Chemical Yields from the First Stars

We examine the dependence of stellar yields on the metallicity Z of the stellar population. This effect may be important for the very first chemical enrichment from Population III stars, at very low Z. In the range of massive stars, mass loss rates varying with Z have remarkable effects. We also estimate chemical yields from Very Massive Objects (from 120 to 1000 Mo), which might have formed more easily in the very low-Z environment of the first stellar generations.