scholarly journals Environmental Determinates of Distribution for Dragonfly Nymphs (Odonata: Anisoptera) in Urban and Non-Urban East Texas Streams, USA

Hydrobiology ◽  
2022 ◽  
Vol 1 (1) ◽  
pp. 76-88
Author(s):  
David E. Bowles ◽  
Leroy J. Kleinsasser
Keyword(s):  
Water Quality ◽  
Correspondence Analysis ◽  
Environmental Variables ◽  
Detrended Correspondence Analysis ◽  
Urban Streams ◽  
T Test ◽  
Benthic Habitats ◽  
Relationship Of ◽  
Quality Assessments ◽  
Dragonfly Species

We collected environmental and habitat data for nymphs of 12 dragonfly species (Odonata: Anisoptera) from 91 stream sites throughout eastern Texas, including urban and non-urban locations. Understanding the relationship of dragonflies to habitat structure and other environmental variables is crucial for the purpose of conserving these insects and better using them as predictive tools for water quality assessments, and refining tolerance values. The objectives of this study were to determine the key environmental variables influencing the diversity and distribution of dragonflies in eastern Texas streams, and further determine if differences in those factors could be observed between urban and nonurban sites. We collected samples separately from benthic habitats and woody snag habitats. Significantly fewer sites were observed to have dragonfly species on snag habitat (mean = 1.25) compared to benthic samples (mean = 14.67) (t-test, p = 0.001). The number of dragonfly species collected among non-urban streams (mean = 9.83) was not significantly different than urban streams (mean = 6.08; t-test, p = 0.07). Detrended correspondence analysis of benthic and snag habitat data collected from non-urban and urban locations showed that most of the species are oriented most closely to benthic habitats in non-urban streams. Snag habitat was shown to be poorly ordinated for all of the species. A canonical correspondence analysis of 29 water quality and habitat variables as environmental determinants of dragonfly diversity and distribution showed that distributional relationships among species are complex and often described by multiple environmental factors.

Patterns of behavior in the Texas tortoise, Gopherus berlandieri: a multivariate ordination approach

2001 ◽  
Vol 79 (8) ◽  
pp. 1363-1371 ◽  
Author(s):  
Richard T Kazmaier ◽  
Eric C Hellgren ◽  
David R Synatzske
Keyword(s):  
Correspondence Analysis ◽  
Wildlife Management ◽  
Environmental Variables ◽  
Detrended Correspondence Analysis ◽  
Behavioral Variability ◽  
Significant Variable ◽  
Active Behavior ◽  
Management Area ◽  
Dry Conditions ◽  
Patterns Of Behavior

We compared the distribution of 19 categories of behavior exhibited by 47 adult Texas tortoises (Gopherus berlandieri) over 3 years with the use of detrended correspondence analysis (DCA) and canonical correspondence analysis (CCA). DCA revealed a gradient from passive to active behavior along axis 1. Tortoises were more active in 1994 and less active in 1996. This pattern was likely due to the extremely hot and dry conditions in 1996. Year was the most significant variable explaining variability in behavior when sex, age, size, year, and grazing treatment (pastures grazed versus ungrazed by cattle) were used as environmental variables in CCA. Age, size, and grazing treatment were not significant variables in CCA. Tortoises used proportionally more burrows, shallow surface depressions termed pallets, and cavity pallets, and ate more cactus in 1996. More foraging and active behaviors, like courtship, were observed in 1994. Sex was a significant variable in explaining behavioral variability after the effects of year were controlled for. Males tended to exhibit more active behaviors than females. Our analyses suggested that the grazing regime used in Chaparral Wildlife Management Area did not affect the patterns of behavior exhibited by this protected tortoise.

Ordination as a tool for substantiating and interpreting floristic classifications: a case study

Bothalia ◽  
1990 ◽  
Vol 20 (2) ◽  
pp. 223-227 ◽  
Author(s):  
G. B. Deall ◽  
G. K. Theron
Keyword(s):  
Correspondence Analysis ◽  
Environmental Variables ◽  
Detrended Correspondence Analysis

Detrended Correspondence Analysis ordination is used as a tool for substantiating the authenticity of hierarchical syntaxa derived from a phytosociological classification of the vegetation of the Eastern Transvaal Escarpment in the Sabie area. Ecological interpretation of syntaxa is facilitated by superimposing environmental variables on axes of ordination.

