( ( ( Water ( during periods ) ) ( of drought ) ) . )
(ROOT (NP (NP (NNP Water)) (PP (IN during) (NP (NNS periods))) (PP (IN of) (NP (NN drought))) (. .)))
Water during periods of drought.
(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)))))) (. .)))