DISTRIBUTION OF TERRESTRIAL ALGAE WITHIN THE NEVADA TEST SITE

Abstract

Shields, Lora Mangum, and Francis Drouet. (New Mexico Highlands U., Las Vegas.) Distribution of terrestrial algae within the Nevada Test Site. Amer. Jour. Bot. 49(6): 547–554. Illus. 1962.—Twelve terrestrial algal species, other than diatoms, were identified by microscopic examination of natural soil growths from the Nevada Test Site. Four soil species appeared in culture only. Fifteen taxa occurred only in the vicinity of the one aquatic habitat. Colloidal sheaths of Microcoleus vaginatus, Schizothrix californica and Schizothrix aculissima stabilize soil particles, forming a surface crust. Nostoc commune, Scytonema hofmannii and Protosiphon cinnamomeus are commonly associated with lichens. With one exception, no natural algal growths were found within 0.6 mile of nuclear detonation points during the 2 years following an event. Since at least one species, Microcoleus vaginatus, survives acute gamma exposures of 2,560 kr, blast and thermal damage, rather than radiation, appear to account for the removal of soil algae. The slow recovery can be explained largely in terms of aridity. Soil texture, which influences cohesiveness and moisture levels, strongly affects the composition of terrestrial algal populations in relation to major shrub types within the test site.