naa a22 4500 51073796X CHVBK 20180411083017.0 cr unu---uuuuu 180411e20130901xx s 000 0 eng 10.1007/s11284-012-1003-z doi (NATIONALLICENCE)springer-10.1007/s11284-012-1003-z Use of carbon-13 and carbon-14 natural abundances for stream food web studies [Elektronische Daten] [Naoto Ishikawa, Fujio Hyodo, Ichiro Tayasu] We review the use of stable carbon isotope ratios (δ13C) and radiocarbon natural abundances (Δ14C) for stream food web studies. The δ13C value of primary producers (e.g., periphytic algae, hereafter periphyton) in streams is controlled by isotopic fractionation during photosynthesis and variable δ13C of dissolved CO2. When periphyton δ13C differs from that of terrestrial primary producers, the relative contribution of autochthony and allochthony to stream food webs can be calculated. Moreover, the variation in periphyton δ13C can reveal how much stream consumers rely on local resources because each stream habitat (e.g., riffle vs. pool, open vs. shaded) usually has a distinctive δ13C. However, periphyton δ13C often overlaps with that of terrestrial organic matter. On the other hand, periphyton Δ14C is less variable than δ13C among habitats, and reflects the Δ14C of dissolved CO2, which could be a mixture of "aged” (Δ14C<0‰) and "modern” (Δ14C>0‰) carbon. This is because the Δ14C is corrected by its δ13C value for the isotopic fractionation during photosynthesis. Recent studies and our data indicate that many stream food webs are supported by "aged” carbon derived from the watershed via autochthonous production. The combined use of δ13C and Δ14C allows robust estimation of the carbon transfer pathway in a stream food web at multiple spatial scales ranging from the stream habitat level (e.g., riffle and pool) to watershed level (autochthony and allochthony). Furthermore, the Δ14C of stream food webs will expand our understanding about the time frame of carbon cycles in the watersheds. The Ecological Society of Japan, 2013 Periphyton nationallicence Terrestrial litter nationallicence Aquatic consumer nationallicence Carbon stable isotope nationallicence Radiocarbon nationallicence Ishikawa Naoto Center for Ecological Research, Kyoto University, 2-509-3 Hirano, 520-2113, Otsu, Shiga, Japan aut Hyodo Fujio Research Core for Interdisciplinary Sciences, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, 700-8530, Okayama, Japan aut Tayasu Ichiro Center for Ecological Research, Kyoto University, 2-509-3 Hirano, 520-2113, Otsu, Shiga, Japan aut Ecological Research Springer Japan 28/5(2013-09-01), 759-769 0912-3814 28:5<759 2013 28 11284 https://doi.org/10.1007/s11284-012-1003-z text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11284-012-1003-z text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ishikawa Naoto Center for Ecological Research, Kyoto University, 2-509-3 Hirano, 520-2113, Otsu, Shiga, Japan aut NATIONALLICENCE 700 1- Hyodo Fujio Research Core for Interdisciplinary Sciences, Okayama University, 3-1-1 Tsushima-naka, Kita-ku, 700-8530, Okayama, Japan aut NATIONALLICENCE 700 1- Tayasu Ichiro Center for Ecological Research, Kyoto University, 2-509-3 Hirano, 520-2113, Otsu, Shiga, Japan aut NATIONALLICENCE 773 0- Ecological Research Springer Japan 28/5(2013-09-01), 759-769 0912-3814 28:5<759 2013 28 11284 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer