the study of the interactions of living organisms with one another and with their environment

Ecologists construct these models to help them understand environmental  interactions and to make predictions about possibly changes.

the part of Earth where life exists; includes all of the living organisms on Earth

a community of organisms and their abiotic environment  

 
a group of various species that live in the same habitat and interact with each other

 
a group of organisms of the same species that live in a specific geographical area and interbreed

the place where an organism usually lives

an environmental factor that is associated with or results from the activities of living organisms

an environmental factor that is not associated with the activities of living organisms

an organism's change in response to a change in the organism's environment

an organism whose physiological reactions follow environmental changes

a state in which seeds, spores, bulbs, and other reproductive organs stop growth and development and reduce their metabolism, especially respiration

in general, any movement of individuals or populations from one location to another; specifically, a periodic group movement that is characteristic of a given population or species

 
the unique position occupied by a species, both in terms of its physical use of its habitat and its function within an ecological community

a species that has a broad niche such that the species can tolerate a wide range of conditions and can use a variety of resources

an individual or a species that is adapted to a particular environmental factor or ecological niche and that can tolerate only a narrow range of conditions