Overview

Since the 1970's scientists have studied the ecology of tundra, streams, and lakes (the terrestrial-aquatic continuum) near Toolik Lake, Alaska. In 1987 Toolik became the Arctic tundra site of the NSF LTER program. Based at the Toolik Field Station (TFS) in the northern foothills of the Brooks Range, the ARC LTER studies model systems for advancing the general ecological understanding is the only terrestrial and freshwater Arctic LTER site and thus represents a major biome with great importance in the integrated Earth system.

The Arctic is also one of the most rapidly warming regions on Earth, and the thawing of large stores of permafrost carbon (C) could amplify global warming. Climate variability is also increasing, with more extreme weather events like heat waves, flooding, and storms. The effects of climate variability (temperature, precipitation) in the Arctic are often realized as increased disturbances, such as increased thermal erosion of permafrost and land-surface failures (“thermokarst”), more frequent tundra wildfires, and a longer thaw season.

Many aspects of ecosystems depend strongly on climate variability. For example, less frequent but more intense storms might change the transport of C and nutrients on the landscape even if the mean precipitation is unaltered, and storms redirect nutrient inputs in lakes and alter lake productivity. Climate variability can have analogous effects on the movement, reproduction, and trophic interactions of species on land and in water.

To understand how ecosystem structure and function are related to disturbance, openness, and connectivity, key ecological themes important in all ecosystems, this project focuses on the role of climate variability. Our approach includes the continuation of long-term datasets and experiments, new syntheses of long-term data to determine links between climate variability and system response, and new experiments and modeling to address research questions on the ecological role of climate variability in ecosystems.