Skip to main content

Changes in taxonomy and species distributions and their influence on estimates of faunal homogenization and differentiation in freshwater fishes

Buy Article:

$43.00 plus tax (Refund Policy)

Abstract Aim 

To assess how changing taxonomy and distribution data affect estimates of faunal homogenization and differentiation as agents of global change in freshwater fishes. Location 

Provinces and territories of Canada. Methods 

Species presence–absence data were collated in 2000 and 2005 from regional and national lists, and faunal homogenization and differentiation were calculated using Jaccard’s faunal similarity index. Differences between time periods and areas were summarized using principal coordinate analysis. Differences in faunal assemblages between native and total faunas were assessed via Whittaker’s (1960) beta diversity (βw) index and tests of differences in multivariate dispersion of fish species compositions. Results 

Among aquatic ecoregions in one province (British Columbia) there were four taxonomic changes and 18 distributional changes between the 2000 and 2005 databases. Pairwise Jaccard’s faunal similarity index between the eight aquatic ecoregions declined by an average of 4.8% from 35.9% in native faunas to 31.1% in total faunas (introductions – extinctions/extirpations) indicating overall faunal differentiation. Average pairwise similarity declined by 0.9% between 2000 and 2005. Across thirteen provinces and territories of Canada, there were five taxonomic changes and 61 distributional changes between the 2000 and 2005 databases. Generally, faunal homogenization increased; pairwise Jaccard’s increased by an average of 1.8% from 27.1% in native faunas to 28.9% in total faunas or an average of 0.6% per comparison. Main conclusions 

Despite changing taxonomy and fish distribution information, comparative analysis of 2000 and 2005 databases consistently show overall faunal differentiation at the smallest (provincial) spatial scale and homogenization at the largest scale (across Canada) and that these trends continued between time periods. Homogenization and differentiation followed expectations from conceptual models based on the relative prevalence of species invasions and extinctions within communities. General conclusions of the onset and extent of homogenization and differentiation were relatively insensitive to our changing understanding of taxonomy and distribution.
No References
No Citations
No Supplementary Data
No Article Media
No Metrics

Keywords: Biodiversity; Canada; freshwater fishes; homogenization; taxonomy; zoogeography

Document Type: Research Article

Publication date: 2010-07-01

  • Access Key
  • Free content
  • Partial Free content
  • New content
  • Open access content
  • Partial Open access content
  • Subscribed content
  • Partial Subscribed content
  • Free trial content
Cookie Policy
Cookie Policy
Ingenta Connect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more