That’s going to just depend on each individual tree. I was hoping someday to make an article on this subject, which softwoods have the most closely spaced growth rings. I’ve got a sample of bristlecone pine, as well as huon pine that are probably pretty serious contenders, but I’ve never sat down and looked at them all for this express purpose.

Longleaf heartwood, usually called “heart pine” is so resinous that it gums up sandpaper. It was once used for factories and heavy construction and exported to England during the industrial revolution. It also was a source of naval stores–turpentine, pine tar, etc. The longleaf pine (pinups palustris) once formed a massive monoculture forest of huge straight slow growth tress across the Southeast. Less than 3 percent remains today. Pines of most if not all species can form heartwood which will contain more resin than sapwood, though larch species (genus larix) may be more resinous than pine and is the source for Venice Turpentine and Canadian balsam. Pine resin is made into colophony aka rosin.

So glad this was asked somewhere, I am curious as the most resinous pines too.