At present nine main pollen zones, I-IX, are defined, based on the work of J. Iversen, published in 1954.
The Twilight Zone | The Twilight Zone (1959 TV series) | Negative Zone | Panama Canal Zone | Eastern Time Zone | Twilight Zone | pollen | Korean Demilitarized Zone | The Dead Zone (TV series) | The Dead Zone | Pacific Time Zone | Hardiness zone | Central Time Zone (North America) | Ponce Historic Zone | Metekel Zone | Arsi Zone | The Twilight Zone (2002 TV series) | O-Zone | Mirab Welega Zone | Hadiya Zone | Gamo Gofa Zone | Debub Omo Zone | Zone | Semien Omo Zone | Pollen | The Ultra Zone | Rapti Zone | Karnali Zone | Debub Wollo Zone | Dawro Zone |