Biases in the analysis of stable isotope discrimination in food webs

Journal of Applied Ecology - Tập 47 Số 4 - Trang 936-941 - 2010
K. Auerswald1, M. Wittmer1, Antoine Zazzo2, Rudi Schäufele1, H. Schnyder1
1Lehrstuhl für Grünlandlehre, Technische Universität München, Am Hochanger 1, D-85350 Freising-Weihenstephan, Germany
2CNRS - Muséum national d’Histoire naturelle, UMR 7209 ‘‘Archéozoologie, Archéobotanique: Sociétés, Pratiques et Environnements’’ USM 303 - Département Ecologie et Gestion de la Biodiversité CP 56, 55, rue Buffon, F-75231 Paris cedex 05, France

Tóm tắt

Summary 1. Recently, Caut, Angulo & Courchamp (2009, Journal of Applied Ecology) published a review on diet‐tissue isotopic shifts in animals. They concluded that diet‐tissue shifts are influenced by the isotopic composition of the diet for both 13C and 15N in a wide range of animal taxa. 2. We suggest that the conclusion of Caut, Angulo & Courchamp is in error, and provide a discussion of sources of error in the assessment of diet‐tissue discrimination. 3. Errors in the derivation of diet‐tissue shifts include imprecise definitions, mathematical artefacts and invalid statistical analysis. It is likely that the work also suffers from experimental bias. The mathematical artefacts and statistical invalidity result from using the same variable (diet isotopic composition) in the independent and dependent variable for regression analysis and failure to correct for the resulting bias. Experimental bias can result from the incomplete turnover of body pools after diet switches or during natural fluctuations in diet isotope composition. Unfortunately, the main sources of error work in the same direction, strengthening the biased relationship between the diet‐tissue shift and diet isotope composition. Therefore, the analysis of Caut et al. (2009) does not provide proof of a relationship between diet‐tissue shift and diet isotope composition. 4. Synthesis and application. Future work on diet‐tissue discrimination factors should (i) follow the mathematical rules resulting from how isotope data are presented, (ii) be based on appropriate statistics analysis that avoids or corrects for spurious self‐correlations, and (iii) consider possible complications associated with the presence of slowly turning‐over stores and non‐equilibrating ‘dead’ body pools.

Từ khóa


Tài liệu tham khảo

Ambrose S.H., 2000, Biogeochemical Approaches to Paleodietary Analysis, 243

10.5194/bg-6-795-2009

10.1007/s00442-003-1479-x

10.1002/hlca.19520350345

10.1002/hlca.19530360403

10.1016/0038-0717(77)90040-2

10.1002/rcm.3691

10.1086/282851

10.1111/j.1365-2435.2007.01360.x

10.1111/j.1365-2664.2009.01620.x

10.1007/s004420050868

10.1073/pnas.0509606102

10.1007/s00442-006-0571-4

10.1086/626141

10.1007/s00442-005-0118-0

10.2193/2006-293

10.1016/0016-7037(78)90199-0

10.1016/0016-7037(81)90244-1

10.1007/s004420050874

10.1146/annurev.pp.40.060189.002443

10.1139/z03-054

10.1002/rcm.3880

Fox J., 1997, Applied Regression, Linear Models, and Related Methods

10.1017/S0021859602002769

10.1007/s00114-003-0496-2

10.1139/z96-236

10.2307/2412813

10.2307/1368808

10.1139/cjz-78-8-1332

10.1139/Z07-019

10.1371/journal.pmed.0020124

IUPAC, 1997, Compendium of Chemical Terminology

10.1111/j.1541-0064.1996.tb00448.x

10.1029/WR018i004p01041

10.1111/j.1466-8238.2007.00322.x

10.1034/j.1600-0706.2003.12098.x

10.1063/1.1745698

10.1016/B978-1-4832-3287-4.50016-7

Mook W.G., 2001, Environmental Isotopes in the Hydrological Cycle, Principles and Applications. Vol. I: Introduction – Theory, Methods

10.1007/s00414-008-0286-7

10.1006/jasc.1998.0383

10.1016/S0022-1910(03)00003-9

10.1016/0031-9422(81)85134-5

10.1016/S0016-7037(60)80006-3

10.1098/rspl.1896.0076

10.1007/s00442-003-1221-8

10.1007/s00442-005-0021-8

10.1139/z00-008

Sachs L., 2006, Angewandte Statistik – Methodensammlung mit R

10.1111/j.1365-2486.2006.01169.x

Sponheimer M., 2003, An experimental study of carbon‐isotope fractionation between diet, hair, and feces of mammalian herbivores, Canadian Journal of Zoology, 8, 871, 10.1139/z03-066

10.1002/oa.655

10.1002/rcm.2454

10.1016/S0022-1910(02)00190-7

10.1111/j.1365-2435.2009.01529.x

10.1002/047009060X

10.1139/Z07-110

10.1002/rcm.3693

Thông tin
Thông tin xuất bản

Journal of Applied Ecology

Tập 47 Số 4

936-941

Thông tin tác giả