Stream food webs and cumulative forestry effects

The River Continuum Concept (RCC) predicts a downstream shift in the reliance of aquatic consumers from terrestrial to aquatic carbon sources, but this concept has rarely been assessed with longitudinal studies. Similarly, there are no studies addressing how forestry related disturbances to the structure of headwater food webs manifest (accumulate/dissipate) downstream and/or whether forest management alters natural longitudinal trends predicted by the RCC. Using stable isotopes of carbon, nitrogen and hydrogen, we investigated how: 1) autochthony in macroinvertebrates and fish change from small streams to larger downstream sites within a basin with minimal forest management (New Brunswick, Canada); 2) longitudinal trends in autochthony and food web length compare among three basins with different forest management intensity [intensive (harvest and replanting), extensive (harvest only), minimal] to detect potential cumulative/dissipative effects; and 3) forest management intensity and other catchment variables are influencing food web dynamics. Attached are the 1) carbon, nitrogen and hydrogen stable isotope data for benthic macroinvertebrates, sculpin and food sources in 18 streams, and 2) the algal contribution to consumer diet calculated based on MixSIAR mixing models (see published article for details). The research resulting from this data is reported in: Erdozain, M., Kidd, K.A., Emilson, E.J.S., Capell, S.S., Kreutzweiser, D.P., Gray, M.A. (in press). Elevated allochthony in stream food webs as a result of longitudinal cumulative effects of forest management. Ecosystems.