scholarly journals Water Quality Assessments for Urban Water Environment

Water ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1686
Author(s):  
Pankaj Kumar
Keyword(s):  
Water Quality ◽  
Water Environment ◽  
Urban Water ◽  
Freshwater Resources ◽  
Intrinsic Connection ◽  
Quality Assessments

Since ages, human societies have witnessed the intrinsic connection between their all-encompassing development and freshwater resources [...]

scholarly journals An Overview on Water Quality Trending for Lake Water Classification in Malaysia

2018 ◽  
Vol 7 (3.23) ◽  
pp. 5
Author(s):  
Muhammad Muzzammil Shahabudin ◽  
Sabariah Musa
Keyword(s):  
Water Quality ◽  
Water Resources ◽  
Lake Water ◽  
Quality Index ◽  
Water Quality Assessment ◽  
Lake Water Quality ◽  
Water Classification ◽  
Quality Classification ◽  
Water Quality Classification ◽  
Quality Assessments

Lake water is important to all life and surroundings with multiples benefits and forms either in natural or man-made conditions. One of the most well-known tools for assessing the water quality is Water Quality Index (WQI) and widely used including Malaysia. Lake water quality should be represented in lucid way like other surface water regarding to the WQI standards for water quality assessment on lakes. This paper aims to review on lake water quality classification and its uses based on WQI standards in Malaysia. In this review, the uses of WQI for assessing the lake water and functioned of lakes are discussed. Results on pH from 5.0 to 9.2, BOD in mg/l from 0 to 180, COD in mg/l from 5 to 150, SS in mg/l from o to 1800, DO in mg/l from 0 to 8 and AN in mg/l N from -1 to 26. Variety of numbers is due to different loading of pollutions and location. With used of WQI on lake water quality assessments, further action can be taken for the uses on water resources by maintaining the quality. It also will broaden the uses of lake water as alternative of water resources in Malaysia.  

Environmental factors including management practices as correlates of weed community composition in spring seeded crops

1992 ◽  
Vol 70 (10) ◽  
pp. 1931-1939 ◽  
Author(s):  
M. R. T. Dale ◽  
A. G. Thomas ◽  
E. A. John
Keyword(s):  
Community Composition ◽  
Correspondence Analysis ◽  
Canonical Correspondence Analysis ◽  
Environmental Variables ◽  
Management Practices ◽  
Geographic Region ◽  
Climatic Conditions ◽  
Weed Species ◽  
Weed Communities ◽  
Seed Crops

The relationship between the weed communities and environmental variables such as soil, crop, and management was investigated in two provinces of Canada. The frequencies of weed species were recorded in cereal and oilseed fields in Saskatchewan (2244 fields over 4 years) and Manitoba (864 fields over 3 years), Canada. Information on some of the physical characteristics of the fields and on the management practices imposed on them was also collected, in part by questionnaire. The two kinds of data were ordinated together using canonical correspondence analysis to assess the relationships between the species and the environmental variables. In the Saskatchewan data, there was a clear and consistent separation of the species into groups along an axis correlated with soil zone and the associated climatic gradient. In the Manitoba data, the same groups of species did not separate as clearly or as consistently, although geographic region was a major determinant of the weed communities. The greater variability may be due to the fact that the gradient of soil types is much more restricted in Manitoba and not as closely correlated with climatic conditions. In both provinces, culture practices were less important as correlates of the weed community composition than soil type or, to a certain extent, the previous crop. Key words: canonical correspondence analysis, cereal crops, oil seed crops.

scholarly journals Study of Relationship of Anemia among Edentulous Patients

2018 ◽  
Vol 5 (2) ◽  
pp. 105-108
Author(s):  
Lijo Isaac ◽  
A. P. Nirmal Raj ◽  
Reshma Karkera ◽  
R Naveen Reddy
Keyword(s):  
Nutritional Status ◽  
T Test ◽  
Dental Status ◽  
Adult Patients ◽  
Control Group ◽  
Age Group ◽  
Edentulous Patients ◽  
Student’S T ◽  
Relationship Of ◽  
Student’S T Test

Very little studies were done on relationship of the dental status and the nutritional status. The present study was done to study relation between edentulism and the presence of anemia. The study was included of 46 adult patients with edentulism and same numbers of patients were taken as controls. The results were tabulated and analyzed with the help of IBM SPSS statistics 20 using student’s t test. The hemoglobin levels were lower in the edentulous patients that that of the control group. The present study had shown that the nutritional status were poor resulting in anemia in case of edentulous patients as compared to control group with the same age group.  

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