Arctic Tundra Disturbance: Recovery on a Fragile Landscape.

Oilfield development on Alaska’s Arctic vast coastal plain has been underway for nearly 50 years and includes construction of industrial roads, airstrips, pads, and pipelines. This infrastructure requires placement of three to five feet of gravel upon the tundra to prevent thawing of the underlying permafrost. When a site enters the tundra rehabilitation program, contaminants are removed and the gravel is excavated to the level of the surrounding tundra grade, which often leaves six inches or more of gravel and low-nutrient silt remaining on the site. While undisturbed tundra typically retains carbon (averaging 20% OC), the disturbed sites have very little to no stored carbon remaining (0-2% OC), and little to no nitrogen or phosphorus. Tundra rehabilitation efforts include fertilizing and seeding with locally-collected indigenous seed. Factors such as hydrologic conditions, depth of remaining gravel, presence of salts, and proximity to the coastline largely influence the rate of recolonization by indigenous plants. Moss development is common, and while it can prevent colonization of vascular plants, it is likely contributing to improvements in soil quality. With over 10,000 acres now under development, and more construction proposed, rehabilitation techniques are continually being developed to improve soil quality and plant establishment outcomes.