CONGENERIC OCCURRENCES OF SPECIES OF DIAPTOMUS IN SOUTHERN ONTARIO LAKES

1967 ◽  
Vol 45 (1) ◽  
pp. 81-90 ◽  
Author(s):  
F. H. Rigler ◽  
R. R. Langford
Keyword(s):  
Vertical Distribution ◽  
Calanoid Copepods ◽  
Southern Ontario ◽  
Ecological Separation ◽  
The Difference ◽  
Limnocalanus Macrurus ◽  
The Vertical Distribution

The vertical distribution of adult calanoid copepods was studied in 100 lakes in southern Ontario. In addition to Epischura lacustris, Limnocalanus macrurus, and Senecella calanoides, seven species of Diaptomus were recorded. Diaptomus minutus and D. oregonensis, the commonest species, coexisted in 45% of the lakes. In 9% a third species was also present. Coexisting populations of D. minutus and D. oregonensis were not well separated by their vertical distribution, but a third species, if present, occurred in deeper water than these two. Size displacement does not contribute to the ecological separation of D. minutus and D. oregonensis. The difference in size between populations coexisting in the same lake is less than between populations living in separate lakes.

A Modified Freeze-Core Technique to Quantify the Depth Distribution of Fauna in Stony Streambeds

1983 ◽  
Vol 40 (5) ◽  
pp. 637-643 ◽  
Author(s):  
C. W. Pugsley ◽  
H. B. N. Hynes
Keyword(s):  
Vertical Distribution ◽  
Liquid Nitrogen ◽  
Benthic Invertebrates ◽  
Depth Distribution ◽  
Sampling Methods ◽  
Freezing Front ◽  
Southern Ontario ◽  
Freeze Core ◽  
Order Of Magnitude ◽  
The Vertical Distribution

A freeze-coring device using liquid nitrogen is described, which enables one person to take a columnar core, extending from the surface to at least 50 cm below a stony streambed. An experiment to validate the technique showed that animals did not flee from the advance of the freezing-front. Using frozen streambed cores, the vertical distribution of benthic invertebrates of two streams in southern Ontario was investigated. In contrast to previous estimates,~70% of the fauna was found in the top 10 cm of the streambed, and invertebrate densities were often lower by an order of magnitude. These differences are attributed to problems of quantifying previous sampling methods.

Calculation Method about Vertical Distribution of Saturated Sediment Concentration Based on Exchange Equilibrium

2013 ◽  
Vol 405-408 ◽  
pp. 2287-2291
Author(s):  
Xiao Xiang Feng ◽  
Pei Jiu Yue
Keyword(s):  
Diffusion Coefficient ◽  
Vertical Distribution ◽  
Diffusion Theory ◽  
Sediment Concentration ◽  
Exchange Equilibrium ◽  
Sediment Diffusion Coefficient ◽  
The Difference ◽  
The Vertical Distribution ◽  
And Diffusion ◽  
Key Parameter

Diffusion theory is the leading one which is used to study the vertical distribution of sediment concentration. And diffusion coefficient is a key parameter to determine the vertical distribution of suspended sediment. First of all, the calculation methods are introduced based on the momentum transfer theory and fluctuating velocity. According to the sediment equation of exchange equilibrium in vertical, the new expression is obtained for sediment diffusion coefficient and the vertical distribution of sediment concentration. By the flume experimental data and field data in natural river, the difference is analyzed among the different expressions.

The vertical distribution of thin features over the Arctic analysed from CALIPSO observations. Part I: Optically thin clouds

Tellus B ◽  
2011 ◽  
Vol 63 (1) ◽  
Author(s):  
Abhay Devasthale ◽  
Michael Tjernström ◽  
Karl-Göran Karlsson ◽  
Manu Anna Thomas ◽  
Colin Jones ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
The Arctic ◽  
The Vertical Distribution
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