( ( ( ( ( Grizzlies ( play ( ( ( ( a ( similar role ) ) ( in ( their ecosystem ) ) ) , ) ( helping ( ( keep down ) ( populations ( of ( moose ( , ( ( caribou and ) deer ) ) ) ) ) ) ) ) ) ) , ) and ) ( thus ( ( their presence ) ( helps ( ensure ( that ( ( the ecosystem ) ( remains ( ( balanced and ) healthy ) ) ) ) ) ) ) ) ) . )
(ROOT (S (S (NP (NNS Grizzlies)) (VP (VBP play) (NP (NP (DT a) (JJ similar) (NN role)) (PP (IN in) (NP (PRP$ their) (NN ecosystem))) (, ,) (VP (VBG helping) (S (VP (VB keep) (PRT (RP down)) (NP (NP (NNS populations)) (PP (IN of) (NP (NN moose) (, ,) (NN caribou) (CC and) (NNS deer)))))))))) (, ,) (CC and) (S (ADVP (RB thus)) (NP (PRP$ their) (NN presence)) (VP (VBZ helps) (VP (VB ensure) (SBAR (IN that) (S (NP (DT the) (NN ecosystem)) (VP (VBZ remains) (ADJP (JJ balanced) (CC and) (JJ healthy)))))))) (. .)))
Grizzlies play a similar role in  their ecosystem, helping keep down populations of moose, caribou and deer, and thus their presence helps ensure that the ecosystem remains balanced and healthy.
(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.