Lithium (λ6707.8 Å) equivalent width versus log T_eff for the stars in the strip (195° < l_II < 205°), observed at low (left panel) and high (right panel) resolution. Three different bins of Galactic latitude were considered (see also Fig. 1). The upper envelope for the Pleiades sample, as adapted from Soderblom et al. (1993), is overplotted as a dashed line. Mean errors in (~60 mÅ), (~10 mÅ), and log T_eff (~100 K, as obtained from the spectral synthesis) are overplotted on the lower-right corner of each panel. Open symbols represent the Alcalá et al. (1996) and Alcalá et al. (2000) results from low- (left panel) and high- (right panel) resolution spectra, respectively.