( Excess ( ( nutrients ( ( ( cause eutrophication ) , ) ( which ( depletes oxygen ) ) ) ) . ) )
(ROOT (S (NP (NNS Excess)) (VP (VBZ nutrients) (NP (NP (NN cause) (NN eutrophication)) (, ,) (SBAR (WHNP (WDT which)) (S (VP (VBZ depletes) (NP (NN oxygen))))))) (. .)))
Excess nutrients cause eutrophication, which depletes oxygen.
(ROOT (S (NP (NP (DT An) (NN excess)) (PP (IN of) (NP (NP (NNS fertilizers)) (CC and) (NP (JJ other) (NNS nutrients))))) (VP (VBZ causes) (ADJP (JJ eutrophication) (S (VP (TO to) (VP (VB occur)))))) (. .)))