| Abstract: | Abstract The level of phosphomonoesterase and sulphatase enzyme activity in Arctic soils subjected to an environmental gradient established by snow patch water melt was examined. Within the environmental gradient, distinct zones of vegetation had been established and could be delineated on the basis of dominant plant growth form. Phosphomonoesterase and sulphatase activity levels were not only influenced by the presence of the plant, but also by the dominant vegetation. The levels of activity for each abiontic enzyme differed with respect to vegetative zone. Although soil moisture and water movement could be implicated as influencing the level of enzyme activity within the environmental gradient, their exact role was not apparent. Various factors associated with water movement and soil moisture level and their possible influence upon phosphomonoesterase and sulphatase activity levels are discussed. In comparison to Virginia temperate soils dominated by single physiognomic vegetation, the levels of phosphomonoesterase and sulphatase activity were generally higher, whether expressed on a dry weight basis or a volume basis. Based upon the higher levels of enzyme activity, mineralization of organic matter by abiontic enzymes may be a major route by which phosphorus and sulphur are replenished in some Arctic soils. |
