How are polar ecosystems responding to changing climate? The role of hydrology in mediation and facilitation

Background/Question/Methods:

Polar regions are warming faster than the rest of the world. As a consequence, polar ecosystems are directly responding to changes in the structure and function of the earth systems at the poles. The hydrology of polar regions is particularly sensitive to climatic conditions. Hence, temporal and spatial patterns of hydrologic inputs, processes, and the distribution of water are changing on seasonal and annual timescales. In this presentation we will discuss specific case studies of substantial changes to hydrologic processes and patterns that directly influence terrestrial and aquatic ecosystems in polar regions.

Results/Conclusions:

In the Arctic, permafrost degradation is driving substantial changes to terrestrial and aquatic systems with new inputs of sediment, nutrients, and carbon to surface systems.  Thermokarst, the change of surface topography due to underlying permafrost degradation is a direct disturbance to local terrestrial ecosystems, though in aquatic systems, the disturbance is more broadly distributed to downstream locations.  In the Antarctic, surface ice (glaciers) has been more reactive to climate variability than permafrost.  This leads to increased liquid water in the ecosystem, namely more water in surface soils, potential for greater stream flow and rising lake levels.  The current challenge to ecologists is to coincidentally expand our fundamental understanding of polar ecosystems and be able to determine and document how they are changing in response to changing climate.