Here's a quote from a recent article by Roger Sadowsky, who has had a fair amount of experience working with various woods.
"Fingerboards: I feel very confident in saying that I have found the fingerboard to be the most important factor in relationship to wood and tone. Here are my observations:
Maple: Tightest and brightest. Best for slap on basses and for bright, glassy tones on guitars. Can produce more string and fret noise than other woods.
Ebony: Not as bright as maple. Most immediate attack and punch of all fingerboard woods. Virtually no “bloom” to the note after the initial attack. Note has more fundamental with less overtones.
Rosewoods: Sweetest and warmest of the fingerboard woods. South American Rosewoods are tighter and punchier than Indian Rosewoods, which are darker and rounder.
Pau Ferro: (Also known as Morado, Caviuna or Bolivian Rosewood): Pau Fero is not a true Rosewood, but I have been a fan of this wood for fingerboards for over 35 years. Grain is very tight and silky smooth. More warmth than Maple or Ebony but tighter sounding than the other Rosewoods."