Which of the following is NOT one of the four belts of Russia?

The Arctic Steppe is not one of the recognized four major ecological belts of Russia. The main belts include the Taiga, which is a vast forested region primarily composed of coniferous trees; the Black Land, known for its fertile soil and agriculture; and the Barren Steppe, characterized by grasslands and a lack of trees. The Arctic Steppe, while it might describe specific environmental conditions in certain areas, does not hold the same status or recognition as a primary belt in the classification of Russia's geographical and ecological landscapes.