The Influence of Perennial Vegetation and Precipitation on Occurrence of Halogeton Glomeratus and Bromus Tectorum in Arid and Semi-Arid Regions

Abstract

An investigation of halogeton (Halogeton glomeratus C. A. Mey.) was initiated in Nevada in 1954 to determine in some detail the characteristics of the soils this plant has occupied in the northern desert shrub type of vegetation, its relations with endemic plants as well as with introduced species and other invaders, and its climatic requirements and responses. This report presents results of the study on occurrence of halogeton, and concurrently of cheatgrass (Bromus tectorum L.), in six types of perennial vegetation in northern Nevada. Results of an investigation of soils occupied by halogeton, together with general characteristics of associated vegetation, were reported in a previous paper (Robocker, 1958). Although considerable literature has been published on ecology of cheatgrass as well as on ecology of halogeton, many conclusions have not been evaluated statistically to obtain an estimate of differences due to chance variations and factors which could be measured. Piemeisel (1951) found on lands formerly occupied by sagebrush in southern Idaho that a succession of three communities of annuals occurred and that the