A Meta-Analysis of Competition in Field Experiments

  title={A Meta-Analysis of Competition in Field Experiments},
  author={Jessica Gurevitch and Laura L. Morrow and Alison Wallace and Joseph S. Walsh},
  journal={The American Naturalist},
  pages={539 - 572}
A meta-analysis was conducted on field-competition experiments published in six journals over a 10-yr period. We analyzed the effects of competition on the biomass of organisms belonging to 93 species in a wide variety of habitats. Competition had a large effect overall, with a great deal of heterogeneity in that effect among organisms. There were large differences among trophic levels in competitive effects, but the relative magnitude of competition at different trophic levels was contrary to… 

The Interaction between Competition and Predation: A Meta‐analysis of Field Experiments

Across all studies, the effects of competition in the presence of predators were less than in the absence of predators, and the interaction between competition and predation for most response variables was statistically significant.

Trophic Cascades in Terrestrial Systems: A Review of the Effects of Carnivore Removals on Plants

Trophic cascades in terrestrial systems, although not a universal phenomenon, are a consistent response throughout the published studies reviewed here, and this analysis suggests that they occur more frequently in terrestrial Systems than currently believed.

Assessing the magnitude of intra- and interspecific competition in two coral reef fishes

It is shown that the per-capita effect of intraspecific competitors on individual growth was at least twice as great as the effect of interspecific competitors, suggesting interference competition.

The shifting balance of facilitation and competition affects the outcome of intra- and interspecific interactions over the life history of California grassland annuals

This work examined interactions at three life history stages (germination, survival, and juvenile-adult growth) for three native and three exotic California annual species in a glasshouse experiment and predicted predictions of neutral, rather than niche, theory for five of six species.

Interactions between Stream Herbivores and Periphyton: A Quantitative Analysis of past Experiments

Results of these analyses suggest that stream herbivore regulate their food resources as or more frequently than herbivores in other ecosystems, and strongly contradict the view held by many ecologists that stream communities are regulated primarily by abiotic factors.

Interspecific competition in small rodents: from populations to individuals

Recent research approaches to interspecific competition in rodents are reviewed based on census data and species assemblages, that use regression analysis, time series analysis, removal and exclusion experiments, and showcase their own experimental research on the effects of inter specific competition on individual life-history traits in boreal voles.

Scale as Modifier in Vegetation Diversity Experiments: Effects on Herbivores and Predators

A meta-analysis of literature reviews and meta-analyses suggesting general trends of herbivore declines associated with increased vegetation diversity may be misleading suggests that effects of vegetation diversification may be enhanced when insects can move uninhibited among control and treatment plots in small scale experiments.

Regional effects on competition–productivity relationship: a set of field experiments in two distant regions

The results suggest that competitive exclusion operates at least in these communities which species pool is large and corroborates the predictions of the hypothesis of exploitation ecosystems, predicting that trophic dynamics account for the relationship between competition intensity and primary productivity.

Effects of herbivory on competition intensity in two arctic-alpine tundra communities with different productivity

It is suggested that the low competition intensity in the unproductive snow bed is caused by herbivorous mammals, which tend to depress plant biomass in relatively unproductive habitats, and between-habitat differences in competition intensity disappear.

Two-species asymmetric competition: effects of age structure on intra- and interspecific interactions.

Switching modes of competition suggest that the relative importance of the mechanisms regulating single-species population dynamics may change when organisms are embedded within a wider community.



On the Prevalence and Relative Importance of Interspecific Competition: Evidence from Field Experiments

  • J. Connell
  • Environmental Science
    The American Naturalist
  • 1983
The present survey illustrates how difficult it is to produce a clear and unambiguous demonstration of interspecific competition.

Equivalence of competitors in plant communities: a null hypothesis and a field experimental approach.

This work presents an experimental design to quantify competitive interactions among plant species under field conditions and therefore enable statistical comparisons of competitive abilities among species and proposes a null hypothesis of equivalence of competitive effects.

Patterns and Consequences of Interspecific Competition in Natural Communities: A Review of Field Experiments with Plants

A quantitative literature review to assess the extent to which field experiments with plants have addressed questions about patterns of competition over time and space, consequences of competition for community structure, and comparisons of competitive ability among species suggests that resource partitioning may not be an important mechanism of coexistence in plants.

Species Diversity Gradients: Synthesis of the Roles of Predation, Competition, and Temporal Heterogeneity

It is suggested that the "predation" and "competition" hypotheses of community organization and species diversity are complementary, and that Predator-mediated escapes by primary producers from herbivores may explain the apparent importance of interspecific competition in certain primary producer associations.

Effects of Competition, Disturbance, and Herbivory on Salicornia Europaea

The effects of interspecific competition, physical disturbance, and insect herbivory on the distribution and abundance of Salicornia europaea in a New England salt marsh were studied using

Intraguild Predation and Competition Among Desert Scorpions

Interactions among four species of desert scorpion were analyzed over a 9-yr period and it is concluded that intraguild predation rather than exploitation competition is the major factor structuring the observed patterns of distribution and abundance of these scorpions.

Variation in Predator Phenology Affects Predator Performance and Prey Community Composition

The results suggest that the predictive power of more general models of species interactions could be improved by incorporating size— or stage—specific effects of predator phenology, and there was strong correlational evidence that the body masses of newt offspring were limited by their own density.

Resource Partitioning in Ecological Communities

To conclude with a list of questions appropriate for studies of resource partitioning, questions this article has related to the theory in a preliminary way.

Priority Effects in Experimental Pond Communities: Competition between Bufo and Rana

The results suggest that optimal oviposition behavior is problematical for female frogs: the time that will be best depends on whether or not another species will be present at the time of hatching.