( These ( ( are ( ( ( ( ( defined ( by ( gradients ( of ( ( ( water temperature ) , ) nutrients ) ) ) ) ) , ) ( dissolved gases ) ) , ) ( ( salt concentrations ) etc. ) ) ) . ) )
(ROOT (S (NP (DT These)) (VP (VBP are) (VP (VP (VBN defined) (PP (IN by) (NP (NP (NNS gradients)) (PP (IN of) (NP (NP (NN water) (NN temperature)) (, ,) (NP (NNS nutrients))))))) (, ,) (VP (VBN dissolved) (NP (NNS gases))) (, ,) (NP (NN salt) (FW concentrations) (FW etc.)))) (. .)))
These are defined by gradients of water temperature, nutrients, dissolved gases, salt concentrations etc.
(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))))) (. .)))