  We continue the study of the Chow ring of the moduli stack
$\mathfrak{M}_{g,n}$ of prestable curves begun in [arXiv:2012.09887v2]. In
genus $0$, we show that the Chow ring of $\mathfrak{M}_{0,n}$ coincides with
the tautological ring and give a complete description in terms of (additive)
generators and relations. This generalizes earlier results by Keel and
Kontsevich-Manin for the spaces of stable curves.
  Our argument uses the boundary stratification of the moduli stack together
with the study of the first higher Chow groups of the strata, in particular
providing a new proof of the results of Kontsevich and Manin.
