Ernie:
I used a smallish piece that seemed to have been dead for at least a year. It still gave off plenty of smoke in my short cook but was completely used up after an hour.
I noticed a little while after I finished cutting that a significant amount of sap came to the surface of the stumps so I am guessing that even though it looked dead, there was still plenty of life left in it. And I'm guessing that there is a lot of moisture in the stump pieces which would probably result in some significant smoke. I may try one of those pieces on a chicken today. If you go with dried pieces you may need to add some wood during your cook depending on how long you will be cooking.
Good luck.
Mark