We need a language to read a book, and that affects our thought process, as we start thinking like the author and behave in a manner we perceive from the books. Like how someone speaks under the influence of alcohol, books n authors too influence.
Sawdust that is created from cutting natural wood is safe for your compost no matter what kind of tree the wood comes from. Just make sure the wood has not been treated with any chemicals. Another option with sawdust is to try mixing it in with potting soil.
Wood chips, shavings and I guess sawdust are good on TOP of soil, as mulch. They don't steal N from soil and roots up there. It is only when mixed into solil that they become a competitor. If you plan to till wood prodcuts under, compost them first or combine with plenty of nitrogen sources like manure.