Ash is probably one of the most popular woods for making polearms. this is the worst wood to use for a bow. it's far too brittle
many of the woods used to make pole based weapons are stiff, brittle woods that are very dense. In general you do not want to use this kind of wood in making a bow. They don't have the tensile strength to withstand the bow making process or the constant flexing needed to use a bow.
bow woods are typically more porous woods. and much softer. Harder woods can be used in bows, but they are typically only used for the backing, or used in making a fiber-glass like material to help hold the bow together. and this was only done because a more suitable woods was not available. Yew is, and always was, expensive. when you're outfitting an army of 500+ archers and you have the choice between cheap, reduced range or expensive long range you typically gave your grunts cheapo bows. because 1) they did not need to be accurate (our arrows will blot out the sky!) 2) you didn't want them to be too far away (or they'll run away/desert you)
Some composite bows can be made elm, oak, ash, hazel and maple. However these bows suffer greatly from reduced range and power compared to an equivalent yew bow. and you wouldn't use these woods in a polearm anyway. some of these woods are suitable for shields, however.
If you want to talk about eastern bows, Bamboo is probably the material of choice. for very obvious reasons. but even bamboo bows need to be very thin due to the tinsel strength.
Mongol bows, probably the best bows in the world, were composite bows witha wooden core and used sinew and horn to help back the bow. the most common wood used was birch.
My personal favorite is the Japanese longbow. it's huge. and it just looks really cool. it can also have very impressive range and power. However it is also one of the most fragile bows. if you draw it incorrectly you can break it. however they are extremely accurate once you get used to them.
I can admit that you can make a bow from almost any type of wood. but you have to really know what you're doing. and there will be pros and cons to teh type of wood you are using. overall, be prepared to suffered reduced range and power from using less ideal woods.
you do not smack people with your bow. you have to be extremely skilled to parry with a bow and not damage it. as an archer you typically dont' want to be in melee range. If you had a bow that was suitable for melee. IE: strong enough to hit someone with and it not break. it would have been designed specifically for this. and would not have as great a range as a bow made for shooting arrows.