( ( ( to ( conduct research ) ) ( on ( ( ( ( ( ( the control ) ( of ( growth periodicity ) ) ) ( in ( tropical trees ) ) ) , ) ( focusing ( on ( ( the interaction ) ( between ( leaf ( ( age and ) drought ) ) ) ) ) ) ) ( within ( the ( same forest ) ) ) ) ) ) ; )
(ROOT (NP (NP (PP (TO to) (NP (NN conduct) (NN research))) (PP (IN on) (NP (NP (DT the) (NN control)) (PP (IN of) (NP (NN growth) (NN periodicity))) (PP (IN in) (NP (JJ tropical) (NNS trees))) (, ,) (VP (VBG focusing) (PP (IN on) (NP (NP (DT the) (NN interaction)) (PP (IN between) (NP (NN leaf) (NN age) (CC and) (NN drought)))))) (PP (IN within) (NP (DT the) (JJ same) (NN forest)))))) (: ;)))
to conduct research on the control of growth periodicity in tropical trees, focusing on the interaction between leaf age and drought within the same forest;
(ROOT (S (SBAR (IN Because) (S (NP (NNS trees)) (VP (VBP add) (NP (NN water) (NN vapor)) (PP (TO to) (NP (NN air)))))) (, ,) (S (VP (VBG cutting) (PRT (RP down)) (NP (NNS forests)))) (VP (VBZ leads) (PP (TO to) (NP (NP (JJR longer) (NNS periods)) (PP (IN of) (NP (NN drought)))))) (. .)))