Temporal and spatial variation in ecosystem metabolism and food web carbon transfer in a wet‐dry tropical river

In the Wet Tropics of Queensland, benthic algae serve as the primary carbon source for benthic invertebrates during the dry season, sustaining their biomass despite high respiration rates. However, higher consumers like fish and crustaceans rely on external carbon subsidies, likely from floodplains, which are not present in channel waterholes during this period. The study, conducted along the Mitchell River, used diel changes in dissolved oxygen to measure ecosystem metabolism and stable isotope analysis to assess food web relationships at the beginning and end of the dry season. Light availability was found to regulate gross primary production (GPP), while temperature explained up to 52% of temporal variation in respiration rates (ER). The research highlights the contrasting roles of autochthonous and allochthonous carbon sources in supporting different trophic levels within this wet-dry tropical river ecosystem.

HUNT, R. J., JARDINE, T. D., HAMILTON, S. K., BUNN, S. E.,. (2011). Temporal and spatial variation in ecosystem metabolism and food web carbon transfer in a wet‐dry tropical river. Freshwater Biology, 57(3), 435–450. Portico. https://doi.org/10.1111/j.1365-2427.2011.02708.x