A revision of the bioregionalisation of freshwater fish communities in the Australian Monsoonal Tropics
| Autor: | Peter J. Unmack, Stephen E. Swearer, Matthew C. Le Feuvre, Tim Dempster, Shawn W. Laffan, James J. Shelley |
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| Rok vydání: | 2019 |
| Předmět: |
0106 biological sciences
Environmental change Biogeography Biome Beta diversity Biodiversity species turnover βsim 010603 evolutionary biology 01 natural sciences tropics 03 medical and health sciences Endemism biogeography Ecology Evolution Behavior and Systematics Original Research 030304 developmental biology Nature and Landscape Conservation 0303 health sciences Ecology biology aquatic communities biology.organism_classification northern Australia Freshwater fish environmental drivers Species richness |
| Zdroj: | Ecology and Evolution |
| ISSN: | 2045-7758 |
| DOI: | 10.1002/ece3.5059 |
| Popis: | The Australian freshwater fish fauna is very unique, but poorly understood. In the Australian Monsoonal Tropics (AMT) biome of northern Australia, the number of described and candidate species has nearly doubled since the last attempt to analyse freshwater fish species composition patterns and determine a bioregionalisation scheme. Here, we utilise the most complete database of catchment‐scale freshwater fish distributions from the AMT to date to: (a) reanalyze spatial patterns of species richness, endemism and turnover of freshwater fishes; (b) propose a biogeographic regionalisation based on species turnover; (c) assess the relationship between species turnover and patterns of environmental change and historic drainage connectivity; and (d) identify sampling gaps. Biogeographic provinces were identified using an agglomerative cluster analysis of a Simpson's beta (β sim) dissimilarity matrix. A generalised dissimilarity model incorporating eighteen environmental variables was used to investigate the environmental correlates of species turnover. Observed and estimated species richness and endemism were calculated and inventory completeness was estimated based on the ratio of observed to estimated species richness. Three major freshwater fish biogeographic provinces and 14 subprovinces are proposed. These differ substantially from the current bioregionalisation scheme. Species turnover was most strongly influenced by environmental variables that are interpreted to reflect changes in terrain (catchment relief and confinement), geology and climate (runoff perenniality, stream density), and biotic responses to climate (net primary productivity). Past connectivity between rivers during low sea‐level events is also influential highlighting the importance of historical processes in explaining contemporary patterns of biodiversity in the AMT. The inclusion of 49 newly discovered species and candidate species only reinforced known focal points of species richness and endemism in the AMT. However, a number of key sampling gaps remain that need to be filled to fully characterise the proposed bioregionalisation. |
| Databáze: | OpenAIRE |
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