( ( ( Extended periods ) ( of ( ( drought and ) heat ) ) ) ( ( can ( ( increase ( ( the susceptibility ) ( of ( urban ( settlements ( and ( forest lands ) ) ) ) ) ) ) ( ( ( to ( ( ( fire , ) ( can ( disrupt ( food ( production ( and ( water supplies ) ) ) ) ) ) ) , ) ) and ) ( in ( ( ( developing regions ) , ) ( ( can 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 (VB increase) (NP (NP (DT the) (NN susceptibility)) (PP (IN of) (NP (JJ urban) (NNS settlements) (CC and) (NN forest) (NNS lands)))) (PP (PP (TO to) (NP (NP (NN fire)) (, ,) (VP (MD can) (VP (VB disrupt) (NP (NN food) (NN production) (CC and) (NN water) (NNS supplies)))) (, ,))) (CC and) (PP (IN in) (NP (NP (VBG developing) (NNS regions)) (, ,) (SBAR (S (VP (MD can) (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 lands to fire, can disrupt food production and water supplies, and in developing regions, can 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)))))) (. .)))