Efficiency of sampling gears (Quadrate and Core) and Taxonomic Resolution on the Soft Bottom Intertidal Macrobenthic community of Port Blair coast

2021 ◽  
Vol 25 (11) ◽  
pp. 93-103
Author(s):  
Nosad Sahu ◽  
Ganesh Thiruchitrambalam ◽  
Raj Kiran Lakra
Keyword(s):  
Correlation Coefficient ◽  
Similarity Index ◽  
Rank Correlation ◽  
Work Capacity ◽  
Information Loss ◽  
Taxonomic Resolution ◽  
Soft Bottom ◽  
Macrobenthic Communities ◽  
Taxonomic Level ◽  
Family Level

Ecological studies of a region cannot proceed forward without the evaluation of species diversity. With the ever-increasing demand for studies to understand the change in the macrobenthic communities, the focus has primarily been shifted towards faster results to track down the changes from the prior environments. Therefore, studying the complete benthos faunal diversity of an area leads to an unrealistic approach. Thus, researchers tend to depend on various sampling gears, which ease the work capacity. The present study compared two samplings gears (core and quadrate) in two different habitats to understand the diversity of the macrobenthic communities. In terms of abundance, the core gear showed higher significant differences as compared to quadrate. However, the gears did not significantly differ among the diversity indices (Margalef's index and Shannon- Winer index) and the cluster analysis (Bray-Curtis similarity index and nMDS). The present study found that the 'information loss' was minimal with the aggregated data at a higher taxonomic level. Spearman rank correlation coefficient revealed that the information loss was low up to family-level and the correlation coefficient decreases as the taxonomic level increases after family-level. Nonetheless, the choice of sampling gears did not influence the diversity of the soft-bottom intertidal macrobenthic communities.

Note on Use of phi as a Simplified Partial Rank Correlation Coefficient

1966 ◽  
Vol 18 (3) ◽  
pp. 973-974 ◽  
Author(s):  
Richard W. Johnson
Keyword(s):  
Correlation Coefficient ◽  
Rank Correlation ◽  
Partial Rank Correlation

Use of phi as a simplified partial rank correlation coefficient is described and illustrated.

Minimal sampling requirements for a precise assessment of soft-bottom macrobenthic communities, using AMBI

2007 ◽  
Vol 349 (2) ◽  
pp. 323-333 ◽  
Author(s):  
Iñigo Muxika ◽  
Leire Ibaibarriaga ◽  
José Ignacio Sáiz ◽  
Ángel Borja
Keyword(s):  
Soft Bottom ◽  
Macrobenthic Communities ◽  
Precise Assessment

scholarly journals Comparing the performance of different stream classification systems using aquatic macroinvertebrates

2013 ◽  
Vol 25 (4) ◽  
pp. 406-417 ◽  
Author(s):  
Márlon de Castro Vasconcelos ◽  
Adriano Sanches Melo ◽  
Albano Schwarzbold
Keyword(s):  
Randomization Test ◽  
Classification Systems ◽  
Data Type ◽  
Taxonomic Resolution ◽  
Stream Classification ◽  
Environment Variables ◽  
Family Level ◽  
Community Data ◽  
Performance Results ◽  
Classification Strength

AIM: We evaluated five stream classification systems observing: 1) differences in richness, abundance and macroinvertebrates communities among stream classes within classification systems; and 2) whether classification systems present better performance using macroinvertebrates. Additionally, we evaluated the effects of taxonomic resolution and data type (abundance and presence) on results. METHODS: Five stream classification systems were used, two based on hydroregions, one based on ecoregions by FEOW, a fourth one based on stream orders and the last one based on clusters of environment variables sampled in 37 streams at Rio Grande do Sul state, Brazil. We used a randomization test to evaluate differences of richness and abundance, a db-MANOVA to evaluate the differences of species assemblages and Classification Strength (CS) to evaluate the classifications performance. RESULTS: There were differences of richness and abundance among stream classes within each stream classification. The same result was found for community data, except for stream order classifications in family level. We observed that stream classes obtained for each stream classification differed in terms of environment variables (db-MANOVA). The classification based on environment variables showed higher CS values than other classification systems. The taxonomic resolution was important to the observed results. Data on genera level presented CS values 12% higher than family level for cluster classification, and the data type was dependent on the classification system and taxonomic resolution employed. CONCLUSION: Our results indicate that classifications based on cluster of environment variables was better than other stream classification systems, and similar results using genera level can be obtained for management programs using family resolution in a geographical context similar to this study.

scholarly journals An analysis of cloud overlap at a midlatitude atmospheric observation facility

2011 ◽  
Vol 11 (12) ◽  
pp. 5557-5567 ◽  
Author(s):  
L. Oreopoulos ◽  
P. M. Norris
Keyword(s):  
Correlation Coefficient ◽  
Seasonal Variations ◽  
Rank Correlation ◽  
Domain Size ◽  
Separation Distance ◽  
Cloud Fraction ◽  
Vertical Resolution ◽  
Clear Tendency ◽  
Systematic Relationships ◽  
Overlap Parameter

Abstract. An analysis of cloud overlap based on high temporal and vertical resolution retrievals of cloud condensate from a suite of ground instruments is performed at a mid-latitude atmospheric observation facility. Two facets of overlap are investigated: cloud fraction overlap, expressed in terms of a parameter "α" indicating the relative contributions of maximum and random overlap, and overlap of horizontal distributions of condensate, expressed in terms of the correlation coefficient of condensate ranks. The degree of proximity to the random and maximum overlap assumptions is also expressed in terms of a decorrelation length, a convenient scalar parameter for overlap parameters assumed to decay exponentially with separation distance. Both cloud fraction overlap and condensate overlap show significant seasonal variations with a clear tendency for more maximum overlap in the summer months. More maximum overlap is also generally observed when the domain size used to define cloud fractions increases. These tendencies also exist for rank correlations, but are significantly weaker. Hitherto unexplored overlap parameter dependencies are investigated by analyzing mean parameter differences at fixed separation distance within different layers of the atmospheric column, and by searching for possible systematic relationships between alpha and rank correlation. We find that for the same separation distance the overlap parameters are significantly distinct in different atmospheric layers, and that random cloud fraction overlap is usually associated with more randomly overlapped condensate ranks.

scholarly journals The relationship between the effectiveness of performing technical elements and indicators of static and dynamic balance in young acrobats 6-7 years old

2021 ◽  
Vol 7 (4) ◽  
pp. 58-68
Author(s):  
T. Chernykh ◽  
V. Mulyk ◽  
K. Mulyk ◽  
А. Skaliy ◽  
А. Ostrowski ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Dynamic Equilibrium ◽  
Dynamic Balance ◽  
Rank Correlation ◽  
Young Athletes ◽  
Spearman’S Rank Correlation ◽  
Spearman’S Rank Correlation Coefficient ◽  
Initial Stage ◽  
Equilibrium Test ◽  
The Relationship

Purpose: to determine the relationship between the performance of basic elements and indicators of static and dynamic balance in the training process of young acrobats 6-7 years. Material and methods. The study involved 16 young acrobats at the stage of initial training (age 6-7 years). All parents of the participants gave written consent for the participation of children in the study. The study involved testing the technique of performing basic elements of sports acrobatics and assessing the static and dynamic balance of young athletes. The relationship between (swallow, shoulder blade, forward squat, wheel (sideways overturning), bridges) and static and dynamic equilibrium tests was determined. Spearman's rank correlation coefficient method was used as a method of statistical analysis. Results. It is established that the largest relationship between the performance of basic elements and static balance in the basic exercises of young acrobats have: Romberg's test with the elements "Swallow", "Stand on the shoulders", "Bridge"; Biryuk test with elements "Swallow", "Wheel", "Bridge"; balance "Swallow" with elements "Swallow", "Wheel"; static equilibrium test with the elements "Swallow", "Rack on the shoulders", "Rolling forward with a squat", "Wheel". Reliable values ​​of the correlation coefficient were established between the tests of dynamic balance and the basic elements of sports acrobatics in young athletes 6-7 years, namely: "Swallow", "Flip forward with a squat", "Wheel" and "Bridge". The analysis of special tests of static and dynamic balance in mastering the basic elements of acrobatics at the first stage of long-term training makes it possible to use them to determine the level of coordination capabilities of young athletes and further improve the use of acrobatic exercises. Conclusions. A reliable relationship between the performance of basic exercises and indicators of static and dynamic balance in young acrobats at the initial stage of training. It is shown that the level of static and dynamic balance is of great importance for the assimilation and improvement of basic elements of technology by young acrobats 6-7 years. Static and dynamic balance tests can be used to individually build training programs and young acrobats. It is shown that sports acrobatics is a significant means of developing the balance of children 6-7 years.

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