What is the meaning of sparse?

: of few and scattered elements especially : not thickly grown or settled.

How do you say the word scarce?

As far as logic goes, “scarce” should be pronounced /skɑɹs/ or /skɑ:s/, because A is followed by two consonants and it is a universal rule that two consonants follow a short sound in English. The emboldened part is infelicitous.