( ( Due ( to ( ( the loss ) ( of ( ( ( energy and ) reduction ) ( in biomass ) ) ) ) ) ) ( , ( ( food chains ) ( ( are ( limited ( to ( ( a maximum ) ( of ( six ( trophic levels ) ) ) ) ) ) ) . ) ) ) )
(ROOT (S (PP (JJ Due) (TO to) (NP (NP (DT the) (NN loss)) (PP (IN of) (NP (NP (NN energy) (CC and) (NN reduction)) (PP (IN in) (NP (NNS biomass))))))) (, ,) (NP (NN food) (NNS chains)) (VP (VBP are) (VP (VBN limited) (PP (TO to) (NP (NP (DT a) (NN maximum)) (PP (IN of) (NP (CD six) (JJ trophic) (NNS levels))))))) (. .)))
Due to the loss of energy and reduction in biomass, food chains are limited to a maximum of six trophic levels.
(ROOT (S (NP (NP (NN Loss)) (PP (IN of) (NP (NN energy)))) (VP (VBZ is) (NP (DT the) (NN reason)) (SBAR (IN that) (S (NP (NN food) (NN chain)) (ADVP (RB typically)) (VP (VBZ has) (NP (JJ few) (NNS levels)))))) (. .)))