( ( For ( salt ( or ( fresh water ) ) ) ) . )
(ROOT (FRAG (PP (IN For) (NP (NN salt) (CC or) (JJ fresh) (NN water))) (. .)))
For salt or fresh water.
(ROOT (S (NP (JJ Fresh) (NN water) (NNS biomes)) (VP (VBP are) (VP (VBN defined) (PP (IN by) (NP (JJ low) (NN salt) (NN concentration))))) (. .)))