( ( ( Extended periods ) ( of ( ( drought and ) heat ) ) ) ( ( can ( ( ( ( ( ( increase ( ( the susceptibility ) ( of ( urban ( ( settlements and ) forest ) ) ) ) ) and ) ( rangelands ( to ( ( ( ( fire ( , ( ( disrupt ( food ( production ( and ( water supplies ) ) ) ) ) , ) ) ) and ) , ) ( in ( developing regions ) ) ) ) ) ) , ) occasionally ) ( lead ( to ( massive ( human migrations ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (JJ Extended) (NNS periods)) (PP (IN of) (NP (NN drought) (CC and) (NN heat)))) (VP (MD can) (VP (VP (VB increase) (NP (NP (DT the) (NN susceptibility)) (PP (IN of) (NP (JJ urban) (NNS settlements) (CC and) (NN forest))))) (CC and) (VP (VBZ rangelands) (S (VP (TO to) (VP (VP (VB fire)) (PRN (, ,) (S (VP (VB disrupt) (NP (NN food) (NN production) (CC and) (NN water) (NNS supplies)))) (, ,)) (CC and) (, ,) (PP (IN in) (NP (VBG developing) (NNS regions))))))) (, ,) (ADVP (RB occasionally)) (VP (VB lead) (PP (TO to) (NP (JJ massive) (JJ human) (NNS migrations)))))) (. .)))
Extended periods of drought and heat can increase the susceptibility of urban settlements and forest and rangelands to fire, disrupt food production and water supplies, and, in developing regions, occasionally lead to massive human migrations.
(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)))))) (. .)))