HOLARCTIC ECOLOGY 12: 2W295. Copenhagen 1989 Some physical and chemical characteristics of an arctic beaded stream

-~~~~~~~ ~ ~ r~~~ ~~~ ~~~~ ~ ~ ~~~~ ~~ ~~~~ ~~~~~~~~~~~ -~~~ ~ ~.~ ~ . . . ~~substrates. The watershed is underlain bv ice-bonded till and is hvdrolo~icallv water~ ~~ ~~ ~ , tight. Because of low rates of weatherine. bedrock and lill do no1 contribute sienifi~~~ ~~ ~ ~~ -~~~~~ c&tly to ionic composition of the stream-water. Breakup occurs in late May to early June with surface flow until Seprember. During periods of low rainfall, channel flow is reduced and oools become hvdroloeicallv isolaled and thcrmallv stratified (with very high surf=& water tempe;aturesj. ~t~eamwaler is acidic ( p ~ values 5.3k.1) with very low alkalinity ( S 3 mg I-'). The major transport of ions occurs in early flow derived from snow melt. Organic carbon concrntratianr arc hieh with vcrv hieh ratios of dissolved to particulate organic carhan. Dirsalvcd inarga& nitrogen cukentratiom appear to he very low. High concentrations of dissolved organic material may indicate a central role for DOM in trophic dynamics.