Rehabilitation Potential of Riparian Systems Disturbed by Placer Mining in Interior Alaska

Abstract

Placer mining severely disrupts the structure and function of riparian ecosystems. Successful planning for the rehabilitation of drastically disturbed lands requires an assessment of the disturbance and a systematic analysis of the rehabilitation potential. Site investigations and preliminary research results were used to analyze the rehabilitation potential of a placer-mined valley in interior Alaska. Revegetation trials were begun in 1990 to identify the site variables having the greatest influence on seed recruitment and germination and seedling emergence. Proximity to water table and presence of fines in the seedbed were found to be key variables in the willow establishment process. In 1991 the trials were expanded in order to focus on seedbed preparation and irrigation variables. Results from the 1990 and 1991 field seasons are being used to design prescriptions for a demonstration rehabilitation project involving a I-km reach of Birch Creek. The intention of the project is to demonstrate that the full land use potential of Birch Creek, including the recreational, scenic, and wildlife habitat values, can be achieved through a proper rehabilitation approach. Additional