|Worldwide freshwater fish homogenization is driven by a few widespread non-native species|Toussaint, A.; Beauchard, O.; Oberdorff, T.; Brosse, S.; Villéger, S. (2016). Worldwide freshwater fish homogenization is driven by a few widespread non-native species. Biological Invasions 18: 1295–1304. dx.doi.org/10.1007/s10530-016-1067-8
In: Biological Invasions. Springer: London. ISSN 1387-3547, more
Freshwater fish; Introduction; Betadiversity; Translocation; Exotic species
|Authors|| || Top |
- Toussaint, A.
- Beauchard, O., more
- Oberdorff, T.
Introduction of non-native species havechanged the composition of freshwater fish assemblagesthroughout the world and hence the dissimilaritybetween them, either toward homogenization (i.e.decrease in dissimilarity) or differentiation (i.e.increase in dissimilarity). However, there is still noassessment of individual contributions of non-nativespecies to this overall trend at the global scale. Here,we disentangle individual non-native species effectfrom the global effect of the whole introduced speciespool at the biogeographic realm scale and test whichdeterminant can explain the effect of non-nativespecies on changes in assemblage dissimilarity. Ourresults show that the contribution of introducedspecies on changes in dissimilarity is highly variableand all directions of changes are observed through theintroduction process, i.e. either toward homogenization,differentiation or no change. Overall, only a fewwidespread species contribute to the worldwidehomogenization pattern, whereas most of introducedspecies slightly contribute to the global change indissimilarity. The effect of species on change indissimilarity was influenced by the introduction pressurebut also by whether introduced species weretranslocated (i.e. introduced to other basins withintheir biogeographic realm) or exotic (i.e. introducedfrom other biogeographic realms). Homogenization isstrongly determined by the species translocated withina realm and only by few widespread exotic specieswhereas the majority of exotics contribute to adifferentiation effect. Nevertheless, under futureintensified human pressure, the exotic species spreadacross realms is predicted to increase and theirdifferentiation effect might turn towards homogenization,and might trigger the global homogenizationtrend.