( ( Evaporation ( of ( water ( from ( between ( the pebbles ) ) ) ) ) ) ( ( will ( ( increase ( the humidity ) ) ( around ( the orchids ) ) ) ) . ) )
(ROOT (S (NP (NP (NNP Evaporation)) (PP (IN of) (NP (NP (NN water)) (PP (IN from) (PP (IN between) (NP (DT the) (NNS pebbles))))))) (VP (MD will) (VP (VB increase) (NP (DT the) (NN humidity)) (PP (IN around) (NP (DT the) (NNS orchids))))) (. .)))
Evaporation of water from between the pebbles will increase the humidity around the orchids.
(ROOT (S (NP (NNP Humidity) (NNP happens)) (VP (VBZ happens) (SBAR (WHADVP (WRB when)) (S (NP (JJ liquid) (NN water)) (VP (VBZ evaporates))))) (. .)))