isophene vs isopleth

isophene and isopleth both are nouns.

Word	Noun	Adjective	Verb	Adverb
isophene	Yes	No	No	No
isopleth	Yes	No	No	No

As nouns, isopleth is a hypernym of isophene; that is, isopleth is a word with a broader meaning than isophene:

isophene: a line indicating biological events occurring with coincidence such as plants flowering.
isopleth: a line drawn on a map connecting points having the same numerical value of some variable

Other hypernyms of isophene include isarithm, isogram.

isophene (noun)	isopleth (noun)
a line indicating biological events occurring with coincidence such as plants flowering.	a line drawn on a map connecting points having the same numerical value of some variable