Ecology Vocabulary

Ecosystem

is the sum of all the organisms living in a given area (the biotic community) and the abiotic factors with which they interact.

Symbiotic Relationship

A close interaction between two different species where at least one organism either benefits, is harmed, or is left unharmed from the relationship. These relationships help keep organisms in check

Intraspecific Competiton

two different species are competing for the same limited resource

Neutralism

Neither organism involved benefits or is harmed from this relationship

Ammensalism

One organism is uneffected from this relationship, but the other in negatively affected by it

Commensalism

One organism is positively affected by this relationship, while the other in left unaffected

Competition

Both organisms are negatively affected as they are fighting for the same limited resource

Mutualism

Both organisms involved are positively affected by the eachother

Predation or Paratism

Only one organism benefits from this relationship, as the other is harmed in the process

Keystone Species

an organism that has a disproportionately large effect on its ecosystem relative to its abundance. If this species is removed, the ecosystem often experiences a dramatic shift or collapse

Species Evenness

The equal distribution of individuals among the various species present. High evenness indicates that a species is present in roughly equal numbers. Low evenness indicates one or a few species dominate the community.

Species Richness

the total number of different species present in a community or geographic area. The more variation of species means higher richness, and higher richness means the community is stable

Simpson’s Index of Diversity

The closer a number is to 1, the more diverse it is. On the other hand, the father it is from 1 the less diverse it is