Explanation:

 1.  Alpine tundra is a type of natural region or biome that does not contain trees because it is at high altitude.  The high altitude causes an adverse climate, which is too cold and windy to support tree growth.

 2.  Alpine tundra occurs at high enough altitude at any latitude. Portions of Montane grasslands and shrublands ecoregions worldwide include alpine tundra. Large regions of alpine tundra occur in the Himalayas in Asia, American Cordillera in North and South America, the Alps, the Scandinavian mountains, Pyrenees and Carpathian Mountains of Europe, the Caucasus Mountains, the Rift Mountains of Africa, and a large portion of the Tibetan Plateau.

3.   The treeline often occurs at higher elevations on warmer equator-facing slopes. Because the alpine zone is present only on mountains, much of the landscape is rugged and broken, with rocky, snowcapped peaks, cliffs, and talus slopes, but also contains areas of gently rolling to almost flat topography.