Plants that significantly modify the physical environment or animals that have important influences on other biota; e.g., removal of a keystone tree species from swamp islands may result in loss of an animal species there and the entire community.
Organisms that play dominant roles in an ecosystem and affect many other organisms. The removal of a keystone predator from an ecosystem causes a reduction of the species diversity among its former prey. [Go to source
The concept that only one or a few species have uniquely important effects of the community or ecosystem by virtue of unique traits or attributes. The removal of a keystone species, like the removal of a keystone from an arch, results in dramatic changes in the functional properties of the ecological system, e.g. changes in diversity, abundance or habitat structure. See Heywood (1995).
A species that is of exceptional importance in maintaining the species diversity of a community; when a keystone species is lost, the diversity of the community decreases and its structure is significantly altered.
Species that interacts with a large number of other species in a community. Because of the interactions, the removal of this species can cause widespread changes to community structure. Compare with immigrant species, indicator species, and native species.
A species of animal on which associated animals depend for support. (For example, starfish are keystone species off the coast of British Columbia. They feed on clams which would otherwise eat all other sea animals in the region. If starfish are removed, the clams flourish, and the marine animal population plunges.)
A species whose impacts on its community or ecosystem are much larger and more influential than would be expected from mere abundance. This could be a top predator, a plant that shelters or feeds other organisms, or an organism that plays a critical ecological role. [Go to source
A species whose loss from an ecosystem would cause a greater than average change in other species populations or ecosystem processes. (See: " Biodiversity Loss: Cascade Effects and " Biodiversity Conservation and Forest Management.")
A species whose loss from an ecosystem would cause a greater than average change in diversity or abundance of other species, community structure, and/or ecosystem processes. The original concept of keystone species was applied to predators who could have such impacts. Over time the term has been applied to species at all trophic levels, and new terminology is evolving for these species based on their mode of action or behavior. Under the broadly applied definition, many consider oysters to be a keystone species.
An organism in the ecosystem that many other species depend upon for continued survival and support. Salmon are keystone species because when they die they supply many species with energy and nutrients, which are cycled throughout the ecosystem again and again.
A plant or animal that plays a more significant role in the habitat than other species; they provide essential services that are unique. Without the work of these key species, the habitat will change significantly.
A keystone species is a species that has a disproportionate effect on its environment relative to its abundance. Such an organism plays a role in its ecosystem that is analogous to the role of a keystone in an arch. While the keystone feels the least pressure of any of the stones in an arch, the arch still collapses without it.