( ( In ( part C ) ) ( , ( ( a ( ( commercially produced ) toxin ) ) ( ( was ( introduced ( into ( ( the ecosystem ) ( via ( dead ( terrestrial ( plant material ) ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (IN In) (NP (NN part) (NNP C))) (, ,) (NP (DT a) (ADJP (RB commercially) (VBN produced)) (NN toxin)) (VP (VBD was) (VP (VBN introduced) (PP (IN into) (NP (NP (DT the) (NN ecosystem)) (PP (IN via) (NP (JJ dead) (JJ terrestrial) (NN plant) (NN material))))))) (. .)))
In part C, a commercially produced toxin was introduced into the ecosystem via dead terrestrial plant material.
(ROOT (S (NP (NP (DT A) (NN role)) (PP (IN of) (NP (NP (NNS mushrooms)) (PP (IN in) (NP (NNS ecosystems)))))) (VP (VBZ is) (VP (VBG breaking) (PRT (RP down)) (NP (JJ dead) (NN plant) (NN material)))) (. .)))