We discuss on the basis of our evolutionary spectral models the impact of chemical composition on the spectrum of stellar population formed in the starburst. Their metallicity range Z=0.0001 - 0.05(0.1) fully covers the observable one; depending on age, wavelength region and IMF the UV-fluxes differ between extreme compositions at least tenfold, usually more. Independently of age, UV-fluxes shortwards of Balmer jump monotonically decline with the growth of metallicity. Optical and especially IR-region are also influenced, with the typical difference 10-50 times in fluxes at wavelengths >1 micron. In IR the situation which composition is the brightest emitter gets reversed with age.
Categories: astro-ph