Wet sedge-dominated communities (sedge meadows) were sampled in five l
owland eases in the Queen Elizabeth Islands of the Canadian High Arcti
c to assess species-environment relationships. The sites spanned 4 deg
rees of latitude, and varied in lithology and intensity of grazing by
muskoxen (Ovibos moschatus). A suite of 8 vascular species were common
in all meadow stands, with an additional 4-6 species found in most st
ands. The position of these species in dominance-diversity curves was
not significantly different between,orated and ungrazed meadows howeve
r, the grazed sites appeared to follow a log-normal distribution, whil
e the ungrazed sites were more geometric. Redundancy analysis indicate
d that grazing intensity is important in determining structure in arct
ic sedge meadows, largely through increasing the cover of bryophytes a
nd the availability of nitrogen. Greatest species richness was found i
n the more southerly sites which were moderately grazed and had divers
ity in microtopography.