We present oxygen abundances for 72 F and G dwarf stars in the solar neighbourhood .
Using the kinematics of the stars we divide them into two sub-samples with space velocities that are typical for the thick and thin disks , respectively .
The metallicities of the stars range from [ Fe/H ] \approx -0.9 to +0.4 and we use the derived oxygen abundances of the stars to : ( 1 ) perform a differential study of the oxygen trends in the thin and the thick disk ; ( 2 ) to follow the trend of oxygen in the thin disk to the highest metallicities .
We analyze the forbidden oxygen lines at 6300 Å and 6363 Å as well as the ( NLTE afflicted ) triplet lines around 7774 Å .
For the forbidden line at 6300 Å we have spectra of very high S / N ( > 400 ) and resolution ( R \gtrsim 215 000 ) .
This has enabled a very accurate modeling of the oxygen line and the blending Ni lines .
The high internal accuracy in our determination of the oxygen abundances from this line is reflected in the very tight trends we find for oxygen relative to iron .
From these abundances we are able to draw the following major conclusions : ( i ) That the [ O/Fe ] trend at super-solar [ Fe/H ] continues downward which is in concordance with models of Galactic chemical evolution .
This is not seen in previous studies as it has not been possible to take the blending Ni lines in the forbidden oxygen line at 6300 Å properly into account ; ( ii ) That the oxygen trends in the thin and the thick disks are distinctly different .
This confirms and extends previous studies of the other \alpha -elements ; ( iii ) That oxygen does not follow Mg at super-solar metallicities ; ( iv ) We also provide an empirical NLTE correction for the infrared O i 
triplet that could be used for dwarf star spectra with a S / N such that only the triplet lines can be analyzed well , e.g .
stars at large distances ; ( v ) Finally , we find that Gratton et al .
( 1999 ) overestimate the NLTE corrections for the permitted oxygen triplet lines at \sim 7774 Å for the parameter space that our stars span .