With the initial release of patch 11.2.7, Draenor trees are not yet ready for harvesting. We expect that they will become harvestable in the coming weeks.
Players looking for Shadowmoon Lumber to craft items with Warlords of Draenor professions should instead harvest Olemba Lumber from Outland. The lumberjack in each neighborhood will trade Olemba Lumber for an equal amount of Shadowmoon Lumber until the trees in Draenor catch up.