The Limnology of Smith Lake

Abstract

Smith Lake (64°52′N and 146°52′W) is located in the Tanana River valley in the interior region of Alaska between two major mountain ranges, the Alaska Range to the south and the Brooks Range to the north (see Fig. 1.1, Chapter 1). Here, rolling hilly terrain is transected by the Yukon-Tanana river system, forming a valley that exceeds 150km in width. The region experiences large seasonal temperature extremes, with warm dry summers and very cold dry winters, and a mean annual precipitation of only about 30 cm. The Smith Lake watershed is occupied by typical taiga forest, composed of spruce, aspen, birch, and alder, with a ground cover of subarctic muskeg (Fig. 5.1). Black spruce (Picea mariana) dominates. The mosses that comprise the muskeg ground cover have low decomposition rates. Research on Smith Lake has focused on the nitrogen cycle, but a considerable body of limnological information has been amassed for this lake in conjunction with that work (Alexander, 1970; Alexander and Barsdate, 1971; Clasby, 1972; Dugdale, 1965; Goering and Dugdale, 1966; Gu, 1992, 1993; Gu and Alexander, 1993a-c; Gu et al., 1994). The initial research was carried out between 1962 and 1967, with a second research program undertaken between 1988 and 1993. The techniques applied to limnological work have changed somewhat in the interim and therefore the results are not exactly comparable; nevertheless this chapter offers an excellent opportunity to make reasonable comparisons to determine whether the lake has changed significantly over the 20 year period.