One possible answer is the “pine cones” may actually be bagworm cocoons suspended from the tree twigs or foliage. Bagworms build a cocoon made of foliage and twigs from the tree they are feeding on.

The tree's bark is either dark or light grey and becomes checked with age. The sugar pine (Pinus lambertiana) can be identified by its huge cones, which can reach lengths of more than 20 inches ...

The Japanese black pine is a godsend ... Male and female cones occur on the same tree. The female ones develop into little woody pine cones. The roots are not invasive, will take most types ...