Blocks of Dark Wildwood Leaves can be harvested/pulled without needing any Power Cells equipped. Wood Mining Cells will lose durability by harvesting Leaves or any other soft material. However if you use Stone Mining Cells or better to pull leaves, these (stronger) Power Cells will not lose durability by that. One block of Dark Wildwood Leaves can be made into 4 blocks of Shredded Leaves in the Processor.