Soil and vegetation recovery after a well blowout and salt water release in northeastern British Columbia.

摘要

The impact of brine release on soil and vegetation due to a gas well blowout in December 1999 near Fort Nelson, British Columbia was evaluated over a 10 year period. The objectives were to study spatial and temporal distribution of soil salinity and vegetation and determine whether reclamation would occur through a natural recovery process. Soil salinity and vegetation diversity indices were measured on six study sites and one control. Average electrical conductivity declined with time from approximately 3.0 dS m-1 and has remained below 2.0 dS m-1 since 2002. Cycling of ions between leaf litter and plant tissue resulted in high variability in topsoil electrical conductivity. Sodium adsorption ratio in the leaf litter and A horizons was low (<7), but remained high in B and C horizons (>14) after 2004. From 2002 to 2010 moss cover increased 40%, whereas shrubs decreased 30%. The most impacted plot showed higher diversity than the least impacted plots and the control (Shannon diversity index=1.49, 1.36, 1.11 for most impacted, least impacted and control, respectively). Soil and vegetation indicated salt-affected plots were recovering naturally. Results from this study could potentially provide guidelines for future remediation and reclamation practices.