For example, plants produce organic matter, which the decomposers utilize as their source of nutrients and in so doing they provide 
(plants; produce; organic matter, which the decomposers utilize as their source of nutrients and in so doing they provide) (organic matter; utilize; the decomposers) (they; provide; )
plants organic matter they
produce utilize provide
organic matter, which the decomposers utilize as their source of nutrients and in so doing they provide
the decomposers