Competition

Keddy, Paul A.

doi:10.1007/978-94-010-0694-1

Cited by 377 publications

(262 citation statements)

References 0 publications

Supporting

Mentioning

252

Contrasting

Unclassified

Order By: Relevance

“…This realized niche is a result of ecological interactions with the organism's fundamental niche (Hutchinson, 1957;Keddy, 2001). The fundamental niche is what a species would occupy in absence of competitors and it is limited by the morphological and physical capabilities of the species.…”

Section: Have All Social Apidae Equally Broad Diets?mentioning

confidence: 99%

The structure of eusocial bee assemblages in Brazil

Biesmeijer

Slaa

2006

Apidologie

View full text Add to dashboard Cite

-Social bee -food plant relationships have been studied extensively, especially in the Neotropics. This is, however, the first quantitative comparison and review of a large set (28) of studies. Patterns in social bee richness, niche breadth and associations between social bee taxa could be explained partly by species-specific differences in behaviour, foraging traits and response to interspecific competition. Bee assemblages contain higher percentages of social Apidae towards the equator. Medium-sized non-aggressive group foragers had the narrowest diet and the super-generalists the broadest diet. Niche breadth generally decreased with the number of social bee species in the assemblage indicating that interspecific competition influences diet choice. Cluster-analysis revealed two main groups in terms of food plant use: medium-sized non-aggressive group foragers and a group containing the aggressive group forager Trigona spinipes, the honeybee and three small scramblers. Four other taxa were not associated with any other taxa. community ecology / stingless bees / competition / niche partitioning / Meliponini / Apidae

show abstract

Section: Have All Social Apidae Equally Broad Diets?mentioning

confidence: 99%

The structure of eusocial bee assemblages in Brazil

Biesmeijer

Slaa

2006

Apidologie

View full text Add to dashboard Cite

show abstract

“…Theories of community structure have been dominated by models of resource competition on the assumption that plants of all species compete for the same limited pools of key nutrients (Tilman 1980;Chesson 2000b;Keddy 2001;Silvertown 2004;Tilman, 2007). In general, the species with the largest long-term population growth rates should outcompete the others, unless strong negative dependence on conspecific density limits their populations before competitive exclusion takes place (Chesson 2000b).…”

Section: Introductionmentioning

confidence: 99%

Testing the roles of competition, facilitation and stochasticity on community structure in a species‐rich assemblage

2013

View full text Add to dashboard Cite

Summary1. There is an ongoing debate about whether communities are closely integrated and bound together via interactions such as competition or facilitation, or are disintegrated and dominated by chance. We still lack community-wide data on the intensities of interactions and randomness, and measurements of their impacts on community structure. 2. Using a long-term data set, we sought to measure the effects of interactions and stochasticity in structuring a highly diverse (>100 species) semi-arid grassland plant community, testing for positive and negative interactions at different stages of population growth of all species. 3. During the colonization of new patches, most species were facilitated or inhibited by several others. These opposite effects can potentially have a large effect on species abundances, but they were correlated and cancelled out at the community level. Nevertheless, competition during colonization was strong enough to cause poor competitors to have small population sizes. 4. The subsequent phase of population growth (increase and subsequent change in numbers within occupied patches) was mainly driven by intraspecific density dependence, and we found little evidence for interspecific interactions. 5. Model results showed that stochasticity and recurrent colonization of transient, favourable patches maintained diversity, keeping poor competitors from becoming extinct. 6. Synthesis: Our results, taken together with recent studies on tropical forests, suggest that weak interactions among established plants may be a general phenomenon, but that local interactions during colonization are important drivers of community composition. Most of the variance in species abundance in our community was explained by intraspecific competition and stochasticity, with interspecific interactions playing a minor role due to their overall weakness, interaction changes over ontogeny, and the cancellation of opposite-sign interactions when all the species in the community are considered. Despite this, some species were rare seemingly because they cannot withstand interspecific competition. Thus, to untangle the effects of interactions on community structure, future research should focus on interactions occurring at different phases of population growth and on whole communities.

show abstract

“…Systems with strong shoot competition generally show a positive relationship between intensity and importance (Grime 2001, Keddy 2001. In contrast, root competition is predicted to have little effect on community structure (Lamb et al 2009) and thus, in systems dominated by root competition, competition intensity may be unrelated to community structure.…”

Section: Introductionmentioning

confidence: 99%

Plant interactions are unimportant in a subarctic–alpine plant community

Mitchell

Cahill

Hik

2009

Ecology

View full text Add to dashboard Cite

Abstract. We investigated whether plant interaction intensity in a subarctic-alpine meadow is important for determining community structure and species abundance. Using two common species as phytometers, we measured interaction intensity using a neighbor removal approach. Eight biotic and abiotic variables known to influence species abundance and community structure were measured, with regression trees used to examine how plant interactions and the biotic and abiotic variables were related to species evenness, richness, and phytometer spatial cover. A range of interactions was present, with both strong competition and facilitation present over small-scale abiotic and biotic gradients. Despite the variation in interaction intensity, it was generally unrelated to either community structure or phytometer cover. In other words, plant interactions were intense in many cases but were not important to community structure. This may be due to the prevalence of clonal species in this system and the influence of previous year's interactions on plant survival and patterns of community structure. These results also suggest how conflicting theories of the role of competition in unproductive environments may be resolved. Our findings suggest that plant interactions may be intense in reducing individual growth, while simultaneously not important in the context of community structure. Plant interactions need to be viewed and tested relative to other factors and stresses to accurately evaluate their importance in plant communities, with continued differentiation between the intensity of plant interactions and their relative importance in communities.

show abstract

Competition

Cited by 377 publications

References 0 publications

The structure of eusocial bee assemblages in Brazil

The structure of eusocial bee assemblages in Brazil

Testing the roles of competition, facilitation and stochasticity on community structure in a species‐rich assemblage

Plant interactions are unimportant in a subarctic–alpine plant community

Contact Info

Product

Resources

About