Statistical quantification of the effect of thermal stratification on patterns of dispersion in a freshwater zooplankton community
Thackeray, Stephen J; George, D. Glen; Jones, Roger I.; Winfield, Ian J.. 2006 Statistical quantification of the effect of thermal stratification on patterns of dispersion in a freshwater zooplankton community. Aquatic Ecology, 40. 23-32. 10.1007/s10452-005-9021-3Full text not available from this repository.
The vertical distribution of crustacean zooplankton species was examined during 2000 in Windermere, Cumbria. Patterns of dispersion were evaluated quantitatively using two different approaches. Firstly, Morisita’s index was used to test whether patterns of dispersion differed significantly from a state of randomness and, secondly, the relative distribution of zooplankton individuals between the epilimnion and hypolimnion was investigated, for a series of standardised vertical profiles of organism density. All six of the dominant species of planktonic crustaceans showed aggregated patterns of dispersion throughout the year. For most species, patterns of dispersion were affected by the onset and breakdown of thermal stratification in the lake. The degree of aggregation in the vertical plane, measured using Morisita’s index, increased when the lake became thermally stratified. Furthermore, for most species, there was a positive association between the degree of vertical differentiation in abundance across the thermocline, and the degree of temperature differentiation in the stratified water column. The results of the present analysis provide quantitative evidence for the phenomenon known as ‘zooplankton stratification’ and for temporal variation in patterns of zooplankton dispersion.
|Programmes:||CEH Programmes pre-2009 publications > Water|
|CEH Sections:||_ Ecosystem Assessment & Forecasting|
|Format Availability:||Electronic, Print|
|Additional Information:||The original publication is available at www.springerlink.com|
|Additional Keywords:||Morisita’s index, plankton, spatial heterogeneity, zooplankton stratification|
|NORA Subject Terms:||Zoology
Ecology and Environment
|Date made live:||27 Jun 2007 09:26|
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