Document Type

Thesis - Open Access

Award Date

1968

Degree Name

Master of Science (MS)

Department

Botany

Abstract

Afforestation of the Missouri River hills along the Great Lakes of South Dakota's reservoirs is a varied problem. Most of the flood plain vegetation, of which Eastern cottonwood, Populus deltoides Bartr is the dominant, has been flooded by the impoundments. The new, shores are mostly grasses of which the potential natural vegetation according to Kuchler (1964) would be in the Agropyron-Stipa association. Hardwood forest, mostly the Ulmus Fraxinus type, exists along tributaries of the Missouri. There are scattered stands of Eastern red cedar, Juniperus virginiana L., on the north facing slopes of the hills. There are several pockets of shrub species in the more mesic areas of which skunk bush sumac, Rhus trilobata Nutt. , and chokecherry, Prunus virginiana L. are the more abundant species. The recreational potential of the lakes has created the desire to plant trees on the shore areas. The U. S. Army Corps of Engineers has designated recreation areas at various locations along the shore. The immediate shore area, about 60 acres per mile of shore, is under the Corps' supervision (U. S. Dept. of Interior, 1965). Afforestation methods are a prime concern to them. The Missouri River represents a location of the terminal moraine of South Dakota's glaciation. Three large classes of parent material from which soils were formed are associated with the Missouri shores. There are those derived from glacial till, which are mostly east of the river; those derived from shale on the unglaciated western side of the river, and varying thicknesses of loss deposits over these materials. Alluvial soils exist along the tributaries to the Missouri River. These are usually redeposited soils of the three that were described. The environmental factors influencing tree establishment are hot, dry, windy summers, cold windy winters, low precipitation and variation in soil texture. The summer evaporation potential generally exceeds the annual precipitation by two times or more (George, 1939). Most of the soil moisture is-used by the existing vegetation to the wilting level. Rarely in-planted trees is there a surplus of moisture in the soil at the end of the growing season (George, 1939). This study was concerned with the reaction of ponderosa pine, and Eastern red cedar to the severe soil moisture stress that occurs in these soils. The relative drought resistance of these two species to the fine-textured soil that occurs in this area was determined. The lethal soil moisture content (SMC) was established for the two species in the two sample soils of the area. Soils used in the test were derived from shale-originated soils and from loess soils. Shale originated soil was used because it is probably the most abundant soil along the shore and is quite extensive west of the river. The relatively coarser loess soils were used as a comparison and a contrast to the shale-derived soil. This study gives a better understanding of the ecological relationships of soil texture to soil moisture availability which will lead to better recommendations towards afforestation along the Missouri lakes. Also, the lethal foliage moisture content, an indicator of drought condition, was established for the two species and may prove helpful in field survival evaluations before visible characteristics of mortality appear.

Library of Congress Subject Headings

Pine -- Afforestation -- South Dakota
Droughts -- South Dakota

Format

application/pdf

Publisher

South Dakota State University

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