Field experiments were established on sites disturbed by exploratory drilling in the oil shale region of northeastern Utah and on disturbed sites on a potential coal mine in south central Utah. Concurrently, greenhouse studies were carried out using soil samples from disturbed sites and processed oil shale. Establishment of container-grown transplants was far more successful than plantings of bare-root seedlings or direct seeding. Early spring planting gave better results than fall planting. Good survival was obtained from summer planting when the soil was moist. Soil surface shaping and application of surface stabilizing materials can be used to collect water runoff and increase plant survival. Propagation of native shrubs from stem cuttings provides a means of multiplying desired biotypes for land rehabilitation. Higher rooting hormone levels are required for some species than are normally used in propagating cultivated species. The most effective container size and shape for growing transplanting materials is one with adequate volume and ribbed sides to prevent root spiraling.
Originally conceived as a symposium topic by the Committee on Arid Lands of the American Association for the Advancement of Science, the resulting series of papers highlights some of the major issues and paradoxes that must be addressed in developing western energy resources. Along with energy development, consideration must be given to the rights of western states to examine alternatives for commitment of valuable water, air, and space as well as how to deal with impacts and changes to their social systems that occur in energy resource development.
Highlight: Two wildland shrubs, little rabbitbrush and snowberry, were subjected to three intensities of defoliation at each of four distinct stages in the carbohydrate Rserve cycle. These treatments, comparable to browsing and other forms of natural defoliation, were designed to determine the effects on sprouting and associated carbohydrate reserve levels the following spring. Little rabbitbrush plants had reduced carbohydrate reserves, shorter sprouts, and more sprouts following most defoliation tretments. In contrast, carbohydrate reserves increased in snowberry plants with all intensities of defoliation, but there were no significant variations in their sprouting characteristics. Most dormant buds on the root crowns of little rabbitbrush and snowberry plants that were protected from defoliation were prevented from developing as basal sprouts because of apical dominance. Removal of twig tips, however, stimulated more of these buds to produce sprouts. Once a sprout began to grow, a direct relationship seemed to exist between its elongation and the amount of carbohydrate reserves available to it.
Abstract Atriplex polycarpa (Torr.) S. Wats. (desert saltbush) seed was found to have the same general range of salt tolerance during germination as the Australian saltbushes. Germination was severely reduced by solutions having osmotic potentials of —4.2 atmospheres or less. Growth of established seedlings, although reduced, was not inhibited by solutions having osmotic potentials of —25 atmospheres. Dry weight of plants in a given NaCl solution varied among populations indicating some populations are more salt tolerant than others. Root growth was somewhat correlated to top growth, however, salt restricted top growth more than root growth resulting in increased root/top ratios as the level of salinity increased. Only the highest concentration of NaCl used reduced 0root length. There was no correlation between percent moisture in top growth of desert saltbush and the osmotic potential of the water culture. Desert saltbush was found to be extremely tolerant of NaCl when grown under the conditions of this study.
