ecology vs biological science

ecology and biological science both are nouns.

Word	Noun	Adjective	Verb	Adverb
ecology	Yes	No	No	No
biological science	Yes	No	No	No

As nouns, biological science is a hypernym of ecology; that is, biological science is a word with a broader meaning than ecology:

ecology: the branch of biology concerned with the relations between organisms and their environment
biological science: the science that studies living organisms

Other hypernyms of ecology include biology.

ecology (noun)	biological science (noun)
the branch of biology concerned with the relations between organisms and their environment	the science that studies living organisms
the environment as it relates to living organisms