We present investigations of the energy transfer dynamics after short-pulse excitation in co-doped silica glasses containing silicon nanoclusters (Si-nc) and Er3+ ions. Using a double pulse setup we find evidence for the occurrence of a fast (few hundreds nanoseconds) Si-nc recovery process in samples containing well-defined Si aggregates, whereas a slower recovery is found in a sample annealed for a very short time. The influence of Auger quenching processes taking place between Si-nc and Er3+ in the excited states on the energy transfer process is also shown and discussed.