To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
R.C. Wissmar, School of Fisheries, Wh-10, and Center for Streamside Studies, AR-10, University of Washington, Seattle, Washington 98195, USA,
J.A. Stanford, Flat head Lake Biological Station, University of Montana, Poison, Montana 59860, USA,
B.K. Ellis, Flat head Lake Biological Station, University of Montana, Poison, Montana 59860, USA
ABSTRACT Natural isotopic abundances of N (d15N) in organic matter are used to examine the trophic relations in river and hyporheic habitats of the Flathead River, Montana. The d15N of biofilms and Plecopteran-dominated food webs are compared for river and hyporheic waters. We examine the concept that the isotope ratio of an animal undergoes both the food source effect and in vivo metabolic effects. Metabolic effects for nitrogen isotopes in animal tissues relates to isotopic fractionation, which exhibits progressive enrichment of the d15N in body tissues at higher trophic levels. These ∇ d15N enrichments are in excess of isotopic abundances of food sources. Comparisons show greater enrichment for the consumer trophic levels of the hyporheic than river channel habitat. The d15N contents of the hyporheic food webs suggest influences of different concentrations and d15N contents of NO3 and NH4. These inorganic conditions may be controlled by physical mixing of various water masses, Ntransformations associated with biofilm microbiota, and feedbacks of NH4 through excretion by animals. Our observations indicate that stable isotopes may be powerful tools for determining nitrogen source and process information in hyporheic habitats.
Little is known about the trophic ecology of food webs within the hyporheic ecotones of river ecosystems (Hendricks, 1993). In our study, stable nitrogen isotopes measurements (d15N) are used to examine the trophic relations in river and hyporheic habitats of the Flathead River, Montana. The d15N of biofilms and Plecopteran-dominated food webs are compared for river and hyporheic waters. The almost total coverage on most rock surfaces by biofilms suggests that attached microbiota comprise a dominant food resource in both the river channel and hyporheic habitats.
Email your librarian or administrator to recommend adding this to your organisation's collection.