Craig W. Osenberg, Orlando Sarnelle, Scott D. Cooper, and Robert D. Holt. 1999. Resolving ecological questions through meta-analysis: goals, metrics, and models. Ecology 80: 1105-1117.

Supplements

Supplement 1: Interaction strength: fish effects on snail biomass density.
Ecological Archives E080-005-S1.

Supplement 2: Mutual interference.
Ecological Archives E080-005-S2.

Authors
File list
Description

Copyright

Author

Craig W. Osenberg
Department of Zoology
University of Florida
Gainesville, FL  32611-8525
osenberg@zoo.ufl.edu

File list

Viewable:

Supplement1
Supplement2

Downloadable:

readme.txt (this file in ascii; contains descriptions of datafiles and details about Supplement 1)
E080005S1.txt (the data file for Supplement 1 in ASCII text)
E080005S2.txt (the data file and description of Supplement 2 in ASCII)

E080005.zip (Download all files at once)

Description

I. Supplement 1

Description of fields in Supplement 1.

Study no. (and citations for sources of data). In all cases, except study #5, original data were provided by authors of the studies.

1. Olson, M. H., G. G. Mittelbach and C. W. Osenberg. 1995. Competition between predator and prey: resource-based mechanisms and implications for stage-structured interactions. Ecology 76: 1758-1771.
2. Huckins, C. J. F. 1996. Functional relationships between morphology, feeding performance, diet, and competitive ability in molluscivorous sunfish. Dissertation. Michigan State University, East Lansing, MI.
3. Mittelbach, G. G. 1988. Competition among refuging sunfishes and effects of fish density on littoral zone invertebrates. Ecology 69: 614-623.
4. Martin, T. H., L. B. Crowder, C. F. Dumas, and J. M. Burkholder. 1992. Indirect effects of fish on macrophytes in Bays Mountain Lake: evidence for littoral trophic cascade. Oecologia 89: 476-481.
5. Crowder, L. B., and W. E. Cooper. 1982. Habitat structural complexity and the interaction between bluegills and their prey. Ecology 63: 1802-1813.
6. Bronmark, C., S. P. Klosiewski, and R. A. Stein. 1992. Indirect effects of predation in a freshwater benthic food chain. Ecology 73: 1662-1674.
7. Bronmark, C. 1994. Effects of two benthivorous fishes, tench and perch, on interactions in a freshwater, benthic food chain. Ecology 75: 1818-1828.
8. Osenberg, C. W. 1988. Body size and the interaction of fish predation and food limitation in a freshwater snail community. Dissertation. Michigan State University, East Lansing, MI. (Chapter 2)
9. Osenberg, C. W. 1988. Body size and the interaction of fish predation and food limitation in a freshwater snail community. Dissertation. Michigan State University, East Lansing, MI. (Chapter 4)
10. Osenberg, C. W., G. G. Mittelbach, and P. C. Wainwright. 1992. Two-stage life histories in fish: the interaction between juvenile competition and adult performance. Ecology 73: 255-267.

 
Study code (redundant name for species no.)

Substudy (code that gives unique descriptor to each comparison used to generate an effect, usually based on a desciption of the treatment with the higher density of fish)

Species (species of fish whose effect was estimated)

LMB = largemouth bass (Micropterus salmoides)
BG = bluegill sunfish (Lepomis machrochirus)
RE = redear sunfish (L. microlophus)
PS = pumpkinseed sunfish (L. gibbosus)
EP = Eurasian perch (Perca fluviatilis)
TENCH = tench (Tinca tinca)

Diet (denotes whether fish species has specialized or generalized morphology and diet)

SPECIALIST (with hypertrophied pharyngeal jaws and bones; able to crush snails), includes large PS, large RE, large TENCH.
GENERALIST = all others.

Duration (number of days the experimental manipulation was in effect before the data were obtained)

Units (units in which snail biomass density was reported)

TFISHwf (density of all fish in treatment with the highest density of fish (i.e., the treatment "with fish", wf)

TFISHwof (density of all fish in the "control" treatment: i.e., the treatment with the lowest density of fish or the treatment "without fish", wof)

SFISHwf, SFISHwof (the density of specialized fishes in the treatments "with" and "without" fish)

DENwf, DENwof (the biomass density of snails in the two treatments)

SDwf, SDwof (the standard deviation of snail biomass density in the two treatments)

Nwf, Nwof (the number of replicate plots in the two treatments)

a (the estimate of interaction strength, calculated as ln(DENwf/DENwof)/dFISH·duration, where dfish is the difference in the density of the fish whose effect is being isolated)

var(a) (the within-study variance of the estimated interaction strength, calculated as:
(1/((dFISH·duration)^2)·((SDwf^2/Nwf·DENwf^2)+(SDwof^2/Nwof·DENwof^2))

Notes:

1. Specialists defined as >50mm SL (smaller fish are less able to feed on snails); compared fish treatment ('targets only') to 'no fish' treatment
2. Specialists defined as >50mm SL (smaller fish are less able to feed on snails); compared fish treatment to 'targets only'
3. Fish densities in table do not include the pumpkinseed targets (densities were set up similarly in all cages, so this has no effect on fish gradient, which was driven by variation in bluegill density); bluegill gradient divided into three categories (high, low, and none); high and low were compared to none to estimate bluegill effects.
4. Compared fish treatment to the treatment with only small fish
5. Estimated from figures 1 and 6; variation in prey biomass ignores variation in percent composition (no error bars given in Fig 6., and data were unavailable from authors).
6. Compared fish treatment to the EP treatment to isolate effect of tench.
7. Fish treatment is based on uncaged lake controls (which had slightly different densities than the caged plots with fish, but no other indication of cage artifacts)
8. Includes slight correction of fish density, which was made after publication of Osenberg et al. (1997, Am Nat). Denoted as "generalist" due to small size of pumpkinseed (50mm SL) and atrophied pharyngeal morphology (Mittelbach et al. 1992, Oecologia 90:8-13).

II. Supplement 2

Description of fields in Supplement 2:  see Supplement 2 (viewable) or download supplement2.txt. Additional information can be found in Arditi and Akçakaya, (1990), Oecologia 83:358.

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