Preliminary planning for the Middle East Technical University (METU) re-forestation and landscaping programme began in 1958 in response to two major incentives. First, the Turkish capital of Ankara suffers from heavy air pollution. Second, support for a green zone next to Ankara exists in the provision by Turkish law that forest land cannot be expropriated. Since METU was established on land donated by the Turkish government, 4500 hectares of the campus were available for this public purpose. By 1960, the university's department of landscaping had tested tree species that would be appropriate, and in 1961, the re-forestation programme commenced.