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Consumer–resource coupling in wet–dry tropical rivers
Citation
Jardine, TD and Pettit, NE and Warfe, DM and Pusey, BJ and Ward, DP and Douglas, MM and Davies, PM and Bunn, SE, Consumer-resource coupling in wet-dry tropical rivers, Journal of Animal Ecology, 81, (2) pp. 310-322. ISSN 0021-8790 (2014) [Refereed Article]
Copyright Statement
Copyright 2011 The Authors. Journal of Animal Ecology, Copyright 2011 British Ecological Society
DOI: doi:10.1111/j.1365-2656.2011.01925.x
Abstract
1. Despite implications for top-down and bottom-up control and the stability of food webs, understanding the links between consumers and their diets remains difficult, particularly in remote tropical locations where food resources are usually abundant and variable and seasonal hydrology produces alternating patterns of connectivity and isolation.
2. We used a large scale survey of freshwater biota from 67 sites in three catchments (Daly River, Northern Territory; Fitzroy River, Western Australia; and the Mitchell River, Queensland) in Australia’s wet–dry tropics and analysed stable isotopes of carbon (δ13C) to search for broad patterns in resource use by consumers in conjunction with known and measured indices of connectivity, the duration of floodplain inundation, and dietary choices (i.e. stomach contents of fish).
3. Regression analysis of biofilm δ13C against consumer δ13C, as an indicator of reliance on local food sources (periphyton and detritus), varied depending on taxa and catchment.
4. The carbon isotope ratios of benthic invertebrates were tightly coupled to those of biofilm in all three catchments, suggesting assimilation of local resources by these largely nonmobile taxa.
5. Stable C isotope ratios of fish, however, were less well-linked to those of biofilm and varied by catchment according to hydrological connectivity; the perennially flowing Daly River with a long duration of floodplain inundation showed the least degree of coupling, the seasonally flowing Fitzroy River with an extremely short flood period showed the strongest coupling, and the Mitchell River was intermediate in connectivity, flood duration and consumer–resource coupling.
6. These findings highlight the high mobility of the fish community in these rivers, and how hydrological connectivity between habitats drives patterns of consumer–resource coupling.
2. We used a large scale survey of freshwater biota from 67 sites in three catchments (Daly River, Northern Territory; Fitzroy River, Western Australia; and the Mitchell River, Queensland) in Australia’s wet–dry tropics and analysed stable isotopes of carbon (δ13C) to search for broad patterns in resource use by consumers in conjunction with known and measured indices of connectivity, the duration of floodplain inundation, and dietary choices (i.e. stomach contents of fish).
3. Regression analysis of biofilm δ13C against consumer δ13C, as an indicator of reliance on local food sources (periphyton and detritus), varied depending on taxa and catchment.
4. The carbon isotope ratios of benthic invertebrates were tightly coupled to those of biofilm in all three catchments, suggesting assimilation of local resources by these largely nonmobile taxa.
5. Stable C isotope ratios of fish, however, were less well-linked to those of biofilm and varied by catchment according to hydrological connectivity; the perennially flowing Daly River with a long duration of floodplain inundation showed the least degree of coupling, the seasonally flowing Fitzroy River with an extremely short flood period showed the strongest coupling, and the Mitchell River was intermediate in connectivity, flood duration and consumer–resource coupling.
6. These findings highlight the high mobility of the fish community in these rivers, and how hydrological connectivity between habitats drives patterns of consumer–resource coupling.
Item Details
| Item Type: | Refereed Article |
|---|---|
| Keywords: | biofilm, energy sources, floodplain, food webs, gut contents, hydrology, stable isotope analysis |
| Research Division: | Biological Sciences |
| Research Group: | Ecology |
| Research Field: | Community ecology (excl. invasive species ecology) |
| Objective Division: | Environmental Management |
| Objective Group: | Marine systems and management |
| Objective Field: | Assessment and management of benthic marine ecosystems |
| UTAS Author: | Warfe, DM (Dr Danielle Warfe) |
| ID Code: | 93663 |
| Year Published: | 2014 |
| Web of Science® Times Cited: | 57 |
| Deposited By: | Biological Sciences |
| Deposited On: | 2014-08-12 |
| Last Modified: | 2014-08-20 |
| Downloads: | 0 |
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