Why is much of the tundra’s plant biomass found below ground?

In the tundra ecosystem, a significant portion of plant biomass is concentrated below ground as an adaptation to the harsh, cold environment. Because the growing season is extremely short and surface conditions are often exposed to freezing temperatures, high winds, and drying effects, many plants have evolved to prioritize root systems and underground structures like runners or stems.12

This strategy allows plants to survive the long, severe winters and initiate growth rapidly as soon as the snow begins to melt. Furthermore, because the active layer of the soil—where most biological activity, such as root growth, occurs—is limited by the presence of permafrost or seasonal freezing, plants must be highly efficient at utilizing this narrow zone for nutrient uptake and stability. By maintaining a large portion of their biomass underground, these plants are better protected from the extreme climate fluctuations that occur above the surface.1234