Ecology
From Memory Alpha, the free Star Trek reference
Ecology is the study of the distribution of lifeforms throughout the galaxy, and how those lifeforms interact with other lifeforms and their environments. It is a multi-disciplinary science which focuses on a broad range of studies relating to living organisms. Ecology is generally considered to be a branch of biology.
Typically, several ecologies would develop independently on a Class M world. These were usually separated by large distances, although there were some rare occurrences where vastly different ecologies co-existed significantly close to one another. Some examples of this included the planet Lactra VII and the Genesis Planet. (TAS: "The Eye of the Beholder", Star Trek III: The Search for Spock)
- It is interesting to note that both these worlds were heavily terraformed, perhaps suggesting a link between terraforming and abnormal ecological development.
In 2151, several crew members of the Enterprise NX-01 made an ecological survey of an M-class planet which would later become known as Archer IV. (ENT: "Strange New World")
In 2369, the USS Enterprise-D brought relief supplies to Tagra IV in the Argolis Cluster. The ecology of this planet had been devastated by the Tagrans' industrial activity. (TNG: "True Q")
