  The quantumness of Dirac paticles for quantized fields in a dilatonic black
hole is estimated by means of quantum channel. We develop a general Bloch
vector representation of quantum channel in black hole spacetimes beyond single
mode approximation. The nonclassicality of Dirac particles can be measured by
the minimization of quantum coherence over all orthonormal basis sets. The
quantumness of the channel decreases as the dilaton parameter increases. The
interplay between the external reservoir noise and dilaton black hole on the
dynamical behavior of quantum coherence and steerability is investigated in the
Pauli basis. The external environment is modelled by a random telegraph noise
channel. The monotonous decay of quantum nonlocality occurs in the weak
coupling case. The degradation and revival of quantum nonlocality are observed
in the strong coupling condition. It is found that quantum fluctuation effects
of the external reservoir can protect quantum coherence and steerability from
the information loss of the black hole.
