The optical and structural properties of m-plane GaN layers grown by metal organic vapor phase epitaxy on LiAlO2 (100) substrates were investigated. Temperature-dependent and time-resolved photoluminescence (PL), X-ray diffraction and Raman scattering measurements were performed to analyze the correlation of the sample properties with the density of l(1)-type basal-plane stacking faults (BSFs). Electron channeling contrast imaging was used to reveal and calculate the density of BSFs reaching the surface of an m-plane GaN/LiAlO2 layer. It was shown that a local increase of BSF density in the investigated samples results in a rise of the total PL efficiency at low temperatures because of the localization of excitons at BSFs and, therefore, a suppression of their diffusion to nonradiative centers. Parameters of time decay and temperature quenching of the BSF-related PL band were determined. A correlation of both epsilon(xx) and epsilon(ZZ) strain components with the BSFs and crystal mosaicity was observed, and possible reasons of this correlation are discussed. (C) 2015 Elsevier B.V. All rights reserved.