Inyo National Forest Research Articles

WATER QUALITY IN MOUNTAIN RECREATIONAL AREAS1

ABSTRACT: Several seasons of water quality study in the eastern Sierra Nevada have provided much useful information. One study element focused in detail on a representative drainage: Bishop Creek, from sampled locations at 12,800 feet to the Owens River at 4,000 feet. Sub‐studies ranged from geohydrology, through chemical and bacterial quality, to benthic ecology. A coordinated study also was made of spatial patterns of use. A second element focused on non‐point source monitoring the length of the Inyo National Forest. From physical, chemical, and bacterial standpoints, water quality is generally very good. Strains of pathogenic bacteria have been confirmed, and substantial further work to establish the importance of their presence is needed. Recreational use survey results have been analyzed to produce a methodology permitting management of the resource as needed. In addition, basic policy recommendations to easily minimize risk have been developed.

A Device to Aid in Selecting and Counting Seeds

to the climate, which is very arid. Average annual precipitation is estimated to be about 6 inches, but in some years it may be much less. At the Deep Springs College gauging station, rainfall was less than 3 inches in 1964 (U. S. Weather Bureau, 1964). We have found other unusually large sagebrush plants in the immediate area, including one reported by Al Norenl, formerly a Forest Ranger on the White Mountain District, Inyo National Forest, that was 15.5 ft tall with a stem diameter of -

Topping Stimulates Bitterbrush Twig Growth

The response of old bitterbrush (Purshia tridentata) shrubs to topping was studied on winter range for deer in southwestern Idaho. Tops of 15 randomly selected shrubs at least 6 ft tall were cut off 3 ft above ground level; 15 similar shrubs were selected as a control. Current year's growth was sampled on each shrub before topping and annually thereafter for 4 years. All shrubs produced similar amounts of twig growth the year before treatment. The year after treatment, topped shrubs produced nearly 9 times as much twig growth as the control shrubs. In subsequent years, topped shrubs outproduced control shrubs but at a declining rate. Topping old shrubs may be a useful, though perhaps temporary, way to increase production of bitterbrush browse. On some mule deer (Odocoileus hemionus) winter ranges in the West, bitterbrush is virtually the sole browse species, but annual production of browse is often much below the potential for the site. Many bitterbrush stands have a few young plants but an abundance of old plants, which produce little new growth either as twigs or sprouts. On areas where there are few or no new bitterbrush plants, range managers have sought methods to stimulate old shrubs to increase twig production, especially near the ground where deer can reach them easily. Encouraging results of a limited preliminary trial of topping old bitterbrush shrubs about 3 ft above ground led us to undertake a larger study designed to obtain a quantitative measure of twig production following topping. That study is the subject of this paper. Bitterbrush shrubs in stagnant stands may be deliberately damaged by burning or by blading or dozing to induce new growth of sprouts. However, to rely on sprouting that results from top-killing is probably a risky way to increase production of forage. Bitterbrush sprouts readily after burning in eastern Idaho (Blaisdell and Mueggler 1956:366), central Oregon (Driscoll 1963: 820), and California (Nord 1965:324), but it sprouts rarely in the western Great Basin area (Billings 1952:257). Unfortunately, many sprouts from fire-killed bitterbrush eventually die. Sprouting may also be induced by complete or partial removal of tops, but mortality may be rather high (Blaisdell and Mueggler 1956:368). Young, vigorous plants produced new sprouts more commonly than older plants. Phillips (1964) reported that railing, dozing with a blade 1-2 ft above the ground, and rolling with a large log each increased production of bitterbrush twigs an estimated 300 percent the following season. However, production in the treated stands during the second and third seasons fell below that of adjacent, untreated stands. Treatments killed 13 percent of the shrubs and seriously injured many others. Personnel of Inyo National Forest in 1964 (unpublished) reported vigorous twig growth from 22 bitterbrush shrubs pruned to a 4-ft height the preceding November.

Chromatographic Technique in the Differentiation of Sagebrush Taxa

dent habitation in the area and nesting litter mixed with the cached seed, none were observed actually entering the tree stand. It appeared the rodents had been very discriminate. The stored seed was large and good quality. Bitterbrush seed production in 1963 was so much heavier than in previous years the Inyo National Forest felt it warranted an intensive effort at seed collection. This observation certainly points out the importance of rodents in bitterbrush ecology. Research by Hormay1 has pointed out the importance of rodents in caching bitterbrush seeds in the ground. Widespread observations and measurements indicate that most of the plants in bitterbrush stands in California become established from seeds cached by rodents. He found the seeds cached 0.25 to 1.5 inches below the soil surface and the seedlings from these varied in number from 2 to 100, although in one case 139 were found. Hormay did not actually observe caching by rodents, but he suspected that chipmunks and golden mantled ground squirrels did most of it, the same rodents that we believe cached the seeds in the hollow aspen tree.

Major Plant Communities in a Transect of the Sierra Nevada Mountains of California

Among the ecological problems in the Sierra Nevada Mountains of eastern California are the contrasts of physiography, climate, and vegetation on the two sides of the mountains, the differences due to their wide range in altitude. and the interactions between local environments and plant communities. A large amount of information pertaining to these problems is to be found in the works of Jepson ('IO, '25), Abrams ('23), Smiley ('I5, '2I), Merriam ('98), Tidestrom ('25), Shantz ('25), Sampson ('25), Sudworth ('o8), Clements ('20), Harshberger ('I I), and others. The recent book on the animal life of the Yosemite by Grinnell and Storer ('24) describes conditions in a belt across the Sierra some distance north of the transect here presented, which traverses the middle part of the range. Some of this region was already known to the writer before beginning, in the spring and summer of I926, the determination and mapping of the major plant communities in a representative belt transect. This was intended from the outset to constitute a foundation survey on which additional and more detailed investigations might be based. The location of the transect chosen as typical of the middle Sierra Nevada is shown in figure I. Except for its west end, it is included in the Sierra National Forest and the Inyo National Forest. Most of it is in Fresno County, although a part of Madera, Mono, and Inyo counties is included. The transect is 7 miles wide and 8o miles long, extending from, the floor of the Great Valley on the west to the Owens River Gorge on the east. It is very nearly at right angles to the long axis of the range, and therefore lies in a southwest to northeast position. The country within this strip is considered typical of the middle Sierra Nevada rather than of the southern Sierra.