( ( ( Arctic and ) ( boreal ecosystems ) ) ( ( play ( ( crucial roles ) ( in ( the ( climate system ) ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Arctic)) (CC and) (NP (JJ boreal) (NNS ecosystems))) (VP (VBP play) (NP (NP (JJ crucial) (NNS roles)) (PP (IN in) (NP (DT the) (NN climate) (NN system))))) (. .)))
Arctic and boreal ecosystems play crucial roles in the climate system.
(ROOT (S (NP (NNP Beneficial) (NNS fungi)) (VP (VBP play) (NP (NP (DT a) (JJ crucial) (NN role)) (PP (IN in) (NP (NP (NN balance)) (PP (IN of) (NP (NNS ecosystems))))))) (. .)))
Beneficial fungi play a crucial role in balance of ecosystems.