( ( The ( ( most obvious ) groupings ) ) ( ( are ( ( based on ) ( ( ( whether or ) not ) ( ( the ecosystem ) ( is ( ( ( on ( land ( -LRB- ( terrestrial -RRB- ) ) ) ) or ) ( in ( ( the water ) ( -LRB- ( aquatic -RRB- ) ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT The) (ADJP (RBS most) (JJ obvious)) (NNS groupings)) (VP (VBP are) (VP (VBN based) (PRT (RP on)) (SBAR (IN whether) (CC or) (RB not) (S (NP (DT the) (NN ecosystem)) (VP (VBZ is) (PP (PP (IN on) (NP (NP (NN land)) (PRN (-LRB- -LRB-) (NP (NNP terrestrial)) (-RRB- -RRB-)))) (CC or) (PP (IN in) (NP (NP (DT the) (NN water)) (PRN (-LRB- -LRB-) (ADJP (JJ aquatic)) (-RRB- -RRB-)))))))))) (. .)))
The most obvious groupings are based on whether or not the ecosystem is on land ( terrestrial ) or in the water ( aquatic ).
(ROOT (S (NP (JJ Terrestrial) (NNS biomes)) (VP (VBP are) (VP (VBN associated) (PP (IN with) (NP (NN land))) (, ,) (SBAR (IN while) (S (NP (JJ aquatic) (NNS ones)) (VP (VBP are) (VP (VBN associated) (PP (IN with) (NP (NN water))))))))) (. .)))