We present luminosity functions for galaxies in loose groups in the Las Campanas Redshift Survey , differentiated by their environment ( defined by the line-of-sight velocity dispersion \sigma of the host groups ) and also by their spectral type ( emission or non-emission , defined by the equivalent width of the 3727Å [ OII ] line ) . We find systematic variations in the Schechter parameters \alpha and M ^ { * } for non-emission line galaxies over a range of 0 < \sigma < 800 km/s : \alpha varies from 0.20 to -0.91 , indicating an increase in the steepness of the faint end slope with increasing \sigma .
The accompanying variation in M ^ { * } appears to be accounted for by the intrinsic correlation with \alpha and does not indicate a significant physical variation in the bright end of the luminosity function .
For emission line galaxies , we find no significant systematic variation of the luminosity function with the environment .
Our results show that emission and non-emission galaxies generally occupy two distinct regions in the \alpha - M ^ { * } parameter space .
From our luminosity functions , we derive the number ratios of emission to non-emission galaxies as a function of environment and absolute magnitude , showing that the relative abundance of non-emission line galaxies generally increases for all magnitudes -23 < M _ { R } < -17.5 towards high- \sigma environments , from \sim 80 \% to > 90 \% at M _ { R } = -22 and from \sim 10 \% to > 50 \% at M _ { R } = -18 ( H _ { 0 } = 100 \ > km\ > s ^ { -1 } Mpc ^ { -1 } and q _ { 0 } = 0.5 ) .