* The "o" in "populate" is a short vowel sound. It sounds like the "o" in "hot" or "lot."
* Long vowel sounds are usually represented by a single vowel with a silent "e" at the end of the word (like "mate," "hope," or "time") or by a double vowel (like "moon," "feet," or "rain").
Therefore, the vowel sound in "populate" is short.