  The spatial distribution of elemental abundances and their time evolution are
among the major constraints to disentangle the scenarios of formation and
evolution of the Galaxy. We used the sample of open clusters available in the
final release of the Gaia-ESO survey to trace the Galactic radial abundance and
abundance to iron ratio gradients, and their time evolution. We selected member
stars in 62 open clusters, with ages from 0.1 to about 7~Gyr, located in the
Galactic thin disc at Galactocentric radii from about 6 to 21~kpc. We analysed
the shape of the resulting [Fe/H] gradient, the average gradients [El/H] and
[El/Fe] combining elements belonging to four different nucleosynthesis
channels, and their individual abundance and abundance ratio gradients. We also
investigated the time evolution of the gradients dividing open clusters in
three age bins. The[Fe/H] gradient has a slope of -0.054 dex~kpc-1. We saw
different behaviours for elements belonging to different channels. We found
that the youngest clusters in the inner disc have lower metallicity than their
older counterpart and they outline a flatter gradient. We considered some
possible explanations, including the effects of gas inflow and migration. We
suggested that it might be a bias introduced by the standard spectroscopic
analysis producing lower metallicities in low gravity stars. To delineate the
shape of the `true' gradient, we should limit our analysis to stars with low
surface gravity logg>2.5 and xi<1.8 km~s-1. Based on this reduced sample, we
can conclude that the gradient has minimally evolved over the time-frame
outlined by the open clusters, indicating a slow and stationary formation of
the thin disc in the latest Gyr. We found a secondary role of clusters'
migration in shaping the gradient, with a more prominent role of migration for
the oldest clusters.
