the present study aims to have a comparative study of the results, from biological monitoring as well as conventional method, based on physico-chemical variables. water quality index (wqi) and planktonic diatom metrics have been used to determine water quality and ecological conditions of the dong nai river (dnr) and canonical correspondence analysis (cca) to find out the main environmental var...

abstract. the purpose of this study was to investigate the effects of topographical factors on the classification of grassland plant communities in the rangelands of ghorkhud, northern khorasan province, iran. for sampling, land units were specified. a floristic list was prepared using minimal area method based on the nested plot (braun-blanquet method). 116 10m2 furrows were selected. within e...

Macroinvertebrate communities and environmental variables were assessed seasonally for 1 year in a temporary river in South Portugal receiving an effluent with high conductivity, pH, sulphates, nitrates and low oxygen content. The usefulness of the ordination method canonical correspondence analysis (CCA) and the classification method cluster analysis (UPGMA) were examined to evaluate the pertu...

We examined woody species composition and its relation to environmental variables in native forest growing on four limestone islands in the southern Cook Islands: Atiu, Mangaia, Ma'uke, and Miti'aro. Relative dominance (percent basal area) of woody species in 74 sites was sampled using the point-centered quarter method, and the data were analyzed using clustering and ordination techniques. Thes...

We examined the taxonomic and morphological diversity of cichlid fish assemblages in a floodplain river in Venezuela during the dry season at two spatial scales: macrohabitats (lagoons, main channels and creeks) and mesohabitats (leaf litter, sand banks, rocky shoals and woody debris). Nonmetric multidimensional scaling did not reveal differences for species assemblages among macro and mesohabi...

background and objective: one way to promote education quality is to evaluate faculty activities by students, departmental heads, and the dean. the degree of correspondence between students' and departmental heads' evaluation shows how honest they are in their assessment. the current paper intends to find the truth.     materials and methods : questionnaires were used to conduct the s...

Weighted metric scaling (Cuadras and Fortiana 1995b) is a natural extension of classic metric scaling which encompasses several well-known techniques of Euclidean representation of data, including correspondence analysis of bivariate contingency tables. A continuous version of this technique, following the trend initiated in (Cuadras and For-tiana 1993, 1995a) is applied to the study of several...

Multivariate regression trees (MRT) are a new statistical technique that can be used to explore, describe, and predict relationships between multispecies data and environmental characteristics. MRT forms clusters of sites by repeated splitting of the data, with each split defined by a simple rule based on environmental values. The splits are chosen to minimize the dissimilarity of sites within ...