Logging is a technology that can be researched at an Alchemy Lab. Every upgrade of Logging increases your wood production by 10%. Each level requires that the Alchemy Lab and Sawmill level is the same or higher than the level to be researched e.g. Level 9 Logging requires at least a level 9 Sawmill and level 9 alchemy lab.
To view a detailed information for the required Resources per research level please view the Research page.