Date of Award:

5-1-1983

Document Type:

Thesis

Degree Name:

Master of Science (MS)

Department:

Biology

Department name when degree awarded

Life Sciences:Biology

Committee Chair(s)

Mary E. Barkworth

Committee

Mary E. Barkworth

Committee

Alvin R. Southard

Committee

Arthur H. Holmgren

Committee

Brien E. Norton

Abstract

A comparison was made of the vegetation on soils derived from the Swan Peak Quartzite and the Fish Haven Dolomite Formations in the Bear River Range of northern Utah and southern Idaho. Eight sites on open slopes were selected for study along the contact line between the two geologic formations. Two 600 m2 plots with similar elevation, slope and aspect were established at each site. The vegetation was analyzed over two field seasons by determining the species present and their percentage of canopy cover. Soils were analyzed for nutrient levels, moisture content and texture. Differences were found in vegetation patterns and distribution of species on the two geologic formations. Both detrended correspondence analysis (DCA), an ordination procedure, and complete linkage cluster analysis revealed that composition and cover of plant species were more similar within than across substrate type. Lomatiu, nuttallii, Eriogonum umbellatum, Monardella odoratissima and Phacelia hastata were among the species which grow primarily on dolomite. Juncus parryi, Carex geyeri, Allium brandegei and Poa nervosa grow primarily on quartzite. Two endemic species, Penstemon compactus and Erigeron cronquistii were restricted to the calcareous dolomite soils. Species richness was similar, but total plant cover was greater on dolomite over the two field seasons. Growth form and life-form types were different on the two substrates. Relative cover of forbs and hemicryptophytes was greater on dolomite, but the relative cover of graminoids, shrubs, chamaephytes, cryptophytes and therophytes was greater on quartzite. Differences in soil characteristics were also significant, particularly in nutrient levels, texture and soil moisture. The soils formed on dolomite were characteristically dark gray, calcareous, alkaline and fine textured. The quartzite soils were light colored, coarse textured and slightly acid. The quartzite soils had significantly lower K, Ca, Mg and N concentrations, lower organic carbon, and lower moisture percent by weight at -1/3 and -15 atm. In general, the soils on quartzite provided a drier, more severe microenvironment for plants than the soils on dolomite

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