The Role Of Mosses In Reclamation Of Brine Spills In Forested Areas

Abstract

Abstract Mosses play an important role in the prevention of erosion by protecting soil from the actions of wind, water and temperature extremes. The regeneration capabilities of mosses could be used in brine spill reclamation programs to help revegetate forest sites and thereby reduce soil erosion. Three feather mosses, common to upland boreal coniferous forests, were used in greenhouse experiments to investigate certain aspects of brine spills. Brine concentration was more important than brine exposure time, in terms of reducing moss re-growth. It is desirable to reduce brine concentrations with a fresh water flush as soon as possible. Under the given experimental conditions, calcium-potassium post flush treatments did not aid moss recovery significantly. However this does not imply that calcium or potassium are ineffective in brine spill situations. The mosses were more drought tolerant (sorbitol stress) than salt tolerant (brine stress). Recovery from these stresses may be influenced by relative humidity or time of year. Response patterns of the three species differed significantly. Invasion of the feather mosses by other moss species (moss invaders), emphasized the regeneration potential of these plants. This potential could be utilized to help reclaim brine spills in forested areas. Brine Spills Brine spills in forested areas can and do cause loss of animal life, soil contamination, water pollution, vegetation loss, and excessive erosion(1,2). The potential for such future incidents is heightened by; increased brine production as oilfields age(3), greater amounts of brine used for enhanced recovery, and use of old equipment not designed for new recovery techniques, e.g. higher pressures required for injection wells(4). Prevention is the best means of avoiding environmental problems (5). However, "every piece of equipment no matter how well constructed, will eventually fail in some way" (Skinner(4)). Therefore a reclamation plan for brine spills should be ready for immediate use(6). In most brines, sodium chloride (NaCl) is assumed to be the main agent of damage. However other inorganic salts, organic components, and various additives may also be harmful(1,7). Spill reclamation methods for forested areas vary from those for agronomic areas because the forest represents a very different ecosystem in terms of animals, vegetation, and soils. There is greater variation in type of vegetation and terrain. Also human/ecosystem interactions, such as tillage or harvesting, differ in the forest from those in agronomic areas. Interaction of all factors and processes, including climate and soil parent material(8), must be considered. Techniques for reclaiming brine spills on well-drained or upland areas may differ from those for poorly drained or low-land areas. Inadequate drainage was the most critical problem with a brine spill on flat timberland, and only physical methods of improving drainage by installation of drains were proposed(9). However chemical or biological methods of improving drainage may have been more feasible. Poor drainage was a problem at a lowland spill site in the Swan Hills area, monitored by Rowell and Crepin(10). Brine damaged the vegetation, but natural leaching reduced the effect of high salt concentrations(10) as the Swan Hills have the highest rainfall in Alberta, excluding mountain areas (11).