Competition between species in theory and reality

This chapter has documented why there is no universally applicable measure of interspecific competition that can be calculated based on measurements of relative consumption rates of different resources.

This means that observations of niche over­lap do not provide good guesses at competitive effects. The chapter has also argued that there is a vanishingly small probability that any two competing species in a natu­ral community are ever competitively equivalent. Even near-equivalence is likely to be rare. Although ecologists have made measurements of competition over small spatial and temporal scales, these do not usually allow an estimate of population-wide effects of one species on another. The bottom line is that we are ignorant of the extent of com­petition in the vast majority of communities. Some of the natural systems in which competitive effects are most likely to be calculable have suggested that levels of inter­specific competition are much lower than intraspecific. Food web theory suggests that a given level of similarity in resource use maybe consistent with many different types and levels of interaction depending on the food web context of the focal com­petitor species. This again means that simple measures of similarity in sets of resource capture/intake rates cannot be translated into a risk of competitive exclusion.

More on the topic Competition between species in theory and reality:

1. The outcome of competition between species can be changed by a broad suite of factors, including features of the physical environment, disturbance, and interactions with other species.
2. As indicated above, ecologists have long thought that competition between species was important in communities.
3. Theory regarding the strength of competition
4. Competition can occur between closely or distantly related species
5. Theory’s roles in ecology and competition
6. The first revival of competition theory
7. Abrams Peter A.. Competition Theory in Ecology. Oxford University Press,2022. — 336 p., 2022
8. Choosing articles to represent current competition theory
9. The need for resources in competition theory
10. The physical environment can affect competition and ultimately the distribution of species
11. Forgotten results in ‘modern competition theory’
12. Competition theory past and present