Growth Conditions and Vitality of <i>Sphagnum</i> in a Tundra Community Along the Alaska Pipeline Haul Road

Abstract

Effects of road dust and road related construction upon Sphagnum lenense were found in one Sphagnum-rich tundra community along the Alaska Pipeline haul road. Dust, arising from vehicular traffic, settled in greatest quantities near the road with the amount rapidly decreasing away from the road. Water content of Sphagnum lenense in quadrats close to the road and to a buried gasline was generally low when compared with those of S. lenense in more distant quadrats. Total conductivity, pH, and calcium content of water extracted from the Sphagnum was greatest in heavily dust-impacted quadrats. Chlorophyll content (µg chlorophyll a/g dry weight plant tip) was greatest in Sphagnum lenense little exposed to dust and lowest in Sphagnum heavily exposed. Carbon uptake rates in Sphagnum lenense from quadrats far from the road were higher than uptake rates in quadrats near the road, as determined by fixation of 14C labeled CO2.