Beyond the treeline the vegetation hugs the ground. Tundra is a cold, treeless biome found in Arctic regions and on high mountains. The growing season is short, winters are long and harsh, and a layer of permafrost often underlies the surface.

Low shrubs, sedges, mosses, and lichens dominate. Animals migrate or adapt to the extreme seasonality. During the brief summer the tundra can be carpeted with wildflowers and alive with insects and nesting birds.

Climate warming is thawing permafrost, releasing greenhouse gases and altering hydrology. Industrial development and resource extraction add further pressure. The tundra remains one of the most sensitive biomes to global temperature change and an important indicator of planetary health.

• Cold treeless biome
• Found in Arctic and alpine regions
• Underlain by permafrost in many areas
• Short growing season and low vegetation