Leaf litter quality
In each campaign, additional leaf material was randomly hand-picked next to each quadrat locations in the riparian and instream area, separately, to estimate overall carbon and nitrogen content of each site’s habitat-specific leaf stocks. Samples were preserved in a freezer and random sub-samples (approx., 10% of original sample) were freeze dried for one day, grinded into powder and encapsulated (0.005g ± 10%) in tin capsules. Nitrogen (%N) and carbon (%C) concentrations were determined with an elemental analyser (FlashEA 1112 HT, Thermo Electron Corporation), using aspartic acid (C: 36.09%; N: 10.52%) as a calibration standard, and sorghum floor as quality control (C: 41.26 % ± 0.20 ; N: 1.47% ± 0.25).