Geoscience Reference
In-Depth Information
Seeing Double: Size-Based and
Taxonomic Views of Food Web Structure
DAVID GILLJAM,
1,
*
AARON THIERRY,
2,3
FRANCOIS
K. EDWARDS,
4
DAVID FIGUEROA,
5,6
ANTON T. IBBOTSON,
7
J. IWAN JONES,
4,5
RASMUS B. LAURIDSEN,
5
OWEN L. PETCHEY,
8
GUY WOODWARD
5
AND BO EBENMAN
1
1
Department of Physics, Chemistry and Biology, Link
¨
ping University, Sweden
2
Department of Animal and Plant Sciences, Alfred Denny Building, University of
Sheffield, Western Bank, Sheffield, United Kingdom
3
Microsoft Research, JJ Thompson Avenue, Cambridge, United Kingdom
4
Centre for Ecology and Hydrology, Wallingford, United Kingdom
5
School of Biological and Chemical Sciences, Queen Mary University of London,
London, United Kingdom
6
Facultad de Recursos Naturales, Universidad Cat´ lica de Temuco, Chile
7
Game and Wildlife Conservation Trust, United Kingdom
8
Institute of Evolutionary Biology and Environmental Studies, University of Z¨rich,
Winterthurerstrasse 190, Z¨rich, Switzerland
Abstract . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
68
I.
Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
68
A. The Allometry of Trophic Relations . . . . . . . . . . . . . . . . . . . . . . . .
69
B. Overcoming Pitfalls Through a Plurality of Viewpoints . . . . . . . . .
71
C.
Individual-Based Food Webs: An Emerging Field . . . . . . . . . . . . .
72
II. Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
74
A. Study Sites—The Seven Food Webs . . . . . . . . . . . . . . . . . . . . . . . .
76
B. Aggregation into Different Levels of Resolution and
Groupings. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
79
C. Response Variables Analysed . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
82
D. Statistical Analyses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
88
III. Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
89
A. Response Variables Compared . . . . . . . . . . . . . . . . . . . . . . . . . . . .
89
IV. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
99
A.
Individuals and Species Averages—Effects of Resolution . . . . . . .
99
B. Taxonomy Versus Size—Effects of Grouping. . . . . . . . . . . . . . . . .
106
C. Dynamic Implications—Parameterisation of Dynamic Food
Web Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
108
D. Caveats . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
110
