nøkkelorganisme

A nøkkelorganisme, or keystone species, is a species that has a disproportionately large effect on its natural environment relative to its abundance. The term was popularized by ecologist Robert T. Paine in 1969. The removal of a keystone species from an ecosystem can lead to dramatic changes in the abundance and distribution of other species, potentially causing the collapse of the ecosystem itself.

Keystone species play crucial roles in maintaining the structure and function of their ecosystems. These roles can include predation, herbivory, pollination, or habitat modification. For example, sea otters are a well-known keystone species in kelp forests. By preying on sea urchins, they prevent urchin populations from exploding and overgrazing the kelp, which provides habitat and food for numerous other species. Without sea otters, the kelp forest ecosystem can be devastated.

Other examples of keystone species include beavers, which create wetlands by building dams, and certain predators that control the populations of prey animals. The concept of a keystone species highlights the interconnectedness of life within an ecosystem and emphasizes that the presence and health of even seemingly rare species can be vital for the overall stability and biodiversity of their environment. Conservation efforts often focus on protecting keystone species as a strategy to preserve entire ecosystems.