These are the Sokol'niki woods, which Catherine the II's aqueduct passed through in order to deliver water to the people. The importance of these woods is that they contributed to the local ecosystem having groundwater that was not entirely safe to drink (as much of the random, natural water found in Moscow wasn't), making it catastrophic when the groundwater seeped into the aqueduct and reduced the quality of water. These are all things that Martin mentioned in his article, in relation the plans to help modernize the city and bring some sort of hygeine and sanitation to it.