How does permafrost support wetlands in polar and high-altitude regions?

In polar and high-altitude regions, permafrost acts as a critical foundation for wetland ecosystems by serving as an impermeable barrier beneath the soil surface.12

This perennially frozen layer supports wetlands through the following mechanisms:

• Water Retention: Because permafrost is impermeable to water, it prevents surface moisture from percolating deep into the ground. During the summer thaw, this barrier causes water to pool at the surface, saturating the ground and creating boggy conditions that sustain wetland habitats.12
• Hydrological Isolation: By blocking downward drainage, permafrost prevents plant roots from accessing deeper mineral groundwater, which helps maintain the specific waterlogged conditions required by many wetland species.2
• Landscape Formation: The presence of permafrost contributes to the development of unique terrain features, such as pingos and patterned ground, which influence the distribution and structure of these ecosystems.1

While permafrost is essential for these habitats, it is highly sensitive to climatic change. Thawing can disrupt the thermal equilibrium of the soil, leading to increased drainage, loss of wetland surface area, and the release of greenhouse gases like methane.34