  In the framework of mean-field based transport approaches, we discuss recent
results concerning collective motion and low-energy heavy ion reactions
involving neutron-rich systems. We focus on aspects which are particularly
sensitive to the isovector terms of the nuclear effective interaction and the
corresponding symmetry energy. As far as collective excitations are concerned,
we discuss the mixed nature of dipole oscillations in neutron-rich systems. On
the other hand, for reactions close to the Coulomb barrier, we investigate the
structure of pre-equilibrium collective dipole oscillations, focusing on their
sensitivity to the symmetry energy behavior below normal density. Nucleon
emission is also considered within the same context. The possible impact of
other relevant terms of the nuclear effective interaction on these mechanisms
is also examined. From this analysis we expect to put further constraints on
the nuclear Equation of State, of crucial importance also in the astrophysical
context.
