( ( ( Decaying ( organic matter ) ) ( -LRB- ( humus -RRB- ) ) ) ( ( holds ( moisture ( in ( the soil ) ) ) ) . ) )
(ROOT (S (NP (NP (JJ Decaying) (JJ organic) (NN matter)) (PRN (-LRB- -LRB-) (NP (NNS humus)) (-RRB- -RRB-))) (VP (VBZ holds) (NP (NP (NN moisture)) (PP (IN in) (NP (DT the) (NN soil))))) (. .)))
Decaying organic matter (humus) holds moisture in the soil.
(ROOT (S (NP (NP (DT The) (JJ decayed) (NNS remains)) (PP (IN of) (NP (VBG living) (NNS organisms)))) (VP (VBZ is) (VP (VBN called) (NP (NNS humus)))) (. .)))