Quercus mongolica-Symplocos chinensis for. pilosa, Carpinus laxiflora, Fraxinus mandshurica and Taxus cuspidata groups. The floristic composition of these groups showed high correlation to soil moisture(r=0.831), altitude(r=0.784), topography(r=-0.722), organic matter(r=0.642), and pH(r=-0.509) among various environmental factors. According to the results of CCA(Canonical Correspondence Analysis) Pinus densiflora group and Quercus variabilis group were situated in a xeric area at a lower altitude where soil nutrients were poor compared with the other groups. Fraxinus mandshurica group was distributed throughout the valley with high soil moisture and good nutrients, Quercus serrata group and Carpinus laxiflora group were found in the low altitude region with good nutrients, Quercus mongolica group, at the high altitude region with good nutrients, and Quercus mongolica-Acer koreana and Taxus cuspidata at higher altitudes(1, 400-1600 m).

• The Korean Journal of Applied Statistics
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• v.28 no.3
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• pp.485-494
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• 2015

Canonical correspondence analysis is an ordination method used to visualize the relationships among sites, species and environmental variables. However, projection results are fluctuations if the samples slightly change and consistent interpretation on ecological similarity among species tends to be difficult. We use the bootstrap methods for canonical correspondence analysis to solve this problem. The bootstrap method results show that the variations of coordinate points are inversely proportional to the number of observations and coverage rates with bootstrap confidence interval approximates to nominal probabilities.

• Journal of Korean Society of Forest Science
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• v.81 no.4
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• pp.310-319
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• 1992

Vegetational data obtained from 24 quadrats of Mt. Paekdu area were analysed by applying two multivariate methods : two-way indicator species analysis(TWIMSPAN) for classification and detrended canonical correspondence analysis(DCCA) for ordination. DCCA technique allowed to extract the ordination axes that could be related to 9 environmental factors. The dominant tree species distributed in the region between 1,700-1,950m from sea level were Betula ermanii, Larix olgensis, Abies nephrolepis, and Picea jezoensis in descending order. The dominant tree species distributed in the region between 1.300-1.500m were Abies nephrolepis, Pinus koraiensis, Larix olgensis, Betula mandshurica, and Picea jezoensis in descending order. The available phosphorus content in forest soil ranged from 7 to 1.153ppm. The distribution of the major communities showed a close relationship with elevation gradient. From high to low elevation, the communities of Alnus fruticosa var. mandshurica, Betula ermanii, Larix olgensis, Abies nephrolepis, Picea jezoensis, Pinus koraiensis, and Quercus mongolica were found in descending order. At the communities where Betula ermanii was dominant, Betula ermanii forest was distributed in the high elevation area, Betula ermanii-Larix olgensis forest in the good nutrition of organic matter and $K^+$, and Abies nephrolepis forest in the good nutrition of $Mg^{{+}{+}}$ and $Ca^{{+}{+}}$. The most dominant factor influencing community distribution was elevation.

• Korean Journal of Environment and Ecology
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• v.21 no.4
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• pp.318-335
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• 2007

Floral study and present vegetation survey were conducted at a representative reclaimed wetland located behind the Rural Research Institute at Ansan, Gyeonggi-do. The importance values were calculated from the ground cover and frequency of recorded species within quadrats and detrended canonical correspondence analysis was conducted using environment variables, such as total nitrogen, electric conductivity, available phosphate, nitrate nitrogen and the distance from the inner roads. And basal areas for the trees encroaching on the reclaimed wetland were estimated to take a look at the on-going situation about the succession routes on land. As a result, 46 families and 158 species of plants were recorded and Pragmites communis was found to be a dominant species as the present vegetation. The ordination analysis results showed that species distribution was purposely explained by total nitrogen in soil and its content in nitrate nitrogen. The invasion of Robinia pseudoacacia and Pinus rigida whose basal areas were $22.3m^2$ and $1.6m^2$ respectively, into the interior areas of the reclaimed wetland was found to cause a disturbance making some parts of the wetland into land. The zoning program using water level control and migratory roads is becoming a contributing factor in destroying a wetland, so it's suggested that some adjustments should be needed to take care of it.

• Journal of Korean Society of Forest Science
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• v.79 no.2
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• pp.216-221
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• 1990

Vegetational data from Mt. Gyeryong and Deokyu in central Korea were analysed in relation to 15 environmental variables. Two multivariate methods were applied : two-way indicator species analysis (TWINSPAN) for classification and detrended canonical correspondence analysis(DCCA), a recent technique which extracts ordination axes that can be related to environmental factors. The relationship between the distribution of dominant species of forest vegetation and soil condition in Mt. Gyeryong and Deokyu was investigated by analyzing elevation and soil nutrition gradient. Quercus mongolica forest was distributed in the high elevation and good nutrition area, Carpinzrs laxiflora and Fraxinus rhynclzophylla forest in the medium elevation and good nutrition area, Piszus densiflora-Quercus mongolica and Quercus variabilis forest in the medium elevation and medium nutrition area, Styrax jabozaica forest in the low elevation and medium nutrition area, and Pinus densiflora forest in the low elevation and poor nutrition area. The dominant compositional gradient related to elevation.

• Journal of Korean Society of Forest Science
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• v.83 no.2
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• pp.262-269
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• 1994

In order to determine ecological niches of forests in Mt. ManDeok, the studies were analyzed on the methods of TWINSPAN and DCCA ordination. The results are summarized as follows ; Four groups were determined by TWINSPAN : Styrax japonica. Quercus variabilis-Quercus mongolica, Carpinus laxiflora and Fraxinus mandshurica-Cornus controversa communities. In the relations of community structures and environmental factors, Styrax japonica community were distributed in the rich site of magnesium and organic matter, Quercus variabilis-Quercus mongolica community in the low potassium, Carpinus laxiflora community in the low available phosphorus, and the factors in influencing community distribution were elevation. The importance value of Quercus variabilis recorded the highest in all the quadrats sampled and the next values then came those Cornus controversa. Quercus variabilis, Lindera erythrocarpa. Quercus mongolica, Fraxinus mandshurica. Cornus controversa, Symplocos chinensis for pilosa, Acer mono, Carpinus laxiflora, and Styrax japonica in the orders. The species diversities of major dominant species recorded the highest value in the communities of Quercus variabilis-Quercus mongolica but they lowest value in the communities of Fraxinus mandshurica-Cornus controversa.

• Korean Journal of Ichthyology
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• v.34 no.2
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• pp.102-112
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• 2022

This study investigated dietary habits and intra- and inter-specific food resource partitioning of co-occurring walleye pollock (Gadus chalcogrammus) and Pacific cod (G. macrocephalus) from the waters off the north-eastern coast of South Korea using stomach contents and stable isotopes (δ¹³C and δ¹⁵N) analyses. Both species are mesopelagic carnivores that consumed mainly benthopelagic crustaceans, but teleosts were also abundant in the diet of Pacific cod. Non-metric multidimensional scaling (nMDS) ordination and permutational multivariate analysis of variance (PERMANOVA) of dietary data revealed significant intra- and inter-specific dietary differences, i.e., food resource partitioning. Nitrogen stable isotope values (δ¹⁵N) were similar between walleye pollock and Pacific cod, but carbon stable isotope values (δ¹³C) were significant different, suggesting different trophic positioning. Canonical analysis of principal coordinate (CAP) ordination plot further demonstrated that differences in the type and range of prey ingested by the two species contributed such an inter-specific difference in the diet compositions. Ontogenetic changes in diet compositions were evident. As walleye pollock, they preyed more upon carid shrimps and cephalopods, but no such trend was observed in the diets of Pacific cod. While stable isotope values indicated that large-sized specimens of both species were significantly enriched in ¹⁵N relative to smaller conspecifics thus supporting these data. Consequently, in this study, both methodologies, i.e., stomach contents and stable isotope analyses, provided evidence of inter- and/or intra-specific dietary segregations and trophic niche partitioning between co-occurring walleye pollock and Pacific cod off eastern Korean waters.