skip to main content


Title: You are not always what we think you eat. Selective assimilation across multiple whole-stream isotopic tracer studies

Analyses of 21 15N stable isotope tracer experiments, designed to examine food web dynamics in streams around the world, indicated that the isotopic composition of food resources assimilated by primary consumers (mostly invertebrates) poorly reflected the presumed food sources. Modeling indicated that consumers assimilated only 33–50% of the N available in sampled food sources such as decomposing leaves, epilithon, and fine particulate detritus over feeding periods of weeks or more. Thus, common methods of sampling food sources consumed by animals in streams do not sufficiently reflect the pool of N they assimilate. Lastly, Isotope tracer studies, combined with modeling and food separation techniques, can improve estimation of N pools in food sources that are assimilated by consumers.
 [1] ;  [2] ;  [3] ;  [4] ;  [5] ;  [6] ;  [7] ;  [8] ;  [8] ;  [9] ;  [10] ;  [11] ;  [12] ;  [13] ;  [11] ;  [14] ;  [2] ;  [14] ;  [15] ;  [16] more »;  [17] ;  [18] « less
  1. Kansas State Univ., Manhattan, KS (United States)
  2. Cornell Univ., Ithaca, NY (United States)
  3. Michigan State Univ., Hickory Corners, MI (United States). W. K. Kellogg Biological Station
  4. Univ. of Notre Dame, IN (United States)
  5. USDA Forest Service, Corvallis, OR (United States)
  6. Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)
  7. Univ. of Auckland, Auckland (New Zealand)
  8. Southern Illinois Univ., Carbondale, IL (United States)
  9. Univ. of New Hampshire, Durham, NH (United States)
  10. Murray State Univ. Murray, KY (United States)
  11. Aarhus Univ. (Denmark)
  12. Univ. of New Mexico, Albuquerque, NM (United States)
  13. Univ. of Nebraska, Lincoln, NE (United States)
  14. Michigan State Univ., East Lansing, MI (United States)
  15. Florida Intl Univ., Miami, FL (United States)
  16. Cary Inst. of Ecosystem Studies, Millbrook, NY (United States)
  17. Univ. of Victoria, BC (Canada)
  18. Centre d' Estudis Avancats de Blanes (CEAB-CSIC), Blanes, Catalonia (Spain)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Additional Journal Information:
Journal Volume: 95; Journal Issue: 10; Journal ID: ISSN 0012-9658
Ecological Society of America (ESA)
Research Org:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge National Environmental Research Park
Sponsoring Org:
USDOE Office of Science (SC)
Country of Publication:
United States
07 ISOTOPE AND RADIATION SOURCES; ¹⁵N; consumer; food resources; food web; label mismatch; nitrogen cycling; stable isotope tracer addition
OSTI Identifier: