  We consider the galactic population of gamma-ray pulsars as possible sources
of cosmic rays at and just above the ``knee'' in the observed cosmic ray
spectrum at $10^{15}$--$10^{16}$ eV. We suggest that iron nuclei may be
accelerated in the outer gaps of pulsars, and then suffer partial
photo-disintegration in the non-thermal radiation fields of the outer gaps. As
a result, protons, neutrons, and surviving heavier nuclei are injected into the
expanding supernova remnant. We compute the spectra of nuclei escaping from
supernova remnants into the interstellar medium, taking into account the
observed population of radio pulsars.
  Our calculations, which include a realistic model for acceleration and
propagation of nuclei in pulsar magnetospheres and supernova remnants, predict
that heavy nuclei accelerated directly by gamma-ray pulsars could contribute
about 20% of the observed cosmic rays in the knee region. Such a contribution
of heavy nuclei to the cosmic ray spectrum at the knee can significantly
increase the average value of $<\ln A>$ with increasing energy as is suggested
by recent observations.
