That depends on the type of compost you're striving for. I use my compost almost as a mulch and the pine straw helps beef it up due to its resistance to composting. It usually ends up with a consistency of anglehair pasta in my pile which works out perfect for my use. Some folks lasagna garden, I pasta gaden. Also due to its resistance to composting, and the fact I use the compost before the needles can break down, it ends up being more of an aerator than either a carbon or nitrogen source (for me, anyway). I have had my pile consist of as much as 1/3 to 1/2 pine needles and as long as the rest of the stuff was the right balance it cooked up fine.

tj

Pine needles, pine straw, has a coating that is highly resistant to bacterial digestion, but I have found that in the right mix in your compost pile, the ratio of the pine straw to the other ingrediants, digestion is not a problem. You just need to find what ratio works in your compost pile.
Someone may come along and state that old myth about pine straw, needles, making soil, compost, or whatever, more acidic. Keep in mind that good, solid research has shown this is not true, that even in very large volumes these will not significantly change the pH.

Pine straw makes even better mulch and doesn't raise the pH by much at all. It will eventually disappear in your compost pile too.

It's the finest mulch there is for strawberry beds, IMO.

My grandmother in AL just raked the pine needles right into the flower beds as a mulch. Less work than trying to pick them up and put them in the compost, and then take them out again to spread in the garden ...

The excess went into the shrub borders, or was mowed over with the lawn mower